Package: zenoh-bridge-mqtt
Version: 1.3.3
Architecture: armhf
Maintainer: zenoh-dev@eclipse.org
Installed-Size: 14964
Filename: 1.3.3/zenoh-bridge-mqtt_1.3.3_armhf.deb
Size: 3962796
MD5sum: 4384d2b4ba39ca6ed5259226e946483e
SHA1: 66de826464ac54e94c72755c7ca4495bcf7d5910
SHA256: 2222edc3d5aa6e5608f8f16dca0253481f82d4fee15e88c477f240bcd01f171a
Section: net
Priority: optional
Homepage: http://zenoh.io
Description: Zenoh bridge for MQTT
Package: zenoh-bridge-mqtt
Version: 1.3.3
Architecture: amd64
Maintainer: zenoh-dev@eclipse.org
Installed-Size: 15984
Depends: libc6 (>= 2.34)
Filename: 1.3.3/zenoh-bridge-mqtt_1.3.3_amd64.deb
Size: 4331168
MD5sum: bbd8485db692f09ef1463d37d4f3ccd0
SHA1: c907dcd1ff4d3ba571aad3556489357f1a361642
SHA256: e3c6b307492bad283fc242dae11af704507b2f6ebbd230590c97df3ac17a49ee
Section: net
Priority: optional
Homepage: http://zenoh.io
Description: Zenoh bridge for MQTT
Package: zenoh-bridge-mqtt
Version: 1.3.3
Architecture: armel
Maintainer: zenoh-dev@eclipse.org
Installed-Size: 15288
Filename: 1.3.3/zenoh-bridge-mqtt_1.3.3_armel.deb
Size: 3970844
MD5sum: 4675138a2123fb15f91c26b8d5b4a6d1
SHA1: af34848ba0aa77f792ad94496fec0ee4583908d5
SHA256: d44b7b42abdda45a210e721f3bc77197ffda7efa6967c17ee7604c46a9720e8a
Section: net
Priority: optional
Homepage: http://zenoh.io
Description: Zenoh bridge for MQTT
Package: zenoh-bridge-mqtt
Version: 1.3.3
Architecture: arm64
Maintainer: zenoh-dev@eclipse.org
Installed-Size: 14682
Filename: 1.3.3/zenoh-bridge-mqtt_1.3.3_arm64.deb
Size: 3852008
MD5sum: bf7475a948036a299a6cead05941f805
SHA1: 23cc44212fff7193dfdc90b555d09baa44bb51f2
SHA256: 09922d315cb5694de68cf6dca1946779365face206c5d926dcdaef461f67eea1
Section: net
Priority: optional
Homepage: http://zenoh.io
Description: Zenoh bridge for MQTT
Package: zenoh-plugin-mqtt
Version: 1.3.3
Architecture: amd64
Maintainer: zenoh-dev@eclipse.org
Installed-Size: 7700
Depends: zenohd (=1.3.3)
Filename: 1.3.3/zenoh-plugin-mqtt_1.3.3_amd64.deb
Size: 1926784
MD5sum: 080b01504e9bcdaa75b8a64635b2853c
SHA1: 047cae704e1e4561c8a068bffcb650d994f02dee
SHA256: 60c26d2f2a41cba8d6deac04942b1ef2911c2f30fe76d2356a8c8ee4e6250bc9
Section: net
Priority: optional
Homepage: http://zenoh.io
Description: Zenoh plugin for MQTT
.
[](https://github.com/eclipse-zenoh/zenoh-plugin-mqtt/actions?query=workflow%3ARust)
[](https://github.com/eclipse-zenoh/roadmap/discussions)
[](https://discord.gg/2GJ958VuHs)
[](https://choosealicense.com/licenses/epl-2.0/)
[](https://opensource.org/licenses/Apache-2.0)
.
# Eclipse Zenoh
.
The Eclipse Zenoh: Zero Overhead Pub/sub, Store/Query and Compute.
.
Zenoh (pronounce _/zeno/_) unifies data in motion, data at rest and
computations. It carefully blends traditional pub/sub with geo-distributed
storages, queries and computations, while retaining a level of time and space
efficiency that is well beyond any of the mainstream stacks.
.
Check the website [zenoh.io](http://zenoh.io) and the
[roadmap](https://github.com/eclipse-zenoh/roadmap) for more detailed
information.
.
-------------------------------
.
# MQTT plugin and standalone `zenoh-bridge-mqtt`
.
:point_right: **Install latest release:** see [below](#how-to-install-it)
.
:point_right: **Docker image:** see [below](#docker-image)
.
:point_right: **Build "main" branch:** see [below](#how-to-build-it)
.
## Background
.
[MQTT](https://mqtt.org/) is a pub/sub protocol leveraging a broker to route
the messages between the MQTT clients.
The MQTT plugin for Eclipse Zenoh acts as a MQTT broker, accepting connections
from MQTT clients (V3 and V5) and translating the MQTT pub/sub into a Zenoh
pub/sub.
I.e.:
.
- a MQTT publication on topic `device/123/temperature` is routed as a Zenoh
publication on key expression `device/123/temperature`
- a MQTT subscription on topic `device/#` is mapped to a Zenoh subscription on
key expression `device/**`
.
This allows a close intergration of any MQTT system with Zenoh, but also brings
to MQTT systems the benefits of a Zenoh routing infrastructure.
Some examples of use cases:
.
- Routing MQTT from the device to the Edge and to the Cloud
- Bridging 2 distinct MQTT systems across the Internet, with NAT traversal
- Pub/sub to MQTT via the Zenoh REST API
- MQTT-ROS2 (robot) communication
- Store MQTT publications in any Zenoh storage (RocksDB, InfluxDB, file
system...)
- MQTT record/replay with InfluxDB as a storage
.
The MQTT plugin for Eclipse Zenoh is available either as a dynamic library to
be loaded by the Zenoh router (`zenohd`), either as a standalone executable
(`zenoh-bridge-mqtt`) that can acts as a Zenoh client or peer.
.
## Configuration
.
`zenoh-bridge-mqtt` can be configured via a JSON5 file passed via the
`-c`argument. You can see a commented example of such configuration file:
[`DEFAULT_CONFIG.json5`](DEFAULT_CONFIG.json5).
.
The `"mqtt"` part of this same configuration file can also be used in the
configuration file for the zenoh router (within its `"plugins"` part). The
router will automatically try to load the plugin library (`zenoh_plugin_mqtt`)
at startup and apply its configuration.
.
`zenoh-bridge-mqtt` also accepts the following arguments. If set, each argument
will override the similar setting from the configuration file:
.
- zenoh-related arguments:
- **`-c, --config `** : a config file
- **`-m, --mode `** : The zenoh session mode. Default: `peer` Possible
values: `peer` or `client`.
See [zenoh
documentation](https://zenoh.io/docs/getting-started/key-concepts/#deployment-units)
for more details.
- **`-l, --listen `** : A locator on which this router will listen
for incoming sessions. Repeat this option to open several listeners. Example of
locator: `tcp/localhost:7447`.
- **`-e, --peer `** : A peer locator this router will try to connect
to (typically another bridge or a zenoh router). Repeat this option to connect
to several peers. Example of locator: `tcp/:7447`.
- **`--no-multicast-scouting`** : disable the zenoh scouting protocol that
allows automatic discovery of zenoh peers and routers.
- **`-i, --id `** : The identifier (as an hexadecimal string -
e.g.: 0A0B23...) that the zenoh bridge must use. **WARNING: this identifier
must be unique in the system!** If not set, a random UUIDv4 will be used.
- **`--rest-http-port [PORT | IP:PORT]`** : Configures HTTP interface for the
REST API (disabled by default, setting this option enables it). Accepted
values:
- a port number
- a string with format `:` (to bind the HTTP server
to a specific interface).
- MQTT-related arguments:
- **`-p, --port [PORT | IP:PORT]`** : The address to bind the MQTT server.
Default: `"0.0.0.0:1883"`. Accepted values:
- a port number (`"0.0.0.0"` will be used as IP to bind, meaning any
interface of the host)
- a string with format `:` (to bind the MQTT server
to a specific interface).
- **`-s, --scope `** : A string added as prefix to all routed MQTT
topics when mapped to a zenoh key expression. This should be used to avoid
conflicts when several distinct MQTT systems using the same topics names are
routed via Zenoh.
- **`-a, --allow `** : A regular expression matching the MQTT topic
name that must be routed via zenoh. By default all topics are allowed. If both
`--allow` and `--deny` are set a topic will be allowed if it matches only the
'allow' expression.
- **`--deny `** : A regular expression matching the MQTT topic name
that must not be routed via zenoh. By default no topics are denied. If both
`--allow` and `--deny` are set a topic will be allowed if it matches only the
'allow' expression.
- **`-w, --generalise-pub `** : A list of key expressions to use for
generalising the declaration of
the zenoh publications, and thus minimizing the discovery traffic (usable
multiple times).
See [this
blog](https://zenoh.io/blog/2021-03-23-discovery/#leveraging-resource-generalisation)
for more details.
- **`-r, --generalise-sub `** : A list of key expressions to use for
generalising the declaration of
the zenoh subscriptions, and thus minimizing the discovery traffic (usable
multiple times).
See [this
blog](https://zenoh.io/blog/2021-03-23-discovery/#leveraging-resource-generalisation)
for more details.
- **`--tx-channel-size `** : Size of the MQTT transmit
channel (default: 65536). The channel buffers messages from Zenoh until they
can be sent to MQTT clients. If the channel capacity is reached new messages
from Zenoh will be dropped until space becomes available.
- **`--dictionary-file `** : Path to a file containing the MQTT client
username/password dictionary.
- **`--server-private-key `** : Path to the TLS private key for the
MQTT server. If specified a valid certificate for the server must also be
provided.
- **`--server-certificate `** : Path to the TLS public certificate for
the MQTT server. If specified a valid private key for the server must also be
provided.
- **`--root-ca-certificate `** : Path to the certificate of the
certificate authority used to validate clients connecting to the MQTT server.
If specified a valid private key and certificate for the server must also be
provided.
.
## Admin space
.
The zenoh bridge for MQTT exposes an administration space allowing to get some
information on its status and configuration.
This administration space is accessible via any zenoh API, including the REST
API that you can activate at `zenoh-bridge-mqtt` startup using the
`--rest-http-port` argument.
.
The `zenoh-bridge-mqtt` exposes this administration space with paths prefixed
by `@/service//mqtt` (where `` is the unique identifier of the
bridge instance). The informations are then organized with such paths:
.
- `@/service//mqtt/version` : the bridge version
- `@/service//mqtt/config` : the bridge configuration
.
Example of queries on administration space using the REST API with the `curl`
command line tool (don't forget to activate the REST API with `--rest-http-port
8000` argument):
.
```bash
curl http://localhost:8000:/@/service/**
```
.
> _Pro tip: pipe the result into [**jq**](https://stedolan.github.io/jq/)
command for JSON pretty print or transformation._
.
## MQTTS support
.
The MQTT plugin and standalone bridge for Eclipse Zenoh supports MQTTS. MQTTS
can be configured in two ways:
.
- server side authentication: MQTT clients validate the servers TLS certificate
but not the other way around.
- mutual authentication (mTLS): where both server and clients validate each
other.
.
MQTTS can be configured via the configuration file or, if using the standalone
bridge, via command line arguments.
.
### Server side authentication configuration
.
Server side authentication requires both a private key and certificate for the
server. These can be provided as either a file or as a base 64 encoded string.
.
In the configuration file, the required **tls** fields when using files are
**server_private_key** and **server_certificate**. When using base 64 encoded
strings the required **tls** fields are **server_private_key_base64** and
**server_certificate_base64**.
.
An example configuration file supporting server side authentication would be:
.
```json
{
"plugins": {
"mqtt": {
"tls": {
"server_private_key": "/path/to/private-key.pem",
"server_certificate": "/path/to/certificate.pem"
}
}
}
}
```
.
The standalone bridge (`zenoh-bridge-mqtt`) also allows the required files to
be provided through the **`--server-private-key`** and
**`--server-certificate`** command line arguments.
.
### Mutual authentication (mTLS) configuration
.
In order to enable mutual authentication a certificate for the certificate
authority used to validate clients connecting to the MQTT server must also be
provided. This can be provided as either a file or a base 64 encoded string.
.
In the configuration file, the required **tls** field when using a file is
**root_ca_certificate**. When using base 64 encoded strings the required
**tls** field when using a file is **root_ca_certificate_base64**.
.
An example configuration file supporting server side authentication would be:
.
```json
{
"plugins": {
"mqtt": {
"tls": {
"server_private_key": "/path/to/private-key.pem",
"server_certificate": "/path/to/certificate.pem",
"root_ca_certificate": "/path/to/root-ca-certificate.pem"
}
}
}
}
```
.
The standalone bridge (`zenoh-bridge-mqtt`) also allows the required file to be
provided through the **`--root-ca-certificate`** command line argument.
.
## Username/password authentication
.
The MQTT plugin and standalone bridge for Eclipse Zenoh supports basic
username/password authentication of MQTT clients. Credentials are provided via
a dictionary file with each line containing the username and password for a
single user in the following format:
.
```raw
username:password
```
.
Username/passord authentication can be configured via the configuration file
or, if using the standalone bridge, via command line arguments.
.
In the configuration file, the required **auth** field for configuring the
dictionary file is **dictionary_file**.
.
An example configuration file supporting username/password authentication would
be:
.
```json
{
"plugins": {
"mqtt": {
"auth": {
"dictionary_file": "/path/to/dictionary-file",
}
}
}
}
```
.
The standalone bridge (`zenoh-bridge-mqtt`) also allows the required file to be
provided through the **`--dictionary-file`** command line argument.
.
### Security considerations
.
Usernames and passwords are sent as part of the MQTT `CONNECT` message in clear
text. As such, they can potentially be viewed using tools such as
[Wireshark](https://www.wireshark.org/).
.
To prevent this, it is highly recommended that this feature is used in
conjunction with the MQTTS feature to ensure credentials are encrypted on the
wire.
.
## How to install it
.
To install the latest release of either the MQTT plugin for the Zenoh router,
either the `zenoh-bridge-mqtt` standalone executable, you can do as follows:
.
### Manual installation (all platforms)
.
All release packages can be downloaded from:
.
-
[https://download.eclipse.org/zenoh/zenoh-plugin-mqtt/latest/](https://download.eclipse.org/zenoh/zenoh-plugin-mqtt/latest/)
.
Each subdirectory has the name of the Rust target. See the platforms each
target corresponds to on
[https://doc.rust-lang.org/stable/rustc/platform-support.html](https://doc.rust-lang.org/stable/rustc/platform-support.html)
.
Choose your platform and download:
.
- the `zenoh-plugin-mqtt--.zip` file for the plugin.
Then unzip it in the same directory than `zenohd` or to any directory where
it can find the plugin library (e.g. /usr/lib)
- the `zenoh-bridge-mqtt--.zip` file for the standalone
executable.
Then unzip it where you want, and run the extracted `zenoh-bridge-mqtt`
binary.
.
### Linux Debian
.
Add Eclipse Zenoh private repository to the sources list:
.
```bash
echo "deb [trusted=yes] https://download.eclipse.org/zenoh/debian-repo/ /" |
sudo tee -a /etc/apt/sources.list > /dev/null
sudo apt update
```
.
Then either:
.
- install the plugin with: `sudo apt install zenoh-plugin-mqtt`.
- install the standalone executable with: `sudo apt install zenoh-bridge-mqtt`.
.
## Docker image
.
The **`zenoh-bridge-mqtt`** standalone executable is also available as a
[Docker
images](https://hub.docker.com/r/eclipse/zenoh-bridge-mqtt/tags?page=1&ordering=last_updated)
for both amd64 and arm64. To get it, do:
.
- `docker pull eclipse/zenoh-bridge-mqtt:latest` for the latest release
- `docker pull eclipse/zenoh-bridge-mqtt:main` for the main branch version
(nightly build)
.
Usage: **`docker run --init -p 1883:1883 eclipse/zenoh-bridge-mqtt`**
It supports the same command line arguments than the `zenoh-bridge-mqtt` (see
above or check with `-h` argument).
.
## How to build it
.
> :warning: **WARNING** :warning: : Zenoh and its ecosystem are under active
development. When you build from git, make sure you also build from git any
other Zenoh repository you plan to use (e.g. binding, plugin, backend, etc.).
It may happen that some changes in git are not compatible with the most recent
packaged Zenoh release (e.g. deb, docker, pip). We put particular effort in
mantaining compatibility between the various git repositories in the Zenoh
project.
>
> :warning: **WARNING** :warning: : As Rust doesn't have a stable ABI, the
plugins should be
built with the exact same Rust version than `zenohd`, and using for `zenoh`
dependency the same version (or commit number) than 'zenohd'.
Otherwise, incompatibilities in memory mapping of shared types between `zenohd`
and the library can lead to a `"SIGSEV"` crash.
.
In order to build the zenoh bridge for MQTT you only need to install
[Rust](https://www.rust-lang.org/tools/install). If you already have the Rust
toolchain installed, make sure it is up-to-date with:
.
```bash
rustup update
```
.
Then, you may clone the repository on your machine:
.
```bash
git clone https://github.com/eclipse-zenoh/zenoh-plugin-mqtt.git
cd zenoh-plugin-mqtt
cargo build --release
```
.
The standalone executable binary `zenoh-bridge-mqtt` and a plugin shared
library (`*.so` on Linux, `*.dylib` on Mac OS, `*.dll` on Windows) to be
dynamically
loaded by the zenoh router `zenohd` will be generated in the `target/release`
subdirectory.
Package: zenoh-plugin-mqtt
Version: 1.3.3
Architecture: armel
Maintainer: zenoh-dev@eclipse.org
Installed-Size: 7046
Depends: zenohd (=1.3.3)
Filename: 1.3.3/zenoh-plugin-mqtt_1.3.3_armel.deb
Size: 1632576
MD5sum: 499ea93970c071e885c180923c1d3f8c
SHA1: 82012a417990924c56d783f107ebeabfefa8e3d6
SHA256: 461880a7b27bfcd5826efa080160e86960ab9be06fd0fcb8cae19f3fe7caa71a
Section: net
Priority: optional
Homepage: http://zenoh.io
Description: Zenoh plugin for MQTT
.
[](https://github.com/eclipse-zenoh/zenoh-plugin-mqtt/actions?query=workflow%3ARust)
[](https://github.com/eclipse-zenoh/roadmap/discussions)
[](https://discord.gg/2GJ958VuHs)
[](https://choosealicense.com/licenses/epl-2.0/)
[](https://opensource.org/licenses/Apache-2.0)
.
# Eclipse Zenoh
.
The Eclipse Zenoh: Zero Overhead Pub/sub, Store/Query and Compute.
.
Zenoh (pronounce _/zeno/_) unifies data in motion, data at rest and
computations. It carefully blends traditional pub/sub with geo-distributed
storages, queries and computations, while retaining a level of time and space
efficiency that is well beyond any of the mainstream stacks.
.
Check the website [zenoh.io](http://zenoh.io) and the
[roadmap](https://github.com/eclipse-zenoh/roadmap) for more detailed
information.
.
-------------------------------
.
# MQTT plugin and standalone `zenoh-bridge-mqtt`
.
:point_right: **Install latest release:** see [below](#how-to-install-it)
.
:point_right: **Docker image:** see [below](#docker-image)
.
:point_right: **Build "main" branch:** see [below](#how-to-build-it)
.
## Background
.
[MQTT](https://mqtt.org/) is a pub/sub protocol leveraging a broker to route
the messages between the MQTT clients.
The MQTT plugin for Eclipse Zenoh acts as a MQTT broker, accepting connections
from MQTT clients (V3 and V5) and translating the MQTT pub/sub into a Zenoh
pub/sub.
I.e.:
.
- a MQTT publication on topic `device/123/temperature` is routed as a Zenoh
publication on key expression `device/123/temperature`
- a MQTT subscription on topic `device/#` is mapped to a Zenoh subscription on
key expression `device/**`
.
This allows a close intergration of any MQTT system with Zenoh, but also brings
to MQTT systems the benefits of a Zenoh routing infrastructure.
Some examples of use cases:
.
- Routing MQTT from the device to the Edge and to the Cloud
- Bridging 2 distinct MQTT systems across the Internet, with NAT traversal
- Pub/sub to MQTT via the Zenoh REST API
- MQTT-ROS2 (robot) communication
- Store MQTT publications in any Zenoh storage (RocksDB, InfluxDB, file
system...)
- MQTT record/replay with InfluxDB as a storage
.
The MQTT plugin for Eclipse Zenoh is available either as a dynamic library to
be loaded by the Zenoh router (`zenohd`), either as a standalone executable
(`zenoh-bridge-mqtt`) that can acts as a Zenoh client or peer.
.
## Configuration
.
`zenoh-bridge-mqtt` can be configured via a JSON5 file passed via the
`-c`argument. You can see a commented example of such configuration file:
[`DEFAULT_CONFIG.json5`](DEFAULT_CONFIG.json5).
.
The `"mqtt"` part of this same configuration file can also be used in the
configuration file for the zenoh router (within its `"plugins"` part). The
router will automatically try to load the plugin library (`zenoh_plugin_mqtt`)
at startup and apply its configuration.
.
`zenoh-bridge-mqtt` also accepts the following arguments. If set, each argument
will override the similar setting from the configuration file:
.
- zenoh-related arguments:
- **`-c, --config `** : a config file
- **`-m, --mode `** : The zenoh session mode. Default: `peer` Possible
values: `peer` or `client`.
See [zenoh
documentation](https://zenoh.io/docs/getting-started/key-concepts/#deployment-units)
for more details.
- **`-l, --listen `** : A locator on which this router will listen
for incoming sessions. Repeat this option to open several listeners. Example of
locator: `tcp/localhost:7447`.
- **`-e, --peer `** : A peer locator this router will try to connect
to (typically another bridge or a zenoh router). Repeat this option to connect
to several peers. Example of locator: `tcp/:7447`.
- **`--no-multicast-scouting`** : disable the zenoh scouting protocol that
allows automatic discovery of zenoh peers and routers.
- **`-i, --id `** : The identifier (as an hexadecimal string -
e.g.: 0A0B23...) that the zenoh bridge must use. **WARNING: this identifier
must be unique in the system!** If not set, a random UUIDv4 will be used.
- **`--rest-http-port [PORT | IP:PORT]`** : Configures HTTP interface for the
REST API (disabled by default, setting this option enables it). Accepted
values:
- a port number
- a string with format `:` (to bind the HTTP server
to a specific interface).
- MQTT-related arguments:
- **`-p, --port [PORT | IP:PORT]`** : The address to bind the MQTT server.
Default: `"0.0.0.0:1883"`. Accepted values:
- a port number (`"0.0.0.0"` will be used as IP to bind, meaning any
interface of the host)
- a string with format `:` (to bind the MQTT server
to a specific interface).
- **`-s, --scope `** : A string added as prefix to all routed MQTT
topics when mapped to a zenoh key expression. This should be used to avoid
conflicts when several distinct MQTT systems using the same topics names are
routed via Zenoh.
- **`-a, --allow `** : A regular expression matching the MQTT topic
name that must be routed via zenoh. By default all topics are allowed. If both
`--allow` and `--deny` are set a topic will be allowed if it matches only the
'allow' expression.
- **`--deny `** : A regular expression matching the MQTT topic name
that must not be routed via zenoh. By default no topics are denied. If both
`--allow` and `--deny` are set a topic will be allowed if it matches only the
'allow' expression.
- **`-w, --generalise-pub `** : A list of key expressions to use for
generalising the declaration of
the zenoh publications, and thus minimizing the discovery traffic (usable
multiple times).
See [this
blog](https://zenoh.io/blog/2021-03-23-discovery/#leveraging-resource-generalisation)
for more details.
- **`-r, --generalise-sub `** : A list of key expressions to use for
generalising the declaration of
the zenoh subscriptions, and thus minimizing the discovery traffic (usable
multiple times).
See [this
blog](https://zenoh.io/blog/2021-03-23-discovery/#leveraging-resource-generalisation)
for more details.
- **`--tx-channel-size `** : Size of the MQTT transmit
channel (default: 65536). The channel buffers messages from Zenoh until they
can be sent to MQTT clients. If the channel capacity is reached new messages
from Zenoh will be dropped until space becomes available.
- **`--dictionary-file `** : Path to a file containing the MQTT client
username/password dictionary.
- **`--server-private-key `** : Path to the TLS private key for the
MQTT server. If specified a valid certificate for the server must also be
provided.
- **`--server-certificate `** : Path to the TLS public certificate for
the MQTT server. If specified a valid private key for the server must also be
provided.
- **`--root-ca-certificate `** : Path to the certificate of the
certificate authority used to validate clients connecting to the MQTT server.
If specified a valid private key and certificate for the server must also be
provided.
.
## Admin space
.
The zenoh bridge for MQTT exposes an administration space allowing to get some
information on its status and configuration.
This administration space is accessible via any zenoh API, including the REST
API that you can activate at `zenoh-bridge-mqtt` startup using the
`--rest-http-port` argument.
.
The `zenoh-bridge-mqtt` exposes this administration space with paths prefixed
by `@/service//mqtt` (where `` is the unique identifier of the
bridge instance). The informations are then organized with such paths:
.
- `@/service//mqtt/version` : the bridge version
- `@/service//mqtt/config` : the bridge configuration
.
Example of queries on administration space using the REST API with the `curl`
command line tool (don't forget to activate the REST API with `--rest-http-port
8000` argument):
.
```bash
curl http://localhost:8000:/@/service/**
```
.
> _Pro tip: pipe the result into [**jq**](https://stedolan.github.io/jq/)
command for JSON pretty print or transformation._
.
## MQTTS support
.
The MQTT plugin and standalone bridge for Eclipse Zenoh supports MQTTS. MQTTS
can be configured in two ways:
.
- server side authentication: MQTT clients validate the servers TLS certificate
but not the other way around.
- mutual authentication (mTLS): where both server and clients validate each
other.
.
MQTTS can be configured via the configuration file or, if using the standalone
bridge, via command line arguments.
.
### Server side authentication configuration
.
Server side authentication requires both a private key and certificate for the
server. These can be provided as either a file or as a base 64 encoded string.
.
In the configuration file, the required **tls** fields when using files are
**server_private_key** and **server_certificate**. When using base 64 encoded
strings the required **tls** fields are **server_private_key_base64** and
**server_certificate_base64**.
.
An example configuration file supporting server side authentication would be:
.
```json
{
"plugins": {
"mqtt": {
"tls": {
"server_private_key": "/path/to/private-key.pem",
"server_certificate": "/path/to/certificate.pem"
}
}
}
}
```
.
The standalone bridge (`zenoh-bridge-mqtt`) also allows the required files to
be provided through the **`--server-private-key`** and
**`--server-certificate`** command line arguments.
.
### Mutual authentication (mTLS) configuration
.
In order to enable mutual authentication a certificate for the certificate
authority used to validate clients connecting to the MQTT server must also be
provided. This can be provided as either a file or a base 64 encoded string.
.
In the configuration file, the required **tls** field when using a file is
**root_ca_certificate**. When using base 64 encoded strings the required
**tls** field when using a file is **root_ca_certificate_base64**.
.
An example configuration file supporting server side authentication would be:
.
```json
{
"plugins": {
"mqtt": {
"tls": {
"server_private_key": "/path/to/private-key.pem",
"server_certificate": "/path/to/certificate.pem",
"root_ca_certificate": "/path/to/root-ca-certificate.pem"
}
}
}
}
```
.
The standalone bridge (`zenoh-bridge-mqtt`) also allows the required file to be
provided through the **`--root-ca-certificate`** command line argument.
.
## Username/password authentication
.
The MQTT plugin and standalone bridge for Eclipse Zenoh supports basic
username/password authentication of MQTT clients. Credentials are provided via
a dictionary file with each line containing the username and password for a
single user in the following format:
.
```raw
username:password
```
.
Username/passord authentication can be configured via the configuration file
or, if using the standalone bridge, via command line arguments.
.
In the configuration file, the required **auth** field for configuring the
dictionary file is **dictionary_file**.
.
An example configuration file supporting username/password authentication would
be:
.
```json
{
"plugins": {
"mqtt": {
"auth": {
"dictionary_file": "/path/to/dictionary-file",
}
}
}
}
```
.
The standalone bridge (`zenoh-bridge-mqtt`) also allows the required file to be
provided through the **`--dictionary-file`** command line argument.
.
### Security considerations
.
Usernames and passwords are sent as part of the MQTT `CONNECT` message in clear
text. As such, they can potentially be viewed using tools such as
[Wireshark](https://www.wireshark.org/).
.
To prevent this, it is highly recommended that this feature is used in
conjunction with the MQTTS feature to ensure credentials are encrypted on the
wire.
.
## How to install it
.
To install the latest release of either the MQTT plugin for the Zenoh router,
either the `zenoh-bridge-mqtt` standalone executable, you can do as follows:
.
### Manual installation (all platforms)
.
All release packages can be downloaded from:
.
-
[https://download.eclipse.org/zenoh/zenoh-plugin-mqtt/latest/](https://download.eclipse.org/zenoh/zenoh-plugin-mqtt/latest/)
.
Each subdirectory has the name of the Rust target. See the platforms each
target corresponds to on
[https://doc.rust-lang.org/stable/rustc/platform-support.html](https://doc.rust-lang.org/stable/rustc/platform-support.html)
.
Choose your platform and download:
.
- the `zenoh-plugin-mqtt--.zip` file for the plugin.
Then unzip it in the same directory than `zenohd` or to any directory where
it can find the plugin library (e.g. /usr/lib)
- the `zenoh-bridge-mqtt--.zip` file for the standalone
executable.
Then unzip it where you want, and run the extracted `zenoh-bridge-mqtt`
binary.
.
### Linux Debian
.
Add Eclipse Zenoh private repository to the sources list:
.
```bash
echo "deb [trusted=yes] https://download.eclipse.org/zenoh/debian-repo/ /" |
sudo tee -a /etc/apt/sources.list > /dev/null
sudo apt update
```
.
Then either:
.
- install the plugin with: `sudo apt install zenoh-plugin-mqtt`.
- install the standalone executable with: `sudo apt install zenoh-bridge-mqtt`.
.
## Docker image
.
The **`zenoh-bridge-mqtt`** standalone executable is also available as a
[Docker
images](https://hub.docker.com/r/eclipse/zenoh-bridge-mqtt/tags?page=1&ordering=last_updated)
for both amd64 and arm64. To get it, do:
.
- `docker pull eclipse/zenoh-bridge-mqtt:latest` for the latest release
- `docker pull eclipse/zenoh-bridge-mqtt:main` for the main branch version
(nightly build)
.
Usage: **`docker run --init -p 1883:1883 eclipse/zenoh-bridge-mqtt`**
It supports the same command line arguments than the `zenoh-bridge-mqtt` (see
above or check with `-h` argument).
.
## How to build it
.
> :warning: **WARNING** :warning: : Zenoh and its ecosystem are under active
development. When you build from git, make sure you also build from git any
other Zenoh repository you plan to use (e.g. binding, plugin, backend, etc.).
It may happen that some changes in git are not compatible with the most recent
packaged Zenoh release (e.g. deb, docker, pip). We put particular effort in
mantaining compatibility between the various git repositories in the Zenoh
project.
>
> :warning: **WARNING** :warning: : As Rust doesn't have a stable ABI, the
plugins should be
built with the exact same Rust version than `zenohd`, and using for `zenoh`
dependency the same version (or commit number) than 'zenohd'.
Otherwise, incompatibilities in memory mapping of shared types between `zenohd`
and the library can lead to a `"SIGSEV"` crash.
.
In order to build the zenoh bridge for MQTT you only need to install
[Rust](https://www.rust-lang.org/tools/install). If you already have the Rust
toolchain installed, make sure it is up-to-date with:
.
```bash
rustup update
```
.
Then, you may clone the repository on your machine:
.
```bash
git clone https://github.com/eclipse-zenoh/zenoh-plugin-mqtt.git
cd zenoh-plugin-mqtt
cargo build --release
```
.
The standalone executable binary `zenoh-bridge-mqtt` and a plugin shared
library (`*.so` on Linux, `*.dylib` on Mac OS, `*.dll` on Windows) to be
dynamically
loaded by the zenoh router `zenohd` will be generated in the `target/release`
subdirectory.
Package: zenoh-plugin-mqtt
Version: 1.3.3
Architecture: arm64
Maintainer: zenoh-dev@eclipse.org
Installed-Size: 7451
Depends: zenohd (=1.3.3)
Filename: 1.3.3/zenoh-plugin-mqtt_1.3.3_arm64.deb
Size: 1750896
MD5sum: f5ac72fc5773e9178441968e0177da60
SHA1: 26f32bf61b49ef54353e96f55c563b382b435be7
SHA256: 7c598f793ce265af5fced22cb4b014fe35328381341468702fdd227a5a1105f4
Section: net
Priority: optional
Homepage: http://zenoh.io
Description: Zenoh plugin for MQTT
.
[](https://github.com/eclipse-zenoh/zenoh-plugin-mqtt/actions?query=workflow%3ARust)
[](https://github.com/eclipse-zenoh/roadmap/discussions)
[](https://discord.gg/2GJ958VuHs)
[](https://choosealicense.com/licenses/epl-2.0/)
[](https://opensource.org/licenses/Apache-2.0)
.
# Eclipse Zenoh
.
The Eclipse Zenoh: Zero Overhead Pub/sub, Store/Query and Compute.
.
Zenoh (pronounce _/zeno/_) unifies data in motion, data at rest and
computations. It carefully blends traditional pub/sub with geo-distributed
storages, queries and computations, while retaining a level of time and space
efficiency that is well beyond any of the mainstream stacks.
.
Check the website [zenoh.io](http://zenoh.io) and the
[roadmap](https://github.com/eclipse-zenoh/roadmap) for more detailed
information.
.
-------------------------------
.
# MQTT plugin and standalone `zenoh-bridge-mqtt`
.
:point_right: **Install latest release:** see [below](#how-to-install-it)
.
:point_right: **Docker image:** see [below](#docker-image)
.
:point_right: **Build "main" branch:** see [below](#how-to-build-it)
.
## Background
.
[MQTT](https://mqtt.org/) is a pub/sub protocol leveraging a broker to route
the messages between the MQTT clients.
The MQTT plugin for Eclipse Zenoh acts as a MQTT broker, accepting connections
from MQTT clients (V3 and V5) and translating the MQTT pub/sub into a Zenoh
pub/sub.
I.e.:
.
- a MQTT publication on topic `device/123/temperature` is routed as a Zenoh
publication on key expression `device/123/temperature`
- a MQTT subscription on topic `device/#` is mapped to a Zenoh subscription on
key expression `device/**`
.
This allows a close intergration of any MQTT system with Zenoh, but also brings
to MQTT systems the benefits of a Zenoh routing infrastructure.
Some examples of use cases:
.
- Routing MQTT from the device to the Edge and to the Cloud
- Bridging 2 distinct MQTT systems across the Internet, with NAT traversal
- Pub/sub to MQTT via the Zenoh REST API
- MQTT-ROS2 (robot) communication
- Store MQTT publications in any Zenoh storage (RocksDB, InfluxDB, file
system...)
- MQTT record/replay with InfluxDB as a storage
.
The MQTT plugin for Eclipse Zenoh is available either as a dynamic library to
be loaded by the Zenoh router (`zenohd`), either as a standalone executable
(`zenoh-bridge-mqtt`) that can acts as a Zenoh client or peer.
.
## Configuration
.
`zenoh-bridge-mqtt` can be configured via a JSON5 file passed via the
`-c`argument. You can see a commented example of such configuration file:
[`DEFAULT_CONFIG.json5`](DEFAULT_CONFIG.json5).
.
The `"mqtt"` part of this same configuration file can also be used in the
configuration file for the zenoh router (within its `"plugins"` part). The
router will automatically try to load the plugin library (`zenoh_plugin_mqtt`)
at startup and apply its configuration.
.
`zenoh-bridge-mqtt` also accepts the following arguments. If set, each argument
will override the similar setting from the configuration file:
.
- zenoh-related arguments:
- **`-c, --config `** : a config file
- **`-m, --mode `** : The zenoh session mode. Default: `peer` Possible
values: `peer` or `client`.
See [zenoh
documentation](https://zenoh.io/docs/getting-started/key-concepts/#deployment-units)
for more details.
- **`-l, --listen `** : A locator on which this router will listen
for incoming sessions. Repeat this option to open several listeners. Example of
locator: `tcp/localhost:7447`.
- **`-e, --peer `** : A peer locator this router will try to connect
to (typically another bridge or a zenoh router). Repeat this option to connect
to several peers. Example of locator: `tcp/:7447`.
- **`--no-multicast-scouting`** : disable the zenoh scouting protocol that
allows automatic discovery of zenoh peers and routers.
- **`-i, --id `** : The identifier (as an hexadecimal string -
e.g.: 0A0B23...) that the zenoh bridge must use. **WARNING: this identifier
must be unique in the system!** If not set, a random UUIDv4 will be used.
- **`--rest-http-port [PORT | IP:PORT]`** : Configures HTTP interface for the
REST API (disabled by default, setting this option enables it). Accepted
values:
- a port number
- a string with format `:` (to bind the HTTP server
to a specific interface).
- MQTT-related arguments:
- **`-p, --port [PORT | IP:PORT]`** : The address to bind the MQTT server.
Default: `"0.0.0.0:1883"`. Accepted values:
- a port number (`"0.0.0.0"` will be used as IP to bind, meaning any
interface of the host)
- a string with format `:` (to bind the MQTT server
to a specific interface).
- **`-s, --scope `** : A string added as prefix to all routed MQTT
topics when mapped to a zenoh key expression. This should be used to avoid
conflicts when several distinct MQTT systems using the same topics names are
routed via Zenoh.
- **`-a, --allow `** : A regular expression matching the MQTT topic
name that must be routed via zenoh. By default all topics are allowed. If both
`--allow` and `--deny` are set a topic will be allowed if it matches only the
'allow' expression.
- **`--deny `** : A regular expression matching the MQTT topic name
that must not be routed via zenoh. By default no topics are denied. If both
`--allow` and `--deny` are set a topic will be allowed if it matches only the
'allow' expression.
- **`-w, --generalise-pub `** : A list of key expressions to use for
generalising the declaration of
the zenoh publications, and thus minimizing the discovery traffic (usable
multiple times).
See [this
blog](https://zenoh.io/blog/2021-03-23-discovery/#leveraging-resource-generalisation)
for more details.
- **`-r, --generalise-sub `** : A list of key expressions to use for
generalising the declaration of
the zenoh subscriptions, and thus minimizing the discovery traffic (usable
multiple times).
See [this
blog](https://zenoh.io/blog/2021-03-23-discovery/#leveraging-resource-generalisation)
for more details.
- **`--tx-channel-size `** : Size of the MQTT transmit
channel (default: 65536). The channel buffers messages from Zenoh until they
can be sent to MQTT clients. If the channel capacity is reached new messages
from Zenoh will be dropped until space becomes available.
- **`--dictionary-file `** : Path to a file containing the MQTT client
username/password dictionary.
- **`--server-private-key `** : Path to the TLS private key for the
MQTT server. If specified a valid certificate for the server must also be
provided.
- **`--server-certificate `** : Path to the TLS public certificate for
the MQTT server. If specified a valid private key for the server must also be
provided.
- **`--root-ca-certificate `** : Path to the certificate of the
certificate authority used to validate clients connecting to the MQTT server.
If specified a valid private key and certificate for the server must also be
provided.
.
## Admin space
.
The zenoh bridge for MQTT exposes an administration space allowing to get some
information on its status and configuration.
This administration space is accessible via any zenoh API, including the REST
API that you can activate at `zenoh-bridge-mqtt` startup using the
`--rest-http-port` argument.
.
The `zenoh-bridge-mqtt` exposes this administration space with paths prefixed
by `@/service//mqtt` (where `` is the unique identifier of the
bridge instance). The informations are then organized with such paths:
.
- `@/service//mqtt/version` : the bridge version
- `@/service//mqtt/config` : the bridge configuration
.
Example of queries on administration space using the REST API with the `curl`
command line tool (don't forget to activate the REST API with `--rest-http-port
8000` argument):
.
```bash
curl http://localhost:8000:/@/service/**
```
.
> _Pro tip: pipe the result into [**jq**](https://stedolan.github.io/jq/)
command for JSON pretty print or transformation._
.
## MQTTS support
.
The MQTT plugin and standalone bridge for Eclipse Zenoh supports MQTTS. MQTTS
can be configured in two ways:
.
- server side authentication: MQTT clients validate the servers TLS certificate
but not the other way around.
- mutual authentication (mTLS): where both server and clients validate each
other.
.
MQTTS can be configured via the configuration file or, if using the standalone
bridge, via command line arguments.
.
### Server side authentication configuration
.
Server side authentication requires both a private key and certificate for the
server. These can be provided as either a file or as a base 64 encoded string.
.
In the configuration file, the required **tls** fields when using files are
**server_private_key** and **server_certificate**. When using base 64 encoded
strings the required **tls** fields are **server_private_key_base64** and
**server_certificate_base64**.
.
An example configuration file supporting server side authentication would be:
.
```json
{
"plugins": {
"mqtt": {
"tls": {
"server_private_key": "/path/to/private-key.pem",
"server_certificate": "/path/to/certificate.pem"
}
}
}
}
```
.
The standalone bridge (`zenoh-bridge-mqtt`) also allows the required files to
be provided through the **`--server-private-key`** and
**`--server-certificate`** command line arguments.
.
### Mutual authentication (mTLS) configuration
.
In order to enable mutual authentication a certificate for the certificate
authority used to validate clients connecting to the MQTT server must also be
provided. This can be provided as either a file or a base 64 encoded string.
.
In the configuration file, the required **tls** field when using a file is
**root_ca_certificate**. When using base 64 encoded strings the required
**tls** field when using a file is **root_ca_certificate_base64**.
.
An example configuration file supporting server side authentication would be:
.
```json
{
"plugins": {
"mqtt": {
"tls": {
"server_private_key": "/path/to/private-key.pem",
"server_certificate": "/path/to/certificate.pem",
"root_ca_certificate": "/path/to/root-ca-certificate.pem"
}
}
}
}
```
.
The standalone bridge (`zenoh-bridge-mqtt`) also allows the required file to be
provided through the **`--root-ca-certificate`** command line argument.
.
## Username/password authentication
.
The MQTT plugin and standalone bridge for Eclipse Zenoh supports basic
username/password authentication of MQTT clients. Credentials are provided via
a dictionary file with each line containing the username and password for a
single user in the following format:
.
```raw
username:password
```
.
Username/passord authentication can be configured via the configuration file
or, if using the standalone bridge, via command line arguments.
.
In the configuration file, the required **auth** field for configuring the
dictionary file is **dictionary_file**.
.
An example configuration file supporting username/password authentication would
be:
.
```json
{
"plugins": {
"mqtt": {
"auth": {
"dictionary_file": "/path/to/dictionary-file",
}
}
}
}
```
.
The standalone bridge (`zenoh-bridge-mqtt`) also allows the required file to be
provided through the **`--dictionary-file`** command line argument.
.
### Security considerations
.
Usernames and passwords are sent as part of the MQTT `CONNECT` message in clear
text. As such, they can potentially be viewed using tools such as
[Wireshark](https://www.wireshark.org/).
.
To prevent this, it is highly recommended that this feature is used in
conjunction with the MQTTS feature to ensure credentials are encrypted on the
wire.
.
## How to install it
.
To install the latest release of either the MQTT plugin for the Zenoh router,
either the `zenoh-bridge-mqtt` standalone executable, you can do as follows:
.
### Manual installation (all platforms)
.
All release packages can be downloaded from:
.
-
[https://download.eclipse.org/zenoh/zenoh-plugin-mqtt/latest/](https://download.eclipse.org/zenoh/zenoh-plugin-mqtt/latest/)
.
Each subdirectory has the name of the Rust target. See the platforms each
target corresponds to on
[https://doc.rust-lang.org/stable/rustc/platform-support.html](https://doc.rust-lang.org/stable/rustc/platform-support.html)
.
Choose your platform and download:
.
- the `zenoh-plugin-mqtt--.zip` file for the plugin.
Then unzip it in the same directory than `zenohd` or to any directory where
it can find the plugin library (e.g. /usr/lib)
- the `zenoh-bridge-mqtt--.zip` file for the standalone
executable.
Then unzip it where you want, and run the extracted `zenoh-bridge-mqtt`
binary.
.
### Linux Debian
.
Add Eclipse Zenoh private repository to the sources list:
.
```bash
echo "deb [trusted=yes] https://download.eclipse.org/zenoh/debian-repo/ /" |
sudo tee -a /etc/apt/sources.list > /dev/null
sudo apt update
```
.
Then either:
.
- install the plugin with: `sudo apt install zenoh-plugin-mqtt`.
- install the standalone executable with: `sudo apt install zenoh-bridge-mqtt`.
.
## Docker image
.
The **`zenoh-bridge-mqtt`** standalone executable is also available as a
[Docker
images](https://hub.docker.com/r/eclipse/zenoh-bridge-mqtt/tags?page=1&ordering=last_updated)
for both amd64 and arm64. To get it, do:
.
- `docker pull eclipse/zenoh-bridge-mqtt:latest` for the latest release
- `docker pull eclipse/zenoh-bridge-mqtt:main` for the main branch version
(nightly build)
.
Usage: **`docker run --init -p 1883:1883 eclipse/zenoh-bridge-mqtt`**
It supports the same command line arguments than the `zenoh-bridge-mqtt` (see
above or check with `-h` argument).
.
## How to build it
.
> :warning: **WARNING** :warning: : Zenoh and its ecosystem are under active
development. When you build from git, make sure you also build from git any
other Zenoh repository you plan to use (e.g. binding, plugin, backend, etc.).
It may happen that some changes in git are not compatible with the most recent
packaged Zenoh release (e.g. deb, docker, pip). We put particular effort in
mantaining compatibility between the various git repositories in the Zenoh
project.
>
> :warning: **WARNING** :warning: : As Rust doesn't have a stable ABI, the
plugins should be
built with the exact same Rust version than `zenohd`, and using for `zenoh`
dependency the same version (or commit number) than 'zenohd'.
Otherwise, incompatibilities in memory mapping of shared types between `zenohd`
and the library can lead to a `"SIGSEV"` crash.
.
In order to build the zenoh bridge for MQTT you only need to install
[Rust](https://www.rust-lang.org/tools/install). If you already have the Rust
toolchain installed, make sure it is up-to-date with:
.
```bash
rustup update
```
.
Then, you may clone the repository on your machine:
.
```bash
git clone https://github.com/eclipse-zenoh/zenoh-plugin-mqtt.git
cd zenoh-plugin-mqtt
cargo build --release
```
.
The standalone executable binary `zenoh-bridge-mqtt` and a plugin shared
library (`*.so` on Linux, `*.dylib` on Mac OS, `*.dll` on Windows) to be
dynamically
loaded by the zenoh router `zenohd` will be generated in the `target/release`
subdirectory.
Package: zenoh-plugin-mqtt
Version: 1.3.3
Architecture: armhf
Maintainer: zenoh-dev@eclipse.org
Installed-Size: 6884
Depends: zenohd (=1.3.3)
Filename: 1.3.3/zenoh-plugin-mqtt_1.3.3_armhf.deb
Size: 1637932
MD5sum: 3aeba35597b5aec6228f33b5f5ef4b88
SHA1: 1a86ac3479d5cc873bf90a40da43a844172bff39
SHA256: ec07581d2ca75461b737280859b8d310d277c79bed352412da854ee22e258e88
Section: net
Priority: optional
Homepage: http://zenoh.io
Description: Zenoh plugin for MQTT
.
[](https://github.com/eclipse-zenoh/zenoh-plugin-mqtt/actions?query=workflow%3ARust)
[](https://github.com/eclipse-zenoh/roadmap/discussions)
[](https://discord.gg/2GJ958VuHs)
[](https://choosealicense.com/licenses/epl-2.0/)
[](https://opensource.org/licenses/Apache-2.0)
.
# Eclipse Zenoh
.
The Eclipse Zenoh: Zero Overhead Pub/sub, Store/Query and Compute.
.
Zenoh (pronounce _/zeno/_) unifies data in motion, data at rest and
computations. It carefully blends traditional pub/sub with geo-distributed
storages, queries and computations, while retaining a level of time and space
efficiency that is well beyond any of the mainstream stacks.
.
Check the website [zenoh.io](http://zenoh.io) and the
[roadmap](https://github.com/eclipse-zenoh/roadmap) for more detailed
information.
.
-------------------------------
.
# MQTT plugin and standalone `zenoh-bridge-mqtt`
.
:point_right: **Install latest release:** see [below](#how-to-install-it)
.
:point_right: **Docker image:** see [below](#docker-image)
.
:point_right: **Build "main" branch:** see [below](#how-to-build-it)
.
## Background
.
[MQTT](https://mqtt.org/) is a pub/sub protocol leveraging a broker to route
the messages between the MQTT clients.
The MQTT plugin for Eclipse Zenoh acts as a MQTT broker, accepting connections
from MQTT clients (V3 and V5) and translating the MQTT pub/sub into a Zenoh
pub/sub.
I.e.:
.
- a MQTT publication on topic `device/123/temperature` is routed as a Zenoh
publication on key expression `device/123/temperature`
- a MQTT subscription on topic `device/#` is mapped to a Zenoh subscription on
key expression `device/**`
.
This allows a close intergration of any MQTT system with Zenoh, but also brings
to MQTT systems the benefits of a Zenoh routing infrastructure.
Some examples of use cases:
.
- Routing MQTT from the device to the Edge and to the Cloud
- Bridging 2 distinct MQTT systems across the Internet, with NAT traversal
- Pub/sub to MQTT via the Zenoh REST API
- MQTT-ROS2 (robot) communication
- Store MQTT publications in any Zenoh storage (RocksDB, InfluxDB, file
system...)
- MQTT record/replay with InfluxDB as a storage
.
The MQTT plugin for Eclipse Zenoh is available either as a dynamic library to
be loaded by the Zenoh router (`zenohd`), either as a standalone executable
(`zenoh-bridge-mqtt`) that can acts as a Zenoh client or peer.
.
## Configuration
.
`zenoh-bridge-mqtt` can be configured via a JSON5 file passed via the
`-c`argument. You can see a commented example of such configuration file:
[`DEFAULT_CONFIG.json5`](DEFAULT_CONFIG.json5).
.
The `"mqtt"` part of this same configuration file can also be used in the
configuration file for the zenoh router (within its `"plugins"` part). The
router will automatically try to load the plugin library (`zenoh_plugin_mqtt`)
at startup and apply its configuration.
.
`zenoh-bridge-mqtt` also accepts the following arguments. If set, each argument
will override the similar setting from the configuration file:
.
- zenoh-related arguments:
- **`-c, --config `** : a config file
- **`-m, --mode `** : The zenoh session mode. Default: `peer` Possible
values: `peer` or `client`.
See [zenoh
documentation](https://zenoh.io/docs/getting-started/key-concepts/#deployment-units)
for more details.
- **`-l, --listen `** : A locator on which this router will listen
for incoming sessions. Repeat this option to open several listeners. Example of
locator: `tcp/localhost:7447`.
- **`-e, --peer `** : A peer locator this router will try to connect
to (typically another bridge or a zenoh router). Repeat this option to connect
to several peers. Example of locator: `tcp/:7447`.
- **`--no-multicast-scouting`** : disable the zenoh scouting protocol that
allows automatic discovery of zenoh peers and routers.
- **`-i, --id `** : The identifier (as an hexadecimal string -
e.g.: 0A0B23...) that the zenoh bridge must use. **WARNING: this identifier
must be unique in the system!** If not set, a random UUIDv4 will be used.
- **`--rest-http-port [PORT | IP:PORT]`** : Configures HTTP interface for the
REST API (disabled by default, setting this option enables it). Accepted
values:
- a port number
- a string with format `:` (to bind the HTTP server
to a specific interface).
- MQTT-related arguments:
- **`-p, --port [PORT | IP:PORT]`** : The address to bind the MQTT server.
Default: `"0.0.0.0:1883"`. Accepted values:
- a port number (`"0.0.0.0"` will be used as IP to bind, meaning any
interface of the host)
- a string with format `:` (to bind the MQTT server
to a specific interface).
- **`-s, --scope `** : A string added as prefix to all routed MQTT
topics when mapped to a zenoh key expression. This should be used to avoid
conflicts when several distinct MQTT systems using the same topics names are
routed via Zenoh.
- **`-a, --allow `** : A regular expression matching the MQTT topic
name that must be routed via zenoh. By default all topics are allowed. If both
`--allow` and `--deny` are set a topic will be allowed if it matches only the
'allow' expression.
- **`--deny `** : A regular expression matching the MQTT topic name
that must not be routed via zenoh. By default no topics are denied. If both
`--allow` and `--deny` are set a topic will be allowed if it matches only the
'allow' expression.
- **`-w, --generalise-pub `** : A list of key expressions to use for
generalising the declaration of
the zenoh publications, and thus minimizing the discovery traffic (usable
multiple times).
See [this
blog](https://zenoh.io/blog/2021-03-23-discovery/#leveraging-resource-generalisation)
for more details.
- **`-r, --generalise-sub `** : A list of key expressions to use for
generalising the declaration of
the zenoh subscriptions, and thus minimizing the discovery traffic (usable
multiple times).
See [this
blog](https://zenoh.io/blog/2021-03-23-discovery/#leveraging-resource-generalisation)
for more details.
- **`--tx-channel-size `** : Size of the MQTT transmit
channel (default: 65536). The channel buffers messages from Zenoh until they
can be sent to MQTT clients. If the channel capacity is reached new messages
from Zenoh will be dropped until space becomes available.
- **`--dictionary-file `** : Path to a file containing the MQTT client
username/password dictionary.
- **`--server-private-key `** : Path to the TLS private key for the
MQTT server. If specified a valid certificate for the server must also be
provided.
- **`--server-certificate `** : Path to the TLS public certificate for
the MQTT server. If specified a valid private key for the server must also be
provided.
- **`--root-ca-certificate `** : Path to the certificate of the
certificate authority used to validate clients connecting to the MQTT server.
If specified a valid private key and certificate for the server must also be
provided.
.
## Admin space
.
The zenoh bridge for MQTT exposes an administration space allowing to get some
information on its status and configuration.
This administration space is accessible via any zenoh API, including the REST
API that you can activate at `zenoh-bridge-mqtt` startup using the
`--rest-http-port` argument.
.
The `zenoh-bridge-mqtt` exposes this administration space with paths prefixed
by `@/service//mqtt` (where `` is the unique identifier of the
bridge instance). The informations are then organized with such paths:
.
- `@/service//mqtt/version` : the bridge version
- `@/service//mqtt/config` : the bridge configuration
.
Example of queries on administration space using the REST API with the `curl`
command line tool (don't forget to activate the REST API with `--rest-http-port
8000` argument):
.
```bash
curl http://localhost:8000:/@/service/**
```
.
> _Pro tip: pipe the result into [**jq**](https://stedolan.github.io/jq/)
command for JSON pretty print or transformation._
.
## MQTTS support
.
The MQTT plugin and standalone bridge for Eclipse Zenoh supports MQTTS. MQTTS
can be configured in two ways:
.
- server side authentication: MQTT clients validate the servers TLS certificate
but not the other way around.
- mutual authentication (mTLS): where both server and clients validate each
other.
.
MQTTS can be configured via the configuration file or, if using the standalone
bridge, via command line arguments.
.
### Server side authentication configuration
.
Server side authentication requires both a private key and certificate for the
server. These can be provided as either a file or as a base 64 encoded string.
.
In the configuration file, the required **tls** fields when using files are
**server_private_key** and **server_certificate**. When using base 64 encoded
strings the required **tls** fields are **server_private_key_base64** and
**server_certificate_base64**.
.
An example configuration file supporting server side authentication would be:
.
```json
{
"plugins": {
"mqtt": {
"tls": {
"server_private_key": "/path/to/private-key.pem",
"server_certificate": "/path/to/certificate.pem"
}
}
}
}
```
.
The standalone bridge (`zenoh-bridge-mqtt`) also allows the required files to
be provided through the **`--server-private-key`** and
**`--server-certificate`** command line arguments.
.
### Mutual authentication (mTLS) configuration
.
In order to enable mutual authentication a certificate for the certificate
authority used to validate clients connecting to the MQTT server must also be
provided. This can be provided as either a file or a base 64 encoded string.
.
In the configuration file, the required **tls** field when using a file is
**root_ca_certificate**. When using base 64 encoded strings the required
**tls** field when using a file is **root_ca_certificate_base64**.
.
An example configuration file supporting server side authentication would be:
.
```json
{
"plugins": {
"mqtt": {
"tls": {
"server_private_key": "/path/to/private-key.pem",
"server_certificate": "/path/to/certificate.pem",
"root_ca_certificate": "/path/to/root-ca-certificate.pem"
}
}
}
}
```
.
The standalone bridge (`zenoh-bridge-mqtt`) also allows the required file to be
provided through the **`--root-ca-certificate`** command line argument.
.
## Username/password authentication
.
The MQTT plugin and standalone bridge for Eclipse Zenoh supports basic
username/password authentication of MQTT clients. Credentials are provided via
a dictionary file with each line containing the username and password for a
single user in the following format:
.
```raw
username:password
```
.
Username/passord authentication can be configured via the configuration file
or, if using the standalone bridge, via command line arguments.
.
In the configuration file, the required **auth** field for configuring the
dictionary file is **dictionary_file**.
.
An example configuration file supporting username/password authentication would
be:
.
```json
{
"plugins": {
"mqtt": {
"auth": {
"dictionary_file": "/path/to/dictionary-file",
}
}
}
}
```
.
The standalone bridge (`zenoh-bridge-mqtt`) also allows the required file to be
provided through the **`--dictionary-file`** command line argument.
.
### Security considerations
.
Usernames and passwords are sent as part of the MQTT `CONNECT` message in clear
text. As such, they can potentially be viewed using tools such as
[Wireshark](https://www.wireshark.org/).
.
To prevent this, it is highly recommended that this feature is used in
conjunction with the MQTTS feature to ensure credentials are encrypted on the
wire.
.
## How to install it
.
To install the latest release of either the MQTT plugin for the Zenoh router,
either the `zenoh-bridge-mqtt` standalone executable, you can do as follows:
.
### Manual installation (all platforms)
.
All release packages can be downloaded from:
.
-
[https://download.eclipse.org/zenoh/zenoh-plugin-mqtt/latest/](https://download.eclipse.org/zenoh/zenoh-plugin-mqtt/latest/)
.
Each subdirectory has the name of the Rust target. See the platforms each
target corresponds to on
[https://doc.rust-lang.org/stable/rustc/platform-support.html](https://doc.rust-lang.org/stable/rustc/platform-support.html)
.
Choose your platform and download:
.
- the `zenoh-plugin-mqtt--.zip` file for the plugin.
Then unzip it in the same directory than `zenohd` or to any directory where
it can find the plugin library (e.g. /usr/lib)
- the `zenoh-bridge-mqtt--.zip` file for the standalone
executable.
Then unzip it where you want, and run the extracted `zenoh-bridge-mqtt`
binary.
.
### Linux Debian
.
Add Eclipse Zenoh private repository to the sources list:
.
```bash
echo "deb [trusted=yes] https://download.eclipse.org/zenoh/debian-repo/ /" |
sudo tee -a /etc/apt/sources.list > /dev/null
sudo apt update
```
.
Then either:
.
- install the plugin with: `sudo apt install zenoh-plugin-mqtt`.
- install the standalone executable with: `sudo apt install zenoh-bridge-mqtt`.
.
## Docker image
.
The **`zenoh-bridge-mqtt`** standalone executable is also available as a
[Docker
images](https://hub.docker.com/r/eclipse/zenoh-bridge-mqtt/tags?page=1&ordering=last_updated)
for both amd64 and arm64. To get it, do:
.
- `docker pull eclipse/zenoh-bridge-mqtt:latest` for the latest release
- `docker pull eclipse/zenoh-bridge-mqtt:main` for the main branch version
(nightly build)
.
Usage: **`docker run --init -p 1883:1883 eclipse/zenoh-bridge-mqtt`**
It supports the same command line arguments than the `zenoh-bridge-mqtt` (see
above or check with `-h` argument).
.
## How to build it
.
> :warning: **WARNING** :warning: : Zenoh and its ecosystem are under active
development. When you build from git, make sure you also build from git any
other Zenoh repository you plan to use (e.g. binding, plugin, backend, etc.).
It may happen that some changes in git are not compatible with the most recent
packaged Zenoh release (e.g. deb, docker, pip). We put particular effort in
mantaining compatibility between the various git repositories in the Zenoh
project.
>
> :warning: **WARNING** :warning: : As Rust doesn't have a stable ABI, the
plugins should be
built with the exact same Rust version than `zenohd`, and using for `zenoh`
dependency the same version (or commit number) than 'zenohd'.
Otherwise, incompatibilities in memory mapping of shared types between `zenohd`
and the library can lead to a `"SIGSEV"` crash.
.
In order to build the zenoh bridge for MQTT you only need to install
[Rust](https://www.rust-lang.org/tools/install). If you already have the Rust
toolchain installed, make sure it is up-to-date with:
.
```bash
rustup update
```
.
Then, you may clone the repository on your machine:
.
```bash
git clone https://github.com/eclipse-zenoh/zenoh-plugin-mqtt.git
cd zenoh-plugin-mqtt
cargo build --release
```
.
The standalone executable binary `zenoh-bridge-mqtt` and a plugin shared
library (`*.so` on Linux, `*.dylib` on Mac OS, `*.dll` on Windows) to be
dynamically
loaded by the zenoh router `zenohd` will be generated in the `target/release`
subdirectory.