Package: zenoh-plugin-webserver
Version: 1.0.3
Architecture: amd64
Maintainer: zenoh-dev@eclipse.org
Installed-Size: 13295
Depends: zenohd (=1.0.3)
Filename: 1.0.3/zenoh-plugin-webserver_1.0.3_amd64.deb
Size: 2521028
MD5sum: 71456e73915e3dd967692c07455e5d7e
SHA1: f840c09aae133cad2d7cac7d203f9031f66810f5
SHA256: 51d8b4dd09cebeed8ef6b8a2fc93be740f44ec1930c7be846da4212a377a4239
Section: net
Priority: optional
Homepage: http://zenoh.io
Description: Plugin for Zenoh implementing an HTTP server that maps URLs to zenoh key
expressions
.
[](https://github.com/eclipse-zenoh/zenoh-plugin-webserver/actions?query=workflow%3A%22CI%22)
[](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.
.
-------------------------------
# Web Server plugin
.
The Web Server plugin implements an HTTP server mapping URLs to zenoh keys.
This plugin can be used to set-up a Web server where the resources are
retrieved from geo-distributed
zenoh storages, each leveraging various backends (file system, database,
memory...).
.
**Library name** `zenoh_plugin_webserver`
.
:point_right: **Download stable versions:**
https://download.eclipse.org/zenoh/zenoh-plugin-webserver/
.
:point_right: **Build "main" branch:** see [below](#How-to-build-it)
.
-------------------------------
## :warning: Documentation for previous 0.5 versions:
The following documentation related to the version currently in development in
"main" branch: 0.6.x.
.
For previous versions see the README and code of the corresponding tagged
version:
-
[0.5.0-beta.9](https://github.com/eclipse-zenoh/zenoh-plugin-webserver/tree/0.5.0-beta.9#readme)
-
[0.5.0-beta.8](https://github.com/eclipse-zenoh/zenoh-plugin-webserver/tree/0.5.0-beta.8#readme)
.
-------------------------------
## **Examples of usage**
.
Assuming you have a static website, you can:
- expose the files as zenoh key/values using the [File System
backend](https://github.com/eclipse-zenoh/zenoh-backend-filesystem)
- set-up this Web Server plugin that will allow HTTP clients to browse the
files.
.
Here are the steps:
1. Make sure the libraries for the File System backend and the Web Server
plugin are available for the zenoh router:
either installing their packages (depending your platform), either
downloading the library files corresponding
to your platform in your `~/.zenoh/lib` directory.
2. Copy the website files into a `~/.zenoh/zbackend_fs/my-site` directory (or
make it a symbolic link to the path of your website)
3. Create a `zenoh.json5` configuration file containing:
```json5
{
plugins: {
webserver: {
http_port: 8080,
},
storage_manager: {
volumes: {
fs: {}
},
storages: {
demo: {
key_expr: "my-site/**",
strip_prefix: "my-site",
volume: {
id: "fs",
dir: "my-site",
read_only: true
}
}
}
}
}
}
```
4. Start the zenoh router (`zenohd`). It will automatically load the Web
Server plugin and make it available on port 8080. It will also create a storage
replying to any zenoh query on key expressions starting with `my-site/`.
Now you can browse your site on http://localhost:8080/my-site.
.
.
For more advanced use cases you can also:
- Have the files of your web sites stored on different hosts. Running a zenoh
router with a File System Storage on
each host allow to make all the files available under the `my-site/` zenoh
key.
- Duplicate the files of your web sites on several hosts to provide fault
tolerance.
- Start several zenoh routers with the Web Service plugin on different hosts
(not necessarly the same than the
hosts running the File System storages). Each host will serve your web site.
- Use other backends than the File System to store your resources and make
them available through zenoh.
(List of available backends
[here](http://zenoh.io/docs/manual/backends-list/)).
- Deploy a zenoh application that will implement `eval` function for a
resource, replying to requests with a
dynamic content (see the `z_eval` example in
[Rust](https://github.com/eclipse-zenoh/zenoh/blob/main/zenoh/examples/zenoh/z_eval.rs)
or
[Python](https://github.com/eclipse-zenoh/zenoh-python/blob/main/examples/zenoh/z_eval.py)).
.
-------------------------------
## **Configuration**
.
In its configuration part, the plugin supports those settings:
- **`http_port`** - int or string - required:
either a port number as an integer or a string, either a string with format
`":"`
.
-------------------------------
## **Troubleshooting**
.
### *Address already in use*
If in `zenohd` logs you see such error log at startup:
```
[2021-04-12T14:20:51Z ERROR zenoh_plugin_webserver] Unable to start http server
for REST : Os { code: 48, kind: AddrInUse, message: "Address already in use" }
```
It means another process is already using this port number that the webserver
plugin would like to use.
In such case, you have 2 solutions:
- stop the other process using this port
- make the webserver plugin to another port changing its `listener` option.
.
### *Permission denied*
If in `zenohd` logs you see such error log at startup:
```
[2021-04-12T13:55:10Z ERROR zenoh_plugin_webserver] Unable to start http server
for REST : Os { code: 13, kind: PermissionDenied, message: "Permission denied"
```
It probably means your OS (this usually happens on Linux) forbids the usage of
the configured port for non-root user (actually it usually restricts all ports
between 0 and 1024).
In such case, you have 2 solutions:
- run zenohd with root privileges (via `sudo`)
- use another changing he webserver plugin's `listener` option.
.
-------------------------------
## **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.
.
At first, install [Cargo and
Rust](https://doc.rust-lang.org/cargo/getting-started/installation.html). If
you already have the Rust toolchain installed, make sure it is up-to-date with:
.
```bash
$ rustup update
```
.
To know the Rust version you're `zenohd` has been built with, use the
`--version` option.
Example:
```bash
$ zenohd --version
The zenoh router v0.6.0-beta.1 built with rustc 1.64.0 (a55dd71d5 2022-09-19)
```
Here, `zenohd` has been built with the rustc version `1.64.0`.
Install and use this toolchain with the following command:
.
```bash
$ rustup default 1.64.0
```
.
And `zenohd` version corresponds to an un-released commit with id `1f20c86`.
Update the `zenoh` dependency in Cargo.lock with this command:
```bash
$ cargo update -p zenoh --precise 1f20c86
```
.
Then build the backend with:
```bash
$ cargo build --release -p zenoh-plugin-webserver
```
Vcs-Browser: https://github.com/eclipse-zenoh/zenoh-plugin-webserver
Vcs-Git: https://github.com/eclipse-zenoh/zenoh-plugin-webserver
Package: zenoh-plugin-webserver
Version: 1.0.3
Architecture: arm64
Maintainer: zenoh-dev@eclipse.org
Installed-Size: 12456
Depends: zenohd (=1.0.3)
Filename: 1.0.3/zenoh-plugin-webserver_1.0.3_arm64.deb
Size: 2345736
MD5sum: 2e6de67e1d18bbc6bd5708f4119889db
SHA1: 9955ed7ea55669080598f58fa9ee47679b03bf5c
SHA256: 47d8498850a0896eb8dd83175f0a4022eb7530b88569ff5a5c7f5466ea41121b
Section: net
Priority: optional
Homepage: http://zenoh.io
Description: Plugin for Zenoh implementing an HTTP server that maps URLs to zenoh key
expressions
.
[](https://github.com/eclipse-zenoh/zenoh-plugin-webserver/actions?query=workflow%3A%22CI%22)
[](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.
.
-------------------------------
# Web Server plugin
.
The Web Server plugin implements an HTTP server mapping URLs to zenoh keys.
This plugin can be used to set-up a Web server where the resources are
retrieved from geo-distributed
zenoh storages, each leveraging various backends (file system, database,
memory...).
.
**Library name** `zenoh_plugin_webserver`
.
:point_right: **Download stable versions:**
https://download.eclipse.org/zenoh/zenoh-plugin-webserver/
.
:point_right: **Build "main" branch:** see [below](#How-to-build-it)
.
-------------------------------
## :warning: Documentation for previous 0.5 versions:
The following documentation related to the version currently in development in
"main" branch: 0.6.x.
.
For previous versions see the README and code of the corresponding tagged
version:
-
[0.5.0-beta.9](https://github.com/eclipse-zenoh/zenoh-plugin-webserver/tree/0.5.0-beta.9#readme)
-
[0.5.0-beta.8](https://github.com/eclipse-zenoh/zenoh-plugin-webserver/tree/0.5.0-beta.8#readme)
.
-------------------------------
## **Examples of usage**
.
Assuming you have a static website, you can:
- expose the files as zenoh key/values using the [File System
backend](https://github.com/eclipse-zenoh/zenoh-backend-filesystem)
- set-up this Web Server plugin that will allow HTTP clients to browse the
files.
.
Here are the steps:
1. Make sure the libraries for the File System backend and the Web Server
plugin are available for the zenoh router:
either installing their packages (depending your platform), either
downloading the library files corresponding
to your platform in your `~/.zenoh/lib` directory.
2. Copy the website files into a `~/.zenoh/zbackend_fs/my-site` directory (or
make it a symbolic link to the path of your website)
3. Create a `zenoh.json5` configuration file containing:
```json5
{
plugins: {
webserver: {
http_port: 8080,
},
storage_manager: {
volumes: {
fs: {}
},
storages: {
demo: {
key_expr: "my-site/**",
strip_prefix: "my-site",
volume: {
id: "fs",
dir: "my-site",
read_only: true
}
}
}
}
}
}
```
4. Start the zenoh router (`zenohd`). It will automatically load the Web
Server plugin and make it available on port 8080. It will also create a storage
replying to any zenoh query on key expressions starting with `my-site/`.
Now you can browse your site on http://localhost:8080/my-site.
.
.
For more advanced use cases you can also:
- Have the files of your web sites stored on different hosts. Running a zenoh
router with a File System Storage on
each host allow to make all the files available under the `my-site/` zenoh
key.
- Duplicate the files of your web sites on several hosts to provide fault
tolerance.
- Start several zenoh routers with the Web Service plugin on different hosts
(not necessarly the same than the
hosts running the File System storages). Each host will serve your web site.
- Use other backends than the File System to store your resources and make
them available through zenoh.
(List of available backends
[here](http://zenoh.io/docs/manual/backends-list/)).
- Deploy a zenoh application that will implement `eval` function for a
resource, replying to requests with a
dynamic content (see the `z_eval` example in
[Rust](https://github.com/eclipse-zenoh/zenoh/blob/main/zenoh/examples/zenoh/z_eval.rs)
or
[Python](https://github.com/eclipse-zenoh/zenoh-python/blob/main/examples/zenoh/z_eval.py)).
.
-------------------------------
## **Configuration**
.
In its configuration part, the plugin supports those settings:
- **`http_port`** - int or string - required:
either a port number as an integer or a string, either a string with format
`":"`
.
-------------------------------
## **Troubleshooting**
.
### *Address already in use*
If in `zenohd` logs you see such error log at startup:
```
[2021-04-12T14:20:51Z ERROR zenoh_plugin_webserver] Unable to start http server
for REST : Os { code: 48, kind: AddrInUse, message: "Address already in use" }
```
It means another process is already using this port number that the webserver
plugin would like to use.
In such case, you have 2 solutions:
- stop the other process using this port
- make the webserver plugin to another port changing its `listener` option.
.
### *Permission denied*
If in `zenohd` logs you see such error log at startup:
```
[2021-04-12T13:55:10Z ERROR zenoh_plugin_webserver] Unable to start http server
for REST : Os { code: 13, kind: PermissionDenied, message: "Permission denied"
```
It probably means your OS (this usually happens on Linux) forbids the usage of
the configured port for non-root user (actually it usually restricts all ports
between 0 and 1024).
In such case, you have 2 solutions:
- run zenohd with root privileges (via `sudo`)
- use another changing he webserver plugin's `listener` option.
.
-------------------------------
## **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.
.
At first, install [Cargo and
Rust](https://doc.rust-lang.org/cargo/getting-started/installation.html). If
you already have the Rust toolchain installed, make sure it is up-to-date with:
.
```bash
$ rustup update
```
.
To know the Rust version you're `zenohd` has been built with, use the
`--version` option.
Example:
```bash
$ zenohd --version
The zenoh router v0.6.0-beta.1 built with rustc 1.64.0 (a55dd71d5 2022-09-19)
```
Here, `zenohd` has been built with the rustc version `1.64.0`.
Install and use this toolchain with the following command:
.
```bash
$ rustup default 1.64.0
```
.
And `zenohd` version corresponds to an un-released commit with id `1f20c86`.
Update the `zenoh` dependency in Cargo.lock with this command:
```bash
$ cargo update -p zenoh --precise 1f20c86
```
.
Then build the backend with:
```bash
$ cargo build --release -p zenoh-plugin-webserver
```
Vcs-Browser: https://github.com/eclipse-zenoh/zenoh-plugin-webserver
Vcs-Git: https://github.com/eclipse-zenoh/zenoh-plugin-webserver
Package: zenoh-plugin-webserver
Version: 1.0.3
Architecture: armel
Maintainer: zenoh-dev@eclipse.org
Installed-Size: 10202
Depends: zenohd (=1.0.3)
Filename: 1.0.3/zenoh-plugin-webserver_1.0.3_armel.deb
Size: 2144704
MD5sum: e3c109502c310c22ffa50137346b238f
SHA1: ec519d6b88b8ba3bf688be2399dc6654d8198292
SHA256: 3953a654de2f6281f6fa5330b3c7e6b0a86ea0e97799de11f9ed5cad779c2ab1
Section: net
Priority: optional
Homepage: http://zenoh.io
Description: Plugin for Zenoh implementing an HTTP server that maps URLs to zenoh key
expressions
.
[](https://github.com/eclipse-zenoh/zenoh-plugin-webserver/actions?query=workflow%3A%22CI%22)
[](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.
.
-------------------------------
# Web Server plugin
.
The Web Server plugin implements an HTTP server mapping URLs to zenoh keys.
This plugin can be used to set-up a Web server where the resources are
retrieved from geo-distributed
zenoh storages, each leveraging various backends (file system, database,
memory...).
.
**Library name** `zenoh_plugin_webserver`
.
:point_right: **Download stable versions:**
https://download.eclipse.org/zenoh/zenoh-plugin-webserver/
.
:point_right: **Build "main" branch:** see [below](#How-to-build-it)
.
-------------------------------
## :warning: Documentation for previous 0.5 versions:
The following documentation related to the version currently in development in
"main" branch: 0.6.x.
.
For previous versions see the README and code of the corresponding tagged
version:
-
[0.5.0-beta.9](https://github.com/eclipse-zenoh/zenoh-plugin-webserver/tree/0.5.0-beta.9#readme)
-
[0.5.0-beta.8](https://github.com/eclipse-zenoh/zenoh-plugin-webserver/tree/0.5.0-beta.8#readme)
.
-------------------------------
## **Examples of usage**
.
Assuming you have a static website, you can:
- expose the files as zenoh key/values using the [File System
backend](https://github.com/eclipse-zenoh/zenoh-backend-filesystem)
- set-up this Web Server plugin that will allow HTTP clients to browse the
files.
.
Here are the steps:
1. Make sure the libraries for the File System backend and the Web Server
plugin are available for the zenoh router:
either installing their packages (depending your platform), either
downloading the library files corresponding
to your platform in your `~/.zenoh/lib` directory.
2. Copy the website files into a `~/.zenoh/zbackend_fs/my-site` directory (or
make it a symbolic link to the path of your website)
3. Create a `zenoh.json5` configuration file containing:
```json5
{
plugins: {
webserver: {
http_port: 8080,
},
storage_manager: {
volumes: {
fs: {}
},
storages: {
demo: {
key_expr: "my-site/**",
strip_prefix: "my-site",
volume: {
id: "fs",
dir: "my-site",
read_only: true
}
}
}
}
}
}
```
4. Start the zenoh router (`zenohd`). It will automatically load the Web
Server plugin and make it available on port 8080. It will also create a storage
replying to any zenoh query on key expressions starting with `my-site/`.
Now you can browse your site on http://localhost:8080/my-site.
.
.
For more advanced use cases you can also:
- Have the files of your web sites stored on different hosts. Running a zenoh
router with a File System Storage on
each host allow to make all the files available under the `my-site/` zenoh
key.
- Duplicate the files of your web sites on several hosts to provide fault
tolerance.
- Start several zenoh routers with the Web Service plugin on different hosts
(not necessarly the same than the
hosts running the File System storages). Each host will serve your web site.
- Use other backends than the File System to store your resources and make
them available through zenoh.
(List of available backends
[here](http://zenoh.io/docs/manual/backends-list/)).
- Deploy a zenoh application that will implement `eval` function for a
resource, replying to requests with a
dynamic content (see the `z_eval` example in
[Rust](https://github.com/eclipse-zenoh/zenoh/blob/main/zenoh/examples/zenoh/z_eval.rs)
or
[Python](https://github.com/eclipse-zenoh/zenoh-python/blob/main/examples/zenoh/z_eval.py)).
.
-------------------------------
## **Configuration**
.
In its configuration part, the plugin supports those settings:
- **`http_port`** - int or string - required:
either a port number as an integer or a string, either a string with format
`":"`
.
-------------------------------
## **Troubleshooting**
.
### *Address already in use*
If in `zenohd` logs you see such error log at startup:
```
[2021-04-12T14:20:51Z ERROR zenoh_plugin_webserver] Unable to start http server
for REST : Os { code: 48, kind: AddrInUse, message: "Address already in use" }
```
It means another process is already using this port number that the webserver
plugin would like to use.
In such case, you have 2 solutions:
- stop the other process using this port
- make the webserver plugin to another port changing its `listener` option.
.
### *Permission denied*
If in `zenohd` logs you see such error log at startup:
```
[2021-04-12T13:55:10Z ERROR zenoh_plugin_webserver] Unable to start http server
for REST : Os { code: 13, kind: PermissionDenied, message: "Permission denied"
```
It probably means your OS (this usually happens on Linux) forbids the usage of
the configured port for non-root user (actually it usually restricts all ports
between 0 and 1024).
In such case, you have 2 solutions:
- run zenohd with root privileges (via `sudo`)
- use another changing he webserver plugin's `listener` option.
.
-------------------------------
## **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.
.
At first, install [Cargo and
Rust](https://doc.rust-lang.org/cargo/getting-started/installation.html). If
you already have the Rust toolchain installed, make sure it is up-to-date with:
.
```bash
$ rustup update
```
.
To know the Rust version you're `zenohd` has been built with, use the
`--version` option.
Example:
```bash
$ zenohd --version
The zenoh router v0.6.0-beta.1 built with rustc 1.64.0 (a55dd71d5 2022-09-19)
```
Here, `zenohd` has been built with the rustc version `1.64.0`.
Install and use this toolchain with the following command:
.
```bash
$ rustup default 1.64.0
```
.
And `zenohd` version corresponds to an un-released commit with id `1f20c86`.
Update the `zenoh` dependency in Cargo.lock with this command:
```bash
$ cargo update -p zenoh --precise 1f20c86
```
.
Then build the backend with:
```bash
$ cargo build --release -p zenoh-plugin-webserver
```
Vcs-Browser: https://github.com/eclipse-zenoh/zenoh-plugin-webserver
Vcs-Git: https://github.com/eclipse-zenoh/zenoh-plugin-webserver
Package: zenoh-plugin-webserver
Version: 1.0.3
Architecture: armhf
Maintainer: zenoh-dev@eclipse.org
Installed-Size: 10072
Depends: zenohd (=1.0.3)
Filename: 1.0.3/zenoh-plugin-webserver_1.0.3_armhf.deb
Size: 2132436
MD5sum: 4a0c78d09c942e57d018e8d701e61bcf
SHA1: 863ad65c0de331b6a658c8e8ee2fb0122fbb564d
SHA256: 260d4e95d2770e5fedbac8a99d57c804f477c122fb05eba50b730c08e90b0274
Section: net
Priority: optional
Homepage: http://zenoh.io
Description: Plugin for Zenoh implementing an HTTP server that maps URLs to zenoh key
expressions
.
[](https://github.com/eclipse-zenoh/zenoh-plugin-webserver/actions?query=workflow%3A%22CI%22)
[](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.
.
-------------------------------
# Web Server plugin
.
The Web Server plugin implements an HTTP server mapping URLs to zenoh keys.
This plugin can be used to set-up a Web server where the resources are
retrieved from geo-distributed
zenoh storages, each leveraging various backends (file system, database,
memory...).
.
**Library name** `zenoh_plugin_webserver`
.
:point_right: **Download stable versions:**
https://download.eclipse.org/zenoh/zenoh-plugin-webserver/
.
:point_right: **Build "main" branch:** see [below](#How-to-build-it)
.
-------------------------------
## :warning: Documentation for previous 0.5 versions:
The following documentation related to the version currently in development in
"main" branch: 0.6.x.
.
For previous versions see the README and code of the corresponding tagged
version:
-
[0.5.0-beta.9](https://github.com/eclipse-zenoh/zenoh-plugin-webserver/tree/0.5.0-beta.9#readme)
-
[0.5.0-beta.8](https://github.com/eclipse-zenoh/zenoh-plugin-webserver/tree/0.5.0-beta.8#readme)
.
-------------------------------
## **Examples of usage**
.
Assuming you have a static website, you can:
- expose the files as zenoh key/values using the [File System
backend](https://github.com/eclipse-zenoh/zenoh-backend-filesystem)
- set-up this Web Server plugin that will allow HTTP clients to browse the
files.
.
Here are the steps:
1. Make sure the libraries for the File System backend and the Web Server
plugin are available for the zenoh router:
either installing their packages (depending your platform), either
downloading the library files corresponding
to your platform in your `~/.zenoh/lib` directory.
2. Copy the website files into a `~/.zenoh/zbackend_fs/my-site` directory (or
make it a symbolic link to the path of your website)
3. Create a `zenoh.json5` configuration file containing:
```json5
{
plugins: {
webserver: {
http_port: 8080,
},
storage_manager: {
volumes: {
fs: {}
},
storages: {
demo: {
key_expr: "my-site/**",
strip_prefix: "my-site",
volume: {
id: "fs",
dir: "my-site",
read_only: true
}
}
}
}
}
}
```
4. Start the zenoh router (`zenohd`). It will automatically load the Web
Server plugin and make it available on port 8080. It will also create a storage
replying to any zenoh query on key expressions starting with `my-site/`.
Now you can browse your site on http://localhost:8080/my-site.
.
.
For more advanced use cases you can also:
- Have the files of your web sites stored on different hosts. Running a zenoh
router with a File System Storage on
each host allow to make all the files available under the `my-site/` zenoh
key.
- Duplicate the files of your web sites on several hosts to provide fault
tolerance.
- Start several zenoh routers with the Web Service plugin on different hosts
(not necessarly the same than the
hosts running the File System storages). Each host will serve your web site.
- Use other backends than the File System to store your resources and make
them available through zenoh.
(List of available backends
[here](http://zenoh.io/docs/manual/backends-list/)).
- Deploy a zenoh application that will implement `eval` function for a
resource, replying to requests with a
dynamic content (see the `z_eval` example in
[Rust](https://github.com/eclipse-zenoh/zenoh/blob/main/zenoh/examples/zenoh/z_eval.rs)
or
[Python](https://github.com/eclipse-zenoh/zenoh-python/blob/main/examples/zenoh/z_eval.py)).
.
-------------------------------
## **Configuration**
.
In its configuration part, the plugin supports those settings:
- **`http_port`** - int or string - required:
either a port number as an integer or a string, either a string with format
`":"`
.
-------------------------------
## **Troubleshooting**
.
### *Address already in use*
If in `zenohd` logs you see such error log at startup:
```
[2021-04-12T14:20:51Z ERROR zenoh_plugin_webserver] Unable to start http server
for REST : Os { code: 48, kind: AddrInUse, message: "Address already in use" }
```
It means another process is already using this port number that the webserver
plugin would like to use.
In such case, you have 2 solutions:
- stop the other process using this port
- make the webserver plugin to another port changing its `listener` option.
.
### *Permission denied*
If in `zenohd` logs you see such error log at startup:
```
[2021-04-12T13:55:10Z ERROR zenoh_plugin_webserver] Unable to start http server
for REST : Os { code: 13, kind: PermissionDenied, message: "Permission denied"
```
It probably means your OS (this usually happens on Linux) forbids the usage of
the configured port for non-root user (actually it usually restricts all ports
between 0 and 1024).
In such case, you have 2 solutions:
- run zenohd with root privileges (via `sudo`)
- use another changing he webserver plugin's `listener` option.
.
-------------------------------
## **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.
.
At first, install [Cargo and
Rust](https://doc.rust-lang.org/cargo/getting-started/installation.html). If
you already have the Rust toolchain installed, make sure it is up-to-date with:
.
```bash
$ rustup update
```
.
To know the Rust version you're `zenohd` has been built with, use the
`--version` option.
Example:
```bash
$ zenohd --version
The zenoh router v0.6.0-beta.1 built with rustc 1.64.0 (a55dd71d5 2022-09-19)
```
Here, `zenohd` has been built with the rustc version `1.64.0`.
Install and use this toolchain with the following command:
.
```bash
$ rustup default 1.64.0
```
.
And `zenohd` version corresponds to an un-released commit with id `1f20c86`.
Update the `zenoh` dependency in Cargo.lock with this command:
```bash
$ cargo update -p zenoh --precise 1f20c86
```
.
Then build the backend with:
```bash
$ cargo build --release -p zenoh-plugin-webserver
```
Vcs-Browser: https://github.com/eclipse-zenoh/zenoh-plugin-webserver
Vcs-Git: https://github.com/eclipse-zenoh/zenoh-plugin-webserver