Package: zenoh-backend-filesystem
Version: 1.0.0~beta.2-1
Architecture: armel
Maintainer: zenoh-dev@eclipse.org
Installed-Size: 16498
Depends: zenoh-plugin-storage-manager (=1.0.0~beta.2-1)
Filename: 1.0.0-beta.2/zenoh-backend-filesystem_1.0.0~beta.2-1_armel.deb
Size: 3906744
MD5sum: efccefd579118dfad4a2518ce80837e4
SHA1: 184021fff2b5979bfb271e9d65b3925be0471cb6
SHA256: 0c7a71c3d0cb8c4cbf259e5d028d58d260b6b782f6b3aeba27501abb1e810365
Section: net
Priority: optional
Homepage: http://zenoh.io
Description: Backend for Zenoh using the file system
.
[](https://github.com/eclipse-zenoh/zenoh-backend-filesystem/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.
.
-------------------------------
# File system backend
.
In zenoh a backend is a storage technology (such as DBMS, time-series database,
file system...) alowing to store the
keys/values publications made via zenoh and return them on queries.
See the [zenoh
documentation](https://zenoh.io/docs/manual/abstractions/#storage) for more
details.
.
This backend relies on the host's file system to implement the storages.
Its library name (without OS specific prefix and extension) that zenoh will
rely on to find it and load it is **`zenoh_backend_fs`**.
.
.
:point_right: **Install latest release:** see [below](#How-to-install-it)
.
:point_right: **Build "main" branch:** see [below](#How-to-build-it)
.
-------------------------------
## **Examples of usage**
.
Prerequisites:
- You have a zenoh router (`zenohd`) installed, and the `zenoh_backend_fs`
library file is available in `~/.zenoh/lib`.
- Declare the `ZENOH_BACKEND_FS_ROOT` environment variable to the directory
where you want the files to be stored (or exposed from).
If you don't declare it, the `~/.zenoh/zenoh_backend_fs` directory will be
used.
.
You can setup storages either at zenoh router startup via a configuration file,
either at runtime via the zenoh admin space, using for instance the REST API.
### **Setup via a JSON5 configuration file**
.
- Create a `zenoh.json5` configuration file containing:
```json5
{
plugins: {
// configuration of "storage-manager" plugin:
storage_manager: {
volumes: {
// configuration of a "fs" volume (the "zenoh_backend_fs" backend
library will be loaded at startup)
fs: {},
},
storages: {
// configuration of a "demo" storage using the "fs" volume
demo: {
// the key expression this storage will subscribes to
key_expr: "demo/example/**",
// this prefix will be stripped from the received key when
converting to file path
// this argument is optional.
strip_prefix: "demo/example",
volume: {
id: "fs",
// the key/values will be stored as files within this directory
(relative to ${ZENOH_BACKEND_FS_ROOT})
dir: "example"
}
}
}
},
// Optionally, add the REST plugin
rest: { http_port: 8000 }
}
}
```
- Run the zenoh router with:
`zenohd -c zenoh.json5`
.
### **Setup at runtime via `curl` commands on the admin space**
.
- Run the zenoh router, with write permissions to its admin space:
`zenohd --adminspace-permissions rw`
- Add the "fs" backend (the "zenoh_backend_fs" library will be loaded):
`curl -X PUT -H 'content-type:application/json' -d '{}'
http://localhost:8000/@/router/local/config/plugins/storage_manager/volumes/fs`
- Add the "demo" storage using the "fs" backend:
`curl -X PUT -H 'content-type:application/json' -d
'{key_expr:"demo/example/**",strip_prefix:"demo/example", volume: {id: "fs",
dir:"example"}}'
http://localhost:8000/@/router/local/config/plugins/storage_manager/storages/demo`
.
### **Tests using the REST API**
.
Using `curl` to publish and query keys/values, you can:
```bash
# Put values that will be stored under ${ZENOH_BACKEND_FS_ROOT}/example
curl -X PUT -d "TEST-1" http://localhost:8000/demo/example/test-1
curl -X PUT -d "B" http://localhost:8000/demo/example/a/b
.
# Retrive the values
curl http://localhost:8000/demo/example/**
```
.
.
-------------------------------
## Configuration
### Extra configuration for filesystem-backed volumes
.
Volumes using the `fs` backend don't need any extra configuration at the volume
level. Any volume can use the `fs` backend by specifying the value `"fs"` for
the `backend` configuration key. A volume named `fs` will automatically be
backed by the `fs` backend if no other backend is specified.
.
-------------------------------
### Storage-level configuration for filesystem-backed volumes
.
Storages relying on a `fs` backed volume must/can specify additional
configuration specific to that volume, as shown in the example
[above](#setup-via-a-json5-configuration-file):
- `dir` (**required**, string) : The directory that will be used to store data.
.
- `read_only` (optional, boolean) : the storage will only answer to GET
queries. It will not accept any PUT or DELETE message, and won't write any
file. `false` by default.
.
- `on_closure` (optional, string) : the strategy to use when the Storage is
removed. There are 2 options:
- `"do_nothing"`: the storage's directory remains untouched (this is the
default behaviour)
- `"delete_all"`: the storage's directory is deleted with all its content.
.
- `follow_links` (optional, boolean) : If set to `true` the storage will follow
the symbolic links. The default value is `false`.
.
- `keep_mime_types` (optional, boolean) : When replying to a GET query with a
file for which the zenoh encoding is not known, the storage guess its mime-type
according to the file extension. If the mime-type doesn't correspond to a
supported zenoh encoding, this option will drive the returned value:
- `true` (default value): a [Custom
value](https://docs.rs/zenoh/latest/zenoh/enum.Value.html#variant.Custom)
is returned with the description set to the mime-type.
- `false`: a [Raw
value](https://docs.rs/zenoh/latest/zenoh/enum.Value.html#variant.Raw) with
APP_OCTET_STREAM encoding is returned.
.
-------------------------------
## **Behaviour of the backend**
.
### Mapping to file system
Each **storage** will map to a directory with path:
`${ZENOH_BACKEND_FS_ROOT}/`, where:
* `${ZENOH_BACKEND_FS_ROOT}` is an environment variable that could be
specified before zenoh router startup.
If this variable is not specified `${ZENOH_HOME}/zenoh_backend_fs` will be
used
(where the default value of `${ZENOH_HOME}` is `~/.zenoh`).
* `` is the `"dir"` property specified at storage creation.
Each zenoh **key/value** put into the storage will map to a file within the
storage's directory where:
* the file path will be
`${ZENOH_BACKEND_FS_ROOT}//`, where
``
will be the zenoh key, stripped from the `"strip_prefix"` property
specified at storage creation.
* the content of the file will be the value written as a RawValue. I.e. the
same bytes buffer that has been
transported by zenoh. For UTF-8 compatible formats (StringUTF8, JSon,
Integer, Float...) it means the file
will be readable as a text format.
* the encoding and the timestamp of the key/value will be stored in a RocksDB
database stored in the storage directory.
.
### Behaviour on deletion
.
On deletion of a key, the corresponding file is removed. An entry with deletion
timestamp is inserted in the
RocksDB database (to avoid re-insertion of points with an older timestamp in
case of un-ordered messages).
At regular interval, a task cleans-up the RocksDB database from entries with
old timestamps that don't have a
corresponding existing file.
.
### Behaviour on GET
.
On GET operations, the storage searches for matching and existing files, and
return their raw content as a reply.
For each, the encoding and timestamp are retrieved from the RocksDB database.
But if no entry is found in the
database for a file (e.g. for files created without zenoh), the encoding is
deduced from the file's extension
(using [mime_guess](https://crates.io/crates/mime_guess)), and the timestamp is
deduced from the file's
modification time.
.
-------------------------------
## How to install it
.
To install the latest release of this backend library, you can do as follows:
.
### Manual installation (all platforms)
.
All release packages can be downloaded from:
- https://download.eclipse.org/zenoh/zenoh-backend-filesystem/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
.
Choose your platform and download the `.zip` file.
Unzip it in the same directory than `zenohd` or to any directory where it can
find the backend library (e.g. /usr/lib or ~/.zenoh/lib)
.
### Linux Debian
.
Add Eclipse Zenoh private repository to the sources list, and install the
`zenoh-backend-filesystem` package:
.
```bash
echo "deb [trusted=yes] https://download.eclipse.org/zenoh/debian-repo/ /" |
sudo tee -a /etc/apt/sources.list.d/zenoh.list > /dev/null
sudo apt update
sudo apt install zenoh-backend-filesystem
```
.
-------------------------------
## 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.
.
At first, install [Clang](https://clang.llvm.org/) and [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
```
.
> :warning: **WARNING** :warning: : As Rust doesn't have a stable ABI, the
backend library 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.
.
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 --all-targets
```
Vcs-Browser: https://github.com/eclipse-zenoh/zenoh-backend-filesystem
Vcs-Git: https://github.com/eclipse-zenoh/zenoh-backend-filesystem
Package: zenoh-backend-filesystem
Version: 1.0.0~beta.2-1
Architecture: armhf
Maintainer: zenoh-dev@eclipse.org
Installed-Size: 14618
Depends: zenoh-plugin-storage-manager (=1.0.0~beta.2-1)
Filename: 1.0.0-beta.2/zenoh-backend-filesystem_1.0.0~beta.2-1_armhf.deb
Size: 4007064
MD5sum: 7a264869de53a407f310043930f2b442
SHA1: e8935db416af2e76c2bbab5ac2e5ba76cea5bff9
SHA256: ba94acfaab8589fd43a17b371e7861b8cad06eb00f817ce6b4f8931dcc40ddb1
Section: net
Priority: optional
Homepage: http://zenoh.io
Description: Backend for Zenoh using the file system
.
[](https://github.com/eclipse-zenoh/zenoh-backend-filesystem/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.
.
-------------------------------
# File system backend
.
In zenoh a backend is a storage technology (such as DBMS, time-series database,
file system...) alowing to store the
keys/values publications made via zenoh and return them on queries.
See the [zenoh
documentation](https://zenoh.io/docs/manual/abstractions/#storage) for more
details.
.
This backend relies on the host's file system to implement the storages.
Its library name (without OS specific prefix and extension) that zenoh will
rely on to find it and load it is **`zenoh_backend_fs`**.
.
.
:point_right: **Install latest release:** see [below](#How-to-install-it)
.
:point_right: **Build "main" branch:** see [below](#How-to-build-it)
.
-------------------------------
## **Examples of usage**
.
Prerequisites:
- You have a zenoh router (`zenohd`) installed, and the `zenoh_backend_fs`
library file is available in `~/.zenoh/lib`.
- Declare the `ZENOH_BACKEND_FS_ROOT` environment variable to the directory
where you want the files to be stored (or exposed from).
If you don't declare it, the `~/.zenoh/zenoh_backend_fs` directory will be
used.
.
You can setup storages either at zenoh router startup via a configuration file,
either at runtime via the zenoh admin space, using for instance the REST API.
### **Setup via a JSON5 configuration file**
.
- Create a `zenoh.json5` configuration file containing:
```json5
{
plugins: {
// configuration of "storage-manager" plugin:
storage_manager: {
volumes: {
// configuration of a "fs" volume (the "zenoh_backend_fs" backend
library will be loaded at startup)
fs: {},
},
storages: {
// configuration of a "demo" storage using the "fs" volume
demo: {
// the key expression this storage will subscribes to
key_expr: "demo/example/**",
// this prefix will be stripped from the received key when
converting to file path
// this argument is optional.
strip_prefix: "demo/example",
volume: {
id: "fs",
// the key/values will be stored as files within this directory
(relative to ${ZENOH_BACKEND_FS_ROOT})
dir: "example"
}
}
}
},
// Optionally, add the REST plugin
rest: { http_port: 8000 }
}
}
```
- Run the zenoh router with:
`zenohd -c zenoh.json5`
.
### **Setup at runtime via `curl` commands on the admin space**
.
- Run the zenoh router, with write permissions to its admin space:
`zenohd --adminspace-permissions rw`
- Add the "fs" backend (the "zenoh_backend_fs" library will be loaded):
`curl -X PUT -H 'content-type:application/json' -d '{}'
http://localhost:8000/@/router/local/config/plugins/storage_manager/volumes/fs`
- Add the "demo" storage using the "fs" backend:
`curl -X PUT -H 'content-type:application/json' -d
'{key_expr:"demo/example/**",strip_prefix:"demo/example", volume: {id: "fs",
dir:"example"}}'
http://localhost:8000/@/router/local/config/plugins/storage_manager/storages/demo`
.
### **Tests using the REST API**
.
Using `curl` to publish and query keys/values, you can:
```bash
# Put values that will be stored under ${ZENOH_BACKEND_FS_ROOT}/example
curl -X PUT -d "TEST-1" http://localhost:8000/demo/example/test-1
curl -X PUT -d "B" http://localhost:8000/demo/example/a/b
.
# Retrive the values
curl http://localhost:8000/demo/example/**
```
.
.
-------------------------------
## Configuration
### Extra configuration for filesystem-backed volumes
.
Volumes using the `fs` backend don't need any extra configuration at the volume
level. Any volume can use the `fs` backend by specifying the value `"fs"` for
the `backend` configuration key. A volume named `fs` will automatically be
backed by the `fs` backend if no other backend is specified.
.
-------------------------------
### Storage-level configuration for filesystem-backed volumes
.
Storages relying on a `fs` backed volume must/can specify additional
configuration specific to that volume, as shown in the example
[above](#setup-via-a-json5-configuration-file):
- `dir` (**required**, string) : The directory that will be used to store data.
.
- `read_only` (optional, boolean) : the storage will only answer to GET
queries. It will not accept any PUT or DELETE message, and won't write any
file. `false` by default.
.
- `on_closure` (optional, string) : the strategy to use when the Storage is
removed. There are 2 options:
- `"do_nothing"`: the storage's directory remains untouched (this is the
default behaviour)
- `"delete_all"`: the storage's directory is deleted with all its content.
.
- `follow_links` (optional, boolean) : If set to `true` the storage will follow
the symbolic links. The default value is `false`.
.
- `keep_mime_types` (optional, boolean) : When replying to a GET query with a
file for which the zenoh encoding is not known, the storage guess its mime-type
according to the file extension. If the mime-type doesn't correspond to a
supported zenoh encoding, this option will drive the returned value:
- `true` (default value): a [Custom
value](https://docs.rs/zenoh/latest/zenoh/enum.Value.html#variant.Custom)
is returned with the description set to the mime-type.
- `false`: a [Raw
value](https://docs.rs/zenoh/latest/zenoh/enum.Value.html#variant.Raw) with
APP_OCTET_STREAM encoding is returned.
.
-------------------------------
## **Behaviour of the backend**
.
### Mapping to file system
Each **storage** will map to a directory with path:
`${ZENOH_BACKEND_FS_ROOT}/`, where:
* `${ZENOH_BACKEND_FS_ROOT}` is an environment variable that could be
specified before zenoh router startup.
If this variable is not specified `${ZENOH_HOME}/zenoh_backend_fs` will be
used
(where the default value of `${ZENOH_HOME}` is `~/.zenoh`).
* `` is the `"dir"` property specified at storage creation.
Each zenoh **key/value** put into the storage will map to a file within the
storage's directory where:
* the file path will be
`${ZENOH_BACKEND_FS_ROOT}//`, where
``
will be the zenoh key, stripped from the `"strip_prefix"` property
specified at storage creation.
* the content of the file will be the value written as a RawValue. I.e. the
same bytes buffer that has been
transported by zenoh. For UTF-8 compatible formats (StringUTF8, JSon,
Integer, Float...) it means the file
will be readable as a text format.
* the encoding and the timestamp of the key/value will be stored in a RocksDB
database stored in the storage directory.
.
### Behaviour on deletion
.
On deletion of a key, the corresponding file is removed. An entry with deletion
timestamp is inserted in the
RocksDB database (to avoid re-insertion of points with an older timestamp in
case of un-ordered messages).
At regular interval, a task cleans-up the RocksDB database from entries with
old timestamps that don't have a
corresponding existing file.
.
### Behaviour on GET
.
On GET operations, the storage searches for matching and existing files, and
return their raw content as a reply.
For each, the encoding and timestamp are retrieved from the RocksDB database.
But if no entry is found in the
database for a file (e.g. for files created without zenoh), the encoding is
deduced from the file's extension
(using [mime_guess](https://crates.io/crates/mime_guess)), and the timestamp is
deduced from the file's
modification time.
.
-------------------------------
## How to install it
.
To install the latest release of this backend library, you can do as follows:
.
### Manual installation (all platforms)
.
All release packages can be downloaded from:
- https://download.eclipse.org/zenoh/zenoh-backend-filesystem/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
.
Choose your platform and download the `.zip` file.
Unzip it in the same directory than `zenohd` or to any directory where it can
find the backend library (e.g. /usr/lib or ~/.zenoh/lib)
.
### Linux Debian
.
Add Eclipse Zenoh private repository to the sources list, and install the
`zenoh-backend-filesystem` package:
.
```bash
echo "deb [trusted=yes] https://download.eclipse.org/zenoh/debian-repo/ /" |
sudo tee -a /etc/apt/sources.list.d/zenoh.list > /dev/null
sudo apt update
sudo apt install zenoh-backend-filesystem
```
.
-------------------------------
## 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.
.
At first, install [Clang](https://clang.llvm.org/) and [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
```
.
> :warning: **WARNING** :warning: : As Rust doesn't have a stable ABI, the
backend library 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.
.
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 --all-targets
```
Vcs-Browser: https://github.com/eclipse-zenoh/zenoh-backend-filesystem
Vcs-Git: https://github.com/eclipse-zenoh/zenoh-backend-filesystem
Package: zenoh-backend-filesystem
Version: 1.0.0~beta.2-1
Architecture: amd64
Maintainer: zenoh-dev@eclipse.org
Installed-Size: 20776
Depends: zenoh-plugin-storage-manager (=1.0.0~beta.2-1)
Filename: 1.0.0-beta.2/zenoh-backend-filesystem_1.0.0~beta.2-1_amd64.deb
Size: 4589680
MD5sum: 78f46bf296d669b35d455c61d065b76d
SHA1: 6ae4534726cd33ea4afe55bd7749d5361ddb8bf2
SHA256: c1264d70068098aff440c16fd43ce26a74a6befb3b1fb161e699c0d7a03ce024
Section: net
Priority: optional
Homepage: http://zenoh.io
Description: Backend for Zenoh using the file system
.
[](https://github.com/eclipse-zenoh/zenoh-backend-filesystem/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.
.
-------------------------------
# File system backend
.
In zenoh a backend is a storage technology (such as DBMS, time-series database,
file system...) alowing to store the
keys/values publications made via zenoh and return them on queries.
See the [zenoh
documentation](https://zenoh.io/docs/manual/abstractions/#storage) for more
details.
.
This backend relies on the host's file system to implement the storages.
Its library name (without OS specific prefix and extension) that zenoh will
rely on to find it and load it is **`zenoh_backend_fs`**.
.
.
:point_right: **Install latest release:** see [below](#How-to-install-it)
.
:point_right: **Build "main" branch:** see [below](#How-to-build-it)
.
-------------------------------
## **Examples of usage**
.
Prerequisites:
- You have a zenoh router (`zenohd`) installed, and the `zenoh_backend_fs`
library file is available in `~/.zenoh/lib`.
- Declare the `ZENOH_BACKEND_FS_ROOT` environment variable to the directory
where you want the files to be stored (or exposed from).
If you don't declare it, the `~/.zenoh/zenoh_backend_fs` directory will be
used.
.
You can setup storages either at zenoh router startup via a configuration file,
either at runtime via the zenoh admin space, using for instance the REST API.
### **Setup via a JSON5 configuration file**
.
- Create a `zenoh.json5` configuration file containing:
```json5
{
plugins: {
// configuration of "storage-manager" plugin:
storage_manager: {
volumes: {
// configuration of a "fs" volume (the "zenoh_backend_fs" backend
library will be loaded at startup)
fs: {},
},
storages: {
// configuration of a "demo" storage using the "fs" volume
demo: {
// the key expression this storage will subscribes to
key_expr: "demo/example/**",
// this prefix will be stripped from the received key when
converting to file path
// this argument is optional.
strip_prefix: "demo/example",
volume: {
id: "fs",
// the key/values will be stored as files within this directory
(relative to ${ZENOH_BACKEND_FS_ROOT})
dir: "example"
}
}
}
},
// Optionally, add the REST plugin
rest: { http_port: 8000 }
}
}
```
- Run the zenoh router with:
`zenohd -c zenoh.json5`
.
### **Setup at runtime via `curl` commands on the admin space**
.
- Run the zenoh router, with write permissions to its admin space:
`zenohd --adminspace-permissions rw`
- Add the "fs" backend (the "zenoh_backend_fs" library will be loaded):
`curl -X PUT -H 'content-type:application/json' -d '{}'
http://localhost:8000/@/router/local/config/plugins/storage_manager/volumes/fs`
- Add the "demo" storage using the "fs" backend:
`curl -X PUT -H 'content-type:application/json' -d
'{key_expr:"demo/example/**",strip_prefix:"demo/example", volume: {id: "fs",
dir:"example"}}'
http://localhost:8000/@/router/local/config/plugins/storage_manager/storages/demo`
.
### **Tests using the REST API**
.
Using `curl` to publish and query keys/values, you can:
```bash
# Put values that will be stored under ${ZENOH_BACKEND_FS_ROOT}/example
curl -X PUT -d "TEST-1" http://localhost:8000/demo/example/test-1
curl -X PUT -d "B" http://localhost:8000/demo/example/a/b
.
# Retrive the values
curl http://localhost:8000/demo/example/**
```
.
.
-------------------------------
## Configuration
### Extra configuration for filesystem-backed volumes
.
Volumes using the `fs` backend don't need any extra configuration at the volume
level. Any volume can use the `fs` backend by specifying the value `"fs"` for
the `backend` configuration key. A volume named `fs` will automatically be
backed by the `fs` backend if no other backend is specified.
.
-------------------------------
### Storage-level configuration for filesystem-backed volumes
.
Storages relying on a `fs` backed volume must/can specify additional
configuration specific to that volume, as shown in the example
[above](#setup-via-a-json5-configuration-file):
- `dir` (**required**, string) : The directory that will be used to store data.
.
- `read_only` (optional, boolean) : the storage will only answer to GET
queries. It will not accept any PUT or DELETE message, and won't write any
file. `false` by default.
.
- `on_closure` (optional, string) : the strategy to use when the Storage is
removed. There are 2 options:
- `"do_nothing"`: the storage's directory remains untouched (this is the
default behaviour)
- `"delete_all"`: the storage's directory is deleted with all its content.
.
- `follow_links` (optional, boolean) : If set to `true` the storage will follow
the symbolic links. The default value is `false`.
.
- `keep_mime_types` (optional, boolean) : When replying to a GET query with a
file for which the zenoh encoding is not known, the storage guess its mime-type
according to the file extension. If the mime-type doesn't correspond to a
supported zenoh encoding, this option will drive the returned value:
- `true` (default value): a [Custom
value](https://docs.rs/zenoh/latest/zenoh/enum.Value.html#variant.Custom)
is returned with the description set to the mime-type.
- `false`: a [Raw
value](https://docs.rs/zenoh/latest/zenoh/enum.Value.html#variant.Raw) with
APP_OCTET_STREAM encoding is returned.
.
-------------------------------
## **Behaviour of the backend**
.
### Mapping to file system
Each **storage** will map to a directory with path:
`${ZENOH_BACKEND_FS_ROOT}/`, where:
* `${ZENOH_BACKEND_FS_ROOT}` is an environment variable that could be
specified before zenoh router startup.
If this variable is not specified `${ZENOH_HOME}/zenoh_backend_fs` will be
used
(where the default value of `${ZENOH_HOME}` is `~/.zenoh`).
* `` is the `"dir"` property specified at storage creation.
Each zenoh **key/value** put into the storage will map to a file within the
storage's directory where:
* the file path will be
`${ZENOH_BACKEND_FS_ROOT}//`, where
``
will be the zenoh key, stripped from the `"strip_prefix"` property
specified at storage creation.
* the content of the file will be the value written as a RawValue. I.e. the
same bytes buffer that has been
transported by zenoh. For UTF-8 compatible formats (StringUTF8, JSon,
Integer, Float...) it means the file
will be readable as a text format.
* the encoding and the timestamp of the key/value will be stored in a RocksDB
database stored in the storage directory.
.
### Behaviour on deletion
.
On deletion of a key, the corresponding file is removed. An entry with deletion
timestamp is inserted in the
RocksDB database (to avoid re-insertion of points with an older timestamp in
case of un-ordered messages).
At regular interval, a task cleans-up the RocksDB database from entries with
old timestamps that don't have a
corresponding existing file.
.
### Behaviour on GET
.
On GET operations, the storage searches for matching and existing files, and
return their raw content as a reply.
For each, the encoding and timestamp are retrieved from the RocksDB database.
But if no entry is found in the
database for a file (e.g. for files created without zenoh), the encoding is
deduced from the file's extension
(using [mime_guess](https://crates.io/crates/mime_guess)), and the timestamp is
deduced from the file's
modification time.
.
-------------------------------
## How to install it
.
To install the latest release of this backend library, you can do as follows:
.
### Manual installation (all platforms)
.
All release packages can be downloaded from:
- https://download.eclipse.org/zenoh/zenoh-backend-filesystem/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
.
Choose your platform and download the `.zip` file.
Unzip it in the same directory than `zenohd` or to any directory where it can
find the backend library (e.g. /usr/lib or ~/.zenoh/lib)
.
### Linux Debian
.
Add Eclipse Zenoh private repository to the sources list, and install the
`zenoh-backend-filesystem` package:
.
```bash
echo "deb [trusted=yes] https://download.eclipse.org/zenoh/debian-repo/ /" |
sudo tee -a /etc/apt/sources.list.d/zenoh.list > /dev/null
sudo apt update
sudo apt install zenoh-backend-filesystem
```
.
-------------------------------
## 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.
.
At first, install [Clang](https://clang.llvm.org/) and [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
```
.
> :warning: **WARNING** :warning: : As Rust doesn't have a stable ABI, the
backend library 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.
.
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 --all-targets
```
Vcs-Browser: https://github.com/eclipse-zenoh/zenoh-backend-filesystem
Vcs-Git: https://github.com/eclipse-zenoh/zenoh-backend-filesystem
Package: zenoh-backend-filesystem
Version: 1.0.0~beta.2-1
Architecture: arm64
Maintainer: zenoh-dev@eclipse.org
Installed-Size: 18894
Depends: zenoh-plugin-storage-manager (=1.0.0~beta.2-1)
Filename: 1.0.0-beta.2/zenoh-backend-filesystem_1.0.0~beta.2-1_arm64.deb
Size: 4126772
MD5sum: a3ba4543e007d2a7c22bddedf80e9a16
SHA1: 4edd01beb84e40c4a7cfaf430218bff045dd32ac
SHA256: d36cdc80d08897735d8139662baabc202ac4bfe2511fb029b93b01f9e465a93e
Section: net
Priority: optional
Homepage: http://zenoh.io
Description: Backend for Zenoh using the file system
.
[](https://github.com/eclipse-zenoh/zenoh-backend-filesystem/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.
.
-------------------------------
# File system backend
.
In zenoh a backend is a storage technology (such as DBMS, time-series database,
file system...) alowing to store the
keys/values publications made via zenoh and return them on queries.
See the [zenoh
documentation](https://zenoh.io/docs/manual/abstractions/#storage) for more
details.
.
This backend relies on the host's file system to implement the storages.
Its library name (without OS specific prefix and extension) that zenoh will
rely on to find it and load it is **`zenoh_backend_fs`**.
.
.
:point_right: **Install latest release:** see [below](#How-to-install-it)
.
:point_right: **Build "main" branch:** see [below](#How-to-build-it)
.
-------------------------------
## **Examples of usage**
.
Prerequisites:
- You have a zenoh router (`zenohd`) installed, and the `zenoh_backend_fs`
library file is available in `~/.zenoh/lib`.
- Declare the `ZENOH_BACKEND_FS_ROOT` environment variable to the directory
where you want the files to be stored (or exposed from).
If you don't declare it, the `~/.zenoh/zenoh_backend_fs` directory will be
used.
.
You can setup storages either at zenoh router startup via a configuration file,
either at runtime via the zenoh admin space, using for instance the REST API.
### **Setup via a JSON5 configuration file**
.
- Create a `zenoh.json5` configuration file containing:
```json5
{
plugins: {
// configuration of "storage-manager" plugin:
storage_manager: {
volumes: {
// configuration of a "fs" volume (the "zenoh_backend_fs" backend
library will be loaded at startup)
fs: {},
},
storages: {
// configuration of a "demo" storage using the "fs" volume
demo: {
// the key expression this storage will subscribes to
key_expr: "demo/example/**",
// this prefix will be stripped from the received key when
converting to file path
// this argument is optional.
strip_prefix: "demo/example",
volume: {
id: "fs",
// the key/values will be stored as files within this directory
(relative to ${ZENOH_BACKEND_FS_ROOT})
dir: "example"
}
}
}
},
// Optionally, add the REST plugin
rest: { http_port: 8000 }
}
}
```
- Run the zenoh router with:
`zenohd -c zenoh.json5`
.
### **Setup at runtime via `curl` commands on the admin space**
.
- Run the zenoh router, with write permissions to its admin space:
`zenohd --adminspace-permissions rw`
- Add the "fs" backend (the "zenoh_backend_fs" library will be loaded):
`curl -X PUT -H 'content-type:application/json' -d '{}'
http://localhost:8000/@/router/local/config/plugins/storage_manager/volumes/fs`
- Add the "demo" storage using the "fs" backend:
`curl -X PUT -H 'content-type:application/json' -d
'{key_expr:"demo/example/**",strip_prefix:"demo/example", volume: {id: "fs",
dir:"example"}}'
http://localhost:8000/@/router/local/config/plugins/storage_manager/storages/demo`
.
### **Tests using the REST API**
.
Using `curl` to publish and query keys/values, you can:
```bash
# Put values that will be stored under ${ZENOH_BACKEND_FS_ROOT}/example
curl -X PUT -d "TEST-1" http://localhost:8000/demo/example/test-1
curl -X PUT -d "B" http://localhost:8000/demo/example/a/b
.
# Retrive the values
curl http://localhost:8000/demo/example/**
```
.
.
-------------------------------
## Configuration
### Extra configuration for filesystem-backed volumes
.
Volumes using the `fs` backend don't need any extra configuration at the volume
level. Any volume can use the `fs` backend by specifying the value `"fs"` for
the `backend` configuration key. A volume named `fs` will automatically be
backed by the `fs` backend if no other backend is specified.
.
-------------------------------
### Storage-level configuration for filesystem-backed volumes
.
Storages relying on a `fs` backed volume must/can specify additional
configuration specific to that volume, as shown in the example
[above](#setup-via-a-json5-configuration-file):
- `dir` (**required**, string) : The directory that will be used to store data.
.
- `read_only` (optional, boolean) : the storage will only answer to GET
queries. It will not accept any PUT or DELETE message, and won't write any
file. `false` by default.
.
- `on_closure` (optional, string) : the strategy to use when the Storage is
removed. There are 2 options:
- `"do_nothing"`: the storage's directory remains untouched (this is the
default behaviour)
- `"delete_all"`: the storage's directory is deleted with all its content.
.
- `follow_links` (optional, boolean) : If set to `true` the storage will follow
the symbolic links. The default value is `false`.
.
- `keep_mime_types` (optional, boolean) : When replying to a GET query with a
file for which the zenoh encoding is not known, the storage guess its mime-type
according to the file extension. If the mime-type doesn't correspond to a
supported zenoh encoding, this option will drive the returned value:
- `true` (default value): a [Custom
value](https://docs.rs/zenoh/latest/zenoh/enum.Value.html#variant.Custom)
is returned with the description set to the mime-type.
- `false`: a [Raw
value](https://docs.rs/zenoh/latest/zenoh/enum.Value.html#variant.Raw) with
APP_OCTET_STREAM encoding is returned.
.
-------------------------------
## **Behaviour of the backend**
.
### Mapping to file system
Each **storage** will map to a directory with path:
`${ZENOH_BACKEND_FS_ROOT}/`, where:
* `${ZENOH_BACKEND_FS_ROOT}` is an environment variable that could be
specified before zenoh router startup.
If this variable is not specified `${ZENOH_HOME}/zenoh_backend_fs` will be
used
(where the default value of `${ZENOH_HOME}` is `~/.zenoh`).
* `` is the `"dir"` property specified at storage creation.
Each zenoh **key/value** put into the storage will map to a file within the
storage's directory where:
* the file path will be
`${ZENOH_BACKEND_FS_ROOT}//`, where
``
will be the zenoh key, stripped from the `"strip_prefix"` property
specified at storage creation.
* the content of the file will be the value written as a RawValue. I.e. the
same bytes buffer that has been
transported by zenoh. For UTF-8 compatible formats (StringUTF8, JSon,
Integer, Float...) it means the file
will be readable as a text format.
* the encoding and the timestamp of the key/value will be stored in a RocksDB
database stored in the storage directory.
.
### Behaviour on deletion
.
On deletion of a key, the corresponding file is removed. An entry with deletion
timestamp is inserted in the
RocksDB database (to avoid re-insertion of points with an older timestamp in
case of un-ordered messages).
At regular interval, a task cleans-up the RocksDB database from entries with
old timestamps that don't have a
corresponding existing file.
.
### Behaviour on GET
.
On GET operations, the storage searches for matching and existing files, and
return their raw content as a reply.
For each, the encoding and timestamp are retrieved from the RocksDB database.
But if no entry is found in the
database for a file (e.g. for files created without zenoh), the encoding is
deduced from the file's extension
(using [mime_guess](https://crates.io/crates/mime_guess)), and the timestamp is
deduced from the file's
modification time.
.
-------------------------------
## How to install it
.
To install the latest release of this backend library, you can do as follows:
.
### Manual installation (all platforms)
.
All release packages can be downloaded from:
- https://download.eclipse.org/zenoh/zenoh-backend-filesystem/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
.
Choose your platform and download the `.zip` file.
Unzip it in the same directory than `zenohd` or to any directory where it can
find the backend library (e.g. /usr/lib or ~/.zenoh/lib)
.
### Linux Debian
.
Add Eclipse Zenoh private repository to the sources list, and install the
`zenoh-backend-filesystem` package:
.
```bash
echo "deb [trusted=yes] https://download.eclipse.org/zenoh/debian-repo/ /" |
sudo tee -a /etc/apt/sources.list.d/zenoh.list > /dev/null
sudo apt update
sudo apt install zenoh-backend-filesystem
```
.
-------------------------------
## 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.
.
At first, install [Clang](https://clang.llvm.org/) and [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
```
.
> :warning: **WARNING** :warning: : As Rust doesn't have a stable ABI, the
backend library 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.
.
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 --all-targets
```
Vcs-Browser: https://github.com/eclipse-zenoh/zenoh-backend-filesystem
Vcs-Git: https://github.com/eclipse-zenoh/zenoh-backend-filesystem