Dobby “Docker based Thingy” is a tool for managing and running OCI containers using crun
Dobby has the following dependencies
- CMake (>3.7)
- crun (>=0.13)
- jsoncpp
- yajl 2 (for libocispec)
- ctemplate (if using
LEGACY_COMPONENTS) - libsystemd
- libnl (if using Networking plugin)
- libnl-route (if using Networking plugin)
- libdbus
- boost (1.61)
Dobby is a CMake project and can be built with the standard CMake workflow. To build, run the following commands.
cd /location/of/dobby/repo
mkdir build && cd build
cmake -DCMAKE_BUILD_TYPE=Debug ../
make -j$(numproc)
sudo make install
During the CMake configure stage, CMake will also configure the libocispec submodule. This is used to generate the necessary C headers for parsing and manipulating OCI bundle specifications.
If the schema files in the bundle/runtime-schemas directory are changed, then you will need to re-run CMake again to regenerate the headers.
When building for the development VM, use the following CMake command:
cmake -DCMAKE_BUILD_TYPE=Debug -DRDK_PLATFORM=DEV_VM -DCMAKE_INSTALL_PREFIX:PATH=/usr ../
| Option | Valid Options | Description |
|---|---|---|
-CMAKE_BUILD_TYPE |
Debug/Release | Build the Debug or Release version |
-DENABLE_DOBBYTOOL |
ON/OFF | Include DobbyTool in the build. For Debug builds, defaults to ON. For Release builds, defaults to OFF. |
-DPLUGIN_PATH |
Valid UNIX path | Specify a different location to load RDK plugins from. Defaults to /usr/lib/plugins/dobby if not set |
-DRDK_PLATFORM |
GENERICXI1LLAMADEV_VM |
Specify which platform Dobby is running on. Defaults to GENERIC if none specified, which should be suitable for the majority of RDK platforms, including Raspberry Pi. Changing this affects which settings file from daemon/process/settings is used |
-DLEGACY_COMPONENTS |
ON/OFF | Enable or disable legacy components (legacy plugins, Dobby specs, ...). Defaults to OFF |
-DENABLE_LTO |
ON/OFF | Enable Link Time Optimisation (https://gcc.gnu.org/onlinedocs/gccint/LTO-Overview.html). Requires GCC >4,5 although versions >6 are strongly recommended. Defaults to OFF |
-DENABLE_PERFETTO_TRACING |
ON/OFF | Option to enable or disable Perfetto tracing. Can not be enabled for release builds. Requires Perfetto SDK to be installed, and Legacy Components enabled |
-DDOBBY_SERVICE |
Reverse domain name string | Specify the Dobby dbus service name. Defaults to org.rdk.dobby if none specified. |
-DDDOBBY_OBJECT |
Valid UNIX path | Specify the Dobby dbus object path. Defaults to /org/rdk/dobby if none specified. |
-DUSE_STARTCONTAINER_HOOK |
ON/OFF | Whether to use the startcontainer OCI hook or not. Defaults to OFF. |
In addition to all the above, each RDK plugin has a setting for enabling it for builds. The Logging, Networking, IPC and Storage plugins are enabled by default.
Use -DPLUGIN_[PLUGINNAME]=[ON|OFF] to enable or disable plugins for your build.
If you with to develop Dobby further, detailed instructions on setting up a development environment can be found in the develop directory in this repo, including a Vagrant VM with all the necessary dependencies pre-installed.
This is the main component of Dobby. This daemon is responsible for managing, controlling and creating containers. The daemon runs in the background and communicates over dbus. It connects on a few dbus addresses - one for admin, one for debugging and the other for Dobby commands.
DobbyDaemon can be started as a systemd service at system boot (the systemd service file can be found at daemon/process/dobby.service) or run manually on the command line by running:
DobbyDaemon --nofork
Additional -v flags can be passed to the daemon to increase it's log verbosity for troubleshooting as needed
Usage: DobbyDaemon <option(s)>
Daemon that starts / stops / manages containers.
-h, --help Print this help and exit
-v, --verbose Increase the log level
-V, --version Display this program's version number
-f, --settings-file=PATH Path to a JSON dobby settings file [/etc/dobby.json]
-a, --dbus-address=ADDRESS The dbus address to put the admin service on [system bus]
-p, --priority=PRIORITY Sets the SCHED_RR priority of the daemon [RR,12]
-n, --nofork Do not fork and daemonise the process
-k, --noconsole Disable console output
-g, --syslog Send all initial logging to syslog rather than the console
-j, --journald Enables logging to journald
Besides the above options the daemon checks for the follow environment variables
AI_WORKSPACE_PATH=<PATH> The path to tmpfs dir to use as workspace
AI_PERSISTENT_PATH=<PATH> The path to dir that is persistent across boots
AI_PLATFORM_IDENT=<IDENT> The 4 characters than make up the STB platform id
This is a command-line wrapper around the DobbyBundleGen library, and allows Dobby spec JSON files to be converted to extended OCI bundles (aka Bundle*'s) with RDK plugin sections. It does not require the DobbyDaemon to be running, so can be run on or off-box.
Usage: DobbyBundleGenerator <option(s)>
Tool to convert Dobby JSON spec to OCI bundle without needing a running Dobby Daemon
-h, --help Print this help and exit
-v, --verbose Increase the log level
-s, --settings=PATH Path to Dobby Settings file for STB
-i, --inputpath=PATH Path to Dobby JSON Spec for container
-o, --outputDirectory=PATH Where to save the generated OCI bundle
This is a simple command line tool that is used for debugging purporses. It connects to the Dobby daemon over dbus and allows for debugging and testing containers.
vagrant@dobby-vagrant:~$ DobbyTool help
quit quit
help help [command]
shutdown shutdown
start start [options...] <id> <specfile/bundlepath> [command]
stop stop <id> [options...]
pause pause <id>
resume resume <id>
exec exec [options...] <id> <command>
list list
info info <id>
dumpspec dumpspec <id> [options...]
bundle bundle <id> <specfile> [options...]
set-dbus set-dbus <private>|<public> <address>
For more information about a command, run DobbyTool help [command]. For example:
$ DobbyTool help start
start start [options...] <id> <specfile/bundlepath> [command]
Starts a container using the given spec file or bundle path. Can optionally specify the command to run inside the container. Any arguments after command are treated as arguments to the command.
This is designed to be run from the OCI runtime to execute Dobby RDK plugins. It loads plugins from the /usr/lib/plugins/dobby directory (configurable at build-time), and runs the appropriate methods based on the specified hook and plugin data.
Usage: DobbyPluginLauncher <option(s)>
Tool to run Dobby plugins loaded from /usr/lib/plugins/dobby
-H, --help Print this help and exit
-v, --verbose Increase the log level
-h, --hook Specify the hook to run
-c, --config=PATH Path to container OCI config
To use Dobby RDK plugins in a container launched via DobbyDaemon, the OCI bundle config should have ociVersion set to 1.0.2-dobby and an rdkPlugins object with plugins present. DobbyDaemon will set up Dobby and OCI hooks to execute the plugins' hookpoints with DobbyPluginLauncher.
An example of the rdkPlugins object's syntax with the networking plugin:
{
"rdkPlugins":{
"networking":{ // plugin name
"required":true, // whether to throw an error if the plugin is missing, or just flag a warning and carry on
"data":{ // data to be passed to the plugin - can contain any valid JSON, depending on the plugin
"type":"nat" // each plugin has its own accepted data structure
}
}
}
}This tool is a simple 'init' process for containers. Instead of relying on runc to manage the lifecycle of processes within the container, DobbyInit is responsible for reaping adopted child processes and forwarding signals to child processes.
The motivation for this tool is described here: https://blog.phusion.nl/2015/01/20/docker-and-the-pid-1-zombie-reaping-problem. It is installed in /usr/libexec.
Usage: DobbyInit <process-to-run> <arg1> <arg2> ... <argN>
If not stated otherwise in this file or this component's LICENSE file the following copyright and licenses apply:
Copyright 2020 Sky UK
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
Dobby makes use of the libocispec library to parse and generate OCI configurations from JSON schemas. This is a code-generator and used only at build-time. libocispec is GPLv3 licensed but includes a specific exception for this purpose.