renode-linux-runner-action

Copyright (c) 2022-2023 Antmicro

This action enables users to run workflows that require certain Linux devices not available in default GitHub runners and provides the means to run entire custom kernels. This is achieved by running an emulated Linux system inside Renode.

Parameters

Tests configuration

• renode-run - A single command, list of commands or a YAML Task containing commands to be run in Renode
• shared-dirs - Shared directory paths. Their contents will be mounted in Renode
• python-packages - Python packages from PyPI or a Git repository that will be sideloaded into the emulated Linux system
• repos - Git repositories that will be sideloaded into the emulated system
• fail-fast - Fail after first non-zero exit code instead of failing at the end. Default: true.

OS configuration

• rootfs-size - Set the size of the rootfs image. Default: auto.
• image-type - native or docker. Read about the differences in the image section
• image - URL path to a Linux rootfs tar.xz archive for the specified architecture or a Docker image identifier. If not specified, the action will use the default one. See releases for examples
• tasks - Allows you to change the way the system is initialized. See Tasks for more details.

Board and devices configuration

• network - Enable Internet access in the emulated Linux system. Default: true
• devices - List of devices to add to the emulated system. If not specified, the action will not add any devices
• kernel - URL or path to the tar.xz archive containing the compiled embedded Linux kernel and initramfs. If not specified, the action will use the default kernel. See releases for examples
• arch - Processor architecture
• board - A specific board name, or default for architecture default, or custom for a custom board
• resc - Custom Renode script
• repl - Custom Renode platform description.

Running your commands in an emulated Linux system

This is the simplest example of how you can run your commands in the emulated Linux system. The default image will boot and log itself into a basic shell session.

- uses: antmicro/renode-linux-runner-action@v1
  with:
    renode-run: uname -a

This is the result:

# uname -a
Linux buildroot 5.10.178 #1 SMP Thu May 11 13:44:01 UTC 2023 riscv64 GNU/Linux
#

If you want to run more than one command, you can use a multiline string. For example, for this configuration:

- uses: antmicro/renode-linux-runner-action@v1
  with:
    renode-run: |
      ls /dev | grep tty | head -n 3
      tty

you get the following result:

# ls /dev | grep tty | head -n 3
tty
tty0
tty1
# tty
/dev/ttySIF0

You can also run shell scripts, but you need to load them into the emulated system first using the shared directories feature or by sideloading Git repositories.

- uses: antmicro/renode-linux-runner-action@v1
  with:
    shared-dirs: scripts
    renode-run: sh my-script.sh

You can also set additional test parameters with Task files. For example:

- uses: antmicro/renode-linux-runner-action@v1
  with:
    network: false
    renode-run: |
      - should-fail: true
      - commands:
        - wget example.org

This test will complete successfully because the network is disabled in the emulated system and wget will return a non-zero exit code.

Special cases

If the action detects that one of your commands has failed, it will also fail with the error code that your command failed with, and no further commands will be executed. This behavior can be changed with the fail-fast action parameter.

Limitations

To keep the system image minimal, there is no standard bash shell, but a busybox ash shell instead. If you need bash, you can provide your own custom image. More on this in the 'Image' section of the documentation.

Examples

The release workflow contains an example usage of this action.

Emulation

The Linux emulation runs on the RISC-V HiFive Unleashed single core platform in Renode 1.13.3. Basic specs like 8GB of RAM and a network connection are configured in the emulated system.

Architecture

You can specify the architecture with the arch parameter. The default architecture is riscv64.

- uses: antmicro/renode-linux-runner-action@v1
  with:
    arch: riscv64
    renode-run: ...

Available architectures:

• riscv64
• arm32 (armv7)

We are working on adding arm64 support.

Shared directories

You can specify many directories that will be added to the rootfs. All files from these directories will be available in the specified target directories.

In the following example, files from the project-files directory will be extracted to the /opt/project directory. If no destination directory is specified, the files will be extracted to /home.

At the end of the action contents of the shared directories will be copied back from the mounted filesystem.

- uses: antmicro/renode-linux-runner-action@v1
  with:
    shared-dirs: |
      shared-dir1
      shared-dir2
      project-files /opt/project
    renode-run: command_to_run

Devices

The action allows you to add additional devices available in a given kernel configuration. For example, if you want to add a stub Video4Linux device, you can specify:

- uses: antmicro/renode-linux-runner-action@v1
  with:
    shared-dirs: |
      scripts
      project-files /opt/project
    renode-run: ./build.sh
    devices: vivid

More about available devices and syntax to customize them can be found in the 'Devices' section of the docs.

Python packages

This action lets you sideload Python packages that you want to use in the emulated system. You can select any package from PyPI or from a Git repository.

For example:

- uses: antmicro/renode-linux-runner-action@v1
  with:
    renode-run: python --version
    python-packages: |
      git+https://github.com/antmicro/pyrav4l2.git
      pytest==5.3.0

The action will download all selected packages and their dependencies and install them later in the emulated Linux environment.

You can read about the details of how the action collects dependencies and installs them in the 'Python packages' section of the docs.

Git repositories

If you want to clone other Git repositories to the emulated system, you can use the repos argument. You can also specify the path into which you want to clone the repository:

- uses: antmicro/renode-linux-runner-action@v1
  with:
    shared-dir: ./shared-dir
    renode-run: python --version
    repos: https://github.com/antmicro/pyrav4l2.git /path/to/repo

Fail fast

By default, execution of the script is aborted on the first failure, and an error code is returned. When this option is disabled, the last non-zero exit code is returned after all commands are executed.

- uses: antmicro/renode-linux-runner-action@v1
  with:
    fail-fast: false
    renode-run:
      gryp --version # fail gryp is not available
      grep --version # will be executed

Network

You can disable networking in the emulated Linux by passing the network: false argument to the action

- uses: antmicro/renode-linux-runner-action@v1
  with:
    shared-dir: ./shared-dir
    renode-run: python --version
    network: false

This can be useful when running the action in a container matrix strategy if you do not have permission to create tap interfaces.

More information about the network can be found in the 'Network' section of the docs.

Image

If you need additional software, you can mount your own filesystem. More information on how it works can be found in the 'Image' section of the docs.

Rootfs size

The size of the mounted rootfs can be specified with the rootfs-size parameter. The parameter accepts sizes in bytes (e.g. 1000000000), kilobytes (e.g. 50000K), megabytes (e.g. 512M) or gigabytes (e.g. 1G). The default rootfs-size value is auto; with this setting the size is calculated automatically. Preceding the value with + sign (e.g. +value) sets the size to auto + value.

- uses: antmicro/renode-linux-runner-action@v1
  with:
    shared-dir: shared-dir
    renode-run: python --version
    rootfs-size: 512M

Tasks

Sometimes, after replacing initramfs or changing the board configuration, you may need to change the default commands that the action executes on each run. You can use Tasks for that. All the commands that the action executes are stored in the Task files in action/tasks/*.yml. If you want to change any of these, you can pass your own Task through the tasks action argument. If your Task has the same name as one of the default ones, it will replace it.

For example:

- uses: antmicro/renode-linux-runner-action@v1
  with:
    shared-dir: shared-dir
    renode-run: |
      command1
      command2
    tasks: |
      path/to/task/1
      https://task2/

Task syntax

A Task file is a YAML file with the following fields:

• name: the only mandatory field; it is used to resolve dependencies between Tasks.
• shell: the name of the shell in which the commands will be executed. The action has three available shells (host, target, renode).
• requires: an array of tasks that must be executed before this task. This list is empty by default.
• before: an array of tasks that will be executed after this task. This list is empty by default and the tasks included in the array do not need to exist.
• echo: Boolean parameter. If true, the output from the shell will be printed. Default: false
• timeout: Default timeout for each command. Commands can override this setting. Default: null, meaning no timeout for your commands.
• fail-fast: Boolean parameter. If true, the action will return the error from the first failed command and stop. Otherwise, the action will fail at the end of the task. Default: true
• sleep: The action will wait for the specified time (in seconds) before proceeding to the next task. Default: 0
• command: List of commands or Command objects to execute. Default: empty
• vars: Dictionary of variables. Read more about it here. Default: empty

For example:

name: task1
shell: target
requires: [renode_config]
echo: true
timeout: 5
fail-fast: true
commands:
  - expect: "buildroot login:"
    timeout: null
    check-exit-code: false
  - root
  - dmesg -n 1
  - date -s "${{NOW}}"
  - echo ${{VAR1}}
vars:
  VAR1: "hello, world!"

Command syntax

For a list of commands you can just use a list of strings, but if you want more customization, you can use a Command object containing the following fields:

• command: A shell command to be run.
• expect: A string the action will wait for from the command's output.
• timeout: Command timeout (in seconds). By default, the timeout is inherited from the task.
• echo: Boolean parameter. If true, the output from the shell is printed. By default this parameter is inherited from the task.
• check-exit-code: Boolean parameter. If true, the shell will check whether the command failed or not. Default: true

Variables

You can define a list of variables and use it later with ${{VAR_NAME}}. In addition, predefined global variables are available:

• ${{BOARD}}: name of the selected board
• ${{NOW}}: current date and time in the format %Y-%m-%d %H:%M:%S

Shell initialization

Any Task that refers to a particular shell will have an additional hidden, shell-specific dependency. They require the Task that has the same name as the shell (for example, renode). These Tasks are used to configure the shell. However, you can replace these Tasks by simply providing your own version with the same name.

Kernel

It is possible to replace a Linux image on which the tests are run and mount a custom file system image. You can find further instructions on the topic in the 'Kernel' section of the docs.

Board

The action allows you to select your own board and choose its configuration. You can select a board from a list (remember that you also need to select a matching processor architecture). Available boards are:

• riscv64 - hifive_unleashed
• arm32 - zynq_7000

You can also choose the default board: default or your own board: custom. In the latter case, you need to provide your own resc and repl files, which will configure the emulation. You can select the configuration files using resc and repl parameters. You can read more about these files in the Renode documentation.