Docker and WSL

Docker and WSL

Background

Windows:

A host can have several WSL images. Each one:

• has a name
• can use either WSL 1 or 2
• contains a particular OS and version.
• may or may not contain Docker and (if it contains Docker) Docker Compose. Each of these has a version.

If the user has installed Docker Desktop, there will be a WSL image named 'docker-desktop' containing Docker and Docker Compose

Mac/Linux:

The host may or may not contain Docker and (if it contains Docker) Docker Compose. Each of these has a version.

User configuration options

All platforms:

<dont_use_docker/>

Windows

<dont_use_wsl/>

if set, don't use WSL (and hence don't use Docker)

<allowed_wsl>name</allowed_wsl>

allow BOINC to use the given WSL image. BOINC is automatically allowed to use the docker-desktop image if it's present.

Apps that use WSL

The whole Windows filesystem is accessible from WSL, so the app can run in the slot directory, accessing only files there and in the project directory.

Apps use a wrapper, wsl_wrapper. This takes a cmdline arg saying which distro to use

On startup, the wrapper runs 'main token' in the container, in the slot dir. This is a shell script that prints its own PID, then prints 'EOM token', then runs the application

so the wrapper knows it's done.

Poll: ps x ; echo token the wrapper parses this to get CPU time and WSS

Suspend/resume: kill SIGSTOP PID ; echo token

Apps that use Docker

There are 2 variants:

regular: the app version includes a complete Docker image

composer: the app version includes a set of layers and a composer script

In both cases the app version includes an executable (generic Linux executable, no BOINC)

Apps use a wrapper, docker_wrapper.

Windows:

docker_wrapper is similar to wsl_wrapper. It picks a WSL image to use (docker-desktop if it exists). If needed it runs composer to build the Docker image (which lives in the slot directory). It runs a Docker command to run the executable. We need to figure out

• how to stop/start the process
• how to get its WSS

Linux/Mac:

docker_wrapper is pretty much like wrapper, except that

• it may need to use Docker composer to build the image
• we need to figure out how to start/stop and get WSS

Scheduler requests

The host_info part of a sched request includes

All hosts:

• whether WSL is allowed
• whether Docker is allowed

Windows:

• a list of WSL images

    for each one:
        whether we're allowed to us it
        WSL 1 or 2
        OS name/version
        whether Docker and Composer are present, and versions

Note: we can potentially store this info in the DB, maybe the host.serialnum field

non-Windows:

whether Docker and Composer are present, and versions

client_state.xml:

we don't need to include any of this

Plan class names

WSL apps:

<plan_class>
   <name>wsl_foo</name>
   <wsl/>
   <wsl_version>1|2</wsl_version>
   [<os_name>regexp</os_name>]
   [<min_os_version>N</min_os_version]
</plan_class>

We can have the convention that the name includes 'wsl', but I don't think this matters.

Docker apps:

<plan_class>
    <name>docker_foo</name>
    <docker/>
    [<composer/>]
    [<min_docker_version>n</min_docker_version>]
    [<min_composer_version>n</min_composer_version>]
</plan_class>

We can have the convention that the name includes 'docker', but I don't think this matters.