Document podman/docker

[bam80]

Working with podman/docker info would also be useful to add in the Readme or Wiki:
#55

Originally posted by @bam80 in #324 (comment)

There are actually a few pretty much ready instructions on the link above, as:
https://gist.github.com/lbssousa/bb081e35d483520928033b2797133d5e

@nikodunk

[francoism90]

I think the gist is missing some information:

• No mention of podman.socket, although not fully required it allows to communicate directly with podman over a secure socket
• No mention of overwrites, e.g. flatpak override --user --filesystem=xdg-run/podman:ro com.visualstudio.code
• The dev.containers.dockerPath, dev.containers.dockerSocketPath and docker.dockerPath should be set, and they should be full paths, instead of just 'podman'.

I added these on https://github.com/francoism90/flathub/blob/my-app-submission/README.md, which accepted should hopefully make it more general (also for VSCodium/PHPStorm). If you have any suggestions please let me know. :)

[bam80]

No mention of overwrites, e.g. flatpak override --user --filesystem=xdg-run/podman:ro com.visualstudio.code

I assume this can work just by accident, in my case it doesn't:

# from the flatpak
sh-5.3$ /run/host/usr/bin/podman
/run/host/usr/bin/podman: error while loading shared libraries: libsubid.so.5: cannot open shared object file: No such file or directory

sh-5.3$ ldd /run/host/usr/bin/podman
        linux-vdso.so.1 (0x00007f384948c000)
        libresolv.so.2 => /usr/lib/x86_64-linux-gnu/libresolv.so.2 (0x00007f3846a5e000)
        libsubid.so.5 => not found
        libgpgme.so.11 => not found
        libsqlite3.so.0 => /usr/lib/x86_64-linux-gnu/libsqlite3.so.0 (0x00007f38468e8000)
        libseccomp.so.2 => /usr/lib/x86_64-linux-gnu/libseccomp.so.2 (0x00007f38468bb000)
        libgcc_s.so.1 => /usr/lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f384688c000)
        libc.so.6 => /usr/lib/x86_64-linux-gnu/libc.so.6 (0x00007f384668d000)
        libm.so.6 => /usr/lib/x86_64-linux-gnu/libm.so.6 (0x00007f384658e000)
        libz.so.1 => /usr/lib/x86_64-linux-gnu/libz.so.1 (0x00007f3846574000)
        /lib64/ld-linux-x86-64.so.2 (0x00007f384948e000)

So --filesystem=xdg-run/podman doesn't seem like a proper way of doing things.

[francoism90]

If you use the sdk, you shouldn't run the host command, because it indeed fails. The purpose is to have it sandboxes (so no host integration).

This should work:

[bam80]

The --filesystem=xdg-run/podman is probably meant to get access to the socket, not to the binary itself.
So my /run/host/usr/bin/podman sample above wasn't correct indeed.

Still, I see no point to have podman installed in the sdk.