Add crate feature to disable libwasmedge static linking

[jprendes]

Fixes #206

[jprendes]

@cpuguy83 @ipuustin PTAL :-)

[cpuguy83]

Can we add tests to validate static vs dynamic linking?

[cpuguy83]

I say this as I'm trying to validate this manually and no matter what I do I'm getting a dynamically linked binary.

cargo build --package containerd-shim-wasmedge --features "static"

[jprendes]

It would still generate a dynamically linked binary, just not to libwasmedge.so (it would still dynamically link to libc, libsystemd, etc).

This is similar to how the wasmtime shim doesn't link against a libwasmtime.so but its still a dynamically linked binary.

If you do ldd containerd-shim-wasmedge you should see an entry to libwasmedge.so only when the static feature is enabled (and its enabled by default).

I can still add a test for it.

[Mossaka]

LGTM!

[cpuguy83]

I don't see wasmedge.so in either case.

$ cargo build --package containerd-shim-wasmedge --features "static"
    Finished dev [unoptimized + debuginfo] target(s) in 0.10s
$ ldd ./target/debug/containerd-shim-wasmedge-v1
        linux-vdso.so.1 (0x00007ffd3e5d3000)
        libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007faadb897000)
        libstdc++.so.6 => /lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007faadb66b000)
        libseccomp.so.2 => /lib/x86_64-linux-gnu/libseccomp.so.2 (0x00007faadb64b000)
        libdbus-1.so.3 => /lib/x86_64-linux-gnu/libdbus-1.so.3 (0x00007faadb5fd000)
        libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007faadb3d5000)
        /lib64/ld-linux-x86-64.so.2 (0x00007faae325f000)
        libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007faadb3b3000)
        libsystemd.so.0 => /lib/x86_64-linux-gnu/libsystemd.so.0 (0x00007faadb2ec000)
        liblzma.so.5 => /lib/x86_64-linux-gnu/liblzma.so.5 (0x00007faadb2c1000)
        libzstd.so.1 => /lib/x86_64-linux-gnu/libzstd.so.1 (0x00007faadb1f2000)
        liblz4.so.1 => /lib/x86_64-linux-gnu/liblz4.so.1 (0x00007faadb1d2000)
        libcap.so.2 => /lib/x86_64-linux-gnu/libcap.so.2 (0x00007faadb1c7000)
        libgcrypt.so.20 => /lib/x86_64-linux-gnu/libgcrypt.so.20 (0x00007faadb087000)
        libgpg-error.so.0 => /lib/x86_64-linux-gnu/libgpg-error.so.0 (0x00007faadb061000)
$ cargo build --package containerd-shim-wasmedge --features "standalone"
    Finished dev [unoptimized + debuginfo] target(s) in 0.11s
$ ldd ./target/debug/containerd-shim-wasmedge-v1
        linux-vdso.so.1 (0x00007ffdc31ef000)
        libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f0db3d53000)
        libstdc++.so.6 => /lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f0db3b27000)
        libseccomp.so.2 => /lib/x86_64-linux-gnu/libseccomp.so.2 (0x00007f0db3b07000)
        libdbus-1.so.3 => /lib/x86_64-linux-gnu/libdbus-1.so.3 (0x00007f0db3ab9000)
        libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f0db3891000)
        /lib64/ld-linux-x86-64.so.2 (0x00007f0dbb71b000)
        libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f0db386f000)
        libsystemd.so.0 => /lib/x86_64-linux-gnu/libsystemd.so.0 (0x00007f0db37a8000)
        liblzma.so.5 => /lib/x86_64-linux-gnu/liblzma.so.5 (0x00007f0db377d000)
        libzstd.so.1 => /lib/x86_64-linux-gnu/libzstd.so.1 (0x00007f0db36ae000)
        liblz4.so.1 => /lib/x86_64-linux-gnu/liblz4.so.1 (0x00007f0db368e000)
        libcap.so.2 => /lib/x86_64-linux-gnu/libcap.so.2 (0x00007f0db3683000)
        libgcrypt.so.20 => /lib/x86_64-linux-gnu/libgcrypt.so.20 (0x00007f0db3543000)
        libgpg-error.so.0 => /lib/x86_64-linux-gnu/libgpg-error.so.0 (0x00007f0db351d000)

[jprendes]

Indeed, my bad, the "static" feature is always enabled here.
I'm fixing that and adding a test in a new PR.