crun and wasm example - could not load `libwasmedge.so.0

[marcelo-modolo]

Hi!

I compiled and installed crun with wasm support

/opt/crun/bin/crun -V
crun version 1.6.0.0.0.77-2c6e
commit: 2c6efdd
rundir: /run/user/1000/crun
spec: 1.0.0
+SYSTEMD +SELINUX +APPARMOR +CAP +SECCOMP +EBPF +WASM:wasmedge +YAJL

I also adjusted the ~/.config/containers/containers.conf file to use the new crun

podman info
host:
arch: amd64
buildahVersion: 1.23.1
cgroupControllers:
... ociRuntime:
name: crun
package: Unknown
path: /opt/crun/bin/crun
version: |-
crun version 1.6.0.0.0.77-2c6e
commit: 2c6efdd
rundir: /run/user/1000/crun
spec: 1.0.0
+SYSTEMD +SELINUX +APPARMOR +CAP +SECCOMP +EBPF +WASM:wasmedge +YAJL

Then follow the example in https://github.com/containers/crun/blob/main/docs/wasm-wasi-example.md.

cat Dockerfile
FROM scratch
COPY wasi-hello-world.rustc.wasm /
CMD ["/wasi-hello-world.rustc.wasm"]

buildah build --annotation "module.wasm.image/variant=compat-smart" -t mywasm-image

podman run --rm -it mywasm-image
Error: could not load libwasmedge.so.0: libwasmedge.so.0: cannot open shared object file: No such file or directory: OCI runtime attempted to invoke a command that was not found

Does anyone have a tip that could help me?

Thanks

[flouthoc]

Hi @marcelo-modolo Could you please confirm which wasmedge version is installed on your host ?

[marcelo-modolo]

Hi @marcelo-modolo Could you please confirm which wasmedge version is installed on your host ?

wasmedge version 0.11.1

[marcelo-modolo]

I believe that I managed to understand the problem and maybe it can be useful to someone else.

opt/crun/bin/crun -V
crun version 1.6.0.0.0.77-2c6e
commit: 2c6efdd
rundir: /run/user/1000/crun
spec: 1.0.0
+SYSTEMD +SELINUX +APPARMOR +CAP +SECCOMP +EBPF +WASM:wasmedge +YAJL

crun is configured to make use of +WASM:wasmedge. By default the installation of wasmedge is in the home folder

tree ~/.wasmedge
/home/modolo/.wasmedge
├── bin
│   ├── wasmedge
│   └── wasmedgec
├── env
├── include
│   └── wasmedge
│   ├── enum_configure.h
│   ├── enum_errcode.h
│   ├── enum.inc
│   ├── enum_types.h
│   ├── int128.h
│   ├── version.h
│   └── wasmedge.h
├── lib
│   ├── libwasmedge.so -> libwasmedge.so.0
│   ├── libwasmedge.so.0 -> libwasmedge.so.0.0.0
│   └── libwasmedge.so.0.0.0
└── plugin
└── libwasmedgePluginWasmEdgeProcess.so

With the following environment variables set:

LD_LIBRARY_PATH=/home/modolo/.wasmedge/lib
LIBRARY_PATH=/home/modolo/.wasmedge/lib

Testing with crun directly without creating the image there are no errors

tree container
container
├── config.json
└── rootfs
└── wasi-hello-world.rustc.wasm

cd container
/opt/crun/bin/crun run wasm-test
Hello, world!

But trying to create a container with the same binary I end up with a load error in the libraries

cat Dockerfile
FROM scratch
COPY wasi-hello-world.rustc.wasm /
CMD ["/wasi-hello-world.rustc.wasm"]

buildah build --annotation "module.wasm.image/variant=compat-smart" -t wasm-test-02

podman run --rm -it wasm-test-02

Error: could not load libwasmedge.so.0: libwasmedge.so.0: cannot open shared object file: No such file or directory: OCI runtime attempted to invoke a command that was not found

The problem was in the location of the libraries!

I copied the libraries to /usr/local/lib/wasmedge/

ls -l /usr/local/lib/wasmedge/
lrwxrwxrwx 20 root 1 nov 13:32  libwasmedge.so -> libwasmedge.so.0.0.0
lrwxrwxrwx 20 root 1 nov 13:32  libwasmedge.so.0 -> libwasmedge.so.0.0.0
.rwxr-xr-x 50M root 1 nov 13:31  libwasmedge.so.0.0.0

I created the file /etc/ld.so.conf.d/wasmedge.conf

cat /etc/ld.so.conf.d/wasmedge.conf
/usr/local/lib/wasmedge

And ran the command sudo ldconfig

No errors after that!

podman run --rm -it wasm-test-02
Hello, world!

I apologize for the mistake made but maybe the solution can be useful.

[rhatdan]

So is this not an issue? Or should crun have been smarter and set the LD_LIBRARY_PATH to point at the same directory?

[marcelo-modolo]

So is this not an issue? Or should crun have been smarter and set the LD_LIBRARY_PATH to point at the same directory?

Honestly I don't know, maybe most people do the installation as root and with that the libraries end up where they can be accessed.

[rhatdan]

Ok I will close then.