Why does kubectl cp command terminates with exit code 126?

Question

I am trying to copy files from the pod to local using following command:

kubectl cp /namespace/pod_name:/path/in/pod /path/in/local

But the command terminates with exit code 126 and copy doesn't take place.

Similarly while trying from local to pod using following command:

kubectl cp /path/in/local /namespace/pod_name:/path/in/pod

It throws the following error:

OCI runtime exec failed: exec failed: container_linux.go:367: starting container process caused: exec: "tar": executable file not found in $PATH: unknown

Please help through this.

Answer 1

kubectl cp is actually a very small wrapper around kubectl exec whatever tar c | tar x. A side effect of this is that you need a working tar executable in the target container, which you do not appear to have.

In general kubectl cp is best avoided, it's usually only good for weird debugging stuff.

Answer 2

An alternative way to copy a file from local filesystem into a container:

cat [local file path] | kubectl exec -i -n [namespace] [pod] -c [container] "--" sh -c "cat > [remote file path]"