Bug 2057633

Description of problem
======================

When I use oc rsync with invalid container name to fetch data from the
container, the error message complains about availability of copy strategies
instead of the root cause (the container doesn't exist).

This problem is similar to old, now fixed, OCP 3.x BZ 1314817, but this time
it's about a container instead of a pod.

Version-Release number of selected component
============================================

OCP 4.10.0-0.nightly-2022-02-22-093600

How reproducible
================

100%

Steps to Reproduce
==================

1. Run `oc rsync --container foo -n NS pod/POD:/etc/redhat-release /tmp/` so
   that NS and POD are valid references for a running pod in a namespace, but
   container foo doesn't exist.
2. Run the same command again, but this time with additiona option
   `--loglevel=4`

Actual results
==============

The oc rsync fails, complaining that rsync and tar are missing in the
container:

```
$ oc rsync --container foo -n openshift-storage pod/rook-ceph-tools-56f88ff6cb-tvpg5:/etc/redhat-release /tmp
WARNING: cannot use rsync: rsync not available in container
WARNING: cannot use tar: tar not available in container
error: No available strategies to copy.
```

The same run with `--loglevel=4` shows that the problem is actually elsewhere:

```
$ oc rsync --loglevel=4  --container foo -n openshift-storage pod/rook-ceph-tools-56f88ff6cb-tvpg5:/etc/redhat-release /tmp
I0223 19:37:10.124688   11013 copy_rsync.go:59] Rsh command: oc rsh --container=foo --loglevel=4 --namespace=openshift-storage
I0223 19:37:10.125136   11013 copy_rsync.go:82] Copying files with rsync
I0223 19:37:10.125380   11013 exec_local.go:19] Local executor running command: rsync --blocking-io --archive --no-owner --no-group --omit-dir-times --numeric-ids -v -e oc rsh --container=foo --loglevel=4 --namespace=openshift-storage rook-ceph-tools-56f88ff6cb-tvpg5:/etc/redhat-release /tmp
I0223 19:37:10.975300   11013 exec_local.go:26] Error from local command execution: exit status 12
I0223 19:37:11.100162   11013 exec_remote.go:29] Remote executor running command: rsync --version
I0223 19:37:11.607211   11013 exec_remote.go:54] Error from remote execution: container foo is not valid for pod rook-ceph-tools-56f88ff6cb-tvpg5
I0223 19:37:11.608690   11013 util.go:25] 
I0223 19:37:11.609671   11013 util.go:26] error: container foo is not valid for pod rook-ceph-tools-56f88ff6cb-tvpg5
I0223 19:37:11.610786   11013 copy_multi.go:30] Error output:
WARNING: cannot use rsync: rsync not available in container
I0223 19:37:11.613163   11013 copy_tar.go:119] Copying files with tar
I0223 19:37:11.614579   11013 copy_tar.go:147] Creating local tar file /tmp/rsync4131236598 from remote path /etc/redhat-release
I0223 19:37:11.615580   11013 copy_tar.go:203] Tarring /etc/redhat-release remotely
I0223 19:37:11.616821   11013 copy_tar.go:227] Remote tar command: tar -C /etc -c redhat-release
I0223 19:37:11.618229   11013 exec_remote.go:29] Remote executor running command: tar -C /etc -c redhat-release
I0223 19:37:12.124460   11013 exec_remote.go:54] Error from remote execution: container foo is not valid for pod rook-ceph-tools-56f88ff6cb-tvpg5
I0223 19:37:12.126566   11013 exec_remote.go:29] Remote executor running command: tar --version
I0223 19:37:12.638972   11013 exec_remote.go:54] Error from remote execution: container foo is not valid for pod rook-ceph-tools-56f88ff6cb-tvpg5
I0223 19:37:12.640420   11013 util.go:25] 
I0223 19:37:12.641621   11013 util.go:26] error: container foo is not valid for pod rook-ceph-tools-56f88ff6cb-tvpg5
I0223 19:37:12.643289   11013 copy_multi.go:30] Error output:
WARNING: cannot use tar: tar not available in container
error: No available strategies to copy
```

Expected results
================

The oc rsync command complains about missing/nonexistent container:

```
$ oc rsync --container foo -n openshift-storage pod/rook-ceph-tools-56f88ff6cb-tvpg5:/etc/redhat-release /tmp
Error from server (NotFound): container "foo" not found
```

Additional info
===============

When the problem is with missing pod or namespace, oc rsync has no problem with
reporting the root cause:

```
$ oc rsync -n openshift-storage pod/rook-ceph-tools-56f88ff6cb-tvpg6:/etc/redhat-release /tmp/etc
Error from server (NotFound): pods "rook-ceph-tools-56f88ff6cb-tvpg6" not found
$ oc rsync -n openshift-storaga pod/rook-ceph-tools-56f88ff6cb-tvpg6:/etc/redhat-release /tmp/etc
Error from server (NotFound): namespaces "openshift-storaga" not found
```

I hit this problem during debugging a misterious failure of an automated test
case, and after some debugging realized that the error here is a red herring.
In my case, the container ceased to exist, which resulted in misleading error
about rsync dissapearing from the container.