podman-top: use containers/psgo

Use github.com/containers/psgo instead of execing `ps (1)`.  The psgo
library enables a much more flexible interface with respect to which
data to be printed (e.g., capabilities, seccomp mode, PID, PCPU, etc.)
while the output can be parsed reliably.  The library does not use
ps (1) but parses /proc and /dev instead.  To list the processes of a
given container, psgo will join the mount namespace of the given
container and extract all data from there.

Notice that this commit breaks compatibility with docker-top.

Signed-off-by: Valentin Rothberg <vrothberg@suse.com>

Closes: #1113
Approved by: rhatdan

1 files changed, 16 insertions, 0 deletions

diff --git a/completions/bash/podman b/completions/bash/podman
index b01a30aaa..424370904 100644
--- a/completions/bash/podman
+++ b/completions/bash/podman
@@ -1809,6 +1809,14 @@ _podman_tag() {
     esac
 }
 
+__podman_top_descriptors() {
+        podman top --list-descriptors
+}
+
+__podman_complete_top_descriptors() {
+        COMPREPLY=($(compgen -W "$(__podman_top_descriptors)" -- "$cur"))
+}
+
 _podman_top() {
     local options_with_args="
     "
@@ -1818,6 +1826,14 @@ _podman_top() {
     --latest
     -l
     "
+
+    # podman-top works on only *one* container, which means that when we have
+    # three or more arguments, we can complete with top descriptors.
+    if [[ "${COMP_CWORD}" -ge 3 ]]; then
+            __podman_complete_top_descriptors
+            return
+    fi
+
     case "$cur" in
         -*)
             COMPREPLY=($(compgen -W "$boolean_options $options_with_args" -- "$cur"))