Ensure that containers in pods properly set hostname

When we moved to the new Namespace types in Specgen, we made a
distinction between taking a namespace from a pod, and taking it
from another container. Due to this new distinction, some code
that previously worked for both `--pod=$ID` and
`--uts=container:$ID` has accidentally become conditional on only
the latter case. This happened for Hostname - we weren't properly
setting it in cases where the container joined a pod.
Fortunately, this is an easy fix once we know to check the
condition.

Also, ensure that `podman pod inspect` actually prints hostname.

Fixes #6494

Signed-off-by: Matthew Heon <matthew.heon@pm.me>

1 files changed, 3 insertions, 1 deletions

diff --git a/pkg/specgen/generate/namespaces.go b/pkg/specgen/generate/namespaces.go
index 138d9e0cd..ffa96a5cf 100644
--- a/pkg/specgen/generate/namespaces.go
+++ b/pkg/specgen/generate/namespaces.go
@@ -265,7 +265,7 @@ func GenerateNamespaceOptions(ctx context.Context, s *specgen.SpecGenerator, rt
 	return toReturn, nil
 }
 
-func specConfigureNamespaces(s *specgen.SpecGenerator, g *generate.Generator, rt *libpod.Runtime) error {
+func specConfigureNamespaces(s *specgen.SpecGenerator, g *generate.Generator, rt *libpod.Runtime, pod *libpod.Pod) error {
 	// PID
 	switch s.PidNS.NSMode {
 	case specgen.Path:
@@ -326,6 +326,8 @@ func specConfigureNamespaces(s *specgen.SpecGenerator, g *generate.Generator, rt
 	hostname := s.Hostname
 	if hostname == "" {
 		switch {
+		case s.UtsNS.NSMode == specgen.FromPod:
+			hostname = pod.Hostname()
 		case s.UtsNS.NSMode == specgen.FromContainer:
 			utsCtr, err := rt.LookupContainer(s.UtsNS.Value)
 			if err != nil {