podman pod create --uts support

add support for the --uts flag in pod create, allowing users to avoid
issues with default values in containers.conf.

uts follows the same format as other namespace flags:
--uts=private (default), --uts=host, --uts=ns:PATH

resolves #13714

Signed-off-by: Charlie Doern <cdoern@redhat.com>

4 files changed, 16 insertions, 1 deletions

diff --git a/pkg/specgen/container_validate.go b/pkg/specgen/container_validate.go
index 5616a4511..e09757d1d 100644
--- a/pkg/specgen/container_validate.go
+++ b/pkg/specgen/container_validate.go
@@ -59,6 +59,7 @@ func (s *SpecGenerator) Validate() error {
 		if s.ContainerBasicConfig.UtsNS.IsPod() {
 			return errors.Wrap(ErrInvalidSpecConfig, "cannot set hostname when joining the pod UTS namespace")
 		}
+
 		return errors.Wrap(ErrInvalidSpecConfig, "cannot set hostname when running in the host UTS namespace")
 	}
 	// systemd values must be true, false, or always
diff --git a/pkg/specgen/generate/container_create.go b/pkg/specgen/generate/container_create.go
index 6b2e90b22..f31e46090 100644
--- a/pkg/specgen/generate/container_create.go
+++ b/pkg/specgen/generate/container_create.go
@@ -133,6 +133,12 @@ func MakeContainer(ctx context.Context, rt *libpod.Runtime, s *specgen.SpecGener
 
 		options = append(options, libpod.WithRootFSFromImage(newImage.ID(), resolvedImageName, s.RawImageName))
 	}
+
+	_, err = rt.LookupPod(s.Hostname)
+	if len(s.Hostname) > 0 && !s.UtsNS.IsPrivate() && err == nil {
+		// ok, we are incorrectly setting the pod as the hostname, lets undo that before validation
+		s.Hostname = ""
+	}
 	if err := s.Validate(); err != nil {
 		return nil, nil, nil, errors.Wrap(err, "invalid config provided")
 	}
diff --git a/pkg/specgen/generate/namespaces.go b/pkg/specgen/generate/namespaces.go
index 4224d16ce..a3719d58e 100644
--- a/pkg/specgen/generate/namespaces.go
+++ b/pkg/specgen/generate/namespaces.go
@@ -176,7 +176,14 @@ func namespaceOptions(s *specgen.SpecGenerator, rt *libpod.Runtime, pod *libpod.
 		if pod == nil || infraCtr == nil {
 			return nil, errNoInfra
 		}
-		toReturn = append(toReturn, libpod.WithUTSNSFrom(infraCtr))
+		if pod.NamespaceMode(spec.UTSNamespace) == host {
+			// adding infra as a nsCtr is not what we want to do when uts == host
+			// this leads the new ctr to try to add an ns path which is should not in this mode
+			logrus.Debug("pod has host uts, not adding infra as a nsCtr")
+			s.UtsNS = specgen.Namespace{NSMode: specgen.Host}
+		} else {
+			toReturn = append(toReturn, libpod.WithUTSNSFrom(infraCtr))
+		}
 	case specgen.FromContainer:
 		utsCtr, err := rt.LookupContainer(s.UtsNS.Value)
 		if err != nil {
diff --git a/pkg/specgen/generate/pod_create.go b/pkg/specgen/generate/pod_create.go
index 4ac8a0aa2..59936c7a8 100644
--- a/pkg/specgen/generate/pod_create.go
+++ b/pkg/specgen/generate/pod_create.go
@@ -60,6 +60,7 @@ func MakePod(p *entities.PodSpec, rt *libpod.Runtime) (*libpod.Pod, error) {
 		if err != nil {
 			return nil, err
 		}
+
 		spec.Pod = pod.ID()
 		opts = append(opts, rt.WithPod(pod))
 		spec.CgroupParent = pod.CgroupParent()