libpod: fix c.Hostname() to respect the utsNsCtr

When we lookup the hostname for a given container we have to check if
the container is joined to another utsns and use this hostname then
instead.
This fixes a problem where the `hostname` command would use the correct
name but /etc/hostname would contain a different name.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/libpod/container.go b/libpod/container.go
index bc3cab439..6e2b7f528 100644
--- a/libpod/container.go
+++ b/libpod/container.go
@@ -628,6 +628,15 @@ func (c *Container) RuntimeName() string {
 
 // Hostname gets the container's hostname
 func (c *Container) Hostname() string {
+	if c.config.UTSNsCtr != "" {
+		utsNsCtr, err := c.runtime.GetContainer(c.config.UTSNsCtr)
+		if err != nil {
+			// should we return an error here?
+			logrus.Errorf("unable to lookup uts namespace for container %s: %v", c.ID(), err)
+			return ""
+		}
+		return utsNsCtr.Hostname()
+	}
 	if c.config.Spec.Hostname != "" {
 		return c.config.Spec.Hostname
 	}