quadlet: support HostName

Add a new `HostName` field to Quadlet `.container` files.

Fixes: #18486
Signed-off-by: Valentin Rothberg <vrothberg@redhat.com>

docs/source/markdown/podman-systemd.unit.5.md

@@ -109,6 +109,7 @@ Valid options for `[Container]` are listed below:
 | HealthStartupSuccess=2           | --health-startup-success=2             |
 | HealthStartupTimeout=1m33s       | --health-startup-timeout=1m33s         |
 | HealthTimeout=20s                | --health-timeout=20s                   |
+| HostName=new-host-name           | --hostname="new-host-name"             |
 | Image=ubi8                       | Image specification - ubi8             |
 | IP=192.5.0.1                     | --ip 192.5.0.0                         |
 | IP6=fd46:db93:aa76:ac37::10      | --ip6 2001:db8::1                      |
@@ -276,6 +277,11 @@ Equivalent to the Podman `--health-startup-timeout` option.
 The maximum time allowed to complete the healthcheck before an interval is considered failed.
 Equivalent to the Podman `--health-timeout` option.
 
+### `HostName=`
+
+Sets the host name that is available inside the container.
+Equivalent to the Podman `--hostname` option.
+
 ### `Image=`
 
 The image to run in the container. This image must be locally installed for the service to work

pkg/systemd/quadlet/quadlet.go

@@ -58,6 +58,7 @@ const (
 	KeyHealthStartupSuccess  = "HealthStartupSuccess"
 	KeyHealthStartupTimeout  = "HealthStartupTimeout"
 	KeyHealthTimeout         = "HealthTimeout"
+	KeyHostName              = "HostName"
 	KeyImage                 = "Image"
 	KeyIP                    = "IP"
 	KeyIP6                   = "IP6"
@@ -129,6 +130,7 @@ var (
 		KeyHealthStartupSuccess:  true,
 		KeyHealthStartupTimeout:  true,
 		KeyHealthTimeout:         true,
+		KeyHostName:              true,
 		KeyImage:                 true,
 		KeyIP:                    true,
 		KeyIP6:                   true,
@@ -614,6 +616,10 @@ func ConvertContainer(container *parser.UnitFile, isUser bool) (*parser.UnitFile
 
 	handleHealth(container, ContainerGroup, podman)
 
+	if hostname, ok := container.Lookup(ContainerGroup, KeyHostName); ok {
+		podman.add("--hostname", hostname)
+	}
+
 	podmanArgs := container.LookupAllArgs(ContainerGroup, KeyPodmanArgs)
 	podman.add(podmanArgs...)
 

test/e2e/quadlet/hostname.container

@@ -0,0 +1,4 @@
+[Container]
+Image=localhost/imagename
+## assert-podman-args "--hostname" "\"quadlet-host\""
+HostName="quadlet-host"

test/e2e/quadlet_test.go

@@ -575,6 +575,7 @@ var _ = Describe("quadlet system generator", func() {
 		Entry("logdriver.container", "logdriver.container"),
 		Entry("mount.container", "mount.container"),
 		Entry("health.container", "health.container"),
+		Entry("hostname.container", "hostname.container"),
 
 		Entry("basic.volume", "basic.volume"),
 		Entry("label.volume", "label.volume"),