podman generate systemd --new: allow -h hostname

podman run/create can accept `-h <hostname>` as argument. When parsing
flags -h throws an help requested error from pflag. To prevent this
error we have to define the help flag.

Fixes #15124

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

pkg/systemd/generate/containers.go

@@ -378,6 +378,9 @@ func executeContainerTemplate(info *containerInfo, options entities.GenerateSyst
 		fs.StringArrayP("env", "e", nil, "")
 		fs.String("sdnotify", "", "")
 		fs.String("restart", "", "")
+		// have to define extra -h flag to prevent help error when parsing -h hostname
+		// https://github.com/containers/podman/issues/15124
+		fs.StringP("help", "h", "", "")
 		if err := fs.Parse(remainingCmd); err != nil {
 			return "", fmt.Errorf("parsing remaining command-line arguments: %w", err)
 		}

pkg/systemd/generate/containers_test.go

@@ -811,6 +811,37 @@ ExecStopPost=/usr/bin/podman rm -f --ignore --cidfile=%t/%n.ctr-id
 Type=notify
 NotifyAccess=all
 
+[Install]
+WantedBy=default.target
+`
+
+	goodNewWithHostname := `# jadda-jadda.service
+# autogenerated by Podman CI
+
+[Unit]
+Description=Podman jadda-jadda.service
+Documentation=man:podman-generate-systemd(1)
+Wants=network-online.target
+After=network-online.target
+RequiresMountsFor=/var/run/containers/storage
+
+[Service]
+Environment=PODMAN_SYSTEMD_UNIT=%n
+Restart=on-failure
+TimeoutStopSec=70
+ExecStartPre=/bin/rm -f %t/%n.ctr-id
+ExecStart=/usr/bin/podman run \
+	--cidfile=%t/%n.ctr-id \
+	--cgroups=no-conmon \
+	--rm \
+	--sdnotify=conmon \
+	-d \
+	-h hostname awesome-image:latest
+ExecStop=/usr/bin/podman stop --ignore --cidfile=%t/%n.ctr-id
+ExecStopPost=/usr/bin/podman rm -f --ignore --cidfile=%t/%n.ctr-id
+Type=notify
+NotifyAccess=all
+
 [Install]
 WantedBy=default.target
 `
@@ -1432,6 +1463,25 @@ WantedBy=default.target
 			false,
 			false,
 		},
+		{"good with -h hostname",
+			containerInfo{
+				Executable:        "/usr/bin/podman",
+				ServiceName:       "jadda-jadda",
+				ContainerNameOrID: "jadda-jadda",
+				PIDFile:           "/var/run/containers/storage/overlay-containers/639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401/userdata/conmon.pid",
+				StopTimeout:       10,
+				PodmanVersion:     "CI",
+				GraphRoot:         "/var/lib/containers/storage",
+				RunRoot:           "/var/run/containers/storage",
+				CreateCommand:     []string{"I'll get stripped", "create", "-h", "hostname", "awesome-image:latest"},
+				EnvVariable:       define.EnvVariable,
+			},
+			goodNewWithHostname,
+			true,
+			false,
+			false,
+			false,
+		},
 		{"good template",
 			containerInfo{
 				Executable:        "/usr/bin/podman",