Generate systemd unit files for containers

the podman generate systemd command will generate a systemd unit file
based on the attributes of an existing container and user inputs.  the
command outputs the unit file to stdout for the user to copy or
redirect.  it is enabled for the remote client as well.

users can set a restart policy as well as define a stop timeout
override for the container.

Signed-off-by: baude <bbaude@redhat.com>

4 files changed, 80 insertions, 1 deletions

diff --git a/cmd/podman/cliconfig/config.go b/cmd/podman/cliconfig/config.go
index 43ba7ddc9..b770aaca0 100644
--- a/cmd/podman/cliconfig/config.go
+++ b/cmd/podman/cliconfig/config.go
@@ -136,12 +136,18 @@ type ExportValues struct {
 	PodmanCommand
 	Output string
 }
-
 type GenerateKubeValues struct {
 	PodmanCommand
 	Service bool
 }
 
+type GenerateSystemdValues struct {
+	PodmanCommand
+	Name          bool
+	RestartPolicy string
+	StopTimeout   int
+}
+
 type HistoryValues struct {
 	PodmanCommand
 	Human   bool
diff --git a/cmd/podman/generate.go b/cmd/podman/generate.go
index a0637ecb2..98bfb00a1 100644
--- a/cmd/podman/generate.go
+++ b/cmd/podman/generate.go
@@ -18,6 +18,7 @@ var (
 	//	Commands that are universally implemented
 	generateCommands = []*cobra.Command{
 		_containerKubeCommand,
+		_containerSystemdCommand,
 	}
 )
 
diff --git a/cmd/podman/generate_systemd.go b/cmd/podman/generate_systemd.go
new file mode 100644
index 000000000..b4779e512
--- /dev/null
+++ b/cmd/podman/generate_systemd.go
@@ -0,0 +1,70 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/containers/libpod/cmd/podman/cliconfig"
+	"github.com/containers/libpod/pkg/adapter"
+	"github.com/containers/libpod/pkg/systemdgen"
+	"github.com/pkg/errors"
+	"github.com/spf13/cobra"
+)
+
+var (
+	containerSystemdCommand     cliconfig.GenerateSystemdValues
+	containerSystemdDescription = `Command generates a systemd unit file for a Podman container
+  `
+	_containerSystemdCommand = &cobra.Command{
+		Use:   "systemd [flags] CONTAINER | POD",
+		Short: "Generate a systemd unit file for a Podman container",
+		Long:  containerSystemdDescription,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			containerSystemdCommand.InputArgs = args
+			containerSystemdCommand.GlobalFlags = MainGlobalOpts
+			containerSystemdCommand.Remote = remoteclient
+			return generateSystemdCmd(&containerSystemdCommand)
+		},
+		Args: func(cmd *cobra.Command, args []string) error {
+			if len(args) > 1 || len(args) < 1 {
+				return errors.New("provide only one container name or ID")
+			}
+			return nil
+		},
+		Example: `podman generate kube ctrID
+`,
+	}
+)
+
+func init() {
+	containerSystemdCommand.Command = _containerSystemdCommand
+	containerSystemdCommand.SetHelpTemplate(HelpTemplate())
+	containerSystemdCommand.SetUsageTemplate(UsageTemplate())
+	flags := containerSystemdCommand.Flags()
+	flags.BoolVarP(&containerSystemdCommand.Name, "name", "n", false, "use the container name instead of ID")
+	flags.IntVarP(&containerSystemdCommand.StopTimeout, "timeout", "t", -1, "stop timeout override")
+	flags.StringVar(&containerSystemdCommand.RestartPolicy, "restart-policy", "on-failure", "applicable systemd restart-policy")
+}
+
+func generateSystemdCmd(c *cliconfig.GenerateSystemdValues) error {
+	runtime, err := adapter.GetRuntime(getContext(), &c.PodmanCommand)
+	if err != nil {
+		return errors.Wrapf(err, "could not get runtime")
+	}
+	defer runtime.Shutdown(false)
+
+	// User input stop timeout must be 0 or greater
+	if c.Flag("timeout").Changed && c.StopTimeout < 0 {
+		return errors.New("timeout value must be 0 or greater")
+	}
+	// Make sure the input restart policy is valid
+	if err := systemdgen.ValidateRestartPolicy(c.RestartPolicy); err != nil {
+		return err
+	}
+
+	unit, err := runtime.GenerateSystemd(c)
+	if err != nil {
+		return err
+	}
+	fmt.Println(unit)
+	return nil
+}
diff --git a/cmd/podman/varlink/io.podman.varlink b/cmd/podman/varlink/io.podman.varlink
index 912d001e9..ace81646c 100644
--- a/cmd/podman/varlink/io.podman.varlink
+++ b/cmd/podman/varlink/io.podman.varlink
@@ -1218,6 +1218,8 @@ method GetLayersMapWithImageInfo() -> (layerMap: string)
 # BuildImageHierarchyMap is for the development of Podman and should not be used.
 method BuildImageHierarchyMap(name: string) -> (imageInfo: string)
 
+method GenerateSystemd(name: string, restart: string, timeout: int, useName: bool) -> (unit: string)
+
 # ImageNotFound means the image could not be found by the provided name or ID in local storage.
 error ImageNotFound (id: string, reason: string)