APIv2 add generate systemd endpoint

Add support for generating systemd units
via the api and podman-remote.

Change the GenerateSystemdReport type to return the
units as map[string]string with the unit name as key.

Add `--format` flag to `podman generate systemd`
to allow the output to be formatted as json.

Signed-off-by: Paul Holzinger <paul.holzinger@web.de>

1 files changed, 68 insertions, 3 deletions

diff --git a/cmd/podman/generate/systemd.go b/cmd/podman/generate/systemd.go
index 851a104bc..f690836a4 100644
--- a/cmd/podman/generate/systemd.go
+++ b/cmd/podman/generate/systemd.go
@@ -1,15 +1,22 @@
 package pods
 
 import (
+	"encoding/json"
 	"fmt"
+	"os"
+	"path/filepath"
 
 	"github.com/containers/podman/v2/cmd/podman/registry"
 	"github.com/containers/podman/v2/cmd/podman/utils"
 	"github.com/containers/podman/v2/pkg/domain/entities"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
 )
 
 var (
+	files              bool
+	format             string
 	systemdTimeout     uint
 	systemdOptions     = entities.GenerateSystemdOptions{}
 	systemdDescription = `Generate systemd units for a pod or container.
@@ -29,19 +36,20 @@ var (
 
 func init() {
 	registry.Commands = append(registry.Commands, registry.CliCommand{
-		Mode:    []entities.EngineMode{entities.ABIMode},
+		Mode:    []entities.EngineMode{entities.ABIMode, entities.TunnelMode},
 		Command: systemdCmd,
 		Parent:  generateCmd,
 	})
 	flags := systemdCmd.Flags()
 	flags.BoolVarP(&systemdOptions.Name, "name", "n", false, "Use container/pod names instead of IDs")
-	flags.BoolVarP(&systemdOptions.Files, "files", "f", false, "Generate .service files instead of printing to stdout")
+	flags.BoolVarP(&files, "files", "f", false, "Generate .service files instead of printing to stdout")
 	flags.UintVarP(&systemdTimeout, "time", "t", containerConfig.Engine.StopTimeout, "Stop timeout override")
 	flags.StringVar(&systemdOptions.RestartPolicy, "restart-policy", "on-failure", "Systemd restart-policy")
 	flags.BoolVarP(&systemdOptions.New, "new", "", false, "Create a new container instead of starting an existing one")
 	flags.StringVar(&systemdOptions.ContainerPrefix, "container-prefix", "container", "Systemd unit name prefix for containers")
 	flags.StringVar(&systemdOptions.PodPrefix, "pod-prefix", "pod", "Systemd unit name prefix for pods")
 	flags.StringVar(&systemdOptions.Separator, "separator", "-", "Systemd unit name separator between name/id and prefix")
+	flags.StringVar(&format, "format", "", "Print the created units in specified format (json)")
 	flags.SetNormalizeFunc(utils.AliasFlags)
 }
 
@@ -50,11 +58,68 @@ func systemd(cmd *cobra.Command, args []string) error {
 		systemdOptions.StopTimeout = &systemdTimeout
 	}
 
+	if registry.IsRemote() {
+		logrus.Warnln("The generated units should be placed on your remote system")
+	}
+
 	report, err := registry.ContainerEngine().GenerateSystemd(registry.GetContext(), args[0], systemdOptions)
 	if err != nil {
 		return err
 	}
 
-	fmt.Println(report.Output)
+	if files {
+		cwd, err := os.Getwd()
+		if err != nil {
+			return errors.Wrap(err, "error getting current working directory")
+		}
+		for name, content := range report.Units {
+			path := filepath.Join(cwd, fmt.Sprintf("%s.service", name))
+			f, err := os.Create(path)
+			if err != nil {
+				return err
+			}
+			_, err = f.WriteString(content)
+			if err != nil {
+				return err
+			}
+			err = f.Close()
+			if err != nil {
+				return err
+			}
+
+			// add newline if default format is given
+			if format == "" {
+				path += "\n"
+			}
+			// modify in place so we can print the
+			// paths when --files is set
+			report.Units[name] = path
+		}
+	}
+
+	switch format {
+	case "json":
+		return printJSON(report.Units)
+	case "":
+		return printDefault(report.Units)
+	default:
+		return errors.Errorf("unknown --format argument: %s", format)
+	}
+
+}
+
+func printDefault(units map[string]string) error {
+	for _, content := range units {
+		fmt.Print(content)
+	}
+	return nil
+}
+
+func printJSON(units map[string]string) error {
+	b, err := json.MarshalIndent(units, "", " ")
+	if err != nil {
+		return err
+	}
+	fmt.Println(string(b))
 	return nil
 }