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>

pkg/api/server/register_generate.go

@@ -8,6 +8,68 @@ import (
 )
 
 func (s *APIServer) registerGenerateHandlers(r *mux.Router) error {
+	// swagger:operation GET /libpod/generate/{name:.*}/systemd libpod libpodGenerateSystemd
+	// ---
+	// tags:
+	//  - containers
+	//  - pods
+	// summary: Generate Systemd Units
+	// description: Generate Systemd Units based on a pod or container.
+	// parameters:
+	//  - in: path
+	//    name: name:.*
+	//    type: string
+	//    required: true
+	//    description: Name or ID of the container or pod.
+	//  - in: query
+	//    name: useName
+	//    type: boolean
+	//    default: false
+	//    description: Use container/pod names instead of IDs.
+	//  - in: query
+	//    name: new
+	//    type: boolean
+	//    default: false
+	//    description: Create a new container instead of starting an existing one.
+	//  - in: query
+	//    name: time
+	//    type: integer
+	//    default: 10
+	//    description: Stop timeout override.
+	//  - in: query
+	//    name: restartPolicy
+	//    default: on-failure
+	//    type: string
+	//    enum: ["no", on-success, on-failure, on-abnormal, on-watchdog, on-abort, always]
+	//    description: Systemd restart-policy.
+	//  - in: query
+	//    name: containerPrefix
+	//    type: string
+	//    default: container
+	//    description: Systemd unit name prefix for containers.
+	//  - in: query
+	//    name: podPrefix
+	//    type: string
+	//    default: pod
+	//    description: Systemd unit name prefix for pods.
+	//  - in: query
+	//    name: separator
+	//    type: string
+	//    default: "-"
+	//    description: Systemd unit name separator between name/id and prefix.
+	// produces:
+	// - application/json
+	// responses:
+	//   200:
+	//     description: no error
+	//     schema:
+	//       type: object
+	//       additionalProperties:
+	//         type: string
+	//   500:
+	//     $ref: "#/responses/InternalError"
+	r.HandleFunc(VersionedPath("/libpod/generate/{name:.*}/systemd"), s.APIHandler(libpod.GenerateSystemd)).Methods(http.MethodGet)
+
 	// swagger:operation GET /libpod/generate/{name:.*}/kube libpod libpodGenerateKube
 	// ---
 	// tags: