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>

10 files changed, 190 insertions, 77 deletions

diff --git a/pkg/api/handlers/libpod/generate.go b/pkg/api/handlers/libpod/generate.go
index 966874a2b..33bb75391 100644
--- a/pkg/api/handlers/libpod/generate.go
+++ b/pkg/api/handlers/libpod/generate.go
@@ -7,10 +7,55 @@ import (
 	"github.com/containers/podman/v2/pkg/api/handlers/utils"
 	"github.com/containers/podman/v2/pkg/domain/entities"
 	"github.com/containers/podman/v2/pkg/domain/infra/abi"
+	"github.com/containers/podman/v2/pkg/util"
 	"github.com/gorilla/schema"
 	"github.com/pkg/errors"
 )
 
+func GenerateSystemd(w http.ResponseWriter, r *http.Request) {
+	runtime := r.Context().Value("runtime").(*libpod.Runtime)
+	decoder := r.Context().Value("decoder").(*schema.Decoder)
+	query := struct {
+		Name            bool   `schema:"useName"`
+		New             bool   `schema:"new"`
+		RestartPolicy   string `schema:"restartPolicy"`
+		StopTimeout     uint   `schema:"stopTimeout"`
+		ContainerPrefix string `schema:"containerPrefix"`
+		PodPrefix       string `schema:"podPrefix"`
+		Separator       string `schema:"separator"`
+	}{
+		RestartPolicy:   "on-failure",
+		StopTimeout:     util.DefaultContainerConfig().Engine.StopTimeout,
+		ContainerPrefix: "container",
+		PodPrefix:       "pod",
+		Separator:       "-",
+	}
+
+	if err := decoder.Decode(&query, r.URL.Query()); err != nil {
+		utils.Error(w, http.StatusText(http.StatusBadRequest), http.StatusBadRequest,
+			errors.Wrapf(err, "failed to parse parameters for %s", r.URL.String()))
+		return
+	}
+
+	containerEngine := abi.ContainerEngine{Libpod: runtime}
+	options := entities.GenerateSystemdOptions{
+		Name:            query.Name,
+		New:             query.New,
+		RestartPolicy:   query.RestartPolicy,
+		StopTimeout:     &query.StopTimeout,
+		ContainerPrefix: query.ContainerPrefix,
+		PodPrefix:       query.PodPrefix,
+		Separator:       query.Separator,
+	}
+	report, err := containerEngine.GenerateSystemd(r.Context(), utils.GetName(r), options)
+	if err != nil {
+		utils.Error(w, "Something went wrong.", http.StatusInternalServerError, errors.Wrap(err, "error generating systemd units"))
+		return
+	}
+
+	utils.WriteResponse(w, http.StatusOK, report.Units)
+}
+
 func GenerateKube(w http.ResponseWriter, r *http.Request) {
 	runtime := r.Context().Value("runtime").(*libpod.Runtime)
 	decoder := r.Context().Value("decoder").(*schema.Decoder)
diff --git a/pkg/api/server/register_generate.go b/pkg/api/server/register_generate.go
index 7db8ee387..60e5b03f7 100644
--- a/pkg/api/server/register_generate.go
+++ b/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:
diff --git a/pkg/bindings/generate/generate.go b/pkg/bindings/generate/generate.go
index b02221765..dde1cc29c 100644
--- a/pkg/bindings/generate/generate.go
+++ b/pkg/bindings/generate/generate.go
@@ -10,6 +10,33 @@ import (
 	"github.com/containers/podman/v2/pkg/domain/entities"
 )
 
+func Systemd(ctx context.Context, nameOrID string, options entities.GenerateSystemdOptions) (*entities.GenerateSystemdReport, error) {
+	conn, err := bindings.GetClient(ctx)
+	if err != nil {
+		return nil, err
+	}
+	params := url.Values{}
+
+	params.Set("useName", strconv.FormatBool(options.Name))
+	params.Set("new", strconv.FormatBool(options.New))
+	if options.RestartPolicy != "" {
+		params.Set("restartPolicy", options.RestartPolicy)
+	}
+	if options.StopTimeout != nil {
+		params.Set("stopTimeout", strconv.FormatUint(uint64(*options.StopTimeout), 10))
+	}
+	params.Set("containerPrefix", options.ContainerPrefix)
+	params.Set("podPrefix", options.PodPrefix)
+	params.Set("separator", options.Separator)
+
+	response, err := conn.DoRequest(nil, http.MethodGet, "/generate/%s/systemd", params, nil, nameOrID)
+	if err != nil {
+		return nil, err
+	}
+	report := &entities.GenerateSystemdReport{}
+	return report, response.Process(&report.Units)
+}
+
 func Kube(ctx context.Context, nameOrID string, options entities.GenerateKubeOptions) (*entities.GenerateKubeReport, error) {
 	conn, err := bindings.GetClient(ctx)
 	if err != nil {
diff --git a/pkg/domain/entities/generate.go b/pkg/domain/entities/generate.go
index a8ad13705..4a0d7537e 100644
--- a/pkg/domain/entities/generate.go
+++ b/pkg/domain/entities/generate.go
@@ -4,8 +4,6 @@ import "io"
 
 // GenerateSystemdOptions control the generation of systemd unit files.
 type GenerateSystemdOptions struct {
-	// Files - generate files instead of printing to stdout.
-	Files bool
 	// Name - use container/pod name instead of its ID.
 	Name bool
 	// New - create a new container instead of starting a new one.
@@ -24,9 +22,8 @@ type GenerateSystemdOptions struct {
 
 // GenerateSystemdReport
 type GenerateSystemdReport struct {
-	// Output of the generate process. Either the generated files or their
-	// entire content.
-	Output string
+	// Units of the generate process. key = unit name -> value = unit content
+	Units map[string]string
 }
 
 // GenerateKubeOptions control the generation of Kubernetes YAML files.
diff --git a/pkg/domain/infra/abi/generate.go b/pkg/domain/infra/abi/generate.go
index 0b73ddd7e..79bf2291e 100644
--- a/pkg/domain/infra/abi/generate.go
+++ b/pkg/domain/infra/abi/generate.go
@@ -19,11 +19,11 @@ func (ic *ContainerEngine) GenerateSystemd(ctx context.Context, nameOrID string,
 	ctr, ctrErr := ic.Libpod.LookupContainer(nameOrID)
 	if ctrErr == nil {
 		// Generate the unit for the container.
-		s, err := generate.ContainerUnit(ctr, options)
+		name, content, err := generate.ContainerUnit(ctr, options)
 		if err != nil {
 			return nil, err
 		}
-		return &entities.GenerateSystemdReport{Output: s}, nil
+		return &entities.GenerateSystemdReport{Units: map[string]string{name: content}}, nil
 	}
 
 	// If it's not a container, we either have a pod or garbage.
@@ -34,11 +34,11 @@ func (ic *ContainerEngine) GenerateSystemd(ctx context.Context, nameOrID string,
 	}
 
 	// Generate the units for the pod and all its containers.
-	s, err := generate.PodUnits(pod, options)
+	units, err := generate.PodUnits(pod, options)
 	if err != nil {
 		return nil, err
 	}
-	return &entities.GenerateSystemdReport{Output: s}, nil
+	return &entities.GenerateSystemdReport{Units: units}, nil
 }
 
 func (ic *ContainerEngine) GenerateKube(ctx context.Context, nameOrID string, options entities.GenerateKubeOptions) (*entities.GenerateKubeReport, error) {
diff --git a/pkg/domain/infra/tunnel/generate.go b/pkg/domain/infra/tunnel/generate.go
index c7d5cd9e2..966f707b1 100644
--- a/pkg/domain/infra/tunnel/generate.go
+++ b/pkg/domain/infra/tunnel/generate.go
@@ -5,11 +5,10 @@ import (
 
 	"github.com/containers/podman/v2/pkg/bindings/generate"
 	"github.com/containers/podman/v2/pkg/domain/entities"
-	"github.com/pkg/errors"
 )
 
 func (ic *ContainerEngine) GenerateSystemd(ctx context.Context, nameOrID string, options entities.GenerateSystemdOptions) (*entities.GenerateSystemdReport, error) {
-	return nil, errors.New("not implemented for tunnel")
+	return generate.Systemd(ic.ClientCxt, nameOrID, options)
 }
 
 func (ic *ContainerEngine) GenerateKube(ctx context.Context, nameOrID string, options entities.GenerateKubeOptions) (*entities.GenerateKubeReport, error) {
diff --git a/pkg/systemd/generate/containers.go b/pkg/systemd/generate/containers.go
index 5f6376977..caf5de357 100644
--- a/pkg/systemd/generate/containers.go
+++ b/pkg/systemd/generate/containers.go
@@ -3,9 +3,7 @@ package generate
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
 	"os"
-	"path/filepath"
 	"sort"
 	"strings"
 	"text/template"
@@ -87,17 +85,22 @@ KillMode=none
 Type=forking
 
 [Install]
-WantedBy=multi-user.target default.target`
+WantedBy=multi-user.target default.target
+`
 
 // ContainerUnit generates a systemd unit for the specified container.  Based
 // on the options, the return value might be the entire unit or a file it has
 // been written to.
-func ContainerUnit(ctr *libpod.Container, options entities.GenerateSystemdOptions) (string, error) {
+func ContainerUnit(ctr *libpod.Container, options entities.GenerateSystemdOptions) (string, string, error) {
 	info, err := generateContainerInfo(ctr, options)
 	if err != nil {
-		return "", err
+		return "", "", err
+	}
+	content, err := executeContainerTemplate(info, options)
+	if err != nil {
+		return "", "", err
 	}
-	return executeContainerTemplate(info, options)
+	return info.ServiceName, content, nil
 }
 
 func generateContainerInfo(ctr *libpod.Container, options entities.GenerateSystemdOptions) (*containerInfo, error) {
@@ -288,18 +291,5 @@ func executeContainerTemplate(info *containerInfo, options entities.GenerateSyst
 		return "", err
 	}
 
-	if !options.Files {
-		return buf.String(), nil
-	}
-
-	buf.WriteByte('\n')
-	cwd, err := os.Getwd()
-	if err != nil {
-		return "", errors.Wrap(err, "error getting current working directory")
-	}
-	path := filepath.Join(cwd, fmt.Sprintf("%s.service", info.ServiceName))
-	if err := ioutil.WriteFile(path, buf.Bytes(), 0644); err != nil {
-		return "", errors.Wrap(err, "error generating systemd unit")
-	}
-	return path, nil
+	return buf.String(), nil
 }
diff --git a/pkg/systemd/generate/containers_test.go b/pkg/systemd/generate/containers_test.go
index b5c736c5a..d27062ef3 100644
--- a/pkg/systemd/generate/containers_test.go
+++ b/pkg/systemd/generate/containers_test.go
@@ -56,7 +56,8 @@ KillMode=none
 Type=forking
 
 [Install]
-WantedBy=multi-user.target default.target`
+WantedBy=multi-user.target default.target
+`
 
 	goodName := `# container-foobar.service
 # autogenerated by Podman CI
@@ -78,7 +79,8 @@ KillMode=none
 Type=forking
 
 [Install]
-WantedBy=multi-user.target default.target`
+WantedBy=multi-user.target default.target
+`
 
 	goodNameBoundTo := `# container-foobar.service
 # autogenerated by Podman CI
@@ -102,7 +104,8 @@ KillMode=none
 Type=forking
 
 [Install]
-WantedBy=multi-user.target default.target`
+WantedBy=multi-user.target default.target
+`
 
 	goodWithNameAndGeneric := `# jadda-jadda.service
 # autogenerated by Podman CI
@@ -125,7 +128,8 @@ KillMode=none
 Type=forking
 
 [Install]
-WantedBy=multi-user.target default.target`
+WantedBy=multi-user.target default.target
+`
 
 	goodWithExplicitShortDetachParam := `# jadda-jadda.service
 # autogenerated by Podman CI
@@ -148,7 +152,8 @@ KillMode=none
 Type=forking
 
 [Install]
-WantedBy=multi-user.target default.target`
+WantedBy=multi-user.target default.target
+`
 
 	goodNameNewWithPodFile := `# jadda-jadda.service
 # autogenerated by Podman CI
@@ -171,7 +176,8 @@ KillMode=none
 Type=forking
 
 [Install]
-WantedBy=multi-user.target default.target`
+WantedBy=multi-user.target default.target
+`
 
 	goodNameNewDetach := `# jadda-jadda.service
 # autogenerated by Podman CI
@@ -194,7 +200,8 @@ KillMode=none
 Type=forking
 
 [Install]
-WantedBy=multi-user.target default.target`
+WantedBy=multi-user.target default.target
+`
 
 	goodIDNew := `# container-639c53578af4d84b8800b4635fa4e680ee80fd67e0e6a2d4eea48d1e3230f401.service
 # autogenerated by Podman CI
@@ -217,7 +224,8 @@ KillMode=none
 Type=forking
 
 [Install]
-WantedBy=multi-user.target default.target`
+WantedBy=multi-user.target default.target
+`
 
 	tests := []struct {
 		name    string
@@ -375,8 +383,7 @@ WantedBy=multi-user.target default.target`
 		test := tt
 		t.Run(tt.name, func(t *testing.T) {
 			opts := entities.GenerateSystemdOptions{
-				Files: false,
-				New:   test.new,
+				New: test.new,
 			}
 			got, err := executeContainerTemplate(&test.info, opts)
 			if (err != nil) != test.wantErr {
diff --git a/pkg/systemd/generate/pods.go b/pkg/systemd/generate/pods.go
index dec9587d9..c41eedd17 100644
--- a/pkg/systemd/generate/pods.go
+++ b/pkg/systemd/generate/pods.go
@@ -3,9 +3,7 @@ package generate
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
 	"os"
-	"path/filepath"
 	"sort"
 	"strings"
 	"text/template"
@@ -88,39 +86,40 @@ KillMode=none
 Type=forking
 
 [Install]
-WantedBy=multi-user.target default.target`
+WantedBy=multi-user.target default.target
+`
 
 // PodUnits generates systemd units for the specified pod and its containers.
 // Based on the options, the return value might be the content of all units or
 // the files they been written to.
-func PodUnits(pod *libpod.Pod, options entities.GenerateSystemdOptions) (string, error) {
+func PodUnits(pod *libpod.Pod, options entities.GenerateSystemdOptions) (map[string]string, error) {
 	// Error out if the pod has no infra container, which we require to be the
 	// main service.
 	if !pod.HasInfraContainer() {
-		return "", errors.Errorf("error generating systemd unit files: Pod %q has no infra container", pod.Name())
+		return nil, errors.Errorf("error generating systemd unit files: Pod %q has no infra container", pod.Name())
 	}
 
 	podInfo, err := generatePodInfo(pod, options)
 	if err != nil {
-		return "", err
+		return nil, err
 	}
 
 	infraID, err := pod.InfraContainerID()
 	if err != nil {
-		return "", err
+		return nil, err
 	}
 
 	// Compute the container-dependency graph for the Pod.
 	containers, err := pod.AllContainers()
 	if err != nil {
-		return "", err
+		return nil, err
 	}
 	if len(containers) == 0 {
-		return "", errors.Errorf("error generating systemd unit files: Pod %q has no containers", pod.Name())
+		return nil, errors.Errorf("error generating systemd unit files: Pod %q has no containers", pod.Name())
 	}
 	graph, err := libpod.BuildContainerGraph(containers)
 	if err != nil {
-		return "", err
+		return nil, err
 	}
 
 	// Traverse the dependency graph and create systemdgen.containerInfo's for
@@ -133,7 +132,7 @@ func PodUnits(pod *libpod.Pod, options entities.GenerateSystemdOptions) (string,
 		}
 		ctrInfo, err := generateContainerInfo(ctr, options)
 		if err != nil {
-			return "", err
+			return nil, err
 		}
 		// Now add the container's dependencies and at the container as a
 		// required service of the infra container.
@@ -149,24 +148,23 @@ func PodUnits(pod *libpod.Pod, options entities.GenerateSystemdOptions) (string,
 		containerInfos = append(containerInfos, ctrInfo)
 	}
 
+	units := map[string]string{}
 	// Now generate the systemd service for all containers.
-	builder := strings.Builder{}
 	out, err := executePodTemplate(podInfo, options)
 	if err != nil {
-		return "", err
+		return nil, err
 	}
-	builder.WriteString(out)
+	units[podInfo.ServiceName] = out
 	for _, info := range containerInfos {
 		info.pod = podInfo
-		builder.WriteByte('\n')
 		out, err := executeContainerTemplate(info, options)
 		if err != nil {
-			return "", err
+			return nil, err
 		}
-		builder.WriteString(out)
+		units[info.ServiceName] = out
 	}
 
-	return builder.String(), nil
+	return units, nil
 }
 
 func generatePodInfo(pod *libpod.Pod, options entities.GenerateSystemdOptions) (*podInfo, error) {
@@ -339,18 +337,5 @@ func executePodTemplate(info *podInfo, options entities.GenerateSystemdOptions)
 		return "", err
 	}
 
-	if !options.Files {
-		return buf.String(), nil
-	}
-
-	buf.WriteByte('\n')
-	cwd, err := os.Getwd()
-	if err != nil {
-		return "", errors.Wrap(err, "error getting current working directory")
-	}
-	path := filepath.Join(cwd, fmt.Sprintf("%s.service", info.ServiceName))
-	if err := ioutil.WriteFile(path, buf.Bytes(), 0644); err != nil {
-		return "", errors.Wrap(err, "error generating systemd unit")
-	}
-	return path, nil
+	return buf.String(), nil
 }
diff --git a/pkg/systemd/generate/pods_test.go b/pkg/systemd/generate/pods_test.go
index 8bf4705a7..7f1f63b7e 100644
--- a/pkg/systemd/generate/pods_test.go
+++ b/pkg/systemd/generate/pods_test.go
@@ -58,7 +58,8 @@ KillMode=none
 Type=forking
 
 [Install]
-WantedBy=multi-user.target default.target`
+WantedBy=multi-user.target default.target
+`
 
 	podGoodNamedNew := `# pod-123abc.service
 # autogenerated by Podman CI
@@ -84,7 +85,8 @@ KillMode=none
 Type=forking
 
 [Install]
-WantedBy=multi-user.target default.target`
+WantedBy=multi-user.target default.target
+`
 
 	tests := []struct {
 		name    string
@@ -130,8 +132,7 @@ WantedBy=multi-user.target default.target`
 		test := tt
 		t.Run(tt.name, func(t *testing.T) {
 			opts := entities.GenerateSystemdOptions{
-				Files: false,
-				New:   test.new,
+				New: test.new,
 			}
 			got, err := executePodTemplate(&test.info, opts)
 			if (err != nil) != test.wantErr {