Support template unit files in podman generate systemd

Signed-off-by: Boaz Shuster <boaz.shuster.github@gmail.com>

8 files changed, 74 insertions, 21 deletions

diff --git a/pkg/api/handlers/libpod/generate.go b/pkg/api/handlers/libpod/generate.go
index 117c5e2aa..5205d875d 100644
--- a/pkg/api/handlers/libpod/generate.go
+++ b/pkg/api/handlers/libpod/generate.go
@@ -17,14 +17,15 @@ func GenerateSystemd(w http.ResponseWriter, r *http.Request) {
 	runtime := r.Context().Value(api.RuntimeKey).(*libpod.Runtime)
 	decoder := r.Context().Value(api.DecoderKey).(*schema.Decoder)
 	query := struct {
-		Name            bool    `schema:"useName"`
-		New             bool    `schema:"new"`
-		NoHeader        bool    `schema:"noHeader"`
-		RestartPolicy   *string `schema:"restartPolicy"`
-		StopTimeout     uint    `schema:"stopTimeout"`
-		ContainerPrefix string  `schema:"containerPrefix"`
-		PodPrefix       string  `schema:"podPrefix"`
-		Separator       string  `schema:"separator"`
+		Name             bool    `schema:"useName"`
+		New              bool    `schema:"new"`
+		NoHeader         bool    `schema:"noHeader"`
+		TemplateUnitFile bool    `schema:"templateUnitFile"`
+		RestartPolicy    *string `schema:"restartPolicy"`
+		StopTimeout      uint    `schema:"stopTimeout"`
+		ContainerPrefix  string  `schema:"containerPrefix"`
+		PodPrefix        string  `schema:"podPrefix"`
+		Separator        string  `schema:"separator"`
 	}{
 		StopTimeout:     util.DefaultContainerConfig().Engine.StopTimeout,
 		ContainerPrefix: "container",
@@ -40,14 +41,15 @@ func GenerateSystemd(w http.ResponseWriter, r *http.Request) {
 
 	containerEngine := abi.ContainerEngine{Libpod: runtime}
 	options := entities.GenerateSystemdOptions{
-		Name:            query.Name,
-		New:             query.New,
-		NoHeader:        query.NoHeader,
-		RestartPolicy:   query.RestartPolicy,
-		StopTimeout:     &query.StopTimeout,
-		ContainerPrefix: query.ContainerPrefix,
-		PodPrefix:       query.PodPrefix,
-		Separator:       query.Separator,
+		Name:             query.Name,
+		New:              query.New,
+		NoHeader:         query.NoHeader,
+		TemplateUnitFile: query.TemplateUnitFile,
+		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)
diff --git a/pkg/bindings/generate/types.go b/pkg/bindings/generate/types.go
index 3c9ea87d4..6f2594604 100644
--- a/pkg/bindings/generate/types.go
+++ b/pkg/bindings/generate/types.go
@@ -16,6 +16,8 @@ type SystemdOptions struct {
 	New *bool
 	// NoHeader - Removes autogenerated by Podman and timestamp if set to true
 	NoHeader *bool
+	// TemplateUnitFile - Create a template unit file that uses the identity specifiers
+	TemplateUnitFile *bool
 	// RestartPolicy - systemd restart policy.
 	RestartPolicy *string
 	// StopTimeout - time when stopping the container.
diff --git a/pkg/bindings/generate/types_systemd_options.go b/pkg/bindings/generate/types_systemd_options.go
index 7a778a52b..b26aa7fc2 100644
--- a/pkg/bindings/generate/types_systemd_options.go
+++ b/pkg/bindings/generate/types_systemd_options.go
@@ -62,6 +62,21 @@ func (o *SystemdOptions) GetNoHeader() bool {
 	return *o.NoHeader
 }
 
+// WithTemplateUnitFile set field TemplateUnitFile to given value
+func (o *SystemdOptions) WithTemplateUnitFile(value bool) *SystemdOptions {
+	o.TemplateUnitFile = &value
+	return o
+}
+
+// GetTemplateUnitFile returns value of field TemplateUnitFile
+func (o *SystemdOptions) GetTemplateUnitFile() bool {
+	if o.TemplateUnitFile == nil {
+		var z bool
+		return z
+	}
+	return *o.TemplateUnitFile
+}
+
 // WithRestartPolicy set field RestartPolicy to given value
 func (o *SystemdOptions) WithRestartPolicy(value string) *SystemdOptions {
 	o.RestartPolicy = &value
diff --git a/pkg/domain/entities/generate.go b/pkg/domain/entities/generate.go
index 7809c5241..dfb5bfc6c 100644
--- a/pkg/domain/entities/generate.go
+++ b/pkg/domain/entities/generate.go
@@ -20,6 +20,8 @@ type GenerateSystemdOptions struct {
 	Separator string
 	// NoHeader - skip header generation
 	NoHeader bool
+	// TemplateUnitFile - make use of %i and %I to differentiate between the different instances of the unit
+	TemplateUnitFile bool
 }
 
 // GenerateSystemdReport
diff --git a/pkg/domain/infra/tunnel/generate.go b/pkg/domain/infra/tunnel/generate.go
index 9f69abb1a..3a35dd59c 100644
--- a/pkg/domain/infra/tunnel/generate.go
+++ b/pkg/domain/infra/tunnel/generate.go
@@ -8,7 +8,7 @@ import (
 )
 
 func (ic *ContainerEngine) GenerateSystemd(ctx context.Context, nameOrID string, opts entities.GenerateSystemdOptions) (*entities.GenerateSystemdReport, error) {
-	options := new(generate.SystemdOptions).WithUseName(opts.Name).WithContainerPrefix(opts.ContainerPrefix).WithNew(opts.New).WithNoHeader(opts.NoHeader)
+	options := new(generate.SystemdOptions).WithUseName(opts.Name).WithContainerPrefix(opts.ContainerPrefix).WithNew(opts.New).WithNoHeader(opts.NoHeader).WithTemplateUnitFile(opts.TemplateUnitFile)
 	options.WithPodPrefix(opts.PodPrefix).WithSeparator(opts.Separator)
 	if opts.RestartPolicy != nil {
 		options.WithRestartPolicy(*opts.RestartPolicy)
diff --git a/pkg/systemd/generate/common.go b/pkg/systemd/generate/common.go
index 3515bb3b7..24c85a27e 100644
--- a/pkg/systemd/generate/common.go
+++ b/pkg/systemd/generate/common.go
@@ -23,7 +23,7 @@ func validateRestartPolicy(restart string) error {
 	return errors.Errorf("%s is not a valid restart policy", restart)
 }
 
-const headerTemplate = `# {{{{.ServiceName}}}}.service
+const headerTemplate = `# {{{{.ServiceName}}}}{{{{- if (eq .IdentifySpecifier true) }}}}@{{{{- end}}}}.service
 {{{{- if (eq .GenerateNoHeader false) }}}}
 # autogenerated by Podman {{{{.PodmanVersion}}}}
 {{{{- if .TimeStamp}}}}
@@ -32,7 +32,7 @@ const headerTemplate = `# {{{{.ServiceName}}}}.service
 {{{{- end}}}}
 
 [Unit]
-Description=Podman {{{{.ServiceName}}}}.service
+Description=Podman {{{{.ServiceName}}}}.service{{{{- if (eq .IdentifySpecifier true) }}}} for %I{{{{- end}}}}
 Documentation=man:podman-generate-systemd(1)
 Wants=network-online.target
 After=network-online.target
diff --git a/pkg/systemd/generate/containers.go b/pkg/systemd/generate/containers.go
index 037652a6d..c0a49c614 100644
--- a/pkg/systemd/generate/containers.go
+++ b/pkg/systemd/generate/containers.go
@@ -90,6 +90,8 @@ type containerInfo struct {
 	// Location of the RunRoot for the container.  Required for ensuring the tmpfs
 	// or volume exists and is mounted when coming online at boot.
 	RunRoot string
+	// Add %i and %I to description and execute parts
+	IdentifySpecifier bool
 }
 
 const containerTemplate = headerTemplate + `
@@ -99,7 +101,7 @@ After={{{{- range $index, $value := .BoundToServices -}}}}{{{{if $index}}}} {{{{
 {{{{- end}}}}
 
 [Service]
-Environment={{{{.EnvVariable}}}}=%n
+Environment={{{{.EnvVariable}}}}=%n{{{{- if (eq .IdentifySpecifier true) }}}}-%i{{{{- end}}}}
 {{{{- if .ExtraEnvs}}}}
 Environment={{{{- range $index, $value := .ExtraEnvs -}}}}{{{{if $index}}}} {{{{end}}}}{{{{ $value }}}}{{{{end}}}}
 {{{{- end}}}}
@@ -273,7 +275,6 @@ func executeContainerTemplate(info *containerInfo, options entities.GenerateSyst
 			"--rm",
 		)
 		remainingCmd := info.CreateCommand[index:]
-
 		// Presence check for certain flags/options.
 		fs := pflag.NewFlagSet("args", pflag.ContinueOnError)
 		fs.ParseErrorsWhitelist.UnknownFlags = true
@@ -389,6 +390,32 @@ func executeContainerTemplate(info *containerInfo, options entities.GenerateSyst
 
 		startCommand = append(startCommand, remainingCmd...)
 		startCommand = escapeSystemdArguments(startCommand)
+		if options.TemplateUnitFile {
+			info.IdentifySpecifier = true
+			runIx := -1
+			nameIx := -1
+			for argIx, arg := range startCommand {
+				if arg == "run" {
+					runIx = argIx
+					continue
+				}
+				if arg == "--name" {
+					nameIx = argIx + 1
+					break
+				}
+				if strings.HasPrefix(arg, "--name=") {
+					nameIx = argIx
+					break
+				}
+			}
+			if nameIx == -1 {
+				startCommand = append(startCommand[:runIx+1], startCommand[runIx:]...)
+				startCommand[runIx+1] = fmt.Sprintf("--name=%s-%%i", info.ServiceName)
+				fmt.Println(startCommand)
+			} else {
+				startCommand[nameIx] = fmt.Sprintf("%s-%%i", startCommand[nameIx])
+			}
+		}
 		info.ExecStart = strings.Join(startCommand, " ")
 	}
 
diff --git a/pkg/systemd/generate/pods.go b/pkg/systemd/generate/pods.go
index e755b8eea..38f7e8e3e 100644
--- a/pkg/systemd/generate/pods.go
+++ b/pkg/systemd/generate/pods.go
@@ -79,6 +79,8 @@ type podInfo struct {
 	// Location of the RunRoot for the pod.  Required for ensuring the tmpfs
 	// or volume exists and is mounted when coming online at boot.
 	RunRoot string
+	// Add %i and %I to description and execute parts - this should not be used
+	IdentifySpecifier bool
 }
 
 const podTemplate = headerTemplate + `Requires={{{{- range $index, $value := .RequiredServices -}}}}{{{{if $index}}}} {{{{end}}}}{{{{ $value }}}}.service{{{{end}}}}
@@ -108,6 +110,9 @@ WantedBy=multi-user.target default.target
 // 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) (map[string]string, error) {
+	if options.TemplateUnitFile {
+		return nil, errors.New("--template is not supported for pods")
+	}
 	// Error out if the pod has no infra container, which we require to be the
 	// main service.
 	if !pod.HasInfraContainer() {