diff options
Diffstat (limited to 'pkg/systemd/generate/containers.go')
| -rw-r--r-- | pkg/systemd/generate/containers.go | 189 |
1 files changed, 111 insertions, 78 deletions
diff --git a/pkg/systemd/generate/containers.go b/pkg/systemd/generate/containers.go index f316d4452..dced1a3da 100644 --- a/pkg/systemd/generate/containers.go +++ b/pkg/systemd/generate/containers.go @@ -33,14 +33,13 @@ type containerInfo struct { // PIDFile of the service. Required for forking services. Must point to the // PID of the associated conmon process. PIDFile string + // ContainerIDFile to be used in the unit. + ContainerIDFile string // GenerateTimestamp, if set the generated unit file has a time stamp. GenerateTimestamp bool // BoundToServices are the services this service binds to. Note that this // service runs after them. BoundToServices []string - // RequiredServices are services this service requires. Note that this - // service runs before them. - RequiredServices []string // PodmanVersion for the header. Will be set internally. Will be auto-filled // if left empty. PodmanVersion string @@ -49,16 +48,23 @@ type containerInfo struct { Executable string // TimeStamp at the time of creating the unit file. Will be set internally. TimeStamp string - // New controls if a new container is created or if an existing one is started. - New bool // CreateCommand is the full command plus arguments of the process the // container has been created with. CreateCommand []string - // RunCommand is a post-processed variant of CreateCommand and used for - // the ExecStart field in generic unit files. - RunCommand string // EnvVariable is generate.EnvVariable and must not be set. EnvVariable string + // ExecStartPre of the unit. + ExecStartPre string + // ExecStart of the unit. + ExecStart string + // ExecStop of the unit. + ExecStop string + // ExecStopPost of the unit. + ExecStopPost string + + // If not nil, the container is part of the pod. We can use the + // podInfo to extract the relevant data. + pod *podInfo } const containerTemplate = headerTemplate + ` @@ -68,25 +74,19 @@ RefuseManualStop=yes BindsTo={{- range $index, $value := .BoundToServices -}}{{if $index}} {{end}}{{ $value }}.service{{end}} After={{- range $index, $value := .BoundToServices -}}{{if $index}} {{end}}{{ $value }}.service{{end}} {{- end}} -{{- if .RequiredServices}} -Requires={{- range $index, $value := .RequiredServices -}}{{if $index}} {{end}}{{ $value }}.service{{end}} -Before={{- range $index, $value := .RequiredServices -}}{{if $index}} {{end}}{{ $value }}.service{{end}} -{{- end}} [Service] Environment={{.EnvVariable}}=%n Restart={{.RestartPolicy}} -{{- if .New}} -ExecStartPre=/usr/bin/rm -f %t/%n-pid %t/%n-ctr-id -ExecStart={{.RunCommand}} -ExecStop={{.Executable}} stop --ignore --cidfile %t/%n-ctr-id {{if (ge .StopTimeout 0)}}-t {{.StopTimeout}}{{end}} -ExecStopPost={{.Executable}} rm --ignore -f --cidfile %t/%n-ctr-id -PIDFile=%t/%n-pid -{{- else}} -ExecStart={{.Executable}} start {{.ContainerNameOrID}} -ExecStop={{.Executable}} stop {{if (ge .StopTimeout 0)}}-t {{.StopTimeout}}{{end}} {{.ContainerNameOrID}} -PIDFile={{.PIDFile}} +{{- if .ExecStartPre}} +ExecStartPre={{.ExecStartPre}} +{{- end}} +ExecStart={{.ExecStart}} +ExecStop={{.ExecStop}} +{{- if .ExecStopPost}} +ExecStopPost={{.ExecStopPost}} {{- end}} +PIDFile={{.PIDFile}} KillMode=none Type=forking @@ -101,11 +101,58 @@ func ContainerUnit(ctr *libpod.Container, options entities.GenerateSystemdOption if err != nil { return "", err } - return createContainerSystemdUnit(info, options) + return executeContainerTemplate(info, options) +} + +func generateContainerInfo(ctr *libpod.Container, options entities.GenerateSystemdOptions) (*containerInfo, error) { + timeout := ctr.StopTimeout() + if options.StopTimeout != nil { + timeout = *options.StopTimeout + } + + config := ctr.Config() + conmonPidFile := config.ConmonPidFile + if conmonPidFile == "" { + return nil, errors.Errorf("conmon PID file path is empty, try to recreate the container with --conmon-pidfile flag") + } + + createCommand := []string{} + if config.CreateCommand != nil { + createCommand = config.CreateCommand + } else if options.New { + return nil, errors.Errorf("cannot use --new on container %q: no create command found", ctr.ID()) + } + + nameOrID, serviceName := containerServiceName(ctr, options) + + info := containerInfo{ + ServiceName: serviceName, + ContainerNameOrID: nameOrID, + RestartPolicy: options.RestartPolicy, + PIDFile: conmonPidFile, + StopTimeout: timeout, + GenerateTimestamp: true, + CreateCommand: createCommand, + } + + return &info, nil +} + +// containerServiceName returns the nameOrID and the service name of the +// container. +func containerServiceName(ctr *libpod.Container, options entities.GenerateSystemdOptions) (string, string) { + nameOrID := ctr.ID() + if options.Name { + nameOrID = ctr.Name() + } + serviceName := fmt.Sprintf("%s%s%s", options.ContainerPrefix, options.Separator, nameOrID) + return nameOrID, serviceName } -// createContainerSystemdUnit creates a systemd unit file for a container. -func createContainerSystemdUnit(info *containerInfo, options entities.GenerateSystemdOptions) (string, error) { +// executeContainerTemplate executes the container template on the specified +// containerInfo. Note that the containerInfo is also post processed and +// completed, which allows for an easier unit testing. +func executeContainerTemplate(info *containerInfo, options entities.GenerateSystemdOptions) (string, error) { if err := validateRestartPolicy(info.RestartPolicy); err != nil { return "", err } @@ -121,6 +168,8 @@ func createContainerSystemdUnit(info *containerInfo, options entities.GenerateSy } info.EnvVariable = EnvVariable + info.ExecStart = "{{.Executable}} start {{.ContainerNameOrID}}" + info.ExecStop = "{{.Executable}} stop {{if (ge .StopTimeout 0)}}-t {{.StopTimeout}}{{end}} {{.ContainerNameOrID}}" // Assemble the ExecStart command when creating a new container. // @@ -130,6 +179,8 @@ func createContainerSystemdUnit(info *containerInfo, options entities.GenerateSy // invalid `info.CreateCommand`. Hence, we're doing a best effort unit // generation and don't try aiming at completeness. if options.New { + info.PIDFile = "%t/" + info.ServiceName + ".pid" + info.ContainerIDFile = "%t/" + info.ServiceName + ".ctr-id" // The create command must at least have three arguments: // /usr/bin/podman run $IMAGE index := 2 @@ -141,13 +192,20 @@ func createContainerSystemdUnit(info *containerInfo, options entities.GenerateSy } // We're hard-coding the first five arguments and append the // CreateCommand with a stripped command and subcomand. - command := []string{ + startCommand := []string{ info.Executable, "run", - "--conmon-pidfile", "%t/%n-pid", - "--cidfile", "%t/%n-ctr-id", + "--conmon-pidfile", "{{.PIDFile}}", + "--cidfile", "{{.ContainerIDFile}}", "--cgroups=no-conmon", } + // If the container is in a pod, make sure that the + // --pod-id-file is set correctly. + if info.pod != nil { + podFlags := []string{"--pod-id-file", info.pod.PodIDFile} + startCommand = append(startCommand, podFlags...) + info.CreateCommand = filterPodFlags(info.CreateCommand) + } // Enforce detaching // @@ -165,12 +223,14 @@ func createContainerSystemdUnit(info *containerInfo, options entities.GenerateSy } } if !hasDetachParam { - command = append(command, "-d") + startCommand = append(startCommand, "-d") } + startCommand = append(startCommand, info.CreateCommand[index:]...) - command = append(command, info.CreateCommand[index:]...) - info.RunCommand = strings.Join(command, " ") - info.New = true + info.ExecStartPre = "/usr/bin/rm -f {{.PIDFile}} {{.ContainerIDFile}}" + info.ExecStart = strings.Join(startCommand, " ") + info.ExecStop = "{{.Executable}} stop --ignore --cidfile {{.ContainerIDFile}} {{if (ge .StopTimeout 0)}}-t {{.StopTimeout}}{{end}}" + info.ExecStopPost = "{{.Executable}} rm --ignore -f --cidfile {{.ContainerIDFile}}" } if info.PodmanVersion == "" { @@ -181,11 +241,17 @@ func createContainerSystemdUnit(info *containerInfo, options entities.GenerateSy } // Sort the slices to assure a deterministic output. - sort.Strings(info.RequiredServices) sort.Strings(info.BoundToServices) // Generate the template and compile it. - templ, err := template.New("systemd_service_file").Parse(containerTemplate) + // + // Note that we need a two-step generation process to allow for fields + // embedding other fields. This way we can replace `A -> B -> C` and + // make the code easier to maintain at the cost of a slightly slower + // generation. That's especially needed for embedding the PID and ID + // files in other fields which will eventually get replaced in the 2nd + // template execution. + templ, err := template.New("container_template").Parse(containerTemplate) if err != nil { return "", errors.Wrap(err, "error parsing systemd service template") } @@ -195,6 +261,17 @@ func createContainerSystemdUnit(info *containerInfo, options entities.GenerateSy return "", err } + // Now parse the generated template (i.e., buf) and execute it. + templ, err = template.New("container_template").Parse(buf.String()) + if err != nil { + return "", errors.Wrap(err, "error parsing systemd service template") + } + + buf = bytes.Buffer{} + if err := templ.Execute(&buf, info); err != nil { + return "", err + } + if !options.Files { return buf.String(), nil } @@ -210,47 +287,3 @@ func createContainerSystemdUnit(info *containerInfo, options entities.GenerateSy } return path, nil } - -func generateContainerInfo(ctr *libpod.Container, options entities.GenerateSystemdOptions) (*containerInfo, error) { - timeout := ctr.StopTimeout() - if options.StopTimeout != nil { - timeout = *options.StopTimeout - } - - config := ctr.Config() - conmonPidFile := config.ConmonPidFile - if conmonPidFile == "" { - return nil, errors.Errorf("conmon PID file path is empty, try to recreate the container with --conmon-pidfile flag") - } - - createCommand := []string{} - if config.CreateCommand != nil { - createCommand = config.CreateCommand - } else if options.New { - return nil, errors.Errorf("cannot use --new on container %q: no create command found", ctr.ID()) - } - - nameOrID, serviceName := containerServiceName(ctr, options) - - info := containerInfo{ - ServiceName: serviceName, - ContainerNameOrID: nameOrID, - RestartPolicy: options.RestartPolicy, - PIDFile: conmonPidFile, - StopTimeout: timeout, - GenerateTimestamp: true, - CreateCommand: createCommand, - } - return &info, nil -} - -// containerServiceName returns the nameOrID and the service name of the -// container. -func containerServiceName(ctr *libpod.Container, options entities.GenerateSystemdOptions) (string, string) { - nameOrID := ctr.ID() - if options.Name { - nameOrID = ctr.Name() - } - serviceName := fmt.Sprintf("%s%s%s", options.ContainerPrefix, options.Separator, nameOrID) - return nameOrID, serviceName -} |