generate systemd: refactor

Refactor the systemd-unit generation code and move all the logic into
`pkg/systemd/generate`.  The code was already hard to maintain but I
found it impossible to wire the `--new` logic for pods in all the chaos.

The code refactoring in this commit will make maintaining the code
easier and should make it easier to extend as well.  Further changes and
refactorings may still be needed but they will easier.

Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

1 files changed, 10 insertions, 148 deletions

diff --git a/pkg/domain/infra/abi/generate.go b/pkg/domain/infra/abi/generate.go
index 08cb87287..fa0cfb389 100644
--- a/pkg/domain/infra/abi/generate.go
+++ b/pkg/domain/infra/abi/generate.go
@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"context"
 	"fmt"
-	"strings"
 
 	"github.com/containers/libpod/libpod"
 	"github.com/containers/libpod/libpod/define"
@@ -16,165 +15,28 @@ import (
 )
 
 func (ic *ContainerEngine) GenerateSystemd(ctx context.Context, nameOrID string, options entities.GenerateSystemdOptions) (*entities.GenerateSystemdReport, error) {
-	opts := generate.Options{
-		Files: options.Files,
-		New:   options.New,
-	}
-
 	// First assume it's a container.
-	if info, found, err := ic.generateSystemdgenContainerInfo(nameOrID, nil, options); found && err != nil {
-		return nil, err
-	} else if found && err == nil {
-		output, err := generate.CreateContainerSystemdUnit(info, opts)
-		if err != nil {
-			return nil, err
+	ctr, err := ic.Libpod.LookupContainer(nameOrID)
+	if err == nil {
+		// Generate the unit for the container.
+		s, err := generate.ContainerUnit(ctr, options)
+		if err == nil {
+			return &entities.GenerateSystemdReport{Output: s}, nil
 		}
-		return &entities.GenerateSystemdReport{Output: output}, nil
-	}
-
-	// --new does not support pods.
-	if options.New {
-		return nil, errors.Errorf("error generating systemd unit files: cannot generate generic files for a pod")
 	}
 
-	// We're either having a pod or garbage.
+	// If it's not a container, we either have a pod or garbage.
 	pod, err := ic.Libpod.LookupPod(nameOrID)
 	if err != nil {
 		return nil, errors.Errorf("%q does not refer to a container or pod", nameOrID)
 	}
 
-	// Error out if the pod has no infra container, which we require to be the
-	// main service.
-	if !pod.HasInfraContainer() {
-		return nil, fmt.Errorf("error generating systemd unit files: Pod %q has no infra container", pod.Name())
-	}
-
-	// Generate a systemdgen.ContainerInfo for the infra container. This
-	// ContainerInfo acts as the main service of the pod.
-	infraID, err := pod.InfraContainerID()
-	if err != nil {
-		return nil, nil
-	}
-	podInfo, _, err := ic.generateSystemdgenContainerInfo(infraID, pod, options)
+	// Generate the units for the pod and all its containers.
+	s, err := generate.PodUnits(pod, options)
 	if err != nil {
 		return nil, err
 	}
-
-	// Compute the container-dependency graph for the Pod.
-	containers, err := pod.AllContainers()
-	if err != nil {
-		return nil, err
-	}
-	if len(containers) == 0 {
-		return nil, fmt.Errorf("error generating systemd unit files: Pod %q has no containers", pod.Name())
-	}
-	graph, err := libpod.BuildContainerGraph(containers)
-	if err != nil {
-		return nil, err
-	}
-
-	// Traverse the dependency graph and create systemdgen.ContainerInfo's for
-	// each container.
-	containerInfos := []*generate.ContainerInfo{podInfo}
-	for ctr, dependencies := range graph.DependencyMap() {
-		// Skip the infra container as we already generated it.
-		if ctr.ID() == infraID {
-			continue
-		}
-		ctrInfo, _, err := ic.generateSystemdgenContainerInfo(ctr.ID(), nil, options)
-		if err != nil {
-			return nil, err
-		}
-		// Now add the container's dependencies and at the container as a
-		// required service of the infra container.
-		for _, dep := range dependencies {
-			if dep.ID() == infraID {
-				ctrInfo.BoundToServices = append(ctrInfo.BoundToServices, podInfo.ServiceName)
-			} else {
-				_, serviceName := generateServiceName(dep, nil, options)
-				ctrInfo.BoundToServices = append(ctrInfo.BoundToServices, serviceName)
-			}
-		}
-		podInfo.RequiredServices = append(podInfo.RequiredServices, ctrInfo.ServiceName)
-		containerInfos = append(containerInfos, ctrInfo)
-	}
-
-	// Now generate the systemd service for all containers.
-	builder := strings.Builder{}
-	for i, info := range containerInfos {
-		if i > 0 {
-			builder.WriteByte('\n')
-		}
-		out, err := generate.CreateContainerSystemdUnit(info, opts)
-		if err != nil {
-			return nil, err
-		}
-		builder.WriteString(out)
-	}
-
-	return &entities.GenerateSystemdReport{Output: builder.String()}, nil
-}
-
-// generateSystemdgenContainerInfo is a helper to generate a
-// systemdgen.ContainerInfo for `GenerateSystemd`.
-func (ic *ContainerEngine) generateSystemdgenContainerInfo(nameOrID string, pod *libpod.Pod, options entities.GenerateSystemdOptions) (*generate.ContainerInfo, bool, error) {
-	ctr, err := ic.Libpod.LookupContainer(nameOrID)
-	if err != nil {
-		return nil, false, err
-	}
-
-	timeout := ctr.StopTimeout()
-	if options.StopTimeout != nil {
-		timeout = *options.StopTimeout
-	}
-
-	config := ctr.Config()
-	conmonPidFile := config.ConmonPidFile
-	if conmonPidFile == "" {
-		return nil, true, 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, true, errors.Errorf("cannot use --new on container %q: no create command found", nameOrID)
-	}
-
-	name, serviceName := generateServiceName(ctr, pod, options)
-	info := &generate.ContainerInfo{
-		ServiceName:       serviceName,
-		ContainerName:     name,
-		RestartPolicy:     options.RestartPolicy,
-		PIDFile:           conmonPidFile,
-		StopTimeout:       timeout,
-		GenerateTimestamp: true,
-		CreateCommand:     createCommand,
-	}
-
-	return info, true, nil
-}
-
-// generateServiceName generates the container name and the service name for systemd service.
-func generateServiceName(ctr *libpod.Container, pod *libpod.Pod, options entities.GenerateSystemdOptions) (string, string) {
-	var kind, name, ctrName string
-	if pod == nil {
-		kind = options.ContainerPrefix //defaults to container
-		name = ctr.ID()
-		if options.Name {
-			name = ctr.Name()
-		}
-		ctrName = name
-	} else {
-		kind = options.PodPrefix //defaults to pod
-		name = pod.ID()
-		ctrName = ctr.ID()
-		if options.Name {
-			name = pod.Name()
-			ctrName = ctr.Name()
-		}
-	}
-	return ctrName, fmt.Sprintf("%s%s%s", kind, options.Separator, name)
+	return &entities.GenerateSystemdReport{Output: s}, nil
 }
 
 func (ic *ContainerEngine) GenerateKube(ctx context.Context, nameOrID string, options entities.GenerateKubeOptions) (*entities.GenerateKubeReport, error) {