podman system prune support prune unused networks

This is an enhancement for the podman system prune feature.

In this issue, it is mentioned that 'network prune' should be
wired into 'podman system prune'
containers#8673

Does not remove cni networks because it could remove external cni networks.

Therefore, I add the function to remove unused netavark networks.

Signed-off-by: Toshiki Sonoda <sonoda.toshiki@fujitsu.com>

cmd/podman/system/prune.go

@@ -75,6 +75,7 @@ func prune(cmd *cobra.Command, args []string) error {
 		}
 	}
 
+	// Remove all unused pods, containers, images, netavark networks, and volume data.
 	pruneOptions.Filters, err = parse.FilterArgumentsIntoFilters(filters)
 	if err != nil {
 		return err
@@ -106,6 +107,11 @@ func prune(cmd *cobra.Command, args []string) error {
 	if err != nil {
 		return err
 	}
+	// Print netavark Network prune results
+	err = utils.PrintNetworkPruneResults(response.NetworkPruneReports, true)
+	if err != nil {
+		return err
+	}
 
 	fmt.Printf("Total reclaimed space: %s\n", units.HumanSize((float64)(response.ReclaimedSpace)))
 	return nil
@@ -115,15 +121,15 @@ func createPruneWarningMessage(pruneOpts entities.SystemPruneOptions) string {
 	if pruneOpts.All {
 		return `WARNING! This command removes:
 	- all stopped containers
-	- all networks not used by at least one container%s
+	- all netavark networks not used by at least one container%s
 	- all images without at least one container associated with them
 	- all build cache
 
 %s`
 	}
 	return `WARNING! This command removes:
 	- all stopped containers
-	- all networks not used by at least one container%s
+	- all netavark networks not used by at least one container%s
 	- all dangling images
 	- all dangling build cache
 

cmd/podman/utils/utils.go

@@ -84,3 +84,18 @@ func PrintImagePruneResults(imagePruneReports []*reports.PruneReport, heading bo
 
 	return nil
 }
+
+func PrintNetworkPruneResults(networkPruneReport []*reports.PruneReport, heading bool) error {
+	var errs OutputErrors
+	if heading && len(networkPruneReport) > 0 {
+		fmt.Println("Deleted netavark Networks")
+	}
+	for _, r := range networkPruneReport {
+		if r.Err == nil {
+			fmt.Println(r.Id)
+		} else {
+			errs = append(errs, r.Err)
+		}
+	}
+	return errs.PrintErrors()
+}

docs/source/markdown/podman-system-prune.1.md

@@ -1,13 +1,13 @@
 % podman-system-prune(1)
 
 ## NAME
-podman\-system\-prune - Remove all unused pod, container, image and volume data
+podman\-system\-prune - Remove all unused pods, containers, images, netavark networks, and volume data
 
 ## SYNOPSIS
 **podman system prune** [*options*]
 
 ## DESCRIPTION
-**podman system prune** removes all unused containers (both dangling and unreferenced), pods and optionally, volumes from local storage.
+**podman system prune** removes all unused containers (both dangling and unreferenced), pods, netavark networks, and optionally, volumes from local storage.
 
 With the **--all** option, you can delete all unused images.  Unused images are dangling images as well as any image that does not have any containers based on it.
 
@@ -16,7 +16,7 @@ By default, volumes are not removed to prevent important data from being deleted
 ## OPTIONS
 #### **--all**, **-a**
 
-Recursively remove all unused pod, container, image and volume data (Maximum 50 iterations.)
+Recursively remove all unused pods, containers, images, netavark networks, and volume data. (Maximum 50 iterations.)
 
 #### **--filter**=*filters*
 

docs/source/markdown/podman-system.1.md

@@ -11,16 +11,16 @@ The system command allows you to manage the podman systems
 
 ## COMMANDS
 
-| Command    | Man Page                                                     | Description                                                          |
-| -------    | ------------------------------------------------------------ | -------------------------------------------------------------------- |
-| connection | [podman-system-connection(1)](podman-system-connection.1.md) | Manage the destination(s) for Podman service(s)                      |
-| df         | [podman-system-df(1)](podman-system-df.1.md)                 | Show podman disk usage.                                              |
-| info       | [podman-system-info(1)](podman-info.1.md)                    | Displays Podman related system information.                          |
-| migrate    | [podman-system-migrate(1)](podman-system-migrate.1.md)       | Migrate existing containers to a new podman version.                 |
-| prune      | [podman-system-prune(1)](podman-system-prune.1.md)           | Remove all unused pod, container, image and volume data.             |
-| renumber   | [podman-system-renumber(1)](podman-system-renumber.1.md)     | Migrate lock numbers to handle a change in maximum number of locks.  |
-| reset      | [podman-system-reset(1)](podman-system-reset.1.md)           | Reset storage back to initial state.                                 |
-| service    | [podman-system-service(1)](podman-system-service.1.md)       | Run an API service                                                   |
+| Command    | Man Page                                                     | Description                                                                                 |
+| -------    | ------------------------------------------------------------ | ------------------------------------------------------------------------------------------- |
+| connection | [podman-system-connection(1)](podman-system-connection.1.md) | Manage the destination(s) for Podman service(s)                                             |
+| df         | [podman-system-df(1)](podman-system-df.1.md)                 | Show podman disk usage.                                                                     |
+| info       | [podman-system-info(1)](podman-info.1.md)                    | Displays Podman related system information.                                                 |
+| migrate    | [podman-system-migrate(1)](podman-system-migrate.1.md)       | Migrate existing containers to a new podman version.                                        |
+| prune      | [podman-system-prune(1)](podman-system-prune.1.md)           | Remove all unused pods, containers, images, netavark networks, and volume data.             |
+| renumber   | [podman-system-renumber(1)](podman-system-renumber.1.md)     | Migrate lock numbers to handle a change in maximum number of locks.                         |
+| reset      | [podman-system-reset(1)](podman-system-reset.1.md)           | Reset storage back to initial state.                                                        |
+| service    | [podman-system-service(1)](podman-system-service.1.md)       | Run an API service                                                                          |
 
 ## SEE ALSO
 **[podman(1)](podman.1.md)**

libpod/runtime.go

@@ -1262,6 +1262,11 @@ func (r *Runtime) GetDefaultNetworkName() string {
 	return r.config.Network.DefaultNetwork
 }
 
+// GetNetworkBackend returns the network interface which is used by the runtime
+func (r *Runtime) GetNetworkBackend() string {
+	return r.config.Network.NetworkBackend
+}
+
 // RemoteURI returns the API server URI
 func (r *Runtime) RemoteURI() string {
 	return r.config.Engine.RemoteURI

pkg/domain/entities/system.go

@@ -28,6 +28,7 @@ type SystemPruneReport struct {
 	PodPruneReport        []*PodPruneReport
 	ContainerPruneReports []*reports.PruneReport
 	ImagePruneReports     []*reports.PruneReport
+	NetworkPruneReports   []*reports.PruneReport
 	VolumePruneReports    []*reports.PruneReport
 	ReclaimedSpace        uint64
 }

pkg/domain/infra/abi/network.go

@@ -142,7 +142,7 @@ func (ic *ContainerEngine) NetworkExists(ctx context.Context, networkname string
 	}, nil
 }
 
-// Network prune removes unused cni networks
+// Network prune removes unused networks
 func (ic *ContainerEngine) NetworkPrune(ctx context.Context, options entities.NetworkPruneOptions) ([]*entities.NetworkPruneReport, error) {
 	cons, err := ic.Libpod.GetAllContainers()
 	if err != nil {

pkg/domain/infra/abi/system.go

@@ -8,6 +8,8 @@ import (
 	"os/exec"
 	"path/filepath"
 
+	"github.com/containers/common/libnetwork/types"
+	netutil "github.com/containers/common/libnetwork/util"
 	"github.com/containers/common/pkg/cgroups"
 	"github.com/containers/common/pkg/config"
 	cutil "github.com/containers/common/pkg/util"
@@ -137,7 +139,7 @@ func (ic *ContainerEngine) SetupRootless(_ context.Context, noMoveProcess bool)
 	return nil
 }
 
-// SystemPrune removes unused data from the system. Pruning pods, containers, volumes and images.
+// SystemPrune removes unused data from the system. Pruning pods, containers, netavark networks, volumes and images.
 func (ic *ContainerEngine) SystemPrune(ctx context.Context, options entities.SystemPruneOptions) (*entities.SystemPruneReport, error) {
 	var systemPruneReport = new(entities.SystemPruneReport)
 	filters := []string{}
@@ -148,25 +150,32 @@ func (ic *ContainerEngine) SystemPrune(ctx context.Context, options entities.Sys
 	found := true
 	for found {
 		found = false
+
+		// TODO: Figure out cleaner way to handle all of the different PruneOptions
+		// Remove all unused pods.
 		podPruneReport, err := ic.prunePodHelper(ctx)
 		if err != nil {
 			return nil, err
 		}
 		if len(podPruneReport) > 0 {
 			found = true
 		}
+
 		systemPruneReport.PodPruneReport = append(systemPruneReport.PodPruneReport, podPruneReport...)
 
-		// TODO: Figure out cleaner way to handle all of the different PruneOptions
+		// Remove all unused containers.
 		containerPruneOptions := entities.ContainerPruneOptions{}
 		containerPruneOptions.Filters = (url.Values)(options.Filters)
 
 		containerPruneReports, err := ic.ContainerPrune(ctx, containerPruneOptions)
 		if err != nil {
 			return nil, err
 		}
+
 		reclaimedSpace += reports.PruneReportsSize(containerPruneReports)
 		systemPruneReport.ContainerPruneReports = append(systemPruneReport.ContainerPruneReports, containerPruneReports...)
+
+		// Remove all unused images.
 		imagePruneOptions := entities.ImagePruneOptions{
 			All:    options.All,
 			Filter: filters,
@@ -183,6 +192,58 @@ func (ic *ContainerEngine) SystemPrune(ctx context.Context, options entities.Sys
 		}
 
 		systemPruneReport.ImagePruneReports = append(systemPruneReport.ImagePruneReports, imagePruneReports...)
+
+		// Remove all unused netavark networks.
+		// Does not remove cni networks because it could remove external cni networks.
+		if ic.Libpod.GetNetworkBackend() == "netavark" {
+			cons, err := ic.Libpod.GetAllContainers()
+			if err != nil {
+				return nil, err
+			}
+			// Gather up all the non-default networks that the
+			// containers want
+			networksToKeep := make(map[string]bool)
+			for _, c := range cons {
+				nets, err := c.Networks()
+				if err != nil {
+					return nil, err
+				}
+				for _, n := range nets {
+					networksToKeep[n] = true
+				}
+			}
+			// ignore the default network, this one cannot be deleted
+			networksToKeep[ic.Libpod.GetDefaultNetworkName()] = true
+
+			// get all filters
+			filters, err := netutil.GenerateNetworkPruneFilters(options.Filters)
+			if err != nil {
+				return nil, err
+			}
+			danglingFilterFunc := func(net types.Network) bool {
+				for network := range networksToKeep {
+					if network == net.Name {
+						return false
+					}
+				}
+				return true
+			}
+			filters = append(filters, danglingFilterFunc)
+			nets, err := ic.Libpod.Network().NetworkList(filters...)
+			if err != nil {
+				return nil, err
+			}
+
+			for _, net := range nets {
+				systemPruneReport.NetworkPruneReports = append(systemPruneReport.NetworkPruneReports, &reports.PruneReport{
+					Id:   net.Name,
+					Err:  ic.Libpod.Network().NetworkRemove(net.Name),
+					Size: 0,
+				})
+			}
+		}
+
+		// Remove unused volume data.
 		if options.Volume {
 			volumePruneOptions := entities.VolumePruneOptions{}
 			volumePruneOptions.Filters = (url.Values)(options.Filters)

test/e2e/prune_test.go

@@ -258,6 +258,34 @@ var _ = Describe("Podman prune", func() {
 		Expect(pods.OutputToStringArray()).To(HaveLen(2))
 	})
 
+	It("podman system prune networks", func() {
+		// About netavark network backend test.
+		session := podmanTest.Podman([]string{"network", "create", "test"})
+		session.WaitWithDefaultTimeout()
+		Expect(session).Should(Exit(0))
+
+		session = podmanTest.Podman([]string{"system", "prune", "-f"})
+		session.WaitWithDefaultTimeout()
+		Expect(session).Should(Exit(0))
+
+		// Default network should exists.
+		session = podmanTest.Podman([]string{"network", "ls", "-q", "--filter", "name=^podman$"})
+		session.WaitWithDefaultTimeout()
+		Expect(session).Should(Exit(0))
+		Expect(session.OutputToStringArray()).To(HaveLen(1))
+
+		// Remove all unused netavark networks.
+		// Does not remove cni networks because it could remove external cni networks.
+		session = podmanTest.Podman([]string{"network", "ls", "-q", "--filter", "name=^test$"})
+		session.WaitWithDefaultTimeout()
+		Expect(session).Should(Exit(0))
+		if podmanTest.NetworkBackend == Netavark {
+			Expect(session.OutputToStringArray()).To(HaveLen(0))
+		} else {
+			Expect(session.OutputToStringArray()).To(HaveLen(1))
+		}
+	})
+
 	It("podman system prune - pod,container stopped", func() {
 		session := podmanTest.Podman([]string{"pod", "create"})
 		session.WaitWithDefaultTimeout()