Add --filter to podman system prune

Also document the allowable filters in podman system prune, podman image prune
and podman container prune.

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

6 files changed, 56 insertions, 2 deletions

diff --git a/cmd/podman/system/prune.go b/cmd/podman/system/prune.go
index f57689584..5ee017581 100644
--- a/cmd/podman/system/prune.go
+++ b/cmd/podman/system/prune.go
@@ -46,6 +46,9 @@ func init() {
 	flags.BoolVarP(&force, "force", "f", false, "Do not prompt for confirmation.  The default is false")
 	flags.BoolVarP(&pruneOptions.All, "all", "a", false, "Remove all unused data")
 	flags.BoolVar(&pruneOptions.Volume, "volumes", false, "Prune volumes")
+	filterFlagName := "filter"
+	flags.StringArrayVar(&pruneOptions.Filter, filterFlagName, []string{}, "Provide filter values (e.g. 'label=<key>=<value>')")
+	_ = pruneCommand.RegisterFlagCompletionFunc(filterFlagName, completion.AutocompleteNone)
 
 }
 
diff --git a/docs/source/markdown/podman-container-prune.1.md b/docs/source/markdown/podman-container-prune.1.md
index 4b4effb0b..b199f9ebb 100644
--- a/docs/source/markdown/podman-container-prune.1.md
+++ b/docs/source/markdown/podman-container-prune.1.md
@@ -15,6 +15,17 @@ podman-container-prune - Remove all stopped containers from local storage
 
 Provide filter values.
 
+The --filter flag format is of “key=value”. If there is more than one filter, then pass multiple flags (e.g., --filter "foo=bar" --filter "bif=baz")
+
+Supported filters:
+
+- `until` (_timestamp_) - only remove containers and images created before given timestamp
+- `label` (label=_key_, label=_key=value_, label!=_key_, or label!=_key=value_) - only remove containers and images, with (or without, in case label!=... is used) the specified labels.
+
+The until filter can be Unix timestamps, date formatted timestamps, or Go duration strings (e.g. 10m, 1h30m) computed relative to the machine’s time.
+
+The label filter accepts two formats. One is the label=... (label=_key_ or label=_key=value_), which removes containers with the specified labels. The other format is the label!=... (label!=_key_ or label!=_key=value_), which removes containers without the specified labels.
+
 #### **--force**, **-f**
 
 Do not provide an interactive prompt for container removal.
@@ -63,3 +74,4 @@ podman(1), podman-ps
 
 ## HISTORY
 December 2018, Originally compiled by Brent Baude (bbaude at redhat dot com)
+December 2020, converted filter information from docs.docker.com documentation by Dan Walsh (dwalsh at redhat dot com)
diff --git a/docs/source/markdown/podman-image-prune.1.md b/docs/source/markdown/podman-image-prune.1.md
index d8558d244..73024ffb8 100644
--- a/docs/source/markdown/podman-image-prune.1.md
+++ b/docs/source/markdown/podman-image-prune.1.md
@@ -22,6 +22,17 @@ Remove dangling images and images that have no associated containers.
 
 Provide filter values.
 
+The --filter flag format is of “key=value”. If there is more than one filter, then pass multiple flags (e.g., --filter "foo=bar" --filter "bif=baz")
+
+Supported filters:
+
+- `until` (_timestamp_) - only remove containers and images created before given timestamp
+- `label` (label=_key_, label=_key=value_, label!=_key_, or label!=_key=value_) - only remove containers and images, with (or without, in case label!=... is used) the specified labels.
+
+The until filter can be Unix timestamps, date formatted timestamps, or Go duration strings (e.g. 10m, 1h30m) computed relative to the machine’s time.
+
+The label filter accepts two formats. One is the label=... (label=_key_ or label=_key=value_), which removes images with the specified labels. The other format is the label!=... (label!=_key_ or label!=_key=value_), which removes images without the specified labels.
+
 #### **--force**, **-f**
 
 Do not provide an interactive prompt for container removal.
@@ -93,3 +104,4 @@ podman(1), podman-images
 
 ## HISTORY
 December 2018, Originally compiled by Brent Baude (bbaude at redhat dot com)
+December 2020, converted filter information from docs.docker.com documentation by Dan Walsh (dwalsh at redhat dot com)
diff --git a/docs/source/markdown/podman-system-prune.1.md b/docs/source/markdown/podman-system-prune.1.md
index 431a11267..791503a2c 100644
--- a/docs/source/markdown/podman-system-prune.1.md
+++ b/docs/source/markdown/podman-system-prune.1.md
@@ -18,6 +18,21 @@ By default, volumes are not removed to prevent important data from being deleted
 
 Recursively remove all unused pod, container, image and volume data (Maximum 50 iterations.)
 
+#### **--filter**=*filters*
+
+Provide filter values.
+
+The --filter flag format is of “key=value”. If there is more than one filter, then pass multiple flags (e.g., --filter "foo=bar" --filter "bif=baz")
+
+Supported filters:
+
+- `until` (_timestamp_) - only remove containers and images created before given timestamp
+- `label` (label=_key_, label=_key=value_, label!=_key_, or label!=_key=value_) - only remove containers and images, with (or without, in case label!=... is used) the specified labels.
+
+The until filter can be Unix timestamps, date formatted timestamps, or Go duration strings (e.g. 10m, 1h30m) computed relative to the machine’s time.
+
+The label filter accepts two formats. One is the label=... (label=_key_ or label=_key=value_), which removes containers and images with the specified labels. The other format is the label!=... (label!=_key_ or label!=_key=value_), which removes containers and images without the specified labels.
+
 #### **--force**, **-f**
 
 Do not prompt for confirmation
@@ -35,3 +50,4 @@ podman(1), podman-image-prune(1), podman-container-prune(1), podman-pod-prune(1)
 
 ## HISTORY
 February 2019, Originally compiled by Dan Walsh (dwalsh at redhat dot com)
+December 2020, converted filter information from docs.docker.com documentation by Dan Walsh (dwalsh at redhat dot com)
diff --git a/pkg/domain/entities/system.go b/pkg/domain/entities/system.go
index bde2b6ef2..4af013134 100644
--- a/pkg/domain/entities/system.go
+++ b/pkg/domain/entities/system.go
@@ -19,6 +19,7 @@ type ServiceOptions struct {
 type SystemPruneOptions struct {
 	All    bool
 	Volume bool
+	Filter []string
 }
 
 // SystemPruneReport provides report after system prune is executed.
diff --git a/pkg/domain/infra/abi/system.go b/pkg/domain/infra/abi/system.go
index 7ed58092b..d6881fdc4 100644
--- a/pkg/domain/infra/abi/system.go
+++ b/pkg/domain/infra/abi/system.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"io/ioutil"
+	"net/url"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -179,7 +180,16 @@ func (ic *ContainerEngine) SystemPrune(ctx context.Context, options entities.Sys
 			found = true
 		}
 		systemPruneReport.PodPruneReport = append(systemPruneReport.PodPruneReport, podPruneReport...)
-		containerPruneReport, err := ic.pruneContainersHelper(nil)
+		containerPruneOptions := entities.ContainerPruneOptions{}
+		for _, f := range options.Filter {
+			t := strings.SplitN(f, "=", 2)
+			containerPruneOptions.Filters = make(url.Values)
+			if len(t) < 2 {
+				return nil, errors.Errorf("filter input must be in the form of filter=value: %s is invalid", f)
+			}
+			containerPruneOptions.Filters.Add(t[0], t[1])
+		}
+		containerPruneReport, err := ic.ContainerPrune(ctx, containerPruneOptions)
 		if err != nil {
 			return nil, err
 		}
@@ -194,7 +204,7 @@ func (ic *ContainerEngine) SystemPrune(ctx context.Context, options entities.Sys
 			}
 		}
 
-		results, err := ic.Libpod.ImageRuntime().PruneImages(ctx, options.All, nil)
+		results, err := ic.Libpod.ImageRuntime().PruneImages(ctx, options.All, options.Filter)
 
 		if err != nil {
 			return nil, err