add podman container|image exists

Add an exists subcommand to podman container and podman image that allows
users to verify the existence of a container or image by ID or name.  The return
code can be 0 (success), 1 (failed to find), or 125 (failed to work with runtime).

Issue #1845

Signed-off-by: baude <bbaude@redhat.com>

cmd/podman/container.go

@@ -9,6 +9,7 @@ var (
 		attachCommand,
 		checkpointCommand,
 		cleanupCommand,
+		containerExistsCommand,
 		commitCommand,
 		createCommand,
 		diffCommand,

cmd/podman/exists.go

@@ -0,0 +1,83 @@
+package main
+
+import (
+	"os"
+
+	"github.com/containers/libpod/cmd/podman/libpodruntime"
+	"github.com/containers/libpod/libpod"
+	"github.com/containers/libpod/libpod/image"
+	"github.com/pkg/errors"
+	"github.com/urfave/cli"
+)
+
+var (
+	imageExistsDescription = `
+	podman image exists
+
+	Check if an image exists in local storage
+`
+
+	imageExistsCommand = cli.Command{
+		Name:         "exists",
+		Usage:        "Check if an image exists in local storage",
+		Description:  imageExistsDescription,
+		Action:       imageExistsCmd,
+		ArgsUsage:    "IMAGE-NAME",
+		OnUsageError: usageErrorHandler,
+	}
+)
+
+var (
+	containerExistsDescription = `
+	podman container exists
+
+	Check if a container exists in local storage
+`
+
+	containerExistsCommand = cli.Command{
+		Name:         "exists",
+		Usage:        "Check if a container exists in local storage",
+		Description:  containerExistsDescription,
+		Action:       containerExistsCmd,
+		ArgsUsage:    "CONTAINER-NAME",
+		OnUsageError: usageErrorHandler,
+	}
+)
+
+func imageExistsCmd(c *cli.Context) error {
+	args := c.Args()
+	if len(args) > 1 || len(args) < 1 {
+		return errors.New("you may only check for the existence of one image at a time")
+	}
+	runtime, err := libpodruntime.GetRuntime(c)
+	if err != nil {
+		return errors.Wrapf(err, "could not get runtime")
+	}
+	defer runtime.Shutdown(false)
+	if _, err := runtime.ImageRuntime().NewFromLocal(args[0]); err != nil {
+		if errors.Cause(err) == image.ErrNoSuchImage {
+			os.Exit(1)
+		}
+		return err
+	}
+	return nil
+}
+
+func containerExistsCmd(c *cli.Context) error {
+	args := c.Args()
+	if len(args) > 1 || len(args) < 1 {
+		return errors.New("you may only check for the existence of one container at a time")
+	}
+	runtime, err := libpodruntime.GetRuntime(c)
+	if err != nil {
+		return errors.Wrapf(err, "could not get runtime")
+	}
+	defer runtime.Shutdown(false)
+	if _, err := runtime.LookupContainer(args[0]); err != nil {
+		if errors.Cause(err) == libpod.ErrNoSuchCtr {
+			os.Exit(1)
+		}
+		return err
+	}
+	return nil
+}

cmd/podman/image.go

@@ -9,6 +9,7 @@ var (
 		buildCommand,
 		historyCommand,
 		importCommand,
+		imageExistsCommand,
 		inspectCommand,
 		loadCommand,
 		lsImagesCommand,

completions/bash/podman

@@ -2178,6 +2178,22 @@ _podman_container_runlabel() {
     esac
 }
 
+_podman_container_exists() {
+    local options_with_args="
+    "
+
+    local boolean_options="
+  "
+}
+
+_podman_image_exists() {
+    local options_with_args="
+    "
+
+    local boolean_options="
+  "
+}
+
 _podman_pod_create() {
   local options_with_args="
       --cgroup-parent

docs/podman-container-exists.1.md

@@ -0,0 +1,40 @@
+% PODMAN(1) Podman Man Pages
+% Brent Baude
+% November 2018
+# NAME
+podman-container-exists- Check if a container exists in local storage
+
+# SYNOPSIS
+**podman container exists**
+[**-h**|**--help**]
+CONTAINER
+
+# DESCRIPTION
+**podman container exists** checks if a container exists in local storage. The **ID** or **Name**
+of the container may be used as input.  Podman will return an exit code
+of `0` when the container is found.  A `1` will be returned otherwise. An exit code of `125` indicates there
+was an issue accessing the local storage.
+
+## Examples ##
+
+Check if an container called `webclient` exists in local storage (the container does actually exist).
+```
+$ sudo podman container exists webclient
+$ echo $?
+0
+$
+```
+
+Check if an container called `webbackend` exists in local storage (the container does not actually exist).
+```
+$ sudo podman container exists webbackend
+$ echo $?
+1
+$
+```
+
+## SEE ALSO
+podman(1)
+
+# HISTORY
+November 2018, Originally compiled by Brent Baude (bbaude at redhat dot com)

docs/podman-container.1.md

@@ -20,6 +20,7 @@ The container command allows you to manage containers
 | create   | [podman-create(1)](podman-create.1.md)              | Create a new container.                                                      |
 | diff     | [podman-diff(1)](podman-diff.1.md)                  | Inspect changes on a container or image's filesystem.                        |
 | exec     | [podman-exec(1)](podman-exec.1.md)                  | Execute a command in a running container.                                    |
+| exists   | [podman-exists(1)](podman-container-exists.1.md)    | Check if a container exists in local storage                                 |
 | export   | [podman-export(1)](podman-export.1.md)              | Export a container's filesystem contents as a tar archive.                   |
 | inspect  | [podman-inspect(1)](podman-inspect.1.md)            | Display a container or image's configuration.                                |
 | kill     | [podman-kill(1)](podman-kill.1.md)                  | Kill the main process in one or more containers.                             |

docs/podman-image-exists.1.md

@@ -0,0 +1,40 @@
+% PODMAN(1) Podman Man Pages
+% Brent Baude
+% November 2018
+# NAME
+podman-image-exists- Check if an image exists in local storage
+
+# SYNOPSIS
+**podman image exists**
+[**-h**|**--help**]
+IMAGE
+
+# DESCRIPTION
+**podman image exists** checks if an image exists in local storage. The **ID** or **Name**
+of the image may be used as input.  Podman will return an exit code
+of `0` when the image is found.  A `1` will be returned otherwise. An exit code of `125` indicates there
+was an issue accessing the local storage.
+
+## Examples ##
+
+Check if an image called `webclient` exists in local storage (the image does actually exist).
+```
+$ sudo podman image exists webclient
+$ echo $?
+0
+$
+```
+
+Check if an image called `webbackend` exists in local storage (the image does not actually exist).
+```
+$ sudo podman image exists webbackend
+$ echo $?
+1
+$
+```
+
+## SEE ALSO
+podman(1)
+
+# HISTORY
+November 2018, Originally compiled by Brent Baude (bbaude at redhat dot com)

docs/podman-image.1.md

@@ -14,6 +14,7 @@ The image command allows you to manage images
 | Command  | Man Page                                  | Description                                                                    |
 | -------- | ----------------------------------------- | ------------------------------------------------------------------------------ |
 | build    | [podman-build(1)](podman-build.1.md)      | Build a container using a Dockerfile.                                          |
+| exists   | [podman-exists(1)](podman-image-exists.1.md)      | Check if a image exists in local storage                                          |
 | history  | [podman-history(1)](podman-history.1.md)  | Show the history of an image.                                                  |
 | import   | [podman-import(1)](podman-import.1.md)    | Import a tarball and save it as a filesystem image.                            |
 | inspect  | [podman-inspect(1)](podman-inspect.1.md)  | Display a image or image's configuration.                                      |

libpod/image/errors.go

@@ -0,0 +1,15 @@
+package image
+
+import (
+	"errors"
+)
+
+// Copied directly from libpod errors to avoid circular imports
+var (
+	// ErrNoSuchCtr indicates the requested container does not exist
+	ErrNoSuchCtr = errors.New("no such container")
+	// ErrNoSuchPod indicates the requested pod does not exist
+	ErrNoSuchPod = errors.New("no such pod")
+	// ErrNoSuchImage indicates the requested image does not exist
+	ErrNoSuchImage = errors.New("no such image")
+)

libpod/image/image.go

@@ -252,7 +252,7 @@ func (i *Image) getLocalImage() (*storage.Image, error) {
 	// The image has a registry name in it and we made sure we looked for it locally
 	// with a tag.  It cannot be local.
 	if decomposedImage.hasRegistry {
-		return nil, errors.Errorf("%s", imageError)
+		return nil, errors.Wrapf(ErrNoSuchImage, imageError)
 
 	}
 
@@ -275,7 +275,7 @@ func (i *Image) getLocalImage() (*storage.Image, error) {
 		return repoImage, nil
 	}
 
-	return nil, errors.Wrapf(err, imageError)
+	return nil, errors.Wrapf(ErrNoSuchImage, err.Error())
 }
 
 // ID returns the image ID as a string

test/e2e/exists_test.go

@@ -0,0 +1,85 @@
+package integration
+
+import (
+	"fmt"
+	"os"
+
+	. "github.com/containers/libpod/test/utils"
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("Podman image|container exists", func() {
+	var (
+		tempdir    string
+		err        error
+		podmanTest *PodmanTestIntegration
+	)
+
+	BeforeEach(func() {
+		tempdir, err = CreateTempDirInTempDir()
+		if err != nil {
+			os.Exit(1)
+		}
+		podmanTest = PodmanTestCreate(tempdir)
+		podmanTest.RestoreAllArtifacts()
+	})
+
+	AfterEach(func() {
+		podmanTest.Cleanup()
+		f := CurrentGinkgoTestDescription()
+		timedResult := fmt.Sprintf("Test: %s completed in %f seconds", f.TestText, f.Duration.Seconds())
+		GinkgoWriter.Write([]byte(timedResult))
+
+	})
+	It("podman image exists in local storage by fq name", func() {
+		session := podmanTest.Podman([]string{"image", "exists", ALPINE})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+	})
+	It("podman image exists in local storage by short name", func() {
+		session := podmanTest.Podman([]string{"image", "exists", "alpine"})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+	})
+	It("podman image does not exist in local storage", func() {
+		session := podmanTest.Podman([]string{"image", "exists", "alpine9999"})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(1))
+	})
+	It("podman container exists in local storage by name", func() {
+		setup := podmanTest.RunTopContainer("foobar")
+		setup.WaitWithDefaultTimeout()
+		Expect(setup.ExitCode()).To(Equal(0))
+
+		session := podmanTest.Podman([]string{"container", "exists", "foobar"})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+	})
+	It("podman container exists in local storage by container ID", func() {
+		setup := podmanTest.RunTopContainer("")
+		setup.WaitWithDefaultTimeout()
+		Expect(setup.ExitCode()).To(Equal(0))
+		cid := setup.OutputToString()
+
+		session := podmanTest.Podman([]string{"container", "exists", cid})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+	})
+	It("podman container exists in local storage by short container ID", func() {
+		setup := podmanTest.RunTopContainer("")
+		setup.WaitWithDefaultTimeout()
+		Expect(setup.ExitCode()).To(Equal(0))
+		cid := setup.OutputToString()[0:12]
+
+		session := podmanTest.Podman([]string{"container", "exists", cid})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+	})
+	It("podman container does not exist in local storage", func() {
+		session := podmanTest.Podman([]string{"container", "exists", "foobar"})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(1))
+	})
+
+})