Add functions useful for interacting with docker images and building …

…remote images (#1062)

* Add functions useful for interacting with docker images

* Use repo:tag syntax

* Don't build multiarch image

* Add t.parallel call to TestGitCloneAndBuild

modules/docker/build.go

@@ -1,6 +1,9 @@
 package docker
 
 import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
 	"strings"
 
 	"github.com/gruntwork-io/terratest/modules/logger"
@@ -97,6 +100,59 @@ func BuildE(t testing.TestingT, path string, options *BuildOptions) error {
 	return nil
 }
 
+// GitCloneAndBuild builds a new Docker image from a given Git repo. This function will clone the given repo at the
+// specified ref, and call the docker build command on the cloned repo from the given relative path (relative to repo
+// root). This will fail the test if there are any errors.
+func GitCloneAndBuild(
+	t testing.TestingT,
+	repo string,
+	ref string,
+	path string,
+	dockerBuildOpts *BuildOptions,
+) {
+	require.NoError(t, GitCloneAndBuildE(t, repo, ref, path, dockerBuildOpts))
+}
+
+// GitCloneAndBuildE builds a new Docker image from a given Git repo. This function will clone the given repo at the
+// specified ref, and call the docker build command on the cloned repo from the given relative path (relative to repo
+// root).
+func GitCloneAndBuildE(
+	t testing.TestingT,
+	repo string,
+	ref string,
+	path string,
+	dockerBuildOpts *BuildOptions,
+) error {
+	workingDir, err := ioutil.TempDir("", "")
+	if err != nil {
+		return err
+	}
+	defer os.RemoveAll(workingDir)
+
+	cloneCmd := shell.Command{
+		Command: "git",
+		Args:    []string{"clone", repo, workingDir},
+	}
+	if err := shell.RunCommandE(t, cloneCmd); err != nil {
+		return err
+	}
+
+	checkoutCmd := shell.Command{
+		Command:    "git",
+		Args:       []string{"checkout", ref},
+		WorkingDir: workingDir,
+	}
+	if err := shell.RunCommandE(t, checkoutCmd); err != nil {
+		return err
+	}
+
+	contextPath := filepath.Join(workingDir, path)
+	if err := BuildE(t, contextPath, dockerBuildOpts); err != nil {
+		return err
+	}
+	return nil
+}
+
 // formatDockerBuildArgs formats the arguments for the 'docker build' command.
 func formatDockerBuildArgs(path string, options *BuildOptions) []string {
 	args := []string{}

modules/docker/build_test.go

@@ -2,8 +2,12 @@ package docker
 
 import (
 	"fmt"
+	"strings"
 	"testing"
 
+	"github.com/gruntwork-io/terratest/modules/git"
+	"github.com/gruntwork-io/terratest/modules/logger"
+	"github.com/gruntwork-io/terratest/modules/random"
 	"github.com/stretchr/testify/require"
 )
 
@@ -60,3 +64,25 @@ func TestBuildWithTarget(t *testing.T) {
 	out := Run(t, tag, &RunOptions{Remove: true})
 	require.Contains(t, out, text1)
 }
+
+func TestGitCloneAndBuild(t *testing.T) {
+	t.Parallel()
+
+	uniqueID := strings.ToLower(random.UniqueId())
+	imageTag := "gruntwork-io-foo-test:" + uniqueID
+	text := "Hello, World!"
+
+	buildOpts := &BuildOptions{
+		Tags:      []string{imageTag},
+		BuildArgs: []string{fmt.Sprintf("text=%s", text)},
+	}
+	gitBranchName := git.GetCurrentBranchName(t)
+	if gitBranchName == "" {
+		logger.Logf(t, "WARNING: git.GetCurrentBranchName returned an empty string; falling back to master")
+		gitBranchName = "master"
+	}
+	GitCloneAndBuild(t, "[email protected]:gruntwork-io/terratest.git", gitBranchName, "test/fixtures/docker", buildOpts)
+
+	out := Run(t, imageTag, &RunOptions{Remove: true})
+	require.Contains(t, out, text)
+}

modules/docker/images.go

@@ -0,0 +1,112 @@
+package docker
+
+import (
+	"bufio"
+	"encoding/json"
+	"fmt"
+	"strings"
+
+	"github.com/gruntwork-io/terratest/modules/collections"
+	"github.com/gruntwork-io/terratest/modules/logger"
+	"github.com/gruntwork-io/terratest/modules/shell"
+	"github.com/gruntwork-io/terratest/modules/testing"
+	"github.com/stretchr/testify/require"
+)
+
+// Image represents a docker image, and exports all the fields that the docker images command returns for the
+// image.
+type Image struct {
+	// ID is the image ID in docker, and can be used to identify the image in place of the repo and tag.
+	ID string
+
+	// Repository is the image repository.
+	Repository string
+
+	// Tag is the image tag wichin the repository.
+	Tag string
+
+	// CreatedAt represents a timestamp for when the image was created.
+	CreatedAt string
+
+	// CreatedSince is a diff between when the image was created to now.
+	CreatedSince string
+
+	// SharedSize is the amount of space that an image shares with another one (i.e. their common data).
+	SharedSize string
+
+	// UniqueSize is the amount of space that is only used by a given image.
+	UniqueSize string
+
+	// VirtualSize is the total size of the image, combining SharedSize and UniqueSize.
+	VirtualSize string
+
+	// Containers represents the list of containers that are using the image.
+	Containers string
+
+	// Digest is the hash digest of the image, if requested.
+	Digest string
+}
+
+func (image Image) String() string {
+	return fmt.Sprintf("%s:%s", image.Repository, image.Tag)
+}
+
+// DeleteImage removes a docker image using the Docker CLI. This will fail the test if there is an error.
+func DeleteImage(t testing.TestingT, img string, logger *logger.Logger) {
+	require.NoError(t, DeleteImageE(t, img, logger))
+}
+
+// DeleteImageE removes a docker image using the Docker CLI.
+func DeleteImageE(t testing.TestingT, img string, logger *logger.Logger) error {
+	cmd := shell.Command{
+		Command: "docker",
+		Args:    []string{"rmi", img},
+		Logger:  logger,
+	}
+	return shell.RunCommandE(t, cmd)
+}
+
+// ListImages calls docker images using the Docker CLI to list the available images on the local docker daemon.
+func ListImages(t testing.TestingT, logger *logger.Logger) []Image {
+	out, err := ListImagesE(t, logger)
+	require.NoError(t, err)
+	return out
+}
+
+// ListImagesE calls docker images using the Docker CLI to list the available images on the local docker daemon.
+func ListImagesE(t testing.TestingT, logger *logger.Logger) ([]Image, error) {
+	cmd := shell.Command{
+		Command: "docker",
+		Args:    []string{"images", "--format", "{{ json . }}"},
+		Logger:  logger,
+	}
+	out, err := shell.RunCommandAndGetOutputE(t, cmd)
+	if err != nil {
+		return nil, err
+	}
+
+	// Parse and return the list of image objects.
+	images := []Image{}
+	scanner := bufio.NewScanner(strings.NewReader(out))
+	for scanner.Scan() {
+		line := scanner.Text()
+		var image Image
+		err := json.Unmarshal([]byte(line), &image)
+		if err != nil {
+			return nil, err
+		}
+		images = append(images, image)
+	}
+	return images, nil
+}
+
+// DoesImageExist lists the images in the docker daemon and returns true if the given image label (repo:tag) exists.
+// This will fail the test if there is an error.
+func DoesImageExist(t testing.TestingT, imgLabel string, logger *logger.Logger) bool {
+	images := ListImages(t, logger)
+	imageTags := []string{}
+	for _, image := range images {
+		imageTags = append(imageTags, image.String())
+	}
+	return collections.ListContains(imageTags, imgLabel)
+}

modules/docker/images_test.go

@@ -0,0 +1,28 @@
+package docker
+
+import (
+	"fmt"
+	"strings"
+	"testing"
+
+	"github.com/gruntwork-io/terratest/modules/random"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestListImagesAndDeleteImage(t *testing.T) {
+	t.Parallel()
+
+	uniqueID := strings.ToLower(random.UniqueId())
+	repo := "gruntwork-io/test-image"
+	tag := fmt.Sprintf("v1-%s", uniqueID)
+	img := fmt.Sprintf("%s:%s", repo, tag)
+
+	options := &BuildOptions{
+		Tags: []string{img},
+	}
+	Build(t, "../../test/fixtures/docker", options)
+
+	assert.True(t, DoesImageExist(t, img, nil))
+	DeleteImage(t, img, nil)
+	assert.False(t, DoesImageExist(t, img, nil))
+}