fix: Enables having a Dockerfile outside the context (#402)

* tests: Add failing test for Dockerfile outside context.

* fix: Enable support for Dockerfiles outside context.

Also extract some code to functions.

* fix: Adding docker outside context test and implementation for docker_registry_image.

internal/provider/resource_docker_image_funcs.go

@@ -9,6 +9,7 @@ import (
 	"io"
 	"log"
 	"net"
+	"os"
 	"path/filepath"
 	"strings"
 
@@ -22,6 +23,7 @@ import (
 	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema"
 	"github.com/mitchellh/go-homedir"
 	"github.com/moby/buildkit/session"
+	"github.com/pkg/errors"
 )
 
 const minBuildkitDockerVersion = "1.39"
@@ -293,6 +295,10 @@ func findImage(ctx context.Context, imageName string, client *client.Client, aut
 }
 
 func buildDockerImage(ctx context.Context, rawBuild map[string]interface{}, imageName string, client *client.Client) error {
+	var (
+		err error
+	)
+
 	buildOptions := types.ImageBuildOptions{}
 
 	buildOptions.Dockerfile = rawBuild["dockerfile"].(string)
@@ -323,11 +329,32 @@ func buildDockerImage(ctx context.Context, rawBuild map[string]interface{}, imag
 	buildOptions.Labels = labels
 	log.Printf("[DEBUG] Labels: %v\n", labels)
 
+	enableBuildKitIfSupported(ctx, client, &buildOptions)
+
+	buildCtx, relDockerfile, err := prepareBuildContext(rawBuild["path"].(string), buildOptions.Dockerfile)
+	if err != nil {
+		return err
+	}
+	buildOptions.Dockerfile = relDockerfile
+
+	var response types.ImageBuildResponse
+	response, err = client.ImageBuild(ctx, buildCtx, buildOptions)
+	if err != nil {
+		return err
+	}
+	defer response.Body.Close()
+
+	buildResult, err := decodeBuildMessages(response)
+	if err != nil {
+		return fmt.Errorf("%s\n\n%s", err, buildResult)
+	}
+	return nil
+}
+
+func enableBuildKitIfSupported(ctx context.Context, client *client.Client, buildOptions *types.ImageBuildOptions) {
 	dockerClientVersion := client.ClientVersion()
 	log.Printf("[DEBUG] DockerClientVersion: %v, minBuildKitDockerVersion: %v\n", dockerClientVersion, minBuildkitDockerVersion)
-
 	if versions.GreaterThanOrEqualTo(dockerClientVersion, minBuildkitDockerVersion) {
-		// docker client supports BuildKit
 		log.Printf("[DEBUG] Enabling BuildKit")
 		s, _ := session.NewSession(ctx, "docker-provider", "")
 		dialSession := func(ctx context.Context, proto string, meta map[string][]string) (net.Conn, error) {
@@ -341,28 +368,50 @@ func buildDockerImage(ctx context.Context, rawBuild map[string]interface{}, imag
 	} else {
 		buildOptions.Version = types.BuilderV1
 	}
-	contextDir := rawBuild["path"].(string)
-	excludes, err := build.ReadDockerignore(contextDir)
-	if err != nil {
-		return err
-	}
-	excludes = build.TrimBuildFilesFromExcludes(excludes, buildOptions.Dockerfile, false)
-
-	var response types.ImageBuildResponse
-	response, err = client.ImageBuild(ctx, getBuildContext(contextDir, excludes), buildOptions)
-	if err != nil {
-		return err
-	}
-	defer response.Body.Close()
-
-	buildResult, err := decodeBuildMessages(response)
-	if err != nil {
-		return fmt.Errorf("%s\n\n%s", err, buildResult)
-	}
-	return nil
 }
 
-func getBuildContext(filePath string, excludes []string) io.Reader {
+func prepareBuildContext(specifiedContext string, specifiedDockerfile string) (io.ReadCloser, string, error) {
+	var (
+		dockerfileCtx io.ReadCloser
+		contextDir    string
+		relDockerfile string
+		err           error
+	)
+	contextDir, relDockerfile, err = build.GetContextFromLocalDir(specifiedContext, specifiedDockerfile)
+	log.Printf("[DEBUG] contextDir %s", contextDir)
+	log.Printf("[DEBUG] relDockerfile %s", relDockerfile)
+	if err == nil && strings.HasPrefix(relDockerfile, ".."+string(filepath.Separator)) {
+		// Dockerfile is outside of build-context; read the Dockerfile and pass it as dockerfileCtx
+		log.Printf("[DEBUG] Dockerfile is outside of build-context")
+		dockerfileCtx, err = os.Open(specifiedDockerfile)
+		if err != nil {
+			return nil, "", errors.Errorf("unable to open Dockerfile: %v", err)
+		}
+		defer dockerfileCtx.Close()
+	}
+	excludes, err := build.ReadDockerignore(contextDir)
+	if err != nil {
+		return nil, "", err
+	}
+
+	specifiedDockerfile = archive.CanonicalTarNameForPath(specifiedDockerfile)
+	excludes = build.TrimBuildFilesFromExcludes(excludes, specifiedDockerfile, false)
+	log.Printf("[DEBUG] Excludes: %v", excludes)
+	buildCtx := getBuildContext(contextDir, excludes)
+
+	// replace Dockerfile if it was added from stdin or a file outside the build-context, and there is archive context
+	if dockerfileCtx != nil && buildCtx != nil {
+		log.Printf("[DEBUG] Adding dockerfile to build context")
+		buildCtx, relDockerfile, err = build.AddDockerfileToBuildContext(dockerfileCtx, buildCtx)
+		if err != nil {
+			return nil, "", err
+		}
+		return buildCtx, relDockerfile, nil
+	}
+	return buildCtx, specifiedDockerfile, nil
+}
+
+func getBuildContext(filePath string, excludes []string) io.ReadCloser {
 	filePath, _ = homedir.Expand(filePath)
 	//TarWithOptions works only with absolute paths in Windows.
 	filePath, err := filepath.Abs(filePath)

internal/provider/resource_docker_image_test.go

@@ -324,6 +324,32 @@ RUN echo ${test_arg} > test_arg.txt
 RUN apt-get update -qq
 `
 
+// Test for implementation of https://github.com/kreuzwerker/terraform-provider-docker/issues/401
+func TestAccDockerImage_buildOutsideContext(t *testing.T) {
+	ctx := context.Background()
+	wd, _ := os.Getwd()
+	dfPath := filepath.Join(wd, "..", "Dockerfile")
+	if err := ioutil.WriteFile(dfPath, []byte(testDockerFileExample), 0o644); err != nil {
+		t.Fatalf("failed to create a Dockerfile %s for test: %+v", dfPath, err)
+	}
+	defer os.Remove(dfPath)
+	resource.Test(t, resource.TestCase{
+		PreCheck:          func() { testAccPreCheck(t) },
+		ProviderFactories: providerFactories,
+		CheckDestroy: func(state *terraform.State) error {
+			return testAccDockerImageDestroy(ctx, state)
+		},
+		Steps: []resource.TestStep{
+			{
+				Config: loadTestConfiguration(t, RESOURCE, "docker_image", "testDockerImageDockerfileOutsideContext"),
+				Check: resource.ComposeTestCheckFunc(
+					resource.TestMatchResourceAttr("docker_image.outside_context", "name", regexp.MustCompile(`\Aoutside-context:latest\z`)),
+				),
+			},
+		},
+	})
+}
+
 func testAccImageCreated(resourceName string, image *types.ImageInspect) resource.TestCheckFunc {
 	return func(s *terraform.State) error {
 		ctx := context.Background()

internal/provider/resource_docker_registry_image_funcs.go

@@ -248,13 +248,15 @@ func buildDockerRegistryImage(ctx context.Context, client *client.Client, buildO
 		buildContext = buildContext[:lastIndex]
 	}
 
-	excludes, err := build.ReadDockerignore(buildContext)
+	enableBuildKitIfSupported(ctx, client, &imageBuildOptions)
+
+	buildCtx, relDockerfile, err := prepareBuildContext(buildContext, imageBuildOptions.Dockerfile)
 	if err != nil {
-		return fmt.Errorf("unable to read dockerignore: %v", err)
+		return err
 	}
-	excludes = build.TrimBuildFilesFromExcludes(excludes, imageBuildOptions.Dockerfile, false)
-	log.Printf("[DEBUG] Excludes: %v", excludes)
-	buildResponse, err := client.ImageBuild(ctx, getBuildContext(buildContext, excludes), imageBuildOptions)
+	imageBuildOptions.Dockerfile = relDockerfile
+
+	buildResponse, err := client.ImageBuild(ctx, buildCtx, imageBuildOptions)
 	if err != nil {
 		return fmt.Errorf("unable to build image for docker_registry_image: %v", err)
 	}

internal/provider/resource_docker_registry_image_test.go

@@ -3,6 +3,7 @@ package provider
 import (
 	"context"
 	"fmt"
+	"io/ioutil"
 	"os"
 	"path/filepath"
 	"reflect"
@@ -249,6 +250,30 @@ func TestAccDockerRegistryImageResource_whitelistDockerignore(t *testing.T) {
 	})
 }
 
+// Test for https://github.com/kreuzwerker/terraform-provider-docker/issues/249
+func TestAccDockerRegistryImageResource_DockerfileOutsideContext(t *testing.T) {
+	pushOptions := createPushImageOptions("127.0.0.1:15000/tftest-dockerregistryimage-dockerfileoutsidecontext:1.0")
+	wd, _ := os.Getwd()
+	dfPath := filepath.Join(wd, "..", "Dockerfile")
+	if err := ioutil.WriteFile(dfPath, []byte(testDockerFileExample), 0o644); err != nil {
+		t.Fatalf("failed to create a Dockerfile %s for test: %+v", dfPath, err)
+	}
+	defer os.Remove(dfPath)
+	context := strings.ReplaceAll((filepath.Join(wd, "..", "..", "scripts", "testing", "docker_registry_image_file_permissions")), "\\", "\\\\")
+	resource.Test(t, resource.TestCase{
+		PreCheck:          func() { testAccPreCheck(t) },
+		ProviderFactories: providerFactories,
+		Steps: []resource.TestStep{
+			{
+				Config: fmt.Sprintf(loadTestConfiguration(t, RESOURCE, "docker_registry_image", "testDockerRegistryImageDockerfileOutsideContext"), pushOptions.Registry, pushOptions.Name, context),
+				Check: resource.ComposeTestCheckFunc(
+					resource.TestCheckResourceAttrSet("docker_registry_image.outside_context", "sha256_digest"),
+				),
+			},
+		},
+	})
+}
+
 func TestAccDockerRegistryImageResource_pushMissingImage(t *testing.T) {
 	resource.Test(t, resource.TestCase{
 		PreCheck:          func() { testAccPreCheck(t) },

testdata/resources/docker_image/testDockerImageDockerfileOutsideContext.tf

@@ -0,0 +1,9 @@
+resource "docker_image" "outside_context" {
+  name = "outside-context:latest"
+
+  build {
+    path = "."
+    dockerfile = "../Dockerfile"
+  }
+}
+

testdata/resources/docker_registry_image/testDockerRegistryImageDockerfileOutsideContext.tf

@@ -0,0 +1,17 @@
+provider "docker" {
+  alias = "private"
+  registry_auth {
+    address = "%s"
+  }
+}
+
+resource "docker_registry_image" "outside_context" {
+  provider             = "docker.private"
+  name                 = "%s"
+  insecure_skip_verify = true
+
+  build {
+    context    = "%s"
+    dockerfile = "../Dockerfile"
+  }
+}