Allow DOCKER_CONFIG to be a filename (#1409)

* Allow DOCKER_CONFIG to be a filename

* UnitTest: DockerConfLocation must return a file if it is existent and passed using env, or default if the file is incorrect

pkg/executor/push.go

@@ -67,8 +67,18 @@ const (
 // "/kaniko/.docker/config.json".
 func DockerConfLocation() string {
 	configFile := "config.json"
-	if dockerConfDir := os.Getenv("DOCKER_CONFIG"); dockerConfDir != "" {
+	if dockerConfig := os.Getenv("DOCKER_CONFIG"); dockerConfig != "" {
-		return filepath.Join(dockerConfDir, configFile)
+		file, err := os.Stat(dockerConfig)
+		if err == nil {
+			if file.IsDir() {
+				return filepath.Join(dockerConfig, configFile)
+			}
+		} else {
+			if os.IsNotExist(err) {
+				return string(os.PathSeparator) + filepath.Join("kaniko", ".docker", configFile)
+			}
+		}
+		return filepath.Clean(dockerConfig)
 	}
 	return string(os.PathSeparator) + filepath.Join("kaniko", ".docker", configFile)
 }

pkg/executor/push_test.go

@@ -37,6 +37,11 @@ import (
 	"github.com/spf13/afero"
 )
 
+const (
+	DefaultKanikoDockerConfigJSON = "/kaniko/.docker/config.json"
+	DockerConfigEnvKey            = "DOCKER_CONFIG"
+)
+
 func mustTag(t *testing.T, s string) name.Tag {
 	tag, err := name.NewTag(s, name.StrictValidation)
 	if err != nil {
@@ -45,43 +50,102 @@ func mustTag(t *testing.T, s string) name.Tag {
 	return tag
 }
 
-func TestDockerConfLocation(t *testing.T) {
+func TestDockerConfLocationWithFileLocation(t *testing.T) {
-	dcfg := "DOCKER_CONFIG"
+	originalDockerConfig := os.Getenv(DockerConfigEnvKey)
-	originalDockerConfig := os.Getenv(dcfg)
+	if err := os.Unsetenv(DockerConfigEnvKey); err != nil {
-
+		t.Fatalf("Failed to unset DOCKER_CONFIG: %v", err)
-	if err := os.Unsetenv(dcfg); err != nil {
+	}
+	file, err := ioutil.TempFile("", "docker.conf")
+	if err != nil {
+		t.Fatalf("could not create temp file: %s", err)
+	}
+	defer os.Remove(file.Name())
+	if err := os.Setenv(DockerConfigEnvKey, file.Name()); err != nil {
 		t.Fatalf("Failed to unset DOCKER_CONFIG: %v", err)
 	}
 	unset := DockerConfLocation()
-	unsetExpected := "/kaniko/.docker/config.json" // will fail on Windows
+	unsetExpected := file.Name()
 	if unset != unsetExpected {
 		t.Errorf("Unexpected default Docker configuration file location: expected:'%s' got:'%s'", unsetExpected, unset)
 	}
+	restoreOriginalDockerConfigEnv(t, originalDockerConfig)
+}
 
-	if err := os.Setenv(dcfg, "/kaniko/.docker"); err != nil {
+func TestDockerConfLocationWithInvalidFileLocation(t *testing.T) {
+	originalDockerConfig := os.Getenv(DockerConfigEnvKey)
+	if err := os.Unsetenv(DockerConfigEnvKey); err != nil {
+		t.Fatalf("Failed to unset DOCKER_CONFIG: %v", err)
+	}
+	tmpDir, err := ioutil.TempDir("", "*")
+	if err != nil {
+		t.Fatalf("could not create temp dir: %s", err)
+	}
+	defer os.RemoveAll(tmpDir)
+	random := "fdgdsfrdfgdf-fdfsf-24dsgfd" //replace with a really random string
+	file := filepath.Join(tmpDir, random)  // an random file name, shouldn't exist
+	if err := os.Setenv(DockerConfigEnvKey, file); err != nil {
+		t.Fatalf("Failed to unset DOCKER_CONFIG: %v", err)
+	}
+	unset := DockerConfLocation()
+	// as file doesn't point to a real file,  DockerConfLocation() should return the default kaniko path for config.json
+	unsetExpected := DefaultKanikoDockerConfigJSON
+	if unset != unsetExpected {
+		t.Errorf("Unexpected default Docker configuration file location: expected:'%s' got:'%s'", unsetExpected, unset)
+	}
+	restoreOriginalDockerConfigEnv(t, originalDockerConfig)
+}
+
+func TestDockerConfLocation(t *testing.T) {
+	originalDockerConfig := os.Getenv(DockerConfigEnvKey)
+
+	if err := os.Unsetenv(DockerConfigEnvKey); err != nil {
+		t.Fatalf("Failed to unset DOCKER_CONFIG: %v", err)
+	}
+	unset := DockerConfLocation()
+	unsetExpected := DefaultKanikoDockerConfigJSON // will fail on Windows
+	if unset != unsetExpected {
+		t.Errorf("Unexpected default Docker configuration file location: expected:'%s' got:'%s'", unsetExpected, unset)
+	}
+	tmpDir, err := ioutil.TempDir("", "*")
+	if err != nil {
+		t.Fatalf("could not create temp dir: %s", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	dir := filepath.Join(tmpDir, "/kaniko/.docker")
+	os.MkdirAll(dir, os.ModePerm)
+	if err := os.Setenv(DockerConfigEnvKey, dir); err != nil {
 		t.Fatalf("Failed to set DOCKER_CONFIG: %v", err)
 	}
 	kanikoDefault := DockerConfLocation()
-	kanikoDefaultExpected := "/kaniko/.docker/config.json" // will fail on Windows
+	kanikoDefaultExpected := filepath.Join(tmpDir, DefaultKanikoDockerConfigJSON) // will fail on Windows
 	if kanikoDefault != kanikoDefaultExpected {
 		t.Errorf("Unexpected kaniko default Docker conf file location: expected:'%s' got:'%s'", kanikoDefaultExpected, kanikoDefault)
 	}
 
-	if err := os.Setenv(dcfg, "/a/different/path"); err != nil {
+	differentPath, err := ioutil.TempDir("", "differentPath")
+	if err != nil {
+		t.Fatalf("could not create temp dir: %s", err)
+	}
+	defer os.RemoveAll(differentPath)
+	if err := os.Setenv(DockerConfigEnvKey, differentPath); err != nil {
 		t.Fatalf("Failed to set DOCKER_CONFIG: %v", err)
 	}
 	set := DockerConfLocation()
-	setExpected := "/a/different/path/config.json" // will fail on Windows
+	setExpected := filepath.Join(differentPath, "config.json") // will fail on Windows ?
 	if set != setExpected {
 		t.Errorf("Unexpected DOCKER_CONF-based file location: expected:'%s' got:'%s'", setExpected, set)
 	}
+	restoreOriginalDockerConfigEnv(t, originalDockerConfig)
+}
 
+func restoreOriginalDockerConfigEnv(t *testing.T, originalDockerConfig string) {
 	if originalDockerConfig != "" {
-		if err := os.Setenv(dcfg, originalDockerConfig); err != nil {
+		if err := os.Setenv(DockerConfigEnvKey, originalDockerConfig); err != nil {
 			t.Fatalf("Failed to set DOCKER_CONFIG back to original value '%s': %v", originalDockerConfig, err)
 		}
 	} else {
-		if err := os.Unsetenv(dcfg); err != nil {
+		if err := os.Unsetenv(DockerConfigEnvKey); err != nil {
 			t.Fatalf("Failed to unset DOCKER_CONFIG after testing: %v", err)
 		}
 	}