Adding code for consistent build context

fixes #445

This PR was partially fixed by docker/libcompose#450, which now gives consistent build context,
also it modifies the function getAbsBuildContext to create accurate build context, Unit test are being modified
according to new structure.

pkg/transformer/openshift/openshift.go

@@ -147,15 +147,16 @@ func getComposeFileDir(inputFiles []string) (string, error) {
 }
 
 // getAbsBuildContext returns build context relative to project root dir
-func getAbsBuildContext(context string, composeFileDir string) (string, error) {
+func getAbsBuildContext(context string) (string, error) {
 	cmd := exec.Command("git", "rev-parse", "--show-prefix")
-	cmd.Dir = composeFileDir
+	cmd.Dir = context
 	out, err := cmd.Output()
 	if err != nil {
 		return "", err
 	}
-	prefix := strings.Trim(string(out), "\n")
-	return filepath.Join(prefix, context), nil
+	//convert output of command to string
+	contextDir := strings.Trim(string(out), "\n")
+	return contextDir, nil
 }
 
 // initImageStream initialize ImageStream object
@@ -197,8 +198,8 @@ func (o *OpenShift) initImageStream(name string, service kobject.ServiceConfig,
 }
 
 // initBuildConfig initialize Openshifts BuildConfig Object
-func initBuildConfig(name string, service kobject.ServiceConfig, composeFileDir string, repo string, branch string) (*buildapi.BuildConfig, error) {
-	contextDir, err := getAbsBuildContext(service.Build, composeFileDir)
+func initBuildConfig(name string, service kobject.ServiceConfig, repo string, branch string) (*buildapi.BuildConfig, error) {
+	contextDir, err := getAbsBuildContext(service.Build)
 	if err != nil {
 		return nil, errors.Wrap(err, name+"buildconfig cannot be created due to error in creating build context, getAbsBuildContext failed")
 	}
@@ -386,7 +387,7 @@ func (o *OpenShift) Transform(komposeObject kobject.KomposeObject, opt kobject.C
 					}
 					hasBuild = true
 				}
-				bc, err := initBuildConfig(name, service, composeFileDir, buildRepo, buildBranch)
+				bc, err := initBuildConfig(name, service, buildRepo, buildBranch)
 				if err != nil {
 					return nil, errors.Wrap(err, "initBuildConfig failed")
 				}

pkg/transformer/openshift/openshift_test.go

@@ -243,24 +243,25 @@ func TestGetAbsBuildContext(t *testing.T) {
 	gitDir := testutils.CreateLocalGitDirectory(t)
 	testutils.SetGitRemote(t, gitDir, "newremote", "https://git.test.com/somerepo")
 	testutils.CreateGitRemoteBranch(t, gitDir, "newbranch", "newremote")
-	testutils.CreateSubdir(t, gitDir, "a/b")
+	testutils.CreateSubdir(t, gitDir, "a/b/build")
+	testutils.CreateSubdir(t, gitDir, "build")
 	dir := testutils.CreateLocalDirectory(t)
 	defer os.RemoveAll(gitDir)
 	defer os.RemoveAll(dir)
 
 	testCases := map[string]struct {
-		expectError    bool
-		context        string
-		composeFileDir string
-		output         string
+		expectError bool
+		context     string
+		output      string
 	}{
-		"Get abs build context success": {false, "./b/build", filepath.Join(gitDir, "a"), "a/b/build"},
-		"Get abs build context error":   {true, "", dir, ""},
+		"Get abs build context success case-1": {false, filepath.Join(gitDir, "a/b/build"), "a/b/build/"},
+		"Get abs build context success case-2": {false, filepath.Join(gitDir, "build"), "build/"},
+		"Get abs build context error":          {true, "example/build", "example/build/"},
 	}
 
 	for name, test := range testCases {
 		t.Log("Test case: ", name)
-		output, err = getAbsBuildContext(test.context, test.composeFileDir)
+		output, err = getAbsBuildContext(test.context)
 
 		if test.expectError {
 			if err == nil {
@@ -284,14 +285,13 @@ func TestInitBuildConfig(t *testing.T) {
 	defer os.RemoveAll(dir)
 
 	serviceName := "serviceA"
-	composeFileDir := filepath.Join(dir, "a")
 	repo := "https://git.test.com/org/repo"
 	branch := "somebranch"
 	sc := kobject.ServiceConfig{
-		Build:      "./build",
+		Build:      filepath.Join(dir, "a/build"),
 		Dockerfile: "Dockerfile-alternate",
 	}
-	bc, err := initBuildConfig(serviceName, sc, composeFileDir, repo, branch)
+	bc, err := initBuildConfig(serviceName, sc, repo, branch)
 	if err != nil {
 		t.Error(errors.Wrap(err, "initBuildConfig failed"))
 	}
@@ -302,7 +302,7 @@ func TestInitBuildConfig(t *testing.T) {
 	}{
 		"Assert buildconfig source git URI":     {bc.Spec.CommonSpec.Source.Git.URI, repo},
 		"Assert buildconfig source git Ref":     {bc.Spec.CommonSpec.Source.Git.Ref, branch},
-		"Assert buildconfig source context dir": {bc.Spec.CommonSpec.Source.ContextDir, "a/build"},
+		"Assert buildconfig source context dir": {bc.Spec.CommonSpec.Source.ContextDir, "a/build/"},
 		"Assert buildconfig output name":        {bc.Spec.CommonSpec.Output.To.Name, serviceName + ":latest"},
 		"Assert buildconfig dockerfilepath":     {bc.Spec.CommonSpec.Strategy.DockerStrategy.DockerfilePath, "Dockerfile-alternate"},
 	}

script/test/cmd/tests.sh

@@ -195,6 +195,17 @@ convert::check_artifacts_generated "kompose -f $KOMPOSE_ROOT/script/test/fixture
 # Behavior with -o <dirname>/<filename>
 convert::check_artifacts_generated "kompose -f $KOMPOSE_ROOT/script/test/fixtures/redis-example/docker-compose.yml convert -o $TEMP_DIR/output_file -j" "$TEMP_DIR/output_file"
 
+####
+# Test regarding build context (running kompose from various directories)
+CURRENT_DIR=$(pwd)
+cd "$KOMPOSE_ROOT/script/test/fixtures/nginx-node-redis/"
+convert::expect_success_and_warning "kompose convert --provider openshift --stdout -j" "$KOMPOSE_ROOT/script/test/fixtures/nginx-node-redis/output-os.json" "Buildconfig using https://github.com/kubernetes-incubator/kompose.git::HEAD as source."
+cd "$KOMPOSE_ROOT/script/test/fixtures/"
+convert::expect_success_and_warning "kompose convert --provider openshift --stdout -j -f nginx-node-redis/docker-compose.yml" "$KOMPOSE_ROOT/script/test/fixtures/nginx-node-redis/output-os.json" "Buildconfig using https://github.com/kubernetes-incubator/kompose.git::HEAD as source."
+cd "$KOMPOSE_ROOT/script/test/fixtures/nginx-node-redis/node"
+convert::expect_success_and_warning "kompose convert  --provider openshift --stdout -j -f ../docker-compose.yml" "$KOMPOSE_ROOT/script/test/fixtures/nginx-node-redis/output-os.json" "Buildconfig using https://github.com/kubernetes-incubator/kompose.git::HEAD as source."
+cd $CURRENT_DIR
+
 # Test related to support docker-compose.yaml beside docker-compose.yml
 # Store the original path
 CURRENT_DIR=$(pwd)