feat(k8s): advanced deployment from Git repo EE-447 (#5166)

* feat(stack): UI updates in git repo deployment method for k8s EE-640. (#5097)

* feat(stack): UI updates in git repo deployment method for k8s EE-640.

* feat(stack): supports the combination of GIT + COMPOSE.

* feat(stack): rename variable

* feat(stack): add git repo deployment method for k8s EE-638

* cleanup

* update payload validation rules

* make repo ref optional in frond end

Co-authored-by: fhanportainer <79428273+fhanportainer@users.noreply.github.com>

api/http/handler/stacks/create_kubernetes_stack_test.go

@@ -0,0 +1,64 @@
+package stacks
+
+import (
+	"io/ioutil"
+	"os"
+	"path"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+type git struct {
+	content string
+}
+
+func (g *git) CloneRepository(destination string, repositoryURL, referenceName, username, password string) error {
+	return g.ClonePublicRepository(repositoryURL, referenceName, destination)
+}
+func (g *git) ClonePublicRepository(repositoryURL string, referenceName string, destination string) error {
+	return ioutil.WriteFile(path.Join(destination, "deployment.yml"), []byte(g.content), 0755)
+}
+func (g *git) ClonePrivateRepositoryWithBasicAuth(repositoryURL, referenceName string, destination, username, password string) error {
+	return g.ClonePublicRepository(repositoryURL, referenceName, destination)
+}
+
+func TestCloneAndConvertGitRepoFile(t *testing.T) {
+	dir, err := os.MkdirTemp("", "kube-create-stack")
+	assert.NoError(t, err, "failed to create a tmp dir")
+	defer os.RemoveAll(dir)
+
+	content := `apiVersion: apps/v1
+	kind: Deployment
+	metadata:
+		name: nginx-deployment
+		labels:
+			app: nginx
+	spec:
+		replicas: 3
+		selector:
+			matchLabels:
+				app: nginx
+		template:
+			metadata:
+				labels:
+					app: nginx
+			spec:
+				containers:
+				- name: nginx
+					image: nginx:1.14.2
+					ports:
+					- containerPort: 80`
+
+	h := &Handler{
+		GitService: &git{
+			content: content,
+		},
+	}
+	gitInfo := &kubernetesGitDeploymentPayload{
+		FilePathInRepository: "deployment.yml",
+	}
+	fileContent, err := h.cloneManifestContentFromGitRepo(gitInfo, dir)
+	assert.NoError(t, err, "failed to clone or convert the file from Git repo")
+	assert.Equal(t, content, fileContent)
+}