Add http support for git repository context

pkg/buildcontext/git.go

@@ -25,6 +25,16 @@ import (
 	"gopkg.in/src-d/go-git.v4/plumbing"
 )
 
+const (
+	gitPullMethodEnvKey = "GIT_PULL_METHOD"
+	gitPullMethodHTTPS  = "https"
+	gitPullMethodHTTP   = "http"
+)
+
+var (
+	supportedGitPullMethods = map[string]bool{gitPullMethodHTTPS: true, gitPullMethodHTTP: true}
+)
+
 // Git unifies calls to download and unpack the build context.
 type Git struct {
 	context string
@@ -35,7 +45,7 @@ func (g *Git) UnpackTarFromBuildContext() (string, error) {
 	directory := constants.BuildContextDir
 	parts := strings.Split(g.context, "#")
 	options := git.CloneOptions{
-		URL:      "https://" + parts[0],
+		URL:      getGitPullMethod() + "://" + parts[0],
 		Progress: os.Stdout,
 	}
 	if len(parts) > 1 {
@@ -44,3 +54,11 @@ func (g *Git) UnpackTarFromBuildContext() (string, error) {
 	_, err := git.PlainClone(directory, false, &options)
 	return directory, err
 }
+
+func getGitPullMethod() string {
+	gitPullMethod := os.Getenv(gitPullMethodEnvKey)
+	if ok := supportedGitPullMethods[gitPullMethod]; !ok {
+		gitPullMethod = gitPullMethodHTTPS
+	}
+	return gitPullMethod
+}

pkg/buildcontext/git_test.go

@@ -0,0 +1,82 @@
+/*
+Copyright 2020 Google LLC
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package buildcontext
+
+import (
+	"os"
+	"testing"
+
+	"github.com/GoogleContainerTools/kaniko/testutil"
+)
+
+func TestGetGitPullMethod(t *testing.T) {
+	tests := []struct {
+		testName string
+		setEnv   func() (expectedValue string)
+	}{
+		{
+			testName: "noEnv",
+			setEnv: func() (expectedValue string) {
+				expectedValue = gitPullMethodHTTPS
+				return
+			},
+		},
+		{
+			testName: "emptyEnv",
+			setEnv: func() (expectedValue string) {
+				_ = os.Setenv(gitPullMethodEnvKey, "")
+				expectedValue = gitPullMethodHTTPS
+				return
+			},
+		},
+		{
+			testName: "httpEnv",
+			setEnv: func() (expectedValue string) {
+				err := os.Setenv(gitPullMethodEnvKey, gitPullMethodHTTP)
+				if nil != err {
+					expectedValue = gitPullMethodHTTPS
+				} else {
+					expectedValue = gitPullMethodHTTP
+				}
+				return
+			},
+		},
+		{
+			testName: "httpsEnv",
+			setEnv: func() (expectedValue string) {
+				_ = os.Setenv(gitPullMethodEnvKey, gitPullMethodHTTPS)
+				expectedValue = gitPullMethodHTTPS
+				return
+			},
+		},
+		{
+			testName: "unknownEnv",
+			setEnv: func() (expectedValue string) {
+				_ = os.Setenv(gitPullMethodEnvKey, "unknown")
+				expectedValue = gitPullMethodHTTPS
+				return
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.testName, func(t *testing.T) {
+			expectedValue := tt.setEnv()
+			testutil.CheckDeepEqual(t, expectedValue, getGitPullMethod())
+		})
+	}
+}