Add ability to set git auth token using environment variables

README.md

@@ -173,6 +173,9 @@ If you are using Azure Blob Storage for context file, you will need to pass [Azu
 ### Using Private Git Repository
 You can use `Personal Access Tokens` for Build Contexts from Private Repositories from [GitHub](https://blog.github.com/2012-09-21-easier-builds-and-deployments-using-git-over-https-and-oauth/).
 
+You can either pass this in as part of the git URL (e.g., `git://TOKEN@github.com/acme/myproject.git#refs/heads/mybranch`)
+or using the environment variable `GIT_USERNAME`.
+
 ### Using Standard Input
 If running kaniko and using Standard Input build context, you will need to add the docker or kubernetes `-i, --interactive` flag.
 Once running, kaniko will then get the data from `STDIN` and create the build context as a compressed tar.

pkg/buildcontext/git.go

@@ -23,12 +23,17 @@ import (
 	"github.com/GoogleContainerTools/kaniko/pkg/constants"
 	git "gopkg.in/src-d/go-git.v4"
 	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/transport"
+	"gopkg.in/src-d/go-git.v4/plumbing/transport/http"
 )
 
 const (
 	gitPullMethodEnvKey = "GIT_PULL_METHOD"
 	gitPullMethodHTTPS  = "https"
 	gitPullMethodHTTP   = "http"
+
+	gitAuthUsernameEnvKey = "GIT_USERNAME"
+	gitAuthPasswordEnvKey = "GIT_PASSWORD"
 )
 
 var (
@@ -46,6 +51,7 @@ func (g *Git) UnpackTarFromBuildContext() (string, error) {
 	parts := strings.Split(g.context, "#")
 	options := git.CloneOptions{
 		URL:      getGitPullMethod() + "://" + parts[0],
+		Auth:     getGitAuth(),
 		Progress: os.Stdout,
 	}
 	if len(parts) > 1 {
@@ -55,6 +61,18 @@ func (g *Git) UnpackTarFromBuildContext() (string, error) {
 	return directory, err
 }
 
+func getGitAuth() transport.AuthMethod {
+	username := os.Getenv(gitAuthUsernameEnvKey)
+	password := os.Getenv(gitAuthPasswordEnvKey)
+	if username != "" || password != "" {
+		return &http.BasicAuth{
+			Username: username,
+			Password: password,
+		}
+	}
+	return nil
+}
+
 func getGitPullMethod() string {
 	gitPullMethod := os.Getenv(gitPullMethodEnvKey)
 	if ok := supportedGitPullMethods[gitPullMethod]; !ok {

pkg/buildcontext/git_test.go

@@ -21,6 +21,8 @@ import (
 	"testing"
 
 	"github.com/GoogleContainerTools/kaniko/testutil"
+	"gopkg.in/src-d/go-git.v4/plumbing/transport"
+	"gopkg.in/src-d/go-git.v4/plumbing/transport/http"
 )
 
 func TestGetGitPullMethod(t *testing.T) {
@@ -80,3 +82,88 @@ func TestGetGitPullMethod(t *testing.T) {
 		})
 	}
 }
+
+func TestGetGitAuth(t *testing.T) {
+	tests := []struct {
+		testName string
+		setEnv   func() (expectedValue transport.AuthMethod)
+	}{
+		{
+			testName: "noEnv",
+			setEnv: func() (expectedValue transport.AuthMethod) {
+				expectedValue = nil
+				return
+			},
+		},
+		{
+			testName: "emptyUsernameEnv",
+			setEnv: func() (expectedValue transport.AuthMethod) {
+				_ = os.Setenv(gitAuthUsernameEnvKey, "")
+				expectedValue = nil
+				return
+			},
+		},
+		{
+			testName: "emptyPasswordEnv",
+			setEnv: func() (expectedValue transport.AuthMethod) {
+				_ = os.Setenv(gitAuthPasswordEnvKey, "")
+				expectedValue = nil
+				return
+			},
+		},
+		{
+			testName: "emptyEnv",
+			setEnv: func() (expectedValue transport.AuthMethod) {
+				_ = os.Setenv(gitAuthUsernameEnvKey, "")
+				_ = os.Setenv(gitAuthPasswordEnvKey, "")
+				expectedValue = nil
+				return
+			},
+		},
+		{
+			testName: "withUsername",
+			setEnv: func() (expectedValue transport.AuthMethod) {
+				username := "foo"
+				_ = os.Setenv(gitAuthUsernameEnvKey, username)
+				expectedValue = &http.BasicAuth{Username: username}
+				return
+			},
+		},
+		{
+			testName: "withPassword",
+			setEnv: func() (expectedValue transport.AuthMethod) {
+				pass := "super-secret-password-1234"
+				_ = os.Setenv(gitAuthPasswordEnvKey, pass)
+				expectedValue = &http.BasicAuth{Password: pass}
+				return
+			},
+		},
+		{
+			testName: "withUsernamePassword",
+			setEnv: func() (expectedValue transport.AuthMethod) {
+				username := "foo"
+				pass := "super-secret-password-1234"
+				_ = os.Setenv(gitAuthUsernameEnvKey, username)
+				_ = os.Setenv(gitAuthPasswordEnvKey, pass)
+				expectedValue = &http.BasicAuth{Username: username, Password: pass}
+				return
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.testName, func(t *testing.T) {
+			// Make sure to unset environment vars to get a clean test each time
+			defer clearTestAuthEnv()
+
+			expectedValue := tt.setEnv()
+			testutil.CheckDeepEqual(t, expectedValue, getGitAuth())
+		})
+	}
+
+}
+
+func clearTestAuthEnv() {
+	_ = os.Unsetenv(gitAuthUsernameEnvKey)
+	_ = os.Unsetenv(gitAuthPasswordEnvKey)
+}