addressed comments

.gitignore

@@ -2,3 +2,4 @@ release
 coverage.out
 vendor
 .idea
+.vscode

cmd/kaniko-acr/main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"encoding/base64"
 	"encoding/json"
 	"fmt"
 	"io/ioutil"
@@ -26,7 +27,7 @@ const (
 	clientSecretKeyEnv string = "AZURE_CLIENT_SECRET"
 	tenantKeyEnv       string = "AZURE_TENANT_ID"
 	certPathEnv        string = "AZURE_CLIENT_CERTIFICATE_PATH"
-	dockerConfigPath   string = "/kaniko/.docker/config.json"
+	dockerConfigPath   string = "/kaniko/.docker"
 	defaultDigestFile  string = "/kaniko/digest-file"
 )
 
@@ -130,7 +131,7 @@ func main() {
 		},
 		cli.StringFlag{
 			Name:   "client-cert",
-			Usage:  "Azure client certificate",
+			Usage:  "Azure client certificate encoded in base64 format",
 			EnvVar: "CLIENT_CERTIFICATE",
 		},
 		cli.StringFlag{
@@ -296,7 +297,7 @@ func getACRToken(tenantId, clientId, clientSecret, cert, registry string) (strin
 	}
 
 	if clientSecret == "" && cert == "" {
-		return "", fmt.Errorf("one of client secert or cert should be defined")
+		return "", fmt.Errorf("one of client secret or cert should be defined")
 	}
 
 	// in case of authentication via cert
@@ -307,15 +308,22 @@ func getACRToken(tenantId, clientId, clientSecret, cert, registry string) (strin
 		}
 	}
 
-	// TODO check for presence of file as well.
-	os.Setenv(clientIdEnv, clientId)
-	os.Setenv(clientSecretKeyEnv, clientSecret)
-	os.Setenv(tenantKeyEnv, tenantId)
+	if err := os.Setenv(clientIdEnv, clientId); err != nil {
+		return "", errors.Wrap(err, "failed to set env variable client Id")
+	}
+	if err := os.Setenv(clientSecretKeyEnv, clientSecret); err != nil {
+		return "", errors.Wrap(err, "failed to set env variable client secret")
+	}
+	if err := os.Setenv(tenantKeyEnv, tenantId); err != nil {
+		return "", errors.Wrap(err, "failed to set env variable tenant Id")
+	}
+	if err := os.Setenv(certPathEnv, ACRCertPath); err != nil {
+		return "", errors.Wrap(err, "failed to set env variable cert path")
+	}
 	env, err := azidentity.NewEnvironmentCredential(nil)
 	if err != nil {
 		return "", errors.Wrap(err, "failed to get env credentials from azure")
 	}
-
 	policy := policy.TokenRequestOptions{
 		Scopes: []string{"https://management.azure.com/.default"},
 	}
@@ -366,14 +374,14 @@ func fetchACRToken(tenantId, token, registry string) (string, error) {
 	return "", errors.New("failed to get refresh token from acr")
 }
 
-func setupACRCert(jsonKey string) error {
-	err := ioutil.WriteFile(ACRCertPath, []byte(jsonKey), 0644)
+func setupACRCert(cert string) error {
+	decoded, err := base64.StdEncoding.DecodeString(cert)
+	if err != nil {
+		return errors.Wrap(err, "failed to base64 decode ACR certificate")
+	}
+	err = ioutil.WriteFile(ACRCertPath, []byte(decoded), 0644)
 	if err != nil {
 		return errors.Wrap(err, "failed to write ACR certificate")
 	}
-	err = os.Setenv(certPathEnv, ACRCertPath)
-	if err != nil {
-		return errors.Wrap(err, fmt.Sprintf("failed to set %s environment variable", certPathEnv))
-	}
 	return nil
 }

pkg/docker/docker_file.go

@@ -26,7 +26,8 @@ func CreateDockerCfgFile(username, password, registry, path string) error {
 	authBytes := []byte(fmt.Sprintf("%s:%s", username, password))
 	encodedString := base64.StdEncoding.EncodeToString(authBytes)
 	jsonBytes := []byte(fmt.Sprintf(`{"auths": {"%s": {"auth": "%s"}}}`, "https://"+registry, encodedString))
-	err = ioutil.WriteFile(path, jsonBytes, 0644)
+	filePath := path + "/config.json"
+	err = ioutil.WriteFile(filePath, jsonBytes, 0644)
 	if err != nil {
 		return errors.Wrap(err, "failed to create docker config file")
 	}