Fix parsing of secrets containing '=' character

__tests__/buildx.test.ts

@@ -3,9 +3,9 @@ import * as path from 'path';
 import * as semver from 'semver';
 import * as buildx from '../src/buildx';
 import * as docker from '../src/docker';
-import * as exec from '@actions/exec';
 import * as context from '../src/context';
 
+const tmpNameSync = path.join('/tmp/.docker-build-push-jest', '.tmpname-jest').split(path.sep).join(path.posix.sep);
 const digest = 'sha256:bfb45ab72e46908183546477a08f8867fc40cebadd00af54b071b097aed127a9';
 
 jest.spyOn(context, 'tmpDir').mockImplementation((): string => {
@@ -17,7 +17,7 @@ jest.spyOn(context, 'tmpDir').mockImplementation((): string => {
 });
 
 jest.spyOn(context, 'tmpNameSync').mockImplementation((): string => {
-  return path.join('/tmp/.docker-build-push-jest', '.tmpname-jest').split(path.sep).join(path.posix.sep);
+  return tmpNameSync;
 });
 
 describe('getImageID', () => {
@@ -115,3 +115,16 @@ describe('parseVersion', () => {
     expect(await buildx.parseVersion(stdout)).toEqual(expected);
   });
 });
+
+describe('getSecret', () => {
+  it('writes correct secret content', async () => {
+    const key = 'MY_KEY';
+    const secret = 'c3RyaW5nLXdpdGgtZXF1YWxzCg==';
+    const secretArgs = await buildx.getSecret(`${key}=${secret}`);
+    console.log(`secretArgs: ${secretArgs}`);
+    expect(secretArgs).toEqual(`id=${key},src=${tmpNameSync}`);
+    const secretContent = await fs.readFileSync(tmpNameSync, 'utf-8');
+    console.log(`secretValue: ${secretContent}`);
+    expect(secretContent).toEqual(secret);
+  });
+});

__tests__/context.test.ts

@@ -1,6 +1,5 @@
 import * as fs from 'fs';
 import * as path from 'path';
-import * as buildx from '../src/buildx';
 import * as context from '../src/context';
 
 jest.spyOn(context, 'defaultContext').mockImplementation((): string => {
@@ -107,7 +106,7 @@ describe('getArgs', () => {
       '0.4.2',
       new Map<string, string>([
         ['context', '.'],
-        ['secrets', 'GIT_AUTH_TOKEN=abcdefghijklmno0123456789'],
+        ['secrets', 'GIT_AUTH_TOKEN=abcdefghijklmno=0123456789'],
       ]),
       [
         'buildx',
@@ -139,7 +138,7 @@ describe('getArgs', () => {
         ['context', 'https://github.com/docker/build-push-action.git#heads/master'],
         ['tag', 'localhost:5000/name/app:latest'],
         ['platforms', 'linux/amd64,linux/arm64'],
-        ['secrets', 'GIT_AUTH_TOKEN=abcdefghijklmno0123456789'],
+        ['secrets', 'GIT_AUTH_TOKEN=abcdefghijklmno=0123456789'],
         ['file', './test/Dockerfile'],
         ['builder', 'builder-git-context-2'],
         ['push', 'true']

src/buildx.ts

@@ -18,7 +18,9 @@ export async function getImageID(): Promise<string | undefined> {
 }
 
 export async function getSecret(kvp: string): Promise<string> {
-  const [key, value] = kvp.split('=');
+  const delimiterIndex = kvp.indexOf('=');
+  const key = kvp.substring(0, delimiterIndex);
+  const value = kvp.substring(delimiterIndex + 1);
   const secretFile = context.tmpNameSync({
     tmpdir: context.tmpDir()
   });