fix registry auth string being suffixed with "/owner/repo:", dynamically determine .docker/config.json, renamed targetRegistries to targetRepos to better clarify content (list of "registry/owner/repo:prefix-" and not actual registries)

src/action.js

@@ -4,6 +4,7 @@ import * as action_information from 'information';
 import {
   addCiRegistryAuth,
   collectTags,
+  determineDockerConfigFileLocation,
   executeDockerBuild,
   isTrueString,
   mergeArgRegistryAuthJson,
@@ -23,27 +24,33 @@ try {
 
   const debug = isTrueString(process.env['ACTIONS_STEP_DEBUG']);
 
-  let targetRegistries = [];
-  const repoStr        = github.context.repo.owner + '/' + github.context.repo.repo;
+  let targetRepos = [];
+  const repoStr   = github.context.repo.owner + '/' + github.context.repo.repo;
 
   let ci_registry = false;
   if (core.getBooleanInput('add_ci_registry_target')) {
-    ci_registry = information.ci_hostname + '/' + repoStr + ':';
-    targetRegistries.push(ci_registry);
+    const ci_registry_repo = information.ci_hostname + '/' + repoStr + ':';
+    targetRepos.push(ci_registry_repo);
+  }
+
+  processAdditionalRegistries(targetRepos);
+
+  const dockerConfigFile = determineDockerConfigFileLocation(core.getInput('docker_auth_json_file'));
+  if (debug) {
+    console.log('determined .docker/config.json location: ', dockerConfigFile);
   }
 
-  processAdditionalRegistries(targetRegistries);
   const registryAuthJson = {auths: {}};
   addCiRegistryAuth(ci_registry, registryAuthJson);
   mergeArgRegistryAuthJson(registryAuthJson);
-  writeRegistryAuthJson(registryAuthJson, '/home/runner/.docker/config.json');
+  writeRegistryAuthJson(registryAuthJson, dockerConfigFile);
 
   const tags = collectTags(information);
   if (debug) {
     console.log('tags:', JSON.stringify(tags, null, 2));
   }
 
-  const destinations = prepareDestinations(targetRegistries, tags);
+  const destinations = prepareDestinations(targetRepos, tags);
   if (debug || core.getBooleanInput('debug_log_destinations')) {
     console.log('destinations:', JSON.stringify(destinations, null, 2));
   }

src/lib.js

@@ -3,6 +3,7 @@ import * as github from '@actions/github';
 import * as child_process from 'child_process';
 import * as fs from 'fs';
 import {Base64} from 'js-base64';
+import * as os from 'os';
 import * as path from 'path';
 
 export function processAdditionalRegistries(targetRegistries) {
@@ -257,6 +258,20 @@ export function executeDockerBuild(dockerArgs, destinations) {
   }
 }
 
+export function determineDockerConfigFileLocation(path) {
+  if (path == null || !path.length) {
+    return os.homedir + '/.docker/config.json';
+  }
+
+  // absolute path
+  if (path.startsWith('/')) {
+    return path;
+  }
+
+  // relative path to home dir
+  return os.homedir + '/' + path;
+}
+
 export function isTrueString(str) {
   return str === '1'
     || str === 'true'