Function initDockerConfigOverride

envbuilder.go:1705–1798

initDockerConfigOverride sets the DOCKER_CONFIG environment variable to a path within the working directory. If a base64 encoded Docker config is provided, it is written to the path/config.json and the DOCKER_CONFIG environment variable is set to the path. If no base64 encoded Docker config is provi

(bfs billy.Filesystem, logf log.Func, workingDir workingdir.WorkingDir, dockerConfigBase64 string)

//
// If a Docker config file is found, its path is set as DOCKER_CONFIG.
func initDockerConfigOverride(bfs billy.Filesystem, logf log.Func, workingDir workingdir.WorkingDir, dockerConfigBase64 string) (func() error, error) {
	// If dockerConfigBase64 is set, it will have priority over file
	// detection.
	var dockerConfigJSON []byte
	var err error
	if dockerConfigBase64 != "" {
		logf(log.LevelInfo, "Using base64 encoded Docker config")

		dockerConfigJSON, err = base64.StdEncoding.DecodeString(dockerConfigBase64)
		if err != nil {
			return nil, fmt.Errorf("decode docker config: %w", err)
		}
	}

	oldDockerConfig := os.Getenv(dockerConfigEnvKey)
	var oldDockerConfigFile string
	if oldDockerConfig != "" {
		oldDockerConfigFile = filepath.Join(oldDockerConfig, dockerConfigFile)
	}
	for _, path := range []string{
		oldDockerConfigFile,               // $DOCKER_CONFIG/config.json
		oldDockerConfig,                   // $DOCKER_CONFIG
		workingDir.Join(dockerConfigFile), // /.envbuilder/config.json
	} {
		if path == "" || !fileExists(bfs, path) {
			continue
		}

		logf(log.LevelWarn, "Found Docker config at %s, this file will remain after the build", path)

		if dockerConfigJSON == nil {
			logf(log.LevelInfo, "Using Docker config at %s", path)

			dockerConfigJSON, err = readFile(bfs, path)
			if err != nil {
				return nil, fmt.Errorf("read docker config: %w", err)
			}
		} else {
			logf(log.LevelWarn, "Ignoring Docker config at %s, using base64 encoded Docker config instead", path)
		}
		break
	}

	if dockerConfigJSON == nil {
		// No user-provided config available.
		return func() error { return nil }, nil
	}

	dockerConfigJSON, err = hujson.Standardize(dockerConfigJSON)
	if err != nil {
		return nil, fmt.Errorf("humanize json for docker config: %w", err)
	}

	if err = logDockerAuthConfigs(logf, dockerConfigJSON); err != nil {
		return nil, fmt.Errorf("log docker auth configs: %w", err)
	}

	// We're going to set the DOCKER_CONFIG environment variable to a