docker/cli · error

failed to add signer to: %s

Error message

failed to add signer to: %s

What it means

Error "failed to add signer to: %s" thrown in docker/cli.

Source

Thrown at cmd/docker-trust/trust/signer_add.go:77

	if options.keys.Len() == 0 {
		return errors.New("path to a public key must be provided using the `--key` flag")
	}
	signerPubKeys, err := ingestPublicKeys(options.keys.GetSlice())
	if err != nil {
		return err
	}
	var errRepos []string
	for _, repoName := range options.repos {
		_, _ = fmt.Fprintf(dockerCLI.Out(), "Adding signer \"%s\" to %s...\n", signerName, repoName)
		if err := addSignerToRepo(ctx, dockerCLI, signerName, repoName, signerPubKeys); err != nil {
			_, _ = fmt.Fprintln(dockerCLI.Err(), err.Error()+"\n")
			errRepos = append(errRepos, repoName)
		} else {
			_, _ = fmt.Fprintf(dockerCLI.Out(), "Successfully added signer: %s to %s\n\n", signerName, repoName)
		}
	}
	if len(errRepos) > 0 {
		return fmt.Errorf("failed to add signer to: %s", strings.Join(errRepos, ", "))
	}
	return nil
}

func addSignerToRepo(ctx context.Context, dockerCLI command.Cli, signerName string, repoName string, signerPubKeys []data.PublicKey) error {
	imgRefAndAuth, err := trust.GetImageReferencesAndAuth(ctx, authResolver(dockerCLI), repoName)
	if err != nil {
		return err
	}

	notaryRepo, err := newNotaryClient(dockerCLI, imgRefAndAuth, trust.ActionsPushAndPull)
	if err != nil {
		return trust.NotaryError(imgRefAndAuth.Reference().Name(), err)
	}

	if _, err = notaryRepo.ListTargets(); err != nil {
		switch err.(type) {
		case client.ErrRepoNotInitialized, client.ErrRepositoryNotExist:

View on GitHub (pinned to e9452d6e78)

When it happens

Trigger: Thrown at cmd/docker-trust/trust/signer_add.go:77 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of docker/cli@e9452d6e78 (2026-08-01). Data as JSON: /data/errors/f902c51dce030f4f.json. Report an issue: GitHub.