glanceapp/glance · error

sending request to socket: %w

Error message

sending request to socket: %w

What it means

client.Do failed for the Docker API request — the TCP/Unix connection could not be established or timed out (5-second context). This is the most common Docker widget error: the socket file is missing, permission is denied, or the remote host is unreachable.

Source

Thrown at internal/glance/widget-docker-containers.go:327

					return net.Dial("unix", source)
				},
			},
		}
	}


	fetchAll := ternary(runningOnly, "false", "true")
	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()

	request, err := http.NewRequestWithContext(ctx, "GET", "http://"+hostname+"/containers/json?all="+fetchAll, nil)
	if err != nil {
		return nil, fmt.Errorf("creating request: %w", err)
	}

	response, err := client.Do(request)
	if err != nil {
		return nil, fmt.Errorf("sending request to socket: %w", err)
	}
	defer response.Body.Close()

	if response.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("non-200 response status: %s", response.Status)
	}

	var containers []dockerContainerJsonResponse
	if err := json.NewDecoder(response.Body).Decode(&containers); err != nil {
		return nil, fmt.Errorf("decoding response: %w", err)
	}

	for i := range containers {
		container := &containers[i]
		name := strings.TrimLeft(itemAtIndexOrDefault(container.Names, 0, ""), "/")

		if name == "" {
			continue

View on GitHub (pinned to 91324e8de7)

Solutions

1. Confirm the socket exists and is accessible: 'test -r /var/run/docker.sock && curl --unix-socket /var/run/docker.sock http://localhost/containers/json'
2. Mount the socket into the glance container and/or add the user to the docker group
3. For remote hosts, verify connectivity: 'nc -zv host 2375'; check firewall rules
4. If timeouts recur, reduce Docker load or increase availability of the daemon

Example fix

# before
services:
  glance:
    image: glanceapp/glance
# after
services:
  glance:
    image: glanceapp/glance
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock

if _, err := os.Stat(socketPath); err != nil {
    return fmt.Errorf("docker socket %s unavailable: %w", socketPath, err)
}

containers, err := fetchDockerContainersFromSource(socketPath, category, runningOnly, overrides)
if err != nil {
    if errors.Is(err, context.DeadlineExceeded) || strings.Contains(err.Error(), "connection refused") {
        // transient daemon issue: skip this update cycle, keep last good data
        return nil, errTransient
    }
    return nil, err
}

When it happens

Trigger: Dialing /var/run/docker.sock that does not exist or is not readable/writable by the glance process; remote tcp:// host refusing connections or firewalled; context deadline exceeded because Docker is unresponsive.

Common situations: Glance in a container without the socket mounted; socket owned by root:docker with glance not in the docker group; Podman socket at a different path; Docker daemon not started; NAT/firewall blocking port 2375/2376; Docker overloaded so the 5s timeout fires.

Related errors

• fetching containers: %w
• reading secret file: %v
• assets directory does not exist: %s
• parsing URL: %w
• creating request: %w

AI-assisted analysis of glanceapp/glance@91324e8de7 (2026-08-15). Data as JSON: /api/errors/0b29a192de244923. Report an issue: GitHub.