container/list

When to Use

• Health monitoring: Enumerate all containers every 5 minutes and alert when any container enters the exited state unexpectedly.
• Resource inventory: List all running containers to build capacity reports and populate infrastructure dashboards.
• Cleanup automation: Find containers with State of exited and names matching temporary job patterns, then queue them for batch removal.
• Deployment verification: After a deploy completes, list containers and confirm the expected image tag is actively running.
• Multi-container coordination: Before starting a dependent service, verify that all prerequisite containers are in the running state.

Configuration

Connection Fields

Operation Fields

Sample Configuration

{
  "resource": "container",
  "operation": "list",
  "connection": {
    "dockerHost": "unix:///var/run/docker.sock",
    "connectionType": "unixsocket",
    "timeoutSeconds": 30
  }
}

Validation Errors

Output

Success Port

Error Port

On failure the error port receives an object with errorCode (string), message (string), resource, and operation. Always connect the error port to a notification or retry node.

Sample Output

{
  "listContainers": [
    {
      "Id": "a1b2c3d4e5f67890abcdef1234567890abcdef1234567890abcdef1234567890",
      "Names": ["/api-service"],
      "Image": "myapp:v2.1.0",
      "ImageID": "sha256:abc123...",
      "Command": "node server.js",
      "Status": "Up 3 hours",
      "State": "running",
      "Created": 1704067200,
      "Ports": [
        { "PrivatePort": 8080, "PublicPort": 3000, "Type": "tcp", "IP": "0.0.0.0" }
      ],
      "Labels": {
        "com.bizfirst.env": "production",
        "com.bizfirst.service": "api"
      },
      "NetworkSettings": {
        "Networks": {
          "bridge": { "IPAddress": "172.17.0.2" }
        }
      }
    },
    {
      "Id": "b2c3d4e5f6a71234567890abcdef1234567890abcdef1234567890abcdef1234",
      "Names": ["/worker-job-42"],
      "Image": "myworker:latest",
      "Command": "python worker.py",
      "Status": "Exited (0) 2 hours ago",
      "State": "exited",
      "Created": 1704060000,
      "Ports": [],
      "Labels": { "com.bizfirst.env": "production" }
    }
  ],
  "status": "success",
  "resource": "container",
  "operation": "list"
}

Expression Reference

Node Policies & GuardRails

Examples

Example 1: Alert on exited containers

A scheduled workflow runs every 5 minutes, lists all containers, filters for those in the exited state, and sends a Slack alert for each one found.

// Function node downstream of container/list
const exited = $input.listContainers.filter(c => c.State === 'exited');
if (exited.length === 0) return { alert: false };
return {
  alert: true,
  count: exited.length,
  containers: exited.map(c => ({
    name: c.Names[0],
    image: c.Image,
    status: c.Status
  }))
};

Example 2: Deployment verification

After a blue-green deploy, list containers and confirm the new image tag is running before removing the old container.

// If Condition node checks:
// $output.listContainers.some(c => c.Image === 'myapp:v2.2.0' && c.State === 'running')
// → true: proceed to remove old container
// → false: trigger rollback workflow

Example 3: Container inventory report

Build a daily inventory CSV by listing all containers and extracting key fields into a data mapping node.

// Data Mapping node expression for each row:
{
  "id": "{{ $output.listContainers[$index].Id.substring(0, 12) }}",
  "name": "{{ $output.listContainers[$index].Names[0] }}",
  "image": "{{ $output.listContainers[$index].Image }}",
  "state": "{{ $output.listContainers[$index].State }}",
  "created": "{{ new Date($output.listContainers[$index].Created * 1000).toISOString() }}"
}