Docker Compose — config, top, events

Inspection and monitoring commands that help you understand what Compose is doing.

docker compose config

Validate and display the resolved compose file:

docker compose config              # Full resolved output
docker compose config --services   # List service names
docker compose config --volumes    # List volume names
docker compose config --images     # List image names
docker compose config -q           # Validate only (quiet)

Why Use config?

1. Validate YAML — Catches syntax errors
2. Resolve variables — Shows expanded values
3. Verify merges — Shows result of overrides and includes
4. Debug — See what Compose actually sees

docker compose config | head -30

name: myapp
services:
  api:
    image: node:20-alpine
    environment:
      NODE_ENV: production
      PORT: "3000"
    ports:
      - "3000:3000"

docker compose top

Show running processes in all containers:

docker compose top
docker compose top api     # Specific service

myapp-api-1
UID    PID     PPID    C   STIME   TTY   TIME       CMD
node   12345   12300   0   10:00   ?     00:01:23   node server.js

myapp-db-1
UID       PID     PPID    C   STIME   TTY   TIME       CMD
postgres  12400   12350   0   10:00   ?     00:02:45   postgres
postgres  12401   12400   0   10:00   ?     00:00:30   postgres: checkpointer

docker compose events

Stream real-time events:

docker compose events             # All events
docker compose events api         # Events for api service
docker compose events --json      # JSON format

2024-01-15 10:00:01 container create myapp-api-1
2024-01-15 10:00:01 container start myapp-api-1
2024-01-15 10:00:05 container health_status: healthy myapp-db-1

Events are useful for:

• Debugging startup issues
• Monitoring container lifecycle
• Triggering external actions

docker compose port

Show the public port mapped to a container port:

docker compose port api 3000

0.0.0.0:3000

docker compose version

docker compose version

Docker Compose version v2.24.0

Summary

Command	Purpose
config	Validate and display resolved file
config --services	List service names
top	Show container processes
events	Stream lifecycle events
port svc N	Show mapped port
version	Show Compose version

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Quick Reference

Item	Detail
config	Validate and resolve compose file
config -q	Validate only (quiet)
top	Show running processes
events	Stream container events
port svc N	Show public port mapping
version	Show Compose version