Check and Manage Logs in Docker Compose

What Compose logs are

Docker Compose logs are the combined output (stdout and stderr) of all services in your docker-compose.yml. They help you watch what your containers do and find errors.

Install Docker Compose on Ubuntu

sudo apt install docker-compose

Or install Docker and its plugins:

sudo apt install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

Check the installation:

docker compose version

Create a test project

1. Create the folders and a page:

mkdir ~/compose-demo
cd ~/compose-demo
mkdir app
nano app/index.html

1. Put this in index.html:

<!doctype html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <title>Docker Compose Demo</title>
</head>
<body>
    <h1>This is a Docker Compose Demo Page.</h1>
</body>
</html>

1. Create the file docker-compose.yml in ~/compose-demo:

services:
  web:
    image: nginx:alpine
    ports:
      - "8000:80"
    volumes:
      - ./app:/usr/share/nginx/html

1. Start the project in the background:

sudo docker compose up -d

1. Check that it runs:

sudo docker compose ps

Read the logs

All services:

sudo docker compose logs

One service:

sudo docker compose logs web

Follow in real time (press Ctrl + C to stop):

sudo docker compose logs -f

Only the last lines:

sudo docker compose logs --tail=10

Add time stamps:

sudo docker compose logs -t

Filter the output with grep:

sudo docker compose logs | grep error

Save the logs to a file:

sudo docker compose logs > logs.txt

Clean up

Stop and remove the test project:

sudo docker compose down

Quick recap

• docker compose logs shows all logs, add a service name for one service.
• -f follows, --tail limits, -t adds time.
• Pipe to grep or save to a file.