docker run to docker-compose

What is docker run to docker-compose?

This tool reads one or more docker run invocations and generates the equivalent docker-compose.yml services: block — useful when a project started as a handful of ad-hoc docker run commands (in a README, a shell script, your shell history) and has grown to the point where a proper compose file is worth having.

How it works

Each docker run command (commands are separated by a blank line for multi-service input) is tokenized the same way a shell would split it — respecting quoted arguments — then walked flag by flag. -p/--publish becomes a ports: entry, -e/--env becomes an environment: entry, and -v/--volume becomes a volumes: entry — a direct, lossless mapping in every case, since compose's syntax for each of these is a superset of what docker run's flags can express. The image name becomes the service's image: field, and any positional arguments after the image become the service's command:. --name becomes the service key directly if present; if it's missing, a name is derived from the image (its last path segment, with the tag stripped), and that inference is called out in a comment at the top of the generated file rather than silently presented as if --name had been there all along.

Features

• Multiple docker run commands in one paste, each becoming its own service
• -p, -e, and -v mapped directly to their compose equivalents
• Container command (anything after the image) preserved as command:
• Missing --name handled by inferring a service key from the image, with an explicit comment noting it
• Copy or download the generated docker-compose.yml

Example

Input:

docker run -d --name web -p 8080:80 -e NODE_ENV=production -v ./html:/usr/share/nginx/html nginx:latest

docker run -d --name db -p 5432:5432 -e POSTGRES_PASSWORD=secret -v db-data:/var/lib/postgresql/data postgres:15

Output:

services:
  web:
    image: nginx:latest
    ports:
      - "8080:80"
    environment:
      - NODE_ENV=production
    volumes:
      - ./html:/usr/share/nginx/html

  db:
    image: postgres:15
    ports:
      - "5432:5432"
    environment:
      - POSTGRES_PASSWORD=secret
    volumes:
      - db-data:/var/lib/postgresql/data

Common errors

A docker run command with no positional image argument at all — for example one where every token was consumed as a flag or its value — produces an error rather than a service with a blank image: field, since a compose service with no image and no build context isn't a valid service. Two commands that don't set --name and happen to use images with the same last path segment (e.g. org1/api:1.0 and org2/api:2.0) get de-duplicated service keys (api, api-2) rather than one silently overwriting the other in the output.

Best practices

Treat the generated file as a starting point, not a finished compose setup: it has no depends_on, restart policy, health check, or network configuration, because docker run commands never carried that information to begin with — there's nothing here to lose, but there's also nothing here to gain for free. Add those manually once you have the base file, and run docker compose config to validate the result before relying on it.