Docker Exec

# Open an interactive bash shell inside a running container
docker exec -it my-container bash

# If bash is not available (Alpine Linux), use sh
docker exec -it my-container sh

# Run a one-off command
docker exec my-container ls /app

# Run as a specific user
docker exec -u root -it my-container bash

# Set environment variable for the exec session
docker exec -e MY_VAR=hello -it my-container bash

# Run command in a specific directory
docker exec -w /app my-container ls

# Debug a Node.js container
docker exec -it my-api sh
> ls /app
> node -v
> cat package.json

# Access MongoDB shell inside container
docker exec -it mongodb mongosh
> show dbs
> use myapp

# Access PostgreSQL inside container
docker exec -it postgres-db psql -U postgres
> \l
> \c myapp

# Check environment variables
docker exec my-container env

# Run database migration
docker exec my-app node migrate.js

# View a config file inside a container
docker exec nginx cat /etc/nginx/nginx.conf