Docker Environment Generator
Every official Docker image has its own environment variables: POSTGRES_PASSWORD, MYSQL_ROOT_PASSWORD, MONGO_INITDB_ROOT_USERNAME, MINIO_ROOT_USER and so on. Choose the image and get a compose service with exactly the variables it documents, strong passwords generated in your browser, a .env file, a connection string for your app, a health check, a data volume and optional Docker secrets with the *_FILE convention.
- Runs in your browser
- No sign-up
- Free to use
How to use Docker Environment Generator
- Choose the official image and version.
- Enter the service, database and user names.
- Choose password generation, secrets and port publishing.
- Copy compose.yaml and .env into your project.
Docker Environment Generator features
Ten images
Databases, caches, queues, storage, auth, CMS and mail testing.
Correct variables
The names each image documents, with required ones enforced.
Strong passwords
Generated with the browser’s cryptographic random generator.
Docker secrets
*_FILE variables and secret files where images support them.
Ready to use
Health checks, data volumes and a connection string.
Safe defaults
Ports bound to 127.0.0.1 and ${VAR:?} checks.
When to use Docker Environment Generator
- Adding a database to a docker compose project.
- Setting up local services for development.
- Moving passwords out of compose.yaml into .env or secrets.
- Looking up which variables an image expects.
Docker Environment Generator FAQ
Why do my variables have no effect?
Database images only use their init variables when the data volume is empty. Change them after the first start inside the database, or remove the volume to start fresh.
What is ${VAR:?…}?
Compose syntax that stops with an error when the variable is missing, so a container never starts with an empty password.
What are *_FILE variables?
Many official images read POSTGRES_PASSWORD_FILE and similar variables: the value is read from a file, usually a Docker secret, so it never appears in the environment or docker inspect.
Why is Redis configured with a command?
The official Redis image has no password variable; the password is passed with --requirepass.
Are the passwords stored?
No. They are generated in your browser and exist only on this page until you copy them.
Why bind to 127.0.0.1?
Publishing a database on all interfaces makes it reachable from the network. Binding to 127.0.0.1 allows only local tools to connect.
Configuring official images
Official Docker images are configured through environment variables, but every image uses its own names and rules. PostgreSQL requires POSTGRES_PASSWORD, MySQL requires MYSQL_ROOT_PASSWORD and offers a separate application user, MongoDB starts without authentication unless the root user variables are set, and Redis has no password variable at all. Looking these up for each project wastes time and invites mistakes.
The generator knows the documented variables for ten widely used images and writes a compose service with them. Values are taken from a .env file through ${VARIABLE} references, so the compose file can be committed while the passwords stay out of Git, and required passwords use ${VAR:?…} so a missing value stops the start instead of creating a database without a password.
Passwords are generated with the browser’s cryptographic random number generator, long and made of letters and digits only so they work in URLs and configuration files without escaping. They exist only on the page; copy them into your .env file or password manager.
For more protection, images that support it can read passwords from Docker secrets: the *_FILE variables point to files mounted under /run/secrets, so the password is not visible in the container environment or in docker inspect. The output includes the commands to create the secret files.
Each service also gets what makes it reliable: a named data volume at the image’s data path, a health check other services can wait for with depends_on, a port bound to 127.0.0.1 only when you need local access, and a connection string your application can use inside the compose network.