Docker Compose File Generator

Most sample compose files on the web have been copied so many times that the indentation has drifted, and the failure lands on whoever pastes it. This generates a complete docker-compose.yml — an application service published on a development port, a data store reachable only inside the network, a named volume and an explicit network — and then reads the YAML back with a separate parser and checks it against compose's own rules before showing it to you.

What this generator does

Builds a two-service compose file as data, renders it to YAML, then reads that YAML back with an independent parser and compares the result field for field. It then checks what compose itself requires: every service has an image or a build, every published port is a valid host:container mapping, every dependency names a service in the same file, and every network a service joins is declared.

How to use this tool

Generate a compose file.
Read the two services and how they are wired together.
Check the verification note under the file.
Copy it, replace the placeholder password, and adjust the image tags for your project.

Understanding the controls

Generate: Draws a fresh combination of application image, data store, ports and project name. Everything else about the file's shape stays the same, because that shape is what makes it a compose file.

Common use cases

Starting a local development stack without writing YAML from memory
Showing someone the shape of a compose file with a database in it
Producing a fixture for testing a tool that reads compose files
Checking your own file against a known-good structure
Teaching how compose networking lets one service address another by name

How this generator works

The file is built as a data structure first, which is what makes the check possible: the YAML is written from it, and then read back into a second data structure by a parser that knows nothing about the writer. If the two differ — an indentation off by a level, a value containing a colon that should have been quoted — the page says so instead of showing the file. Port mappings like 8080:80 are exactly the case that breaks naive YAML writers, since unquoted they can be read as a sexagesimal number.

Randomness and fairness

Images, ports, project names and the data store are drawn with the browser's cryptographic random source. Published ports are always in the 3000-9999 range, so a sample never suggests binding a privileged port.

For how randomness is produced across the whole site, see how Generate Random works.

Limitations and good to know

It writes the modern schema with no top-level version key, which recent Docker Compose expects and very old versions do not.
Two services only — a real stack often has more, and this is a starting shape rather than a finished deployment.
Healthchecks, build contexts, secrets and profiles are not covered.
The check confirms the file is well-formed compose, not that the images exist or that the services would actually start.

Privacy and your data

The file is built entirely in your browser from built-in sample values. You enter nothing, nothing is uploaded or stored, and analytics records only that the tool ran.