Hi everyone! I'm a beginner with Docker and Docker Compose, and I'm trying to set up a Mealie instance for testing purposes. I already have PostgreSQL running on my host, complete with a user and database. The default Docker Compose file for Mealie includes 'POSTGRES_SERVER: postgres', which directs it to a PostgreSQL container that's part of that stack, but I want to connect it to my existing PostgreSQL instance instead of using that container. How can I point it to my existing database using a hostname? Alternatively, would using an IP address work? Do I need to format it differently since it's not within a container? Thanks for your help!
3 Answers
If your PostgreSQL instance is running outside of Docker on the host, containers have trouble connecting directly to it. A common solution is to use the special hostname `host.docker.internal` to reach your host services. You'll need to add it to your Docker Compose file under `extra_hosts`, like so:
```
extra_hosts:
- host.docker.internal:host-gateway
```
Then, set the `POSTGRES_SERVER` variable in the Mealie environment to `host.docker.internal`. Just a heads up, using your host's IP directly might not work due to Docker's networking restrictions. Also, be cautious—while it may seem convenient to skip running a separate PostgreSQL container, it's generally best practice to have a dedicated database instance for each project. This keeps everything stable and helps you avoid version compatibility issues down the road!
Just change the `POSTGRES_SERVER` variable in your Mealie setup to your existing server’s IP address or hostname. But remember, if your PostgreSQL service is running on the Docker host, this method might not work directly. It should work just fine if the database is on a different machine in your network, though!
You can definitely take the PostgreSQL service out of your Docker Compose file and skip the `depends_on` section. Just plug in the existing database server's IP address, port number, user, and password details into the Mealie environment variables. That should connect Mealie to your existing database without any issue!
Exactly! Just make sure you're aware of the networking rules with Docker. If it's on the same host, you might need to tweak things a bit to ensure connectivity.