Added n8n to samples

[KevyVo]

By popular require, n8n is added to the list of samples. Since we do not support volumes right now, all the volumes in the compose.dev.yaml will be used for only local development.

Here are some resources I used while developing this:

• https://github.com/n8n-io/n8n-hosting/tree/main/docker-compose/withPostgres
• https://docs.n8n.io/hosting/installation/server-setups/docker-compose/

Samples Checklist

✅ All good!

[raphaeltm]

@KevyVo extends relationship should be reversed: the compose.dev.yaml file should extend the compose.yaml file and modify things that are dev-specific.

[raphaeltm]

@KevyVo you referenced the external storage docs in the PR description, but I don't see it used here.

I'd recommend adding those env vars in here and then documenting any additional steps. Tigris Data is a free option we can point people to that offers s3-compatible storage.

[raphaeltm]

Production compose.yaml file should include the x-defang-postgres extension.

[raphaeltm]

If we say it's not compatible with Defang, I think we should highlight why/what isn't compatible.

[raphaeltm]

One awkward thing is that any .env file we put here will be loaded when we run defang compose up because the docker SDK will pick it up. Config vals should override them but I believe they won't be marked as missing if the .env file exists. I'd recommend hard-coding in the development compose file for that reason.

[lionello]

I personally prefer if compose.yaml is for local/dev and compose.prod.yaml extends that one.

[raphaeltm]

I personally prefer if compose.yaml is for local/dev and compose.prod.yaml extends that one.

We had so many conversations about this and I used to push that idea, but we collectively agreed a long time ago that that was exactly what we wanted to avoid because it means passing an extra -f flag to get things deployed properly with Defang. That's why we structured every other sample with compose.yaml to cloud, and compose.dev.yaml for local dev.