manage database from erlang shipment

[ToddG]

CONTEXT

I have 3 hosts: [build, web, db]

On build, I build the gleam web app:

gleam export erlang-shipment

I tar the shipment up and extract it into web.

In web, I want to run my database migration scripts to update my database in db host.

ERROR

On web hos:

# cd to the directory with the entrypoint.sh
cd $APP_DIR
 
# show what's here
[root@web] # ls $APP_NAME/
ebin    include priv

# we have all the db migrations:
[root@web]# ls $APP_NAME/priv/migrations/
20250101010101-foo-01.sql
...

# cigogne fails to run b/c it cannot find the gleam.toml file
[root@web]# gleam run -m cigogne up
error: Project not found

We were unable to find gleam.toml.

We searched in /opt/file/app/gws and all parent directories.

DISCUSSION

I'd like to use cigogne from the deployed app rather than from the source code because:

1. I use ansible for my infrastructure as code (IAC) and with this I can automate my database management across my server fleet
2. For reasons, I don't want to push my source code to my web or db hosts
3. For reasons, I don't want to install sshd or open ssh ports on my web or db hosts

I have a firewall and postgresql pg_hba.conf rules that only allow traffic from the web host to the db host. So I'd like all db management to originate from the web host, but without the application source code installed.

I'll try to sort out work-arounds to unblock my work... for starters I'll temporarily bring in the source code and see if I can get cigogne to work with that.

[Billuc]

Hi !
I get why you are doing things that way ! However, I don't think the issue is related to cigogne.
The error you get is a Gleam one. Gleam is looking for the gleam.toml file when running gleam run while cigogne only uses cigogne.toml as a configuration file (for now).
I think you'll have to adapt the way you run cigogne. I'll make some tests to try and help you 😉

[Billuc]

Okay my bad, we do look for the gleam.toml file to get the application name ! However, I still think the error you get is from Gleam. I managed to go further by running erl -pa ./*/ebin -eval "cigogne:main()" -extra "show", but I get an error from cigogne because of the missing gleam.toml file...

I now wonder how other libraries that require a gleam.toml file do...

[ToddG]

Bill,

While I really like cigogne, I found an existing db migration tool in freebsd that's working well for me and my use case:

https://pressly.github.io/goose/

I'll use goose for awhile and see how things go, and swing back to cigogne if goose doesn't work out.

Thank you!

[Billuc]

Hi, use whatever work best for you 😉