[Task (CI)]: start postgres server to run graphql e2e tests

[kodemartin]

Description

After merging #1969 iota-graphql-e2e-tests will run successfully in a local setup.

Thus, we could run the tests also in the CI, subject to starting a postgres server before running the tests.

The most straight forward way is to use a docker image directly:

docker run -d --name postgres \
 -e POSTGRES_PASSWORD=postgrespw \
 -e POSTGRES_INITDB_ARGS="-U postgres" \
 -p 5432:5432 \
 postgres:15 \
 -c max_connections=1000

[thibault-martinez]

According to the Github docs, the way we are using the postgres service is good. I wish there was a way to share the service across workflows because it's used in two of them but couldn't find ahything.

Before I close the issues, some questions for you:

• Is it important we use postgres:15 specifically?
• Is it important we set max_connections=1000?
• Is POSTGRES_INITDB_ARGS="-U postgres" equivalent to POSTGRES_USER=postgres?

I'll adapt our services accordingly.

[kodemartin]

* Is it important we use `postgres:15` specifically?

This is the version we use in the iota-private-network and I suppose this is the one that we have already deployed in alphanet. Right @junwei0117 ?

* Is it important we set `max_connections=1000`?

No.

* Is `POSTGRES_INITDB_ARGS="-U postgres"` equivalent to `POSTGRES_USER=postgres`?

No, but not necessary as well, since the current setup works.

Thanks @thibault-martinez

[thibault-martinez]

* Is it important we use `postgres:15` specifically?

This is the version we use in the iota-private-network and I suppose this is the one that we have already deployed in alphanet. Right @junwei0117 ?

Opened a PR to use postgres:15 for consistency, apart from that I think we're fine to close this issue.