Support postgresql

[Tonkonozhenko]

Fixes #148

[klesh]

@JorgeGar @matrixji @ZhangNing10 Would you like to take a look? Thanks

[matrixji]

Do we need to support Postgres? As #148 says, the devlake-dashboard(Grafana) currently supports MySQL syntax only.

[JorgeGar]

The issue with having PSQL supported by the helm chart is that it sends a confusing message. The chart is offering a toolset that includes both devlake and the grafana boards, but PostgreSQL is only supported by the former.
We removed it from the chart because of this very same reason.

[Tonkonozhenko]

@klesh @JorgeGar @matrixji @ZhangNing10 did you think about supporting Postgres?
I decided to switch to PG completely because I want to collect other data too. I want to use some Airflow DAGs to populate it and do transformations with DBT, but I definitely can't rely on https://github.com/dbeatty10/dbt-mysql.

Looks like on the backend everything works for me with a small change: apache/incubator-devlake#7284
The issue is with Grafana. I migrated several dashboards (Dora, Dora Validation, Gitlab) to PostgreSQL, but I don't know how to make a generic solution.

[klesh]

@Tonkonozhenko It would be nice if we could support both. Just like you, we have yet to figure out a generic solution so far. 😂

[Tonkonozhenko]

@klesh the only option I see is extracting SQL queries from dashboards' JSONs and having two queries (or if conditions) per database.

grafana/
  dashboards/
    DORA.json
  queries/
    postgresql/
      01 Overall DORA Metrics.sql
    mysql/
      01 Overall DORA Metrics.sql

It would be great if Grafana had go templating in queries, but it only has it in alerting.

[klesh]

@Tonkonozhenko Maybe you could file a feature request for Grafana?

[Tonkonozhenko]

@klesh I'll try. For now, maybe add support to the chart? I have a working fork: main...Tonkonozhenko:incubator-devlake-helm-chart:main

[klesh]

@richardinemi There is a Space at the beginning of your Connection String, right after the double-quote.

[richardinemi]

@richardinemi There is a Space at the beginning of your Connection String, right after the double-quote.

I found the problem. It’s work now.
Thank you @klesh .