Support to deploy prometheus stack for greptimedb observability

[zyy17]

Background

When starting a greptimedb cluster, we always want to observe it through metrics and visualize them using Grafana. The doc shows some deploying details:

1. Start the GreptimeDB;
2. Start the Prometheus(maybe we can run another greptimedb instance in the future);
3. Start the Grafana;
4. Import the Grafana dashboard(not in the doc);

It's not convenient to deploy Prometheus and Grafana separately.

In my opinion, maybe we can integrate the process into gtctl. For example, we can add the cli options --deploy-prometheus and --deploy-grafana:

gtctl cluster create mydb \
  --deploy-prometheus \
  --deploy-grafana

After the deployment, we can open the URL link to observe the GreptimeDB.

Challenges

We can reuse the code of deploying GreptimeDB to deploy the Prometheus stack. For example:

1. For bare-metal mode, we can download the binary of prometheus and grafana and then start the deployment;
2. For K8s mode, we can download the chart to deploy the Prometheus stack;

However, we still need to:

1. Make the original code clean and have a good interface to reuse. Maybe it still has some refactoring work to do;
2. Don't make the deployment too complicated to use. The whole developer experience must be as smooth as we can;

[JetSquirrel]

I'd like to work this issue, can you assign to me and provide more context?

[zyy17]

@JetSquirrel That's great 😊! I appreciate you taking this on.

I have added background and challenges to the original issue. Is the entire issue clear enough for you?

[JetSquirrel]

@zyy17 great! I think it's enough. Thank you for providing me information. I'd like to try. Please assign to me.

[zyy17]

@JetSquirrel already assigned. Feel free to ask if you have any questions 🤝!