Prometheus source plugin

[huseyinbabal]

Description

Changes proposed in this pull request:

• prometheus source plugin is added.

Test

Checkout branch

gh pr checkout 942

Build plugins

make build-plugins

Generate plugin index

PLUGIN_DOWNLOAD_URL_BASE_PATH=http://localhost:8080/dist make gen-plugins-index

Run local plugin repository

npx serve --listen 8080

Install Prometheus stack in k8s

helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
helm repo update
helm install prom prometheus-community/kube-prometheus-stack

Export prometheus endpoint

kubectl port-forward prometheus-botkube-kube-prometheus-st-prometheus-0 9090

Prepare botkube config

## /tmp/botkubecfg.yaml
communications:
  'default-group':
    # Settings for Slack
    socketSlack:
      enabled: true
      appToken: "xapp...."
      botToken: "xoxb..."
      notification:
        type: "long" # TODO: Change to `short` during testing
      channels:
        'default':
          name: botkube-demo
          bindings:
            sources:
              - plugin-based

settings:
  clusterName: gke-playground
  configWatcher: true
  lifecycleServer:
    deployment:
      name: botkube
      namespace: botkube
    port: "2113"

configWatcher:
  enabled: false
  initialSyncTimeout: 0

sources:
  'plugin-based':
    botkube/prometheus:
      enabled: true
      config:
        url: http://localhost:9090
        ignoreOldAlerts: false
        alertStates: ["pending"]

plugins:
  repositories:
    botkube:
      url: http://localhost:8080/plugins-index.yaml

Run botkube

export BOTKUBE_CONFIG_PATHS="./helm/botkube/values.yaml,/tmp/botkubecfg.yaml"
export BOTKUBE_SETTINGS_KUBECONFIG="/path/to/.kube/config"

go run cmd/botkube/main.go

Deploy problematic nginx

kubectl run nginx --image nginx:1.23_err -n default

Related issue(s)

#849

[huseyinbabal]

@mszostok addressed all of your suggestions except this one, let me know what you think about that. Thanks :)

[mszostok]

LGTM 🚀

[mszostok]

Suggested change

	"title": "botkube/prometheus",
	"title": "Prometheus",

the repository name can be change in different part of the configuration, so I would not put that here.

[mszostok]

nit

we can move it to Stream method, same as you did with MergeConfigs, so you will return an error there

	prometheus, err := p.getPrometheusClient(config.URL)
	if err != nil {
		return source.StreamOutput{}, fmt.Errorf("while creating Prometheus client: %w", err)
	}

or move that into for loop, and just do the log.Errorf only, so client creation will be "retried" in case of error.

[huseyinbabal]

ok I kept it in consumeAlerts function, and removed mutex