HashiCorp Consul Raft Leader Stability and Quorum Sentinel

id: consul-raft-leader-stability-sentinel
namespace: company.infra

inputs:
  - id: consul_addr
    type: STRING
    defaults: "http://consul.internal:8500"
    description: Host and port of the HashiCorp Consul HTTP API.

tasks:
  - id: inspect_raft_leader
    type: io.kestra.plugin.scripts.shell.Commands
    commands:
      - |
        # Query Consul Raft leader and peer configuration
        curl -s "{{ inputs.consul_addr }}/v1/status/leader" > /tmp/consul_leader.txt
        curl -s "{{ inputs.consul_addr }}/v1/operator/raft/configuration" > /tmp/consul_raft.json

        python3 -c "
        import json
        try:
            with open('/tmp/consul_leader.txt') as f:
                leader = f.read().strip().replace('\"', '')
            with open('/tmp/consul_raft.json') as f:
                raft = json.load(f)
            servers = raft.get('Servers', [])
            voter_count = len([s for s in servers if s.get('Voter', False)])
            is_healthy = 1 if leader and voter_count >= 3 else 0
            is_breach = 1 if is_healthy == 0 else 0
            print(f'{is_breach}|{leader}|{voter_count}')
        except Exception:
            print('1|none|0')
        " > /tmp/consul_summary.txt

        IS_BREACH=$(cut -d '|' -f 1 /tmp/consul_summary.txt)
        LEADER_ADDR=$(cut -d '|' -f 2 /tmp/consul_summary.txt)
        VOTER_COUNT=$(cut -d '|' -f 3 /tmp/consul_summary.txt)

        echo "::set-output name=is_breach::${IS_BREACH:-0}::"
        echo "::set-output name=leader_addr::$LEADER_ADDR::"
        echo "::set-output name=voter_count::$VOTER_COUNT::"

  - id: evaluate_raft_quorum
    type: io.kestra.plugin.core.flow.If
    condition: "{{ outputs.inspect_raft_leader.vars.is_breach | int == 1 }}"
    then:
      - id: notify_infra_team
        type: io.kestra.plugin.slack.notifications.SlackIncomingWebhook
        url: "{{ secret('SLACK_WEBHOOK') }}"
        payload: |
          {
            "channel": "#infra-alerts",
            "attachments": [
              {
                "color": "danger",
                "title": "🚨 HashiCorp Consul Raft Quorum Degradation Alert",
                "text": "Consul Cluster at {{ inputs.consul_addr }} has lost leader stability (Leader: {{ outputs.inspect_raft_leader.vars.leader_addr }}, Active Voters: {{ outputs.inspect_raft_leader.vars.voter_count }}). Risk of split-brain or service discovery collapse.",
                "footer": "Kestra Infrastructure Sentinel • HashiCorp Consul"
              }
            ]
          }

errors:
  - id: alert_pipeline_failure
    type: io.kestra.plugin.slack.notifications.SlackIncomingWebhook
    url: "{{ secret('SLACK_WEBHOOK') }}"
    payload: |
      {
        "channel": "#infra-alerts",
        "attachments": [
          {
            "color": "danger",
            "title": "⚠️ Consul Sentinel Failure",
            "text": "Failed to communicate with HashiCorp Consul HTTP API at {{ inputs.consul_addr }}.",
            "footer": "Kestra Failure Sentinel"
          }
        ]
      }

triggers:
  - id: periodic_schedule
    type: io.kestra.plugin.core.trigger.Schedule
    cron: "*/10 * * * *"
    disabled: true