# Multi-site active failover pilot (see
# /home/scooby/.claude/plans/jiggly-snacking-iverson.md) - home's half of
# the failover-watcher. This is deliberately NOT a general Postgres HA
# controller: its only job is writing a fresh unix timestamp to etcd every
# 10s at key /ha-failover/home-heartbeat. The VPS's watcher
# (scripts/ha-failover-watcher.sh, deployed via systemd - see that
# script's own header) reads this key and decides whether to promote
# based purely on how stale it is - no custom voting/consensus logic
# needed here, etcd's own Raft consensus already provides the "majority
# agrees" guarantee: a write only succeeds if a majority of the 3 etcd
# members (home/vps/witness) are reachable and agree, and a linearizable
# read (the JSON gateway's default) only ever returns majority-confirmed
# state.
#
# Talks to etcd via its LOCAL ClusterIP (ha-etcd.ha-failover.svc.cluster.local
# :2379) - home reads/writes its OWN cluster member directly, no need to
# round-trip externally for this side.
#
# No RBAC/ServiceAccount needed - this pod never touches the K8s API,
# only etcd's HTTP gateway via curl.
apiVersion: v1
kind: ConfigMap
metadata:
  name: ha-heartbeat-script
  namespace: ha-failover
data:
  heartbeat.sh: |
    #!/bin/sh
    set -eu
    KEY_B64="$(printf '%s' '/ha-failover/home-heartbeat' | base64 | tr -d '\n')"
    while true; do
      NOW="$(date +%s)"
      VAL_B64="$(printf '%s' "$NOW" | base64 | tr -d '\n')"
      if curl -sf --max-time 5 -X POST \
          http://ha-etcd.ha-failover.svc.cluster.local:2379/v3/kv/put \
          -d "{\"key\":\"${KEY_B64}\",\"value\":\"${VAL_B64}\"}" >/dev/null; then
        echo "heartbeat ${NOW} ok"
      else
        echo "heartbeat ${NOW} FAILED (etcd unreachable or no quorum)"
      fi
      sleep 10
    done
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: ha-heartbeat-writer
  namespace: ha-failover
spec:
  replicas: 1
  selector:
    matchLabels:
      app: ha-heartbeat-writer
  template:
    metadata:
      labels:
        app: ha-heartbeat-writer
    spec:
      securityContext:
        runAsNonRoot: true
        runAsUser: 1000
        seccompProfile:
          type: RuntimeDefault
      containers:
        - name: heartbeat
          image: alpine/k8s:1.32.13
          command: ["/bin/sh", "/scripts/heartbeat.sh"]
          securityContext:
            allowPrivilegeEscalation: false
            capabilities:
              drop: ["ALL"]
          resources:
            requests:
              cpu: 5m
              memory: 16Mi
            limits:
              memory: 64Mi
          volumeMounts:
            - name: script
              mountPath: /scripts
      volumes:
        - name: script
          configMap:
            name: ha-heartbeat-script
            defaultMode: 0755