#!/usr/bin/env bash
# Despliega unibus_exporter en un nodo (por defecto magnus, el hub) como servicio
# systemd. El exporter sondea el /healthz de los 3 nodos del cluster unibus por
# IP pública y empuja métricas de estado/posture a la VictoriaMetrics local.
#
# Uso: ./deploy_unibus_exporter.sh [node_name] [ssh_host]
#   node_name : nombre lógico del host donde corre el exporter (default magnus)
#   ssh_host  : alias SSH de ese host (default om)
#
# Requisitos:
#   - Go instalado localmente (compila el binario amd64).
#   - La CA del cluster unibus en projects/message_bus/apps/unibus/deploy/tls/ca.crt
#     (o cluster/out/<n>/ca.crt — son idénticas).
#   - sudo -n (sin password) en el host remoto.
set -euo pipefail

NODE="${1:-magnus}"
HOST="${2:-om}"

ROOT="$(cd "$(dirname "$0")/.." && pwd)"          # projects/fleet_monitoring
APP="$ROOT/apps/unibus_exporter"
CA="$ROOT/../message_bus/apps/unibus/deploy/tls/ca.crt"
HUB="http://127.0.0.1:8428/api/v1/import/prometheus"   # VM local en el hub (sin auth)

[ -f "$CA" ] || { echo "ERROR: falta la CA del cluster en $CA"; exit 1; }

echo ">> compilando unibus_exporter (linux/amd64)"
mkdir -p "$APP/dist"
( cd "$APP" && CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -ldflags="-s -w" -o dist/unibus_exporter_amd64 . )
BIN="$APP/dist/unibus_exporter_amd64"

echo ">> subiendo binario + CA a $HOST"
scp -q -o BatchMode=yes "$BIN" "$HOST:/tmp/unibus_exporter"
scp -q -o BatchMode=yes "$CA" "$HOST:/tmp/unibus_ca.crt"

echo ">> instalando servicio en $NODE ($HOST)"
ssh -o BatchMode=yes "$HOST" "NODE='$NODE' HUB='$HUB' bash -s" <<'OUTER'
set -e
sudo -n mkdir -p /opt/unibus-exporter /etc/unibus-exporter
sudo -n mv /tmp/unibus_exporter /opt/unibus-exporter/unibus_exporter
sudo -n chmod 755 /opt/unibus-exporter/unibus_exporter
sudo -n mv /tmp/unibus_ca.crt /etc/unibus-exporter/ca.crt
sudo -n chmod 644 /etc/unibus-exporter/ca.crt
sudo -n tee /etc/unibus-exporter/unibus.json >/dev/null <<JSON
{
  "nodes": [
    { "name": "magnus",   "url": "https://135.125.201.30:8470/healthz" },
    { "name": "homer",    "url": "https://141.94.69.66:8470/healthz" },
    { "name": "datardos", "url": "https://51.91.100.142:8470/healthz" }
  ],
  "ca_cert_path": "/etc/unibus-exporter/ca.crt",
  "hub_url": "${HUB}",
  "user": "",
  "pass": "",
  "interval_sec": 15,
  "timeout_sec": 8,
  "labels": { "job": "unibus_exporter" }
}
JSON
sudo -n chmod 600 /etc/unibus-exporter/unibus.json
sudo -n tee /etc/systemd/system/unibus-exporter.service >/dev/null <<'UNIT'
[Unit]
Description=unibus cluster exporter (fleet_monitoring)
After=network-online.target
Wants=network-online.target

[Service]
Type=simple
ExecStart=/opt/unibus-exporter/unibus_exporter -config /etc/unibus-exporter/unibus.json
Restart=always
RestartSec=10
NoNewPrivileges=true

[Install]
WantedBy=multi-user.target
UNIT
sudo -n systemctl daemon-reload
sudo -n systemctl enable unibus-exporter >/dev/null 2>&1
sudo -n systemctl restart unibus-exporter
sleep 3
echo -n "status: "; systemctl is-active unibus-exporter
OUTER

echo ">> $NODE: unibus_exporter desplegado"