feat(service): adding install support for promtail

If you setup an API url in the service configuration,
the postdeploy script will install promtail and configure it to
use the provided URL.

Fixes #15

one-appliance/service.d/postdeploy.sh

@@ -239,6 +239,25 @@ installCertManager() {
 
 }
 
+installPromtail() {
+  loki_server_url=$(onegate vm show --json | jq -rc ".VM.USER_TEMPLATE.LOKI_SERVER_URL")
+  if [ "${loki_server_url}" = "disabled" ]; then
+    echo "[INFO] Loki service support is disabled"
+    return 0
+  elif [ "${loki_server_url}" = "local" ]; then
+    echo "[INFO] Installing loki stack in place"
+    #FIXME
+    echo "[WARN] loki-stack local install not implemented yet (it's a bad idea)"
+    return 0
+  fi
+
+  echo "[INFO] Installing promtail with URL '${loki_server_url}'"
+  helm repo add grafana https://grafana.github.io/helm-charts
+  helm repo update
+  helm upgrade --install promtail grafana/promtail --set "config.lokiAddress='${loki_server_url}'"
+  return $?
+}
+
 setupHelmRepos() {
   echo "[INFO] Setup Helm repositories"
 
@@ -328,7 +347,15 @@ if [ "$?" -ne 0 ]; then
 fi
 
 installCertManager
+if [ "${?}" -ne 0 ]; then
+  echo "[ERROR} Certmanager installation failed !"
+  _end_log
+  exit 8
+fi
+
+installPromtail
 res="${?}"
+
 _end_log
 
 exit "${res}"