Nginx proxy for basic-auth from Loki to AlertManager

nginx-proxy-to-alertmanager.yaml

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-proxy-to-alertmanager
  namespace: kube-system
  labels:
    app: nginx-proxy-to-alertmanager
    group: monitoring
    component: loki
spec:
  selector:
    matchLabels:
      app: nginx-proxy-to-alertmanager
  replicas: 1
  template:
    metadata:
      labels:
        app: nginx-proxy-to-alertmanager
    spec:
      containers:
      - name: nginx
        image: nginx:1.20.0
        ports:
        - containerPort: 9093
        env:
        - name: NGINX_PORT
          value: "9093"
        volumeMounts:
        - name: config
          mountPath: /etc/nginx/conf.d/
      volumes:
      - name: config
        configMap:
          name: nginx-proxy-to-alertmanager
---
apiVersion: v1
kind: Service
metadata:
  name: nginx-proxy-to-alertmanager
  namespace: kube-system
  labels:
    app: nginx-proxy-to-alertmanager
    group: monitoring
    component: loki
spec:
  type: ClusterIP
  sessionAffinity: None
  ports:
  - name: http
    port: 9093
    protocol: TCP
    targetPort: 9093
  selector:
    app: nginx-proxy-to-alertmanager
---
apiVersion: v1
kind: ConfigMap
metadata:
  labels:
    app: nginx-proxy-to-alertmanager
    group: monitoring
    component: loki
  name: nginx-proxy-to-alertmanager
  namespace: kube-system
data:
  nginx-proxy-to-alertmanager.conf: |
    server {
      listen       9093;
      server_name  _;

      location / {
        proxy_pass https://<ALERTMANAGER_URL_WITHOUT_PORT>;
        proxy_set_header Authorization "Basic <BASE64_PASSWORD>";
      }
      location /api/v1/alerts {
        proxy_pass https://<ALERTMANAGER_URL_WITHOUT_PORT>;
        proxy_set_header Authorization "Basic <BASE64_PASSWORD>";
      }
    }