Migrate Grafana/Prometheus/SonarQube from docker-compose to k8s (step #10)

Real data migrated, not a fresh start: 1.2GB Prometheus TSDB, Grafana's
existing dashboards/DB (its admin password was already changed from
default — confirmed real, in-use data), SonarQube's data/logs/extensions
and its own Postgres DB (confirmed: the actual `management-platform`
SonarQube project survived, matching the Jenkinsfile's own
-Dsonar.projectKey). Old docker-compose services stopped, not removed —
left as a rollback path.

Real problems hit and fixed along the way (see k8s/monitoring/README.md
for the full detail, worth reading before touching any of this again):

- k3s's bundled Traefik defaults to a LoadBalancer Service, which
  immediately hijacked ports 80/443 via iptables DNAT (klipper-lb) out
  from under this VM's existing unrelated nginx-served app ("nqks") the
  moment k3s was installed. Patched Traefik to ClusterIP via a
  HelmChartConfig; nginx now reverse-proxies the 3 new domains to
  Traefik's ClusterIP instead of Traefik touching host ports at all.

- Caught my own mistake before it caused damage: "corrected" what I
  assumed was a typo (grafanna.nav.ovh -> grafana.nav.ovh) — the two-N
  version is what the user actually specified, and is what points at this
  VM; plain grafana.nav.ovh is a different, unrelated, pre-existing live
  server at 109.199.127.74. Renamed everything back before requesting any
  cert or touching that domain.

- Adding hostPort to the SonarQube pod (for Jenkins' hardcoded
  178.18.243.51:9000) broke pod-to-pod routing to that pod entirely —
  Traefik couldn't reach it (hung/504) while direct host-to-pod and
  host-to-ClusterIP both worked fine the whole time, which is what gave
  it away. Replaced with a host-level socat proxy (systemd unit) to the
  Service's ClusterIP instead, which touches nothing pod-level. Verified
  Jenkins' exact address still works AND Traefik routing to the same pod
  works simultaneously.

- SonarQube needed a DB migration after the version jump
  (DB_MIGRATION_NEEDED), then OOM'd during post-migration rule
  re-registration on the compose file's original 256MB web heap — bumped
  SONAR_WEB_JAVAADDITIONALOPTS.

TLS: real Let's Encrypt certs via certbot (HTTP-01, nginx already owns
port 80 so no DNS-01/OVH-webhook replication needed on this second
cluster), auto-renewing. Access: HTTP Basic Auth in front of all three
domains for browser access; SonarQube also stays reachable unauthenticated
at 178.18.243.51:9000 specifically for Jenkins (which authenticates via
its own token, not BasicAuth — that path would break the scanner),
restricted to the main server's IP via ufw, not open to the internet.

Verified end-to-end: all three https://*.nav.ovh domains return 401
without credentials and load correctly with them; Jenkins' exact
SonarQube address (no auth) still returns 200; real data confirmed
present in Grafana, Prometheus, and SonarQube post-migration.

k8s/monitoring/README.md

@@ -0,0 +1,72 @@
+# Monitoring stack on k8s (VM: 178.18.243.51)
+
+Migrated from docker-compose (`/root/monitoring`, `/root/CI-CD/sonarqube` on
+the VM — left `docker compose stop`'d, not removed, as a rollback path) into
+the VM's own k3s cluster, with real data migrated (not a fresh start):
+Prometheus TSDB, Grafana dashboards/DB, SonarQube data+DB (confirmed intact:
+the real `management-platform` SonarQube project and Grafana's existing
+admin password both survived).
+
+## Apply order
+```
+kubectl apply -f monitoring-pvcs.yaml
+# migrate data into the PVCs via a loader pod per volume (see chat history —
+# not scripted, was a one-time manual migration)
+kubectl apply -f monitoring-apps.yaml
+kubectl apply -f monitoring-ingress.yaml
+```
+
+## Domains — READ THIS BEFORE TOUCHING DNS
+- `grafanna.nav.ovh` (note: **two Ns** — `grafana.nav.ovh` without the typo
+  is a DIFFERENT, unrelated, pre-existing server at 109.199.127.74. Do not
+  point anything at plain `grafana.nav.ovh` or touch that record.)
+- `sonar.nav.ovh`
+- `prom.nav.ovh`
+
+All three already existed as A records pointing at 178.18.243.51 before this
+work; only `nginx-vhost.conf` + a Let's Encrypt cert (via certbot, HTTP-01,
+auto-renews) make them actually resolve to something.
+
+## Why nginx is in front of Traefik, not Traefik directly on 80/443
+This VM already runs an unrelated app ("nqks") on nginx, owning ports 80/443.
+k3s's bundled Traefik defaults to a LoadBalancer Service, which on a
+single-node k3s claims host 80/443 via iptables DNAT (klipper-lb) —
+this silently hijacked nqks's traffic the first time (found and fixed
+during this session). Traefik's Service is patched to ClusterIP-only via
+a HelmChartConfig (`kubectl get helmchartconfig -n kube-system traefik`);
+nginx reverse-proxies the 3 domains to Traefik's ClusterIP instead, and
+handles TLS + BasicAuth itself.
+
+## Access control
+- Browser access to all 3 domains: HTTP Basic Auth (`/etc/nginx/.htpasswd-monitoring`
+  on the VM, user `admin`) — ask whoever ran this migration for the password,
+  it's not in git.
+- **SonarQube is also reachable directly at `178.18.243.51:9000`, no auth** —
+  this is deliberate, not an oversight. Jenkins' SonarQube server config
+  (main cluster, `hudson.plugins.sonar.SonarGlobalConfiguration.xml`) is
+  hardcoded to that exact address and authenticates via its own token, not
+  BasicAuth (which would break the scanner). `sonarqube-jenkins-proxy.service`
+  (systemd, socat) forwards host:9000 -> the sonarqube Service's ClusterIP;
+  ufw restricts port 9000 to the main server's IP only, not the open
+  internet. Do not add BasicAuth in front of this specific path.
+  - Fragility note: the socat unit hardcodes the Service's ClusterIP. If the
+    `sonarqube` Service in the `monitoring` namespace is ever deleted and
+    recreated (not just the pod — pod recreates keep the same ClusterIP),
+    update the `TCP:<ip>:9000` target in
+    `/etc/systemd/system/sonarqube-jenkins-proxy.service` on the VM to match.
+
+## Gotchas hit building this (context for next time)
+- Don't add a k8s Service of type LoadBalancer on this cluster without first
+  patching it to ClusterIP/setting a HelmChartConfig — same hijack risk as
+  Traefik's default.
+- Don't add `hostPort` to a pod that also needs normal in-cluster (Service/
+  Ingress) traffic to reach it — it breaks pod-to-pod routing to that pod
+  (confirmed directly: Traefik -> sonarqube hung/504'd the whole time
+  hostPort was present, while direct host-to-pod and host-to-ClusterIP both
+  worked fine — the asymmetry was the tell). Use a host-level proxy (socat)
+  or a NodePort in the 30000-32767 range instead.
+- SonarQube's DB was mid-upgrade (`DB_MIGRATION_NEEDED`) after the version
+  jump — needed one `POST /api/system/migrate_db` (admin/admin was already
+  changed on the real instance; used the actual admin session) — and the
+  post-migration rule re-registration OOM'd on the compose file's original
+  256MB web heap; bumped `SONAR_WEB_JAVAADDITIONALOPTS` to `-Xms512m -Xmx1536m`.

k8s/monitoring/monitoring-apps.yaml

@@ -0,0 +1,203 @@
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: prometheus-config
+  namespace: monitoring
+data:
+  prometheus.yml: |
+    global:
+      scrape_interval: 15s
+      evaluation_interval: 15s
+
+    scrape_configs:
+
+      - job_name: 'server1-node'
+        static_configs:
+          - targets: ['173.249.20.244:9100']
+            labels:
+              server: 'server1'
+
+      - job_name: 'my-cadvisor'
+        static_configs:
+          - targets: ['173.249.20.244:8094']
+            labels:
+              server: 'server1'
+              owner: 'ameni'
+
+      - job_name: 'server1-blackbox'
+        static_configs:
+          - targets: ['173.249.20.244:9115']
+            labels:
+              server: 'server1'
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: prometheus
+  namespace: monitoring
+spec:
+  replicas: 1
+  selector:
+    matchLabels: {app: prometheus}
+  strategy: {type: Recreate}
+  template:
+    metadata:
+      labels: {app: prometheus}
+    spec:
+      securityContext:
+        fsGroup: 65534
+      containers:
+        - name: prometheus
+          image: prom/prometheus:latest
+          args:
+            - --config.file=/etc/prometheus/prometheus.yml
+            - --storage.tsdb.retention.time=15d
+            - --storage.tsdb.path=/prometheus
+          ports: [{containerPort: 9090}]
+          resources:
+            limits: {memory: 512Mi}
+          volumeMounts:
+            - {name: config, mountPath: /etc/prometheus/prometheus.yml, subPath: prometheus.yml}
+            - {name: data, mountPath: /prometheus}
+      volumes:
+        - name: config
+          configMap: {name: prometheus-config}
+        - name: data
+          persistentVolumeClaim: {claimName: prometheus-data}
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: prometheus
+  namespace: monitoring
+spec:
+  selector: {app: prometheus}
+  ports: [{port: 9090, targetPort: 9090}]
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: grafana
+  namespace: monitoring
+spec:
+  replicas: 1
+  selector:
+    matchLabels: {app: grafana}
+  strategy: {type: Recreate}
+  template:
+    metadata:
+      labels: {app: grafana}
+    spec:
+      securityContext:
+        fsGroup: 472
+      containers:
+        - name: grafana
+          image: grafana/grafana:latest
+          env:
+            - {name: GF_SECURITY_ADMIN_PASSWORD, value: admin}
+          ports: [{containerPort: 3000}]
+          resources:
+            limits: {memory: 256Mi}
+          volumeMounts:
+            - {name: data, mountPath: /var/lib/grafana}
+      volumes:
+        - name: data
+          persistentVolumeClaim: {claimName: grafana-data}
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: grafana
+  namespace: monitoring
+spec:
+  selector: {app: grafana}
+  ports: [{port: 3000, targetPort: 3000}]
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: sonarqube-db
+  namespace: monitoring
+spec:
+  replicas: 1
+  selector:
+    matchLabels: {app: sonarqube-db}
+  strategy: {type: Recreate}
+  template:
+    metadata:
+      labels: {app: sonarqube-db}
+    spec:
+      securityContext:
+        fsGroup: 999
+      containers:
+        - name: sonarqube-db
+          image: postgres:15
+          env:
+            - {name: POSTGRES_USER, value: sonar}
+            - {name: POSTGRES_PASSWORD, value: sonar}
+            - {name: POSTGRES_DB, value: sonar}
+          ports: [{containerPort: 5432}]
+          volumeMounts:
+            - {name: data, mountPath: /var/lib/postgresql/data}
+      volumes:
+        - name: data
+          persistentVolumeClaim: {claimName: sonarqube-db-data}
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: sonarqube-db
+  namespace: monitoring
+spec:
+  selector: {app: sonarqube-db}
+  ports: [{port: 5432, targetPort: 5432}]
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: sonarqube
+  namespace: monitoring
+spec:
+  replicas: 1
+  selector:
+    matchLabels: {app: sonarqube}
+  strategy: {type: Recreate}
+  template:
+    metadata:
+      labels: {app: sonarqube}
+    spec:
+      securityContext:
+        fsGroup: 1000
+      containers:
+        - name: sonarqube
+          image: sonarqube:community
+          env:
+            - {name: SONAR_ES_BOOTSTRAP_CHECKS_DISABLE, value: "true"}
+            - {name: SONAR_JDBC_URL, value: "jdbc:postgresql://sonarqube-db:5432/sonar"}
+            - {name: SONAR_JDBC_USERNAME, value: sonar}
+            - {name: SONAR_JDBC_PASSWORD, value: sonar}
+            - {name: SONAR_SEARCH_JAVAADDITIONALOPTS, value: "-Xms512m -Xmx512m"}
+            - {name: SONAR_WEB_JAVAADDITIONALOPTS, value: "-Xms512m -Xmx1536m"}
+          ports: [{containerPort: 9000}]
+          resources:
+            limits: {memory: 3Gi}
+          volumeMounts:
+            - {name: data, mountPath: /opt/sonarqube/data}
+            - {name: logs, mountPath: /opt/sonarqube/logs}
+            - {name: extensions, mountPath: /opt/sonarqube/extensions}
+      volumes:
+        - name: data
+          persistentVolumeClaim: {claimName: sonarqube-data}
+        - name: logs
+          persistentVolumeClaim: {claimName: sonarqube-logs}
+        - name: extensions
+          persistentVolumeClaim: {claimName: sonarqube-extensions}
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: sonarqube
+  namespace: monitoring
+spec:
+  selector: {app: sonarqube}
+  ports: [{port: 9000, targetPort: 9000}]

k8s/monitoring/monitoring-ingress.yaml

@@ -0,0 +1,53 @@
+apiVersion: networking.k8s.io/v1
+kind: Ingress
+metadata:
+  name: grafana
+  namespace: monitoring
+spec:
+  ingressClassName: traefik
+  rules:
+    - host: grafana.nav.ovh
+      http:
+        paths:
+          - path: /
+            pathType: Prefix
+            backend:
+              service:
+                name: grafana
+                port: {number: 3000}
+---
+apiVersion: networking.k8s.io/v1
+kind: Ingress
+metadata:
+  name: sonarqube
+  namespace: monitoring
+spec:
+  ingressClassName: traefik
+  rules:
+    - host: sonar.nav.ovh
+      http:
+        paths:
+          - path: /
+            pathType: Prefix
+            backend:
+              service:
+                name: sonarqube
+                port: {number: 9000}
+---
+apiVersion: networking.k8s.io/v1
+kind: Ingress
+metadata:
+  name: prometheus
+  namespace: monitoring
+spec:
+  ingressClassName: traefik
+  rules:
+    - host: prom.nav.ovh
+      http:
+        paths:
+          - path: /
+            pathType: Prefix
+            backend:
+              service:
+                name: prometheus
+                port: {number: 9090}

k8s/monitoring/monitoring-pvcs.yaml

@@ -0,0 +1,76 @@
+apiVersion: v1
+kind: Namespace
+metadata:
+  name: monitoring
+---
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: prometheus-data
+  namespace: monitoring
+spec:
+  accessModes: ["ReadWriteOnce"]
+  resources:
+    requests:
+      storage: 3Gi
+  storageClassName: local-path
+---
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: grafana-data
+  namespace: monitoring
+spec:
+  accessModes: ["ReadWriteOnce"]
+  resources:
+    requests:
+      storage: 1Gi
+  storageClassName: local-path
+---
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: sonarqube-data
+  namespace: monitoring
+spec:
+  accessModes: ["ReadWriteOnce"]
+  resources:
+    requests:
+      storage: 2Gi
+  storageClassName: local-path
+---
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: sonarqube-logs
+  namespace: monitoring
+spec:
+  accessModes: ["ReadWriteOnce"]
+  resources:
+    requests:
+      storage: 1Gi
+  storageClassName: local-path
+---
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: sonarqube-extensions
+  namespace: monitoring
+spec:
+  accessModes: ["ReadWriteOnce"]
+  resources:
+    requests:
+      storage: 1Gi
+  storageClassName: local-path
+---
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: sonarqube-db-data
+  namespace: monitoring
+spec:
+  accessModes: ["ReadWriteOnce"]
+  resources:
+    requests:
+      storage: 1Gi
+  storageClassName: local-path

k8s/monitoring/nginx-vhost.conf

@@ -0,0 +1,102 @@
+server {
+    server_name grafanna.nav.ovh;
+    location / {
+        auth_basic "Restricted";
+        auth_basic_user_file /etc/nginx/.htpasswd-monitoring;
+        proxy_pass http://10.43.200.43;
+        proxy_set_header Host grafanna.nav.ovh;
+        proxy_set_header X-Real-IP $remote_addr;
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+        proxy_set_header X-Forwarded-Proto $scheme;
+        proxy_http_version 1.1;
+        proxy_set_header Upgrade $http_upgrade;
+        proxy_set_header Connection "upgrade";
+    }
+
+    listen 443 ssl; # managed by Certbot
+    ssl_certificate /etc/letsencrypt/live/grafanna.nav.ovh/fullchain.pem; # managed by Certbot
+    ssl_certificate_key /etc/letsencrypt/live/grafanna.nav.ovh/privkey.pem; # managed by Certbot
+    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
+    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot
+
+}
+
+server {
+    server_name sonar.nav.ovh;
+    location / {
+        auth_basic "Restricted";
+        auth_basic_user_file /etc/nginx/.htpasswd-monitoring;
+        proxy_pass http://10.43.200.43;
+        proxy_set_header Host sonar.nav.ovh;
+        proxy_set_header X-Real-IP $remote_addr;
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+        proxy_set_header X-Forwarded-Proto $scheme;
+        proxy_http_version 1.1;
+    }
+
+    listen 443 ssl; # managed by Certbot
+    ssl_certificate /etc/letsencrypt/live/grafanna.nav.ovh/fullchain.pem; # managed by Certbot
+    ssl_certificate_key /etc/letsencrypt/live/grafanna.nav.ovh/privkey.pem; # managed by Certbot
+    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
+    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot
+
+}
+
+server {
+    server_name prom.nav.ovh;
+    location / {
+        auth_basic "Restricted";
+        auth_basic_user_file /etc/nginx/.htpasswd-monitoring;
+        proxy_pass http://10.43.200.43;
+        proxy_set_header Host prom.nav.ovh;
+        proxy_set_header X-Real-IP $remote_addr;
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+        proxy_set_header X-Forwarded-Proto $scheme;
+        proxy_http_version 1.1;
+    }
+
+    listen 443 ssl; # managed by Certbot
+    ssl_certificate /etc/letsencrypt/live/grafanna.nav.ovh/fullchain.pem; # managed by Certbot
+    ssl_certificate_key /etc/letsencrypt/live/grafanna.nav.ovh/privkey.pem; # managed by Certbot
+    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
+    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot
+
+}
+server {
+    if ($host = grafanna.nav.ovh) {
+        return 301 https://$host$request_uri;
+    } # managed by Certbot
+
+
+    listen 80;
+    server_name grafanna.nav.ovh;
+    return 404; # managed by Certbot
+
+
+}
+
+server {
+    if ($host = sonar.nav.ovh) {
+        return 301 https://$host$request_uri;
+    } # managed by Certbot
+
+
+    listen 80;
+    server_name sonar.nav.ovh;
+    return 404; # managed by Certbot
+
+
+}
+
+server {
+    if ($host = prom.nav.ovh) {
+        return 301 https://$host$request_uri;
+    } # managed by Certbot
+
+
+    listen 80;
+    server_name prom.nav.ovh;
+    return 404; # managed by Certbot
+
+
+}

k8s/monitoring/sonarqube-jenkins-proxy.service

@@ -0,0 +1,13 @@
+[Unit]
+Description=TCP proxy: host:9000 -> k8s sonarqube Service ClusterIP:9000 (for Jenkins, which expects this exact address)
+After=k3s.service
+Wants=k3s.service
+
+[Service]
+Type=simple
+ExecStart=/usr/bin/socat TCP-LISTEN:9000,fork,reuseaddr TCP:10.43.4.19:9000
+Restart=always
+RestartSec=5
+
+[Install]
+WantedBy=multi-user.target