diff --git a/argocd/applications/gitlab-staging/prometheus-application.yaml b/argocd/applications/gitlab-staging/prometheus-application.yaml
index 4ca3f44..5a41537 100644
--- a/argocd/applications/gitlab-staging/prometheus-application.yaml
+++ b/argocd/applications/gitlab-staging/prometheus-application.yaml
@@ -1,77 +1,96 @@
 # Declare the application to manage cert-manager
 apiVersion: argoproj.io/v1alpha1
 kind: Application
 metadata:
   name: gitlab-staging-prometheus
   namespace: argocd
 spec:
   revisionHistoryLimit: 2
   project: default
   source:
     chart: kube-prometheus-stack
     repoURL: https://prometheus-community.github.io/helm-charts
     targetRevision: v41.3.2
     helm:
       releaseName: prometheus
       # The crds must be manually applied to avoid the following error:
       # one or more objects failed to apply, reason: CustomResourceDefinition.apiextensions.k8s.io "prometheuses.monitoring.coreos.com" is invalid: metadata.annotations: Too long: must have at most 262144 bytes
       # it should be possible to fix this error
       # The commands to run can be found on the operator page:
       # https://github.com/prometheus-community/helm-charts/tree/main/charts/kube-prometheus-stack#from-33x-to-34x
       skipCrds: true
       values: |
 
         alertmanager:
           enabled: true  # Temporary for tests
         grafana:
           enabled: true  # Temporary before federation with pergamon
           service:
             port: 3000
             type: LoadBalancer
             loadBalancerIP: 10.240.0.100
             annotations:
               service.beta.kubernetes.io/azure-load-balancer-internal: "true"
         prometheus:
           service:
             annotations:
             type: LoadBalancer
             loadBalancerIP: 10.240.0.100
             annotations:
               service.beta.kubernetes.io/azure-load-balancer-internal: "true"
           prometheusSpec:
             storageSpec: # Make the data persistent across the redeployments
               volumeClaimTemplate:
                 spec:
                   storageClassName: default
                   resources:
                     requests:
                       storage: 10Gi
             podMonitorSelectorNilUsesHelmValues: false
             serviceMonitorSelectorNilUsesHelmValues: false
-            prometheusExternalLabelName: euwest-gitlab-staging
+            prometheusExternalLabelName: euwest_gitlab_staging
             externalLabels:
               environment: staging
               infrastructure: kubernetes
               domain: staging
               cluster: euwest-gitlab-staging
+            thanos:
+              # thanos-objstore-config-secret is installed in namespace cattle-monitoring-system
+              # see k8s-private-data:archive-production/thanos-objstore-config-secret.yaml. And
+              # https://prometheus-operator.dev/docs/operator/thanos/#configuring-thanos-object-storage
+              objectStorageConfig:
+                key: thanos.yaml
+                name: thanos-objstore-config-secret
+          # thanosServiceExternal:
+          #   enable: false
+          #   loadBalancerIP: 10.240.0.100
+          thanosIngress:
+            enabled: true
+            ingressClassName: nginx
+            hosts: ["gitlab-staging-thanos.internal.softwareheritage.org"]
+            loadBalancerIP: 10.240.0.100
+            pathType: Prefix
+            annotations:
+              kubernetes.io/tls-acme: "true"
+              nginx.ingress.kubernetes.io/backend-protocol: GRPC
   destination:
     server: https://192.168.200.13
     namespace: monitoring
   syncPolicy:
     automated:
       prune: true
       selfHeal: true
     syncOptions:
     - RespectIgnoreDifferences=true
   ignoreDifferences:
     - group: '*'
       kind: Service
       name: prometheus-kube-prometheus-kube-controller-manager
       jqPathExpressions:
         - .metadata.labels."app.kubernetes.io/instance"
         - .spec.ports[] | select(.name == "http-metrics")
     - group: '*'
       kind: CustomResourceDefinition
       name: prometheuses.monitoring.coreos.com
       jqPathExpressions:
         - .metadata.annotations."controller-gen.kubebuilder.io/version"
diff --git a/gitlab-staging/namespaces.yaml b/gitlab-staging/namespaces.yaml
index 5c4fc4f..eb14293 100644
--- a/gitlab-staging/namespaces.yaml
+++ b/gitlab-staging/namespaces.yaml
@@ -1,15 +1,20 @@
 ---
 apiVersion: v1
 kind: Namespace
 metadata:
   name: gitlab-system
 ---
 apiVersion: v1
 kind: Namespace
 metadata:
   name: cert-manager
 ---
 apiVersion: v1
 kind: Namespace
 metadata:
   name: monitoring
+---
+apiVersion: v1
+kind: Namespace
+metadata:
+  name: ingress-nginx