TLS proxy

Serve a Kubernetes deployment over HTTPS through an ingress, a load balancer or HAProxy.

Inside the pod, the container’s nginx serves plain HTTP on port 80. HTTPS ends in front of the pods: in your ingress controller, your cloud load balancer, or HAProxy as in Horizontal scaling. The Toolkit’s NGINX proxy (bin/init --tls, NGINX_* and TLS_* in overleaf.rc) has no counterpart; see TLS proxy for the Toolkit.

Service	your ingress or load balancer; web reads the settings below when it starts
Browser → proxy	HTTPS on 443, including the editor’s WebSocket
Proxy → pods	plain HTTP to port 80 of the pods
Periodic jobs	none (certificate renewal is your proxy’s business)

What the proxy must do

• Pass WebSockets (/socket.io).
• Allow requests of 10 minutes (long compiles) and request bodies of 50 MB (uploads), or MAX_UPLOAD_SIZE.
• Keep its idle keep-alive timeout towards the pods below 65 seconds, the timeout of the nginx in the pod.
• Send X-Forwarded-For and X-Forwarded-Proto: https.
• With several replicas, keep a user on one replica, see Horizontal scaling.

ConfigMap

  OVERLEAF_SITE_URL: https://overleaf.example.com
  OVERLEAF_SECURE_COOKIE: "true"
  # loopback plus the network the proxy connects from; 10.244.0.0/16 is flannel's pod network
  OVERLEAF_TRUSTED_PROXY_IPS: loopback,10.244.0.0/16

kubectl apply -f 30-config.yaml
kubectl -n overleaf rollout restart deployment/overleaf     # or statefulset/overleaf

Without X-Forwarded-Proto: https from a trusted address, Ayakaleaf Pro thinks requests arrive over HTTP and does not set its secure session cookie: logins then fail. Set OVERLEAF_SECURE_COOKIE only when users really reach the site over HTTPS; any value turns it on, also "false".

HAProxy example

To terminate HTTPS in the HAProxy DaemonSet of Horizontal scaling, put the certificate and its key into one PEM file and a Secret:

cat certificate.pem key.pem > tls.pem
kubectl -n overleaf create secret generic haproxy-tls --from-file=tls.pem

Then change 80-haproxy.yaml:

80-haproxy.yaml (changes)

    listen overleaf
      bind :8080
      bind :8443 ssl crt /etc/haproxy-certs/tls.pem
      http-request redirect scheme https unless { ssl_fc }
      http-request set-header X-Forwarded-Proto https if { ssl_fc }
      option forwardfor
      # ... rest unchanged
---
# DaemonSet: mount the Secret and open the port
          ports:
            - containerPort: 8080
            - containerPort: 8443
          volumeMounts:
            - {name: config, mountPath: /usr/local/etc/haproxy}
            - {name: tls, mountPath: /etc/haproxy-certs, readOnly: true}
      volumes:
        - name: config
          configMap:
            name: haproxy-config
        - name: tls
          secret:
            secretName: haproxy-tls
---
# Service
  ports:
    - {name: http, port: 80, targetPort: 8080, nodePort: 30081}
    - {name: https, port: 443, targetPort: 8443, nodePort: 30443}

Bump config-hash so that HAProxy restarts, then set the ConfigMap as above and restart the replicas.

The redirect keeps the port of the request: it suits a load balancer on ports 80 and 443, but on the NodePorts it sends http://host:30081 to https://host:30081. Without a load balancer in front, leave the redirect line out and give users the https://...:30443 address.

Tested on Kubernetes

On Kubernetes 1.37 with three replicas and HAProxy terminating HTTPS as above, with OVERLEAF_SITE_URL on https:// and OVERLEAF_SECURE_COOKIE: users activated through https:// links, logged in with a session cookie marked Secure, uploaded and compiled projects with the PDF fetched, stayed on their replica, opened the editor’s WebSocket (wss), and cloned and pushed with Git over HTTPS. http:// requests on the NodePort were redirected to https:// with the same port, as described above.