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FSM Ingress Controller

Kubernetes Ingress Controller implementation provided by FSM

The Kubernetes Ingress API is designed with a separation of concerns, where the Ingress implementation provides an entry feature infrastructure managed by operations staff; it also allows application owners to control the routing of requests to the backend through rules.

Ingress is an API object for managing external access to services in a cluster, with typical access through HTTP. It provides load balancing, SSL termination, and name-based virtual hosting. For the Ingress resource to work, the cluster must have a running Ingress controller.

Ingress controller configures the HTTP load balancer by monitoring Ingress resources in the cluster.

1 - Installation

Enable Ingress Controller in cluster



  • Kubernetes cluster version v1.19.0 or higher.
  • FSM version >= v1.1.0.
  • FSM CLI to install FSM and enable FSM Ingress.

There are two options to install FSM Ingress Controller. One is installing it along with FSM during FSM installation. It won’t be enabled by default so we need to enable it explicitly:

fsm install \

Another is installing it separately if you already have FSM mesh installed.

Using the fsm command line tool to enable FSM Ingress Controller.

fsm ingress enable

Check the resource.

kubectl get pod,svc -n fsm-system -l app=fsm-ingress                                                                            
NAME                               READY   STATUS    RESTARTS   AGE
pod/fsm-ingress-574465b678-xj8l6   1/1     Running   0          14h

NAME                  TYPE           CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
service/fsm-ingress   LoadBalancer      80:30508/TCP   14h

Once all done, we can start to play with FSM Ingress Controller.

2 - Basics

Guide on basics of FSM Ingress basics


3 - Advanced TLS

Guide on configuring FSM Ingress with TLS and its advanced use

FSM Ingress Controller - Advanced TLS

In the document of FSM Ingress Controller, we introduced FSM Ingress and some of its basic functinoality. In this part of series, we will continue on where we left and look into advanced TLS features and we can configure FSM Ingress to use them.

Normally, we see below four combinations of communication with upstream services

  • Client -> HTTP Ingress -> HTTP Upstream
  • Client -> HTTPS Ingress -> HTTP Upstream
  • Client -> HTTP Ingress -> HTTPS Upstream
  • Client -> HTTPS Ingress -> HTTPS Upstream

Two of the above combinations has been covered in basics introduction blog post and in this article we will introduce the remaining two combinations i.e. communicating with an upstream HTTPS service.

  • HTTPS Upstream: The certificate of the backend service, the upstream, must be checked.
  • Client Verification: Mainly when using HTTPS entrance, the certificate used by the client is checked.



4 - TLS Passthrough

Guide on configuring TLS offloading/termination, passthrough on FSM Ingress

FSM Ingress Controller - TLS Passthrough

This guide will demonstrate TLS passthrough feature of FSM Ingress.

What is TLS passthrough

TLS (Secure Socket Layer), also known as TLS (Transport Layer Security), protects the security communication between the client and the server through encryption.


TLS Passthrough is one of the two ways that a proxy server handles TLS requests (the other is TLS offload). In TLS passthrough mode, the proxy does not decrypt the TLS request from the client but instead forwards it to the upstream server for decryption, meaning the data remains encrypted while passing through the proxy, thus ensuring the security of important and sensitive data.

Advantages of TLS passthrough

  • Since the data is not decrypted on the proxy but is forwarded to the upstream server in an encrypted manner, the data is protected from network attacks.
  • Encrypted data arrives at the upstream server without decryption, ensuring the confidentiality of the data.
  • This is also the simplest method of configuring TLS for the proxy.

Disadvantages of TLS passthrough

  • Malicious code may be present in the traffic, which will directly reach the backend server.
  • In the TLS passthrough process, switching servers is not possible.
  • Layer-7 traffic processing cannot be performed.


The TLS passthrough feature can be enabled during installation of FSM.

fsm install --set=fsm.image.registry=addozhang --set=fsm.image.tag=latest-main --set=fsm.fsmIngress.enabled=true --set=fsm.fsmIngress.tls.enabled=true --set=fsm.fsmIngress.tls.sslPassthrough.enabled=true

Or you can enable it during FSM Ingress enabling when already have FSM installed.

fsm ingress enable --tls-enable --passthrough-enable