Mimik

Simulate being a service (or many) in a mesh.

Helpful to test Istio features like traffic routing, tracing, security and more.

Introduction

Basically what Mimik does is to imitate a service that listens to certain paths and methods, and connects these with upstream connections (that usually are Mimik instances too) forming a service mesh.

Getting started

Mimik instances run on Kubernetes clusters. The easiest way to create them is with Mimik operator. Check the documentation to install it.

Hello World Example

The following example will deploy a minimal mesh based on two services, a frontend and a backend and also configure Istio basic resources to expose the frontend:

apiVersion: mimik.veicot.io/v1alpha1
kind: Mimik
metadata:
  name: hello-world-frontend-v1
  namespace: hello-world
spec:
  service: hello-world-frontend
  version: v1
  endpoints:
    - path: /
      method: GET
      connections:
        - service: hello-world-backend
          port: 8080
          path: hello
          method: GET
---      
apiVersion: mimik.veicot.io/v1alpha1
kind: Mimik
metadata:
  name: hello-world-backend-v1
  namespace: hello-world
spec:
  service: hello-world-backend
  version: v1
  endpoints:
    - path: /hello
      method: GET
      connections: []
---
apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
  name: hello-world
  namespace: hello-world
spec:
  selector:
    istio: ingressgateway
  servers:
    - port:
        number: 80
        name: http
        protocol: HTTP
      hosts:
        - "*"
---
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: hello-world
  namespace: hello-world
spec:
  hosts:
    - "*"
  gateways:
    - hello-world
  http:
    - route:
        - destination:
            host: hello-world-ui
            port:
              number: 8080

After a few requests, the following topology can be seen in the graph generated by Kiali:

Generator

A generator is available to create random topologies and test different situations:

Installation

Create the application:

kubectl create ns topology-generator
kubectl apply -n topology-generator -f https://raw.githubusercontent.com/kiali/demos/master/topology-generator/generator.yaml 

Visit the application through a proxy:

kubectl port-forward svc/topology-generator 8080:8080 -n topology-generator

Configure the following parameters and then generate the topology:

• Number of namespaces
• Number of services per namespace
• Number of connections between services in the same namespace
• Number of random connections between services in different namespaces

Copy the generated command and execute it in a terminal.

As a result, the topology will be created to be observed and managed by Kiali:

Cleanup

Delete all namespaces generated by the application:

kubectl delete ns --selector=generated-by=mimik

Delete the topology generator:

kubectl delete namespace topology-generator