/polaris-controller

K8s Controller for K8s Service Sync and Polaris Sidecar Injection

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Polaris Controller

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Introduce

polaris-controller For the docking of Polaris and K8s ecology, providing two optional functions:

  • K8s Service Sync to Polaris: Sync K8s Service to Polaris, use Polaris for service discovery and governance
  • polaris-sidecar Auto-inject: inject polaris-sidecar in app pod

The operating mode of sidecar in the Polaris-Controller provides two optional functions:

  • LocalDNS (dns): Inject polaris-sidecar, realize service discovery and governance by intercepting DNS requests
  • ServiceMesh (mesh): Inject polaris-sidecar and envoy, realize service discovery and governance through hijacking traffic, and develop low invasion

This document describes how to install and use polaris-controller in a K8s cluster.

Installation

Official documentation

Annotations

Annotations name Annotations description
polarismesh.cn/sync Whether to synchronize this service to Polarismesh.TRUE synchronization, False is not synchronized, default is not synchronized
polarismesh.cn/aliasService Synchronize K8S Service to PolarisMesh, and the name of the service alias created at the same time
polarismesh.cn/aliasNamespace The named space where the owner is located, with PolarisMesh.cn/aliasservice use

Guidance

Full synchronization service

Start polaris-controller in full synchronization service mode, and synchronize all K8s services to Polaris. The startup configuration is as follows:

apiVersion: v1
kind: ConfigMap
data:
  mesh: |-
    serviceSync
      mode: "all"

On-demand sync service

Start polaris-controller in the mode of on-demand synchronization service. By default, K8s Service will not be synchronized to Polaris. The startup configuration is as follows:

apiVersion: v1
kind: ConfigMap
data:
  mesh: |-
    serviceSync
      mode: "demand"

If you need to synchronize all services in a Namespace to Polaris, please add Polaris annotation on the Namespace, the configuration is as follows:

apiVersion: v1
kind: Namespace
metadata:
  name: default
  annotations:
    polarismesh.cn/sync: "true"

If you need to synchronize a Service to Polaris, please add the Polaris annotation on the Service, the configuration is as follows:

apiVersion: v1
kind: Service
metadata:
  namespace: default
  name: test
  annotations:
    polarismesh.cn/sync: "true"

If you need to synchronize a Service in a Namespace to Polaris and exclude a Service, the configuration is as follows:

apiVersion: v1
kind: Namespace
metadata:
  name: default
  annotations:
    polarismesh.cn/sync: "true"

apiVersion: v1
kind: Service
metadata:
  namespace: default
  name: test
  annotations:
    polarismesh.cn/sync: "false"

Create service alias

Polaris supports the function of service alias, allowing one or more service aliases to be set for a service. The effect of using service alias for service discovery is the same as that of using service name for service discovery.

The name mapping rules for polaris-controller to synchronize K8s Service to Polaris are as follows:

  • K8s Namespace as Polaris namespace name
  • K8s Service as the service name of Polaris

If you need to create a service alias for Service when it is synchronized to Polaris, the configuration is as follows:

apiVersion: v1
kind: Service
metadata:
  namespace: default
  name: test
  annotations:
    polarismesh.cn/aliasNamespace: aliasDefault
    polarismesh.cn/aliasService: aliasTest

Sidecar auto inject

If polaris-sidecar needs to be used, it can be automatically injected in the application Pod, and the configuration is as follows:

kubectl label namespace default polaris-injection=enabled 

Check whether K8s Namespace supports automatic injection of polaris-sidecar:

kubectl get namespace -L polaris-injection

NAME             STATUS   AGE    POLARIS-INJECTION
default          Active   3d2h   enabled

View the operation mode after polaris-sidecar injection corresponding to K8s Namespace:

kubectl get namespace -L polaris-sidecar-mode

NAME              STATUS   AGE   POLARIS-SIDECAR-MODE
default           Active   10d   mesh

After automatic injection is enabled, newly created Pods will be automatically injected, and existing Pods will not be automatically injected into polaris-sidecar. If you want stock pods to experience polaris-sidecar as well, for pods managed by Deployment, DaemonSet or StatefulSet controllers, you can run the following command

# Deployment
kubectl rollout restart deployment/DEPLOYMENT_NAME --namespace NAMESPACE

# DaemonSet
kubectl rollout restart daemonset/DAEMONSET_NAME --namespace NAMESPACE

# StatefulSet
kubectl rollout restart statefulset/STATEFULSET_NAME --namespace NAMESPACE