NanoPod

NanoPod help you to patch your pods automatically without changing your Deployment/StatefulSet/Job/ReplicaSet etc.

Description

The NanoPods for pods is like the nano-armor for the Iron-Man, It can automatically arm your pods without changing Deployment/StatefulSet/Job/ReplicaSet etc. Only the pods labeled with "nano-pods" would be accessed to. It provides an aspect oriented configuration.

How To Work

The following picture shows how does Nano Pod work.

Getting Started

NanoPod Operator required cert-manager, so firstly make sure you have cert-manager installed

Then run the following scripts in your Kubernetes, to install NanoPod Operator and related CRDs, register webhooks.

kubectl apply -f https://github.com/Duncan-tree-zhou/nano-pod/releases/download/v0.0.1/nano-pod-operator.yaml

After the nano-pod-controller-manager deployment is ready, the functionality of NanoPod is enabled.

Then create namespace nano-pod-test for testing, and apply the following yaml to nano-pod-test namespace:

# my-nano-pod.yaml
apiVersion: nanopod.nanopod.treezh.cn/v1
kind: NanoPod
metadata:
  name: my-nano-pod
  namespace: nano-pod-test
spec:
  template:
    spec:
      containers:
        - name: mysql
          env:
            - name: MYSQL_ALLOW_EMPTY_PASSWORD
              value: "true"
            - name: MYSQL_DATABASE
              value: mydb02
          resources:
            limits:
              cpu: 500m
              memory: 512Mi
            requests:
              cpu: 100m
              memory: 256Mi

The structure of spec.template is exactly the same as of deployment.spec.template.

Make sure the NanoPod had been created.

kubectl get nanopod -n nano-pod-test

NAME          AGE
my-nano-pod   12s

Since then, the pods created with label nano-pods: "my-nano-pod" would be automatically patched by NanoPod my-nano-pod.

If you apply a Deployment like this:

# mysql.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: mysql
  namespace: nano-pod-test
  labels:
    app: mysql
spec:
  replicas: 1
  selector:
    matchLabels:
      app:  mysql
  template:
    metadata:
      labels:
        app:  mysql
        nano-pods: "my-nano-pod"
    spec:
      containers:
        - name: mysql
          image: treezh-docker.pkg.coding.net/demo03/public/mysql:8.0.31
          env:
            - name: MYSQL_DATABASE
              value: mydb01

Run the following script to get the pod.

kubectl get pod -l app=mysql -o yaml

you will get a pod with NanoPod patched.

apiVersion: v1
kind: Pod
metadata:
  name: mysql-869c5bd95b-bkd4p
  namespace: nano-pod-test
spec:
  containers:
    - name: mysql
      image: treezh-docker.pkg.coding.net/demo03/public/mysql:8.0.31
      env:
        - name: MYSQL_ALLOW_EMPTY_PASSWORD # this env is added by NanoPod
          value: "true"
        - name: MYSQL_DATABASE
          value: mydb02 # this value is overwritten by NanoPod
      resources: # resources are added by NanoPod
        limits:
          cpu: 500m
          memory: 512Mi
        requests:
          cpu: 100m
          memory: 256Mi

Then you can see env env0101 and resources are added, the value of env env0102 is overwritten from value0102 to value0103.

Contributing

If you have any problem, welcome to create issue or PR to this repo ,or contact me by email duncan.tree.zhou@gmail.com.

License

Apache 2.0 License.