Can we have same kind of multiple containers in a Pod in Kubernetes?

Question

For instance can I have following yaml to produce a pod with multiple containers:

apiVersion: v1
kind: Pod
metadata:
name: lampapp
labels:
    app: app
spec:
  containers:
  - name: lampdb
    image: mysql_test
  - name: app
    image: php-app-db-url-env
    env:
     - name: DB_URL
      value: 127.0.0.1:3306
  - name: app2
    image: php-app-db-url-env
    env:
    - name: DB_URL
      value: 127.0.0.1:3306

Answer 1

Yes, you can add multiple container with same image.

The containers object must contain:

1. name: Name of the container. It must be a DNS_LABEL and be unique within the pod. Cannot be updated.
2. image: Docker image name.

You have to make container name unique

You can do following:

- name: app
  image: php-app-db-url-env   ---
- name: app2                    |> same image
  image: php-app-db-url-env   ---

But not this one:

- name: app
  image: php-app-db-url-env
- name: app
  image: <any image>

Also the containers spec should include a unique port number within the Pod

Answer 2

可以存在相同类型的容器，但是它们的端口将不同。

Answer 3

好吧，这就是Pod的确切含义：共享某些命名空间和卷的多个容器。