Can two containers in the same Pod use the same port?

In Kubernetes, two containers within the same Pod can use the same port because each container has its own network isolation at the process level. However, since all containers in a Pod share a single network namespace, they effectively use the same IP address. This means that if two containers try to listen on the same port on this IP, a conflict will occur.

Therefore, for two containers in the same Pod to use the same port, they must listen on different interfaces or use different protocols, or one of them should not listen on the port directly. In practice, different ports are usually assigned to each container within a Pod to avoid conflicts.

Example:

containers:
- name: container1
  image: app1
  ports:
  - containerPort: 8080
- name: container2
  image: app2
  ports:
  - containerPort: 8081

Here, the containers use different ports 8080 and 8081, which is safe.