Observability - Liveness Probes

Question 1

What problems do liveness probes solve?

Answer 1

• an application running in an container could be stuck because of a bug
• would still be shown as a ready container with traffic routed to it
• liveness probe can help

Question 2

What can liveness probes do?

Answer 2

• periodically test if the application within a container is acutally healthy
• if unhealthy, container is destroyed and recreated

Question 3

What kind of Liveness probes exist?

Answer 3

• HTTP Tests against URL
• TCP Test for socket
• exec command to perform certain test

Question 4

How are Liveness probes defined?

Answer 4

like to Readiness Probes:
~~~
…
spec:
containers:
- name:
livenessProbe:
httpGet:
path:
port:
////
tcpSocket:
port: 3306
////
exec:
command:
- cat
- /app/is_healthy
~~~