Multiple liveness probes in kuberenetes - kubernetes

Question

I have a program which has multiple independent1 components.
It is trivial to add a liveness probe in all of the components, however it's not easy to have a single liveness probe which would determine the health of all of the program's components.
How can I make kubernetes look at multiple liveness probes and restart the container when any of those are defunct?
I know it can be achieved by adding more software, for example an additional bash script which does the liveness checks, but I am looking for a native way to do this.
1By independent I mean that failure of one component does not make the other components fail.

Answer 1

The Kubernetes API allows one liveness and one readness per application (Deployment / POD). I recommend creating a validations centralizing service that has an endpoint rest:
livenessProbe:
httpGet:
path: /monitoring/alive
port: 3401
httpHeaders:
- name: X-Custom-Header
value: Awesome
initialDelaySeconds: 15
timeoutSeconds: 1
periodSeconds: 15
or try one bash to same task, like:
livenessProbe:
exec:
command:
- bin/bash
- -c
- ./liveness.sh
initialDelaySeconds: 220
timeoutSeconds: 5
liveness.sh
#!/bin/sh
if [ $(ps -ef | grep java | wc -l) -ge 1 ]; then
echo 0
else
echo "Nothing happens!" 1>&2
exit 1
fi
Recalling what the handling of messages can see in the events the failure in question:
"Warning Unhealthy Pod Liveness probe failed: Nothing happens!"
Hope this helps

Answer 2

It doesn't do that. The model is pretty simple, one probe per container, follow the restart policy on failure.
Understood about the designed-for-containers problem with legacy apps, but there really are a lot of ways to arrange for resources to be shared for legacy compatibility. If the components of this system are already different processes, then there should be a way to partition them into containers.
If the components are threads or some other intra-application modularization technique, then the liveness determination really has to come from inside the app.