TCP checks

Kubernetes also supports health checks via simple TCP socket checks and also with custom command-line scripts. The following snippets are examples of what both use cases look like in the YAML file:

livenessProbe: 
  exec: 
    command: 
    -/usr/bin/health/checkHttpServce.sh 
  initialDelaySeconds:90 
  timeoutSeconds: 1

Listing 2-9: Health check using command-line script

livenessProbe: 
  tcpSocket: 
    port: 80 
  initialDelaySeconds: 15 
  timeoutSeconds: 1

Listing 2-10: Health check using simple TCP Socket connection