I have an application that can receive commands from a specific port like so:

echo <command> | nc <hostname> <port>

In this case it is opening port 22082, I believe in it's Docker container.

When I place this application into a kubernetes pod, I need to expose it by creating a kubernetes service. Here is my service:

 apiVersion: v1                                                                                                                                                                            
 kind: Service                                                                                                                
 metadata:                                                                                                                    
  name: commander                                                                                                            
 spec:                                                                                                                        
   selector:                                                                                                                  
     app: commander                                                                                                           
   ports:                                                                                                                     
     - protocol: TCP                                                                                                          
       port: 22282                                                                                                            
       targetPort: 22082                                                                                                      
   #type: NodePort                                                                                                            
   externalIPs:                                                                                                               
   -  10.10.30.19

NOTE: I commented out NodePort because I haven't been able to expose the port using that method. Whenever I use sudo netstat -nlp | grep 22282 I get nothing.

Using an external IP i'm able to find the port and connect to it using netcat, but whenever I issue a command over the port, it just hangs.

Normally I should be able to issue a 'help' command and get information on the app. With kubernetes I can't get that same output.

Now, if I use hostNetwork: true in my app yaml (not the service), I can connect to the port and get my 'help' info.

What could be keeping my command from reaching the app while not using hostNetwork configuration?

Thanks

UPDATE: Noticed this message from sudo iptables --list:

Chain KUBE-SERVICES (1 references)
target     prot opt source               destination         
REJECT     tcp  --  anywhere             172.21.155.23        /* default/commander: has no endpoints */ tcp dpt:22282 reject-with icmp-port-unreachable

UPDATE #2: I solved the above error by setting spec.template.metadata.labels.app to commander. I still, however, am experiencing an inability to send any command to the app.