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Hi, let us understand about services. Earlier we saw the deployments, pods,

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replica sets and that's going to make sure n number or desired number

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of pods up and running. Now each and every pod will be having an internal IP

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address and that will not be accessible from the outside world and that's part of

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networking, let's not get into this at this stage we will be having detailed

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discussion later and since the internal IP address is not accessible I need some

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sort of an abstract way to expose the application, so that the pods can be

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accessed from the outside world and that's where the service comes into

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picture and there are different ways I can expose the IP address use that DNS and

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use a load balancer. I'm going to go with a very simple option of mapping it to the

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node port and expose the service or the pod to the outside world. For that I am

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going to create a service, let me get the details about the service yaml file. I do

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have a sample yaml file service.yaml where I do have the kind as service. Here I

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do have the specs where within the ports I am going to expose the node port 30200

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and that will be targeting to the port 80 of the container or the pod which are

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having the selector or the label as app. So it's going to again use the selector and

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select the pods using the selector it's going to route all the traffic that it is getting in port 30200

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to the port 80 of the container. So basically it's going to act like a load balancer and receive the

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request in port 30200 and route it to port 80 of the pod. So within the host it's going

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to get the request in port 30200 and it's going to route it to the port 80 of the

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container that is running within the pod and there are some restrictions

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available where the service can be started only within the ports ranges of

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30,000 to 32767. Let me go ahead and get the details about the current pods that

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are running, I can use the option dash o there is output with wide where I will be

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getting the IP address that is the internal IP address of these pods. Now directly I

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cannot access these pods, so what I'm going to do I'm going to create a service.

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Let me create a service using this specific service.yaml file and service should get

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created, let me go ahead and get the service so I do have the service in the

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name nginx and that's going to have the type as node port. For the time being don't

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worry about this particular type where I'm going to have a very high level overview

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on different concepts, in the detailed discussion we will discuss about

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different types and how to map the ports all other advanced discussions. Here I am

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mapping the port 30200 to the port 80. Let me go ahead and access specific port
different types and how to map the ports all other advanced discussions. Here I am

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mapping the port 30200 to the port 80. Let me go ahead and access specific port

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30200. Where I am getting into a specific pod or one of the pods within the replica

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set available within the deployment and I am getting the output, for time being

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we don't need to worry about which pod is serving this specific request and that

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can be very well identified using the custom php applications that we created

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earlier, deploy that and identify the IP address that we will be discussing it later

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point of time. So the quick takeaway or the summary about services is it's going

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to create an abstract layer and route the traffic to the pods available within the

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deployments or the replica sets. Again let me reiterate all we are saying is just a quick

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overview on different concepts so that we can get started on the

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detailed discussion about deploying the cluster and then getting

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back to the detailed discussion about these concepts.