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Update debug-service.md's tasks file to remove $ from kubectl and turn questions into bullet list #12798

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Feb 28, 2019
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Update debug-service.md's tasks file to remove $ from kubectl and turn questions into bullet list #12798

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40 changes: 22 additions & 18 deletions content/en/docs/tasks/debug-application-cluster/debug-service.md
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Original file line number Diff line number Diff line change
Expand Up @@ -41,7 +41,7 @@ OUTPUT
If the command is "kubectl ARGS":

```shell
$ kubectl ARGS
kubectl ARGS
OUTPUT
```

Expand All @@ -51,16 +51,18 @@ For many steps here you will want to see what a `Pod` running in the cluster
sees. The simplest way to do this is to run an interactive busybox `Pod`:

```none
$ kubectl run -it --rm --restart=Never busybox --image=busybox sh
If you don't see a command prompt, try pressing enter.
kubectl run -it --rm --restart=Never busybox --image=busybox sh
/ #
```
{{< note >}}
If you don't see a command prompt, try pressing enter.
{{< /note >}}

If you already have a running `Pod` that you prefer to use, you can run a
command in it using:

```shell
$ kubectl exec <POD-NAME> -c <CONTAINER-NAME> -- <COMMAND>
kubectl exec <POD-NAME> -c <CONTAINER-NAME> -- <COMMAND>
```

## Setup
Expand All @@ -70,7 +72,7 @@ probably debugging your own `Service` you can substitute your own details, or yo
can follow along and get a second data point.

```shell
$ kubectl run hostnames --image=k8s.gcr.io/serve_hostname \
kubectl run hostnames --image=k8s.gcr.io/serve_hostname \
--labels=app=hostnames \
--port=9376 \
--replicas=3
Expand Down Expand Up @@ -108,7 +110,7 @@ spec:
Confirm your `Pods` are running:

```shell
$ kubectl get pods -l app=hostnames
kubectl get pods -l app=hostnames
NAME READY STATUS RESTARTS AGE
hostnames-632524106-bbpiw 1/1 Running 0 2m
hostnames-632524106-ly40y 1/1 Running 0 2m
Expand All @@ -134,7 +136,7 @@ wget: unable to resolve host address 'hostnames'
So the first thing to check is whether that `Service` actually exists:

```shell
$ kubectl get svc hostnames
kubectl get svc hostnames
No resources found.
Error from server (NotFound): services "hostnames" not found
```
Expand All @@ -143,14 +145,14 @@ So we have a culprit, let's create the `Service`. As before, this is for the
walk-through - you can use your own `Service`'s details here.

```shell
$ kubectl expose deployment hostnames --port=80 --target-port=9376
kubectl expose deployment hostnames --port=80 --target-port=9376
service/hostnames exposed
```

And read it back, just to be sure:

```shell
$ kubectl get svc hostnames
kubectl get svc hostnames
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
hostnames ClusterIP 10.0.1.175 <none> 80/TCP 5s
```
Expand Down Expand Up @@ -301,7 +303,7 @@ It might sound silly, but you should really double and triple check that your
and verify it:

```shell
$ kubectl get service hostnames -o json
kubectl get service hostnames -o json
```
```json
{
Expand Down Expand Up @@ -341,11 +343,13 @@ $ kubectl get service hostnames -o json
}
```

Is the port you are trying to access in `spec.ports[]`? Is the `targetPort`
correct for your `Pods` (many `Pods` choose to use a different port than the
`Service`)? If you meant it to be a numeric port, is it a number (9376) or a
string "9376"? If you meant it to be a named port, do your `Pods` expose a port
with the same name? Is the port's `protocol` the same as the `Pod`'s?
* Is the port you are trying to access in `spec.ports[]`?
* Is the `targetPort` correct for your `Pods` (many `Pods` choose to use a different port than the `Service`)?
* If you meant it to be a numeric port, is it a number (9376) or a
string "9376"?
* If you meant it to be a named port, do your `Pods` expose a port
with the same name?
* Is the port's `protocol` the same as the `Pod`'s?

## Does the Service have any Endpoints?

Expand All @@ -356,7 +360,7 @@ actually being selected by the `Service`.
Earlier we saw that the `Pods` were running. We can re-check that:

```shell
$ kubectl get pods -l app=hostnames
kubectl get pods -l app=hostnames
NAME READY STATUS RESTARTS AGE
hostnames-0uton 1/1 Running 0 1h
hostnames-bvc05 1/1 Running 0 1h
Expand All @@ -371,7 +375,7 @@ has. Inside the Kubernetes system is a control loop which evaluates the
selector of every `Service` and saves the results into an `Endpoints` object.

```shell
$ kubectl get endpoints hostnames
kubectl get endpoints hostnames
NAME ENDPOINTS
hostnames 10.244.0.5:9376,10.244.0.6:9376,10.244.0.7:9376
```
Expand Down Expand Up @@ -414,7 +418,7 @@ Another thing to check is that your `Pods` are not crashing or being restarted.
Frequent restarts could lead to intermittent connectivity issues.

```shell
$ kubectl get pods -l app=hostnames
kubectl get pods -l app=hostnames
NAME READY STATUS RESTARTS AGE
hostnames-632524106-bbpiw 1/1 Running 0 2m
hostnames-632524106-ly40y 1/1 Running 0 2m
Expand Down