kubernetes
/
website
mirror of https://github.com/kubernetes/website.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

fix style and grammar 

1. Make plural nouns into same style. See it is `Services` in first sentence and `Pods` in the line 286 , but others are `Service`s and `Pod`s .So change style for these plural nouns for consistency and beauty.
2. Fix minor grammar.
pull/2053/head
Peter Lee 2016-12-27 10:46:48 +08:00 committed by GitHub
parent 67be6311ee
commit 42e015d8f8
1 changed files with 23 additions and 23 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

46
docs/user-guide/debugging-services.md
View File

@ -7,8 +7,8 @@ title: Debugging Services
---
An issue that comes up rather frequently for new installations of Kubernetes is
that `Services` are not working properly. You've run all your `Pod`s and
`Deployment`s, but you get no response when you try to access them.
that `Services` are not working properly. You've run all your `Pods` and
`Deployments`, but you get no response when you try to access them.
This document will hopefully help you to figure out what's going wrong.
* TOC
@ -17,7 +17,7 @@ This document will hopefully help you to figure out what's going wrong.
## Conventions
Throughout this doc you will see various commands that you can run. Some
commands need to be run within `Pod`, others on a Kubernetes `Node`, and others
commands need to be run within a `Pod`, others on a Kubernetes `Node`, and others
can run anywhere you have `kubectl` and credentials for the cluster. To make it
clear what is expected, this document will use the following conventions.
@ -71,7 +71,7 @@ $ kubectl exec -ti <POD-NAME> -c <CONTAINER-NAME> sh
## Setup
For the purposes of this walk-through, let's run some `Pod`s. Since you're
For the purposes of this walk-through, let's run some `Pods`. Since you're
probably debugging your own `Service` you can substitute your own details, or you
can follow along and get a second data point.
@ -109,7 +109,7 @@ spec:
protocol: TCP
```
Confirm your `Pod`s are running:
Confirm your `Pods` are running:
```shell
$ kubectl get pods -l app=hostnames
@ -196,7 +196,7 @@ Address: 10.0.1.175
```
If this fails, perhaps your `Pod` and `Service` are in different
`Namespace`s, try a namespace-qualified name:
`Namespaces`, try a namespace-qualified name:
```shell
u@pod$ nslookup hostnames.default
@ -207,7 +207,7 @@ Name: hostnames.default
Address: 10.0.1.175
```
If this works, you'll need to ensure that `Pod`s and `Service`s run in the same
If this works, you'll need to ensure that `Pods` and `Services` run in the same
`Namespace`. If this still fails, try a fully-qualified name:
```shell
@ -326,18 +326,18 @@ $ kubectl get service hostnames -o json
```
Is the port you are trying to access in `spec.ports[]`? Is the `targetPort`
correct for your `Pod`s? 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 `Pod`s
correct for your `Pods`? 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?
If you got this far, we assume that you have confirmed that your `Service`
exists and resolves by DNS. Now let's check that the `Pod`s you ran are
exists and is resolved by DNS. Now let's check that the `Pods` you ran are
actually being selected by the `Service`.
Earlier we saw that the `Pod`s were running. We can re-check that:
Earlier we saw that the `Pods` were running. We can re-check that:
```shell
$ kubectl get pods -l app=hostnames
@ -347,7 +347,7 @@ hostnames-bvc05 1/1 Running 0 1h
hostnames-yp2kp 1/1 Running 0 1h
```
The "AGE" column says that these `Pod`s are about an hour old, which implies that
The "AGE" column says that these `Pods` are about an hour old, which implies that
they are running fine and not crashing.
The `-l app=hostnames` argument is a label selector - just like our `Service`
@ -360,16 +360,16 @@ NAME ENDPOINTS
hostnames 10.244.0.5:9376,10.244.0.6:9376,10.244.0.7:9376
```
This confirms that the control loop has found the correct `Pod`s for your
This confirms that the control loop has found the correct `Pods` for your
`Service`. If the `hostnames` row is blank, you should check that the
`spec.selector` field of your `Service` actually selects for `metadata.labels`
values on your `Pod`s.
values on your `Pods`.
## Are the Pods working?
At this point, we know that your `Service` exists and has selected your `Pod`s.
Let's check that the `Pod`s are actually working - we can bypass the `Service`
mechanism and go straight to the `Pod`s.
At this point, we know that your `Service` exists and has selected your `Pods`.
Let's check that the `Pods` are actually working - we can bypass the `Service`
mechanism and go straight to the `Pods`.
```shell
u@pod$ wget -qO- 10.244.0.5:9376
@ -384,19 +384,19 @@ hostnames-yp2kp
We expect each `Pod` in the `Endpoints` list to return its own hostname. If
this is not what happens (or whatever the correct behavior is for your own
`Pod`s), you should investigate what's happening there. You might find
`kubectl logs` to be useful or `kubectl exec` directly to your `Pod`s and check
`Pods`), you should investigate what's happening there. You might find
`kubectl logs` to be useful or `kubectl exec` directly to your `Pods` and check
service from there.
## Is the kube-proxy working?
If you get here, your `Service` is running, has `Endpoints`, and your `Pod`s
If you get here, your `Service` is running, has `Endpoints`, and your `Pods`
are actually serving. At this point, the whole `Service` proxy mechanism is
suspect. Let's confirm it, piece by piece.
### Is kube-proxy running?
Confirm that `kube-proxy` is running on your `Node`s. You should get something
Confirm that `kube-proxy` is running on your `Nodes`. You should get something
like the below:
```shell
@ -429,7 +429,7 @@ should double-check your `Node` configuration and installation steps.
### Is kube-proxy writing iptables rules?
One of the main responsibilities of `kube-proxy` is to write the `iptables`
rules which implement `Service`s. Let's check that those rules are getting
rules which implement `Services`. Let's check that those rules are getting
written.
The kube-proxy can run in either "userspace" mode or "iptables" mode.
@ -620,7 +620,7 @@ UP BROADCAST RUNNING PROMISC MULTICAST MTU:1460 Metric:1
## Seek help
If you get this far, something very strange is happening. Your `Service` is
running, has `Endpoints`, and your `Pod`s are actually serving. You have DNS
running, has `Endpoints`, and your `Pods` are actually serving. You have DNS
working, `iptables` rules installed, and `kube-proxy` does not seem to be
misbehaving. And yet your `Service` is not working. You should probably let
us know, so we can help investigate!