whentimeslows/website
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

1.2 additions for user-guide/

Browse Source
This commit is contained in:
John Mulhausen
2016-03-07 12:09:02 +00:00
parent e899d54a1b
commit f16668b45f
60 changed files with 2547 additions and 948 deletions
Download Patch File Download Diff File Expand all files Collapse all files
docs/user-guide/liveness/index.md
+7 -22
View File
@@ -5,15 +5,7 @@ This example shows two types of pod [health checks](/docs/user-guide/production-
The [exec-liveness.yaml](/docs/user-guide/liveness/exec-liveness.yaml) demonstrates the container execution check.
```yaml
livenessProbe:
exec:
command:
- cat
- /tmp/health
initialDelaySeconds: 15
timeoutSeconds: 1
```
{% include code.html language="yaml" file="exec-liveness.yaml" ghlink="/docs/user-guide/liveness/exec-liveness.yaml" %}
Kubelet executes the command `cat /tmp/health` in the container and reports failure if the command returns a non-zero exit code.
@@ -27,17 +19,10 @@ so when Kubelet executes the health check 15 seconds (defined by initialDelaySec
The [http-liveness.yaml](/docs/user-guide/liveness/http-liveness.yaml) demonstrates the HTTP check.
{% include code.html language="yaml" file="http-liveness.yaml" ghlink="/docs/user-guide/liveness/http-liveness.yaml" %}
```yaml
livenessProbe:
httpGet:
path: /healthz
port: 8080
initialDelaySeconds: 15
timeoutSeconds: 1
```
The Kubelet sends an HTTP request to the specified path and port to perform the health check. If you take a look at image/server.go, you will see the server starts to respond with an error code 500 after 10 seconds, so the check fails. The Kubelet sends the probe to the container's ip address by default which could be specified with `host` as part of httpGet probe. If the container listens on `127.0.0.1`, `host` should be specified as `127.0.0.1`. In general, if the container listens on its ip address or on all interfaces (0.0.0.0), there is no need to specify the `host` as part of the httpGet probe.
The Kubelet sends an HTTP request to the specified path and port to perform the health check. If you take a look at image/server.go, you will see the server starts to respond with an error code 500 after 10 seconds, so the check fails. The Kubelet sends probes to the container's IP address, unless overridden by the optional `host` field in httpGet. If the container listens on `127.0.0.1` and `hostNetwork` is `true` (i.e., it does not use the pod-specific network), then `host` should be specified as `127.0.0.1`. Be warned that, outside of less common cases like that, `host` does probably not result in what you would expect. If you set it to a non-existing hostname (or your competitor's!), probes will never reach the pod, defeating the whole point of health checks. If your pod relies on e.g. virtual hosts, which is probably the more common case, you should not use `host`, but rather set the `Host` header in `httpHeaders`.
This [guide](/docs/user-guide/k8s201/#health-checking) has more information on health checks.
@@ -75,8 +60,8 @@ At the bottom of the *kubectl describe* output there are messages indicating tha
```shell
$ kubectl describe pods liveness-exec
[...]
Sat, 27 Jun 2015 13:43:03 +0200 Sat, 27 Jun 2015 13:44:34 +0200 4 {kubelet kubernetes-minion-6fbi} spec.containers{liveness} unhealthy Liveness probe failed: cat: can't open '/tmp/health': No such file or directory
Sat, 27 Jun 2015 13:44:44 +0200 Sat, 27 Jun 2015 13:44:44 +0200 1 {kubelet kubernetes-minion-6fbi} spec.containers{liveness} killing Killing with docker id 65b52d62c635
Sat, 27 Jun 2015 13:44:44 +0200 Sat, 27 Jun 2015 13:44:44 +0200 1 {kubelet kubernetes-minion-6fbi} spec.containers{liveness} created Created with docker id ed6bb004ee10
Sat, 27 Jun 2015 13:44:44 +0200 Sat, 27 Jun 2015 13:44:44 +0200 1 {kubelet kubernetes-minion-6fbi} spec.containers{liveness} started Started with docker id ed6bb004ee10
Sat, 27 Jun 2015 13:43:03 +0200 Sat, 27 Jun 2015 13:44:34 +0200 4 {kubelet kubernetes-node-6fbi} spec.containers{liveness} unhealthy Liveness probe failed: cat: can't open '/tmp/health': No such file or directory
Sat, 27 Jun 2015 13:44:44 +0200 Sat, 27 Jun 2015 13:44:44 +0200 1 {kubelet kubernetes-node-6fbi} spec.containers{liveness} killing Killing with docker id 65b52d62c635
Sat, 27 Jun 2015 13:44:44 +0200 Sat, 27 Jun 2015 13:44:44 +0200 1 {kubelet kubernetes-node-6fbi} spec.containers{liveness} created Created with docker id ed6bb004ee10
Sat, 27 Jun 2015 13:44:44 +0200 Sat, 27 Jun 2015 13:44:44 +0200 1 {kubelet kubernetes-node-6fbi} spec.containers{liveness} started Started with docker id ed6bb004ee10
```