mirror of https://github.com/k3s-io/k3s
docs: update rkt guide, add debugging tips.
Yifan Gu
parent
4f6f5586d2
commit
cbee5c36f4
|
|
@ -38,36 +38,31 @@ We still have [a bunch of work](http://issue.k8s.io/8262) to do to make the expe
|
|||
|
||||
### **Prerequisite**
|
||||
|
||||
- [systemd](http://www.freedesktop.org/wiki/Software/systemd/) should be installed on your machine and should be enabled. The minimum version required at this moment (2015/05/28) is [215](http://lists.freedesktop.org/archives/systemd-devel/2014-July/020903.html).
|
||||
- [systemd](http://www.freedesktop.org/wiki/Software/systemd/) should be installed on the machine and should be enabled. The minimum version required at this moment (2015/09/01) is 219
|
||||
*(Note that systemd is not required by rkt itself, we are using it here to monitor and manage the pods launched by kubelet.)*
|
||||
|
||||
- Install the latest rkt release according to the instructions [here](https://github.com/coreos/rkt).
|
||||
The minimum version required for now is [v0.5.6](https://github.com/coreos/rkt/releases/tag/v0.5.6).
|
||||
|
||||
- Make sure the `rkt metadata service` is running because it is necessary for running pod in private network mode.
|
||||
More details about the networking of rkt can be found in the [documentation](https://github.com/coreos/rkt/blob/master/Documentation/networking.md).
|
||||
|
||||
To start the `rkt metadata service`, you can simply run:
|
||||
|
||||
```console
|
||||
$ sudo rkt metadata-service
|
||||
```
|
||||
|
||||
If you want the service to be running as a systemd service, then:
|
||||
|
||||
```console
|
||||
$ sudo systemd-run rkt metadata-service
|
||||
```
|
||||
|
||||
Alternatively, you can use the [rkt-metadata.service](https://github.com/coreos/rkt/blob/master/dist/init/systemd/rkt-metadata.service) and [rkt-metadata.socket](https://github.com/coreos/rkt/blob/master/dist/init/systemd/rkt-metadata.socket) to start the service.
|
||||
The minimum version required for now is [v0.8.0](https://github.com/coreos/rkt/releases/tag/v0.8.0).
|
||||
|
||||
- Note that for rkt version later than v0.7.0, `metadata service` is not required for running pods in private networks. So now rkt pods will not register the metadata service be default.
|
||||
|
||||
### Local cluster
|
||||
|
||||
To use rkt as the container runtime, you just need to set the environment variable `CONTAINER_RUNTIME`:
|
||||
To use rkt as the container runtime, we need to supply `--container-runtime=rkt` and `--rkt-path=$PATH_TO_RKT_BINARY` to kubelet. Additionally we can provide `--rkt-stage1-image` flag
|
||||
as well to select which [stage1 image](https://github.com/coreos/rkt/blob/master/Documentation/running-lkvm-stage1.md) we want to use.
|
||||
|
||||
If you are using the [hack/local-up-cluster.sh](../../../hack/local-up-cluster.sh) script to launch the local cluster, then you can edit the environment variable `CONTAINER_RUNTIME`, `RKT_PATH` and `RKT_STAGE1_IMAGE` to
|
||||
set these flags:
|
||||
|
||||
```console
|
||||
$ export CONTAINER_RUNTIME=rkt
|
||||
$ export RKT_PATH=$PATH_TO_RKT_BINARY
|
||||
$ export RKT_STAGE1_IMAGE=PATH=$PATH_TO_STAGE1_IMAGE
|
||||
```
|
||||
|
||||
Then we can launch the local cluster using the script:
|
||||
|
||||
```console
|
||||
$ hack/local-up-cluster.sh
|
||||
```
|
||||
|
||||
|
|
@ -85,7 +80,7 @@ $ export KUBE_CONTAINER_RUNTIME=rkt
|
|||
You can optionally choose the version of rkt used by setting `KUBE_RKT_VERSION`:
|
||||
|
||||
```console
|
||||
$ export KUBE_RKT_VERSION=0.5.6
|
||||
$ export KUBE_RKT_VERSION=0.8.0
|
||||
```
|
||||
|
||||
Then you can launch the cluster by:
|
||||
|
|
@ -109,7 +104,7 @@ $ export KUBE_CONTAINER_RUNTIME=rkt
|
|||
You can optionally choose the version of rkt used by setting `KUBE_RKT_VERSION`:
|
||||
|
||||
```console
|
||||
$ export KUBE_RKT_VERSION=0.5.6
|
||||
$ export KUBE_RKT_VERSION=0.8.0
|
||||
```
|
||||
|
||||
You can optionally choose the CoreOS channel by setting `COREOS_CHANNEL`:
|
||||
|
|
@ -134,6 +129,46 @@ See [a simple nginx example](../../../docs/user-guide/simple-nginx.md) to try ou
|
|||
For more complete applications, please look in the [examples directory](../../../examples/).
|
||||
|
||||
|
||||
### Debugging
|
||||
|
||||
Here are severals tips for you when you run into any issues.
|
||||
|
||||
##### Check logs
|
||||
|
||||
By default, the log verbose level is 2. In order to see more logs related to rkt, we can set the verbose level to 4.
|
||||
For local cluster, we can set the environment variable: `LOG_LEVEL=4`.
|
||||
If the cluster is using salt, we can edit the [logging.sls](../../../cluster/saltbase/pillar/logging.sls) in the saltbase.
|
||||
|
||||
##### Check rkt pod status
|
||||
|
||||
To check the pods' status, we can use rkt command, such as `rkt list`, `rkt status`, `rkt image list`, etc.
|
||||
More information about rkt command line can be found [here](https://github.com/coreos/rkt/blob/master/Documentation/commands.md)
|
||||
|
||||
##### Check journal logs
|
||||
|
||||
As we use systemd to launch rkt pods(by creating service files which will run `rkt run-prepared`, we can check the pods' log
|
||||
using `journalctl`:
|
||||
|
||||
- Check the running state of the systemd service:
|
||||
|
||||
```console
|
||||
$ sudo journalctl -u $SERVICE_FILE
|
||||
```
|
||||
|
||||
where `$SERVICE_FILE` is the name of the service file created for the pod, you can find it in the kubelet logs.
|
||||
|
||||
##### Check the log of the container in the pod:
|
||||
|
||||
```console
|
||||
$ sudo journalctl -M rkt-$UUID -u $CONTAINER_NAME
|
||||
```
|
||||
|
||||
where `$UUID` is the rkt pod's UUID, which you can find via `rkt list --full`, and `$CONTAINER_NAME` is the container's name.
|
||||
|
||||
##### Check Kubernetes events, logs.
|
||||
|
||||
Besides above tricks, Kubernetes also provides us handy tools for debugging the pods. More information can be found [here](../../../docs/user-guide/application-troubleshooting.md)
|
||||
|
||||
<!-- BEGIN MUNGE: GENERATED_ANALYTICS -->
|
||||
[]()
|
||||
<!-- END MUNGE: GENERATED_ANALYTICS -->
|
||||
|
|
|
|||
Loading…
Reference in New Issue