Update the mesos.md getting started guide

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Dr. Stefan Schimanski 2015-06-15 10:34:47 +02:00
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@ -17,26 +17,31 @@ Getting started with Kubernetes on Mesos
<!-- TODO: Update, clean up. -->
Mesos allows dynamic sharing of cluster resources between Kubernetes and other first-class Mesos frameworks such as [Hadoop][1], [Spark][2], and [Chronos][3].
Mesos also ensures applications from different frameworks running on your cluster are isolated and that resources are allocated fairly.
Mesos also ensures applications from different frameworks running on your cluster are isolated and that resources are allocated fairly among them.
Running Kubernetes on Mesos allows you to easily move Kubernetes workloads from one cloud provider to another to your own physical datacenter.
Mesos clusters can be deployed on nearly every IaaS cloud provider infrastructure or in your own physical datacenter. Kubernetes on Mesos runs on-top of that and therefore allows you to easily move Kubernetes workloads from one of these environments to the other.
This tutorial will walk you through setting up Kubernetes on a Mesos cluster.
It provides a step by step walk through of adding Kubernetes to a Mesos cluster and running the classic GuestBook demo application.
The walkthrough presented here is based on the v0.4.x series of the Kubernetes-Mesos project, which itself is based on Kubernetes v0.11.0.
It provides a step by step walk through of adding Kubernetes to a Mesos cluster and starting your first pod with an nginx webserver.
**NOTE:** There are [known issues with the current implementation][11].
Please [file an issue against the kubernetes-mesos project][12] if you have problems completing the steps below.
**NOTE:** There are [known issues with the current implementation][7] and support for centralized logging and monitoring is not yet available.
Please [file an issue against the kubernetes-mesos project][8] if you have problems completing the steps below.
### Prerequisites
* Understanding of [Apache Mesos][10]
* Mesos cluster on [Google Compute Engine][5]
* A VPN connection to the cluster.
* Understanding of [Apache Mesos][6]
* A running [Mesos cluster on Google Compute Engine][5]
* A [VPN connection][10] to the cluster
* A machine in the cluster which should become the Kubernetes *master node* with:
* GoLang > 1.2
* make (i.e. build-essential)
* Docker
**Note**: You *can*, but you *don't have to* deploy Kubernetes-Mesos on the same machine the Mesos master is running on.
### Deploy Kubernetes-Mesos
Log into the master node over SSH, replacing the placeholder below with the correct IP address.
Log into the future Kubernetes *master node* over SSH, replacing the placeholder below with the correct IP address.
```bash
ssh jclouds@${ip_address_of_master_node}
@ -45,74 +50,81 @@ ssh jclouds@${ip_address_of_master_node}
Build Kubernetes-Mesos.
```bash
$ git clone https://github.com/mesosphere/kubernetes-mesos k8sm
$ mkdir -p bin && sudo docker run --rm -v $(pwd)/bin:/target \
-v $(pwd)/k8sm:/snapshot -e GIT_BRANCH=release-0.4 \
mesosphere/kubernetes-mesos:build
$ git clone https://github.com/GoogleCloudPlatform/kubernetes
$ cd kubernetes
$ export KUBERNETES_CONTRIB=mesos
$ make
```
Set some environment variables.
The internal IP address of the master may be obtained via `hostname -i`.
```bash
$ export servicehost=$(hostname -i)
$ export mesos_master=${servicehost}:5050
$ export KUBERNETES_MASTER=http://${servicehost}:8888
$ export KUBERNETES_MASTER_IP=$(hostname -i)
$ export KUBERNETES_MASTER=http://${KUBERNETES_MASTER_IP}:8888
```
### Deploy etcd
Start etcd and verify that it is running:
```bash
$ sudo docker run -d --hostname $(uname -n) --name etcd -p 4001:4001 -p 7001:7001 coreos/etcd
$ sudo docker run -d --hostname $(uname -n) --name etcd -p 4001:4001 -p 7001:7001 quay.io/coreos/etcd:v2.0.12
```
```bash
$ sudo docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
fd7bac9e2301 coreos/etcd:latest "/etcd" 5s ago Up 3s 2379/tcp, 2380/... etcd
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
fd7bac9e2301 quay.io/coreos/etcd:v2.0.12 "/etcd" 5s ago Up 3s 2379/tcp, 2380/... etcd
```
It's also a good idea to ensure your etcd instance is reachable by testing it
```bash
curl -L http://$servicehost:4001/v2/keys/
curl -L http://${KUBERNETES_MASTER_IP}:4001/v2/keys/
```
If connectivity is OK, you will see an output of the available keys in etcd (if any).
### Start Kubernetes-Mesos Services
Start the kubernetes-mesos API server, controller manager, and scheduler on a Mesos master node:
Update your PATH to more easily run the Kubernetes-Mesos binaries:
```bash
$ ./bin/km apiserver \
--address=${servicehost} \
--mesos_master=${mesos_master} \
--etcd_servers=http://${servicehost}:4001 \
--service-cluster-ip-range=10.10.10.0/24 \
--port=8888 \
--cloud_provider=mesos \
--v=1 >apiserver.log 2>&1 &
$ ./bin/km controller-manager \
--master=$servicehost:8888 \
--mesos_master=${mesos_master} \
--v=1 >controller.log 2>&1 &
$ ./bin/km scheduler \
--address=${servicehost} \
--mesos_master=${mesos_master} \
--etcd_servers=http://${servicehost}:4001 \
--mesos_user=root \
--api_servers=$servicehost:8888 \
--v=2 >scheduler.log 2>&1 &
$ export PATH="$(pwd)/_output/local/go/bin:$PATH"
```
Identify your Mesos master: depending on your Mesos installation this is either a `host:port` like `mesos_master:5050` or a ZooKeeper URL like `zk://zookeeper:2181/mesos`.
In order to let Kubernetes survive Mesos master changes, the ZooKeeper URL is recommended for production environments.
```bash
$ export MESOS_MASTER=<host:port or zk:// url>
```
Create a cloud config file `mesos-cloud.conf` in the current directory with the following contents:
```bash
$ cat <<EOF >mesos-cloud.conf
[mesos-cloud]
mesos-master = ${MESOS_MASTER}
EOF
```
Also on the master node, we'll start up a proxy instance to act as a
public-facing service router, for testing the web interface a little
later on.
Now start the kubernetes-mesos API server, controller manager, and scheduler on the master node:
```bash
$ sudo ./bin/km proxy \
--bind_address=${servicehost} \
--etcd_servers=http://${servicehost}:4001 \
--logtostderr=true >proxy.log 2>&1 &
$ km apiserver \
--address=${KUBERNETES_MASTER_IP} \
--etcd-servers=http://${KUBERNETES_MASTER_IP}:4001 \
--service-cluster-ip-range=10.10.10.0/24 \
--port=8888 \
--cloud-provider=mesos \
--cloud-config=mesos-cloud.conf \
--v=1 >apiserver.log 2>&1 &
$ km controller-manager \
--master=${KUBERNETES_MASTER_IP}:8888 \
--cloud-provider=mesos \
--cloud-config=./mesos-cloud.conf \
--v=1 >controller.log 2>&1 &
$ km scheduler \
--address=${KUBERNETES_MASTER_IP} \
--mesos-master=${MESOS_MASTER} \
--etcd-servers=http://${KUBERNETES_MASTER_IP}:4001 \
--mesos-user=root \
--api-servers=${KUBERNETES_MASTER_IP}:8888 \
--v=2 >scheduler.log 2>&1 &
```
Disown your background jobs so that they'll stay running if you log out.
@ -124,22 +136,20 @@ $ disown -a
Interact with the kubernetes-mesos framework via `kubectl`:
```bash
$ bin/kubectl get pods
POD IP CONTAINER(S) IMAGE(S) HOST LABELS STATUS
$ kubectl get pods
NAME READY REASON RESTARTS AGE
```
```bash
$ bin/kubectl get services # your service IPs will likely differ
NAME LABELS SELECTOR IP PORT
kubernetes component=apiserver,provider=kubernetes <none> 10.10.10.2 443
# NOTE: your service IPs will likely differ
$ kubectl get services
NAME LABELS SELECTOR IP(S) PORT(S)
k8sm-scheduler component=scheduler,provider=k8sm <none> 10.10.10.113 10251/TCP
kubernetes component=apiserver,provider=kubernetes <none> 10.10.10.1 443/TCP
```
Lastly, use the Mesos CLI tool to validate the Kubernetes scheduler framework has been registered and running:
```bash
$ mesos state | grep "Kubernetes"
"name": "Kubernetes",
```
Or, look for Kubernetes in the Mesos web GUI by pointing your browser to
`http://${mesos_master}`. Make sure you have an active VPN connection.
Lastly, look for Kubernetes in the Mesos web GUI by pointing your browser to
`http://<mesos_master_ip:port>`. Make sure you have an active VPN connection.
Go to the Frameworks tab, and look for an active framework named "Kubernetes".
## Spin up a pod
@ -147,175 +157,57 @@ Go to the Frameworks tab, and look for an active framework named "Kubernetes".
Write a JSON pod description to a local file:
```bash
$ cat <<EOPOD >nginx.json
{ "kind": "Pod",
"apiVersion": "v1beta1",
"id": "nginx-id-01",
"desiredState": {
"manifest": {
"version": "v1beta1",
"containers": [{
"name": "nginx-01",
"image": "nginx",
"ports": [{
"containerPort": 80,
"hostPort": 31000
}],
"livenessProbe": {
"enabled": true,
"type": "http",
"initialDelaySeconds": 30,
"httpGet": {
"path": "/index.html",
"port": "8081"
}
}
}]
}
},
"labels": {
"name": "foo"
} }
$ cat <<EOPOD >nginx.yaml
apiVersion: v1
kind: Pod
metadata:
name: nginx
spec:
containers:
- name: nginx
image: nginx
ports:
- containerPort: 80
EOPOD
```
Send the pod description to Kubernetes using the `kubectl` CLI:
```bash
$ bin/kubectl create -f nginx.json
nginx-id-01
$ kubectl create -f nginx.yaml
pods/nginx
```
Wait a minute or two while `dockerd` downloads the image layers from the internet.
We can use the `kubectl` interface to monitor the status of our pod:
```bash
$ bin/kubectl get pods
POD IP CONTAINER(S) IMAGE(S) HOST LABELS STATUS
nginx-id-01 172.17.5.27 nginx-01 nginx 10.72.72.178/10.72.72.178 cluster=gce,name=foo Running
$ kubectl get pods
NAME READY REASON RESTARTS AGE
nginx 1/1 Running 0 14s
```
Verify that the pod task is running in the Mesos web GUI. Click on the
Kubernetes framework. The next screen should show the running Mesos task that
started the Kubernetes pod.
## Run the Example Guestbook App
## What next?
Following the instructions from the kubernetes-mesos [examples/guestbook][6]:
Try out some of the standard [Kubernetes examples][9].
```bash
$ export ex=k8sm/examples/guestbook
$ bin/kubectl create -f $ex/redis-master.json
$ bin/kubectl create -f $ex/redis-master-service.json
$ bin/kubectl create -f $ex/redis-slave-controller.json
$ bin/kubectl create -f $ex/redis-slave-service.json
$ bin/kubectl create -f $ex/frontend-controller.json
**NOTE:** Some examples require Kubernetes DNS to be installed on the cluster.
Future work will add instructions to this guide to enable support for Kubernetes DNS.
$ cat <<EOS >/tmp/frontend-service
{
"id": "frontend",
"kind": "Service",
"apiVersion": "v1beta1",
"port": 9998,
"selector": {
"name": "frontend"
},
"publicIPs": [
"${servicehost}"
]
}
EOS
$ bin/kubectl create -f /tmp/frontend-service
```
Watch your pods transition from `Pending` to `Running`:
```bash
$ watch 'bin/kubectl get pods'
```
Review your Mesos cluster's tasks:
```bash
$ mesos ps
TIME STATE RSS CPU %MEM COMMAND USER ID
0:00:05 R 41.25 MB 0.5 64.45 none root 0597e78b-d826-11e4-9162-42010acb46e2
0:00:08 R 41.58 MB 0.5 64.97 none root 0595b321-d826-11e4-9162-42010acb46e2
0:00:10 R 41.93 MB 0.75 65.51 none root ff8fff87-d825-11e4-9162-42010acb46e2
0:00:10 R 41.93 MB 0.75 65.51 none root 0597fa32-d826-11e4-9162-42010acb46e2
0:00:05 R 41.25 MB 0.5 64.45 none root ff8e01f9-d825-11e4-9162-42010acb46e2
0:00:10 R 41.93 MB 0.75 65.51 none root fa1da063-d825-11e4-9162-42010acb46e2
0:00:08 R 41.58 MB 0.5 64.97 none root b9b2e0b2-d825-11e4-9162-42010acb46e2
```
The number of Kubernetes pods listed earlier (from `bin/kubectl get pods`) should equal to the number active Mesos tasks listed the previous listing (`mesos ps`).
Next, determine the internal IP address of the front end [service][7]:
```bash
$ bin/kubectl get services
NAME LABELS SELECTOR IP PORT
kubernetes component=apiserver,provider=kubernetes <none> 10.10.10.2 443
redismaster <none> name=redis-master 10.10.10.49 10000
redisslave name=redisslave name=redisslave 10.10.10.109 10001
frontend <none> name=frontend 10.10.10.149 9998
```
Interact with the frontend application via curl using the front-end service IP address from above:
```bash
$ curl http://${frontend_service_ip_address}:9998/index.php?cmd=get\&key=messages
{"data": ""}
```
Or via the Redis CLI:
```bash
$ sudo apt-get install redis-tools
$ redis-cli -h ${redis_master_service_ip_address} -p 10000
10.233.254.108:10000> dump messages
"\x00\x06,world\x06\x00\xc9\x82\x8eHj\xe5\xd1\x12"
```
#### Test Guestbook App
Or interact with the frontend application via your browser, in 2 steps:
First, open the firewall on the master machine.
```bash
# determine the internal port for the frontend service
$ sudo iptables-save|grep -e frontend # -- port 36336 in this case
-A KUBE-PORTALS-CONTAINER -d 10.10.10.149/32 -p tcp -m comment --comment frontend -m tcp --dport 9998 -j DNAT --to-destination 10.22.183.23:36336
-A KUBE-PORTALS-CONTAINER -d 10.22.183.23/32 -p tcp -m comment --comment frontend -m tcp --dport 9998 -j DNAT --to-destination 10.22.183.23:36336
-A KUBE-PORTALS-HOST -d 10.10.10.149/32 -p tcp -m comment --comment frontend -m tcp --dport 9998 -j DNAT --to-destination 10.22.183.23:36336
-A KUBE-PORTALS-HOST -d 10.22.183.23/32 -p tcp -m comment --comment frontend -m tcp --dport 9998 -j DNAT --to-destination 10.22.183.23:36336
# open up access to the internal port for the frontend service
$ sudo iptables -A INPUT -i eth0 -p tcp -m state --state NEW,ESTABLISHED -m tcp \
--dport ${internal_frontend_service_port} -j ACCEPT
```
Next, add a firewall rule in the Google Cloud Platform Console. Choose Compute >
Compute Engine > Networks, click on the name of your mesosphere-* network, then
click "New firewall rule" and allow access to TCP port 9998.
![Google Cloud Platform firewall configuration][8]
Now, you can visit the guestbook in your browser!
![Kubernetes Guestbook app running on Mesos][9]
**NOTE:** Please be aware that there are [known issues with the current Kubernetes-Mesos implementation][7].
[1]: http://mesosphere.com/docs/tutorials/run-hadoop-on-mesos-using-installer
[2]: http://mesosphere.com/docs/tutorials/run-spark-on-mesos
[3]: http://mesosphere.com/docs/tutorials/run-chronos-on-mesos
[4]: http://cloud.google.com
[5]: https://cloud.google.com/compute/
[6]: https://github.com/mesosphere/kubernetes-mesos/tree/v0.4.0/examples/guestbook
[7]: https://github.com/GoogleCloudPlatform/kubernetes/blob/v0.11.0/docs/services.md#ips-and-vips
[8]: mesos/k8s-firewall.png
[9]: mesos/k8s-guestbook.png
[10]: http://mesos.apache.org/
[11]: https://github.com/mesosphere/kubernetes-mesos/blob/master/docs/issues.md
[12]: https://github.com/mesosphere/kubernetes-mesos/issues
[5]: http://open.mesosphere.com/getting-started/cloud/google/mesosphere/
[6]: http://mesos.apache.org/
[7]: https://github.com/mesosphere/kubernetes-mesos/blob/master/docs/issues.md
[8]: https://github.com/mesosphere/kubernetes-mesos/issues
[9]: ../../examples/
[10]: http://open.mesosphere.com/getting-started/cloud/google/mesosphere/#vpn-setup
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