c12s-kubespray/docs/getting-started.md
2017-09-11 12:47:04 +03:00

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Getting started
===============
The easiest way to run the deployement is to use the **kubespray-cli** tool.
A complete documentation can be found in its [github repository](https://github.com/kubespray/kubespray-cli).
Here is a simple example on AWS:
* Create instances and generate the inventory
```
kubespray aws --instances 3
```
* Run the deployment
```
kubespray deploy --aws -u centos -n calico
```
Building your own inventory
---------------------------
Ansible inventory can be stored in 3 formats: YAML, JSON, or INI-like. There is
an example inventory located
[here](https://github.com/kubernetes-incubator/kubespray/blob/master/inventory/inventory.example).
You can use an
[inventory generator](https://github.com/kubernetes-incubator/kubespray/blob/master/contrib/inventory_builder/inventory.py)
to create or modify an Ansible inventory. Currently, it is limited in
functionality and is only use for making a basic Kubespray cluster, but it does
support creating large clusters. It now supports
separated ETCD and Kubernetes master roles from node role if the size exceeds a
certain threshold. Run inventory.py help for more information.
Example inventory generator usage:
```
cp -r inventory my_inventory
declare -a IPS=(10.10.1.3 10.10.1.4 10.10.1.5)
CONFIG_FILE=my_inventory/inventory.cfg python3 contrib/inventory_builder/inventory.py ${IPS[@]}
```
Starting custom deployment
--------------------------
Once you have an inventory, you may want to customize deployment data vars
and start the deployment:
**IMPORTANT: Edit my_inventory/groups_vars/*.yaml to override data vars**
```
ansible-playbook -i my_inventory/inventory.cfg cluster.yml -b -v \
--private-key=~/.ssh/private_key
```
See more details in the [ansible guide](ansible.md).
Adding nodes
------------
You may want to add worker nodes to your existing cluster. This can be done by re-running the `cluster.yml` playbook, or you can target the bare minimum needed to get kubelet installed on the worker and talking to your masters. This is especially helpful when doing something like autoscaling your clusters.
- Add the new worker node to your inventory under kube-node (or utilize a [dynamic inventory](https://docs.ansible.com/ansible/intro_dynamic_inventory.html)).
- Run the ansible-playbook command, substituting `scale.yml` for `cluster.yml`:
```
ansible-playbook -i my_inventory/inventory.cfg scale.yml -b -v \
--private-key=~/.ssh/private_key
```
Connecting to Kubernetes
------------------------
By default, Kubespray configures kube-master hosts with insecure access to
kube-apiserver via port 8080. A kubeconfig file is not necessary in this case,
because kubectl will use http://localhost:8080 to connect. The kubeconfig files
generated will point to localhost (on kube-masters) and kube-node hosts will
connect either to a localhost nginx proxy or to a loadbalancer if configured.
More details on this process is in the [HA guide](ha.md).
Kubespray permits connecting to the cluster remotely on any IP of any
kube-master host on port 6443 by default. However, this requires
authentication. One could generate a kubeconfig based on one installed
kube-master hosts (needs improvement) or connect with a username and password.
By default, a user with admin rights is created, named `kube`.
The password can be viewed after deployment by looking at the file
`PATH_TO_KUBESPRAY/credentials/kube_user`. This contains a randomly generated
password. If you wish to set your own password, just precreate/modify this
file yourself.
For more information on kubeconfig and accessing a Kubernetes cluster, refer to
the Kubernetes [documentation](https://kubernetes.io/docs/tasks/access-application-cluster/configure-access-multiple-clusters/).
Accessing Kubernetes Dashboard
------------------------------
If the variable `dashboard_enabled` is set (default is true), then you can
access the Kubernetes Dashboard at the following URL:
https://kube:_kube-password_@_host_:6443/ui/
To see the password, refer to the section above, titled *Connecting to
Kubernetes*. The host can be any kube-master or kube-node or loadbalancer
(when enabled).