105 lines
5 KiB
Markdown
105 lines
5 KiB
Markdown
Getting started
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===============
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Building your own inventory
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---------------------------
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Ansible inventory can be stored in 3 formats: YAML, JSON, or INI-like. There is
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an example inventory located
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[here](https://github.com/kubernetes-incubator/kubespray/blob/master/inventory/inventory.example).
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You can use an
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[inventory generator](https://github.com/kubernetes-incubator/kubespray/blob/master/contrib/inventory_builder/inventory.py)
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to create or modify an Ansible inventory. Currently, it is limited in
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functionality and is only used for configuring a basic Kubespray cluster inventory, but it does
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support creating inventory file for large clusters as well. It now supports
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separated ETCD and Kubernetes master roles from node role if the size exceeds a
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certain threshold. Run `python3 contrib/inventory_builder/inventory.py help` help for more information.
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Example inventory generator usage:
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```
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cp -r inventory my_inventory
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declare -a IPS=(10.10.1.3 10.10.1.4 10.10.1.5)
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CONFIG_FILE=my_inventory/inventory.cfg python3 contrib/inventory_builder/inventory.py ${IPS[@]}
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```
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Starting custom deployment
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--------------------------
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Once you have an inventory, you may want to customize deployment data vars
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and start the deployment:
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**IMPORTANT: Edit my_inventory/groups_vars/*.yaml to override data vars**
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```
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ansible-playbook -i my_inventory/inventory.cfg cluster.yml -b -v \
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--private-key=~/.ssh/private_key
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```
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See more details in the [ansible guide](ansible.md).
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Adding nodes
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------------
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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.
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- 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)).
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- Run the ansible-playbook command, substituting `scale.yml` for `cluster.yml`:
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```
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ansible-playbook -i my_inventory/inventory.cfg scale.yml -b -v \
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--private-key=~/.ssh/private_key
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```
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Connecting to Kubernetes
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------------------------
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By default, Kubespray configures kube-master hosts with insecure access to
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kube-apiserver via port 8080. A kubeconfig file is not necessary in this case,
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because kubectl will use http://localhost:8080 to connect. The kubeconfig files
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generated will point to localhost (on kube-masters) and kube-node hosts will
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connect either to a localhost nginx proxy or to a loadbalancer if configured.
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More details on this process are in the [HA guide](ha-mode.md).
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Kubespray permits connecting to the cluster remotely on any IP of any
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kube-master host on port 6443 by default. However, this requires
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authentication. One could generate a kubeconfig based on one installed
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kube-master hosts (needs improvement) or connect with a username and password.
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By default, a user with admin rights is created, named `kube`.
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The password can be viewed after deployment by looking at the file
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`PATH_TO_KUBESPRAY/credentials/kube_user`. This contains a randomly generated
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password. If you wish to set your own password, just precreate/modify this
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file yourself.
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For more information on kubeconfig and accessing a Kubernetes cluster, refer to
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the Kubernetes [documentation](https://kubernetes.io/docs/tasks/access-application-cluster/configure-access-multiple-clusters/).
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Accessing Kubernetes Dashboard
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------------------------------
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As of kubernetes-dashboard v1.7.x:
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* New login options that use apiserver auth proxying of token/basic/kubeconfig by default
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* Requires RBAC in authorization_modes
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* Only serves over https
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* No longer available at https://first_master:6443/ui until apiserver is updated with the https proxy URL
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If the variable `dashboard_enabled` is set (default is true), then you can access the Kubernetes Dashboard at the following URL, You will be prompted for credentials:
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https://first_master:6443/api/v1/namespaces/kube-system/services/https:kubernetes-dashboard:/proxy/#!/login
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Or you can run 'kubectl proxy' from your local machine to access dashboard in your browser from:
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http://localhost:8001/api/v1/namespaces/kube-system/services/https:kubernetes-dashboard:/proxy/#!/login
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It is recommended to access dashboard from behind a gateway (like Ingress Controller) that enforces an authentication token. Details and other access options here: https://github.com/kubernetes/dashboard/wiki/Accessing-Dashboard---1.7.X-and-above
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Accessing Kubernetes API
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------------------------
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The main client of Kubernetes is `kubectl`. It is installed on each kube-master
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host and can optionally be configured on your ansible host by setting
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`kubeconfig_localhost: true` in the configuration. If enabled, kubectl and
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admin.conf will appear in the artifacts/ directory after deployment. You can
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see a list of nodes by running the following commands:
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cd artifacts/
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./kubectl --kubeconfig admin.conf get nodes
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If desired, copy kubectl to your bin dir and admin.conf to ~/.kube/config.
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