Ansible Playbooks and Roles for Rancher

Disclaimer!: We use this as a base for our own and customer setup at puzzle. Heavy work in progress and a lot of things that can be improved. Feel free to contribute. We are happy to assist.

These Ansible playbook and roles can be used to:

• create a Rancher Control Plane using rke and helm
• add a custom Kubernetes cluster to an existing Rancher Control Plane

Prerequisites

We recommend you to run this playbooks inside a pipenv.

All dependencies are managed using pipenv, to get a virtual environment use:

# Only if you don't have pipenv yet:
pip install --user pipenv

Switch to the virtual environment and install dependencies into:

pipenv shell --three
pipenv install
# Now you can run ansible-playbook commands inside this pipenv shell:
ansible-playbook ...

You can verify the installed dependencies using pipenv graph (inside the pipenv shell):

$ pipenv graph
ansible==2.9.12
  - cryptography [required: Any, installed: 3.2]
  <--- output truncated --->
  - PyYAML [required: Any, installed: 5.3.1]
jmespath==0.10.0
openshift==0.11.2
  - jinja2 [required: Any, installed: 2.11.2]
    - MarkupSafe [required: >=0.23, installed: 1.1.1]
  - kubernetes [required: ~=11.0.0, installed: 11.0.0]
    - certifi [required: >=14.05.14, installed: 2020.6.20]
  <--- output truncated --->
  - six [required: Any, installed: 1.15.0]
selinux==0.2.1
  - distro [required: >=1.3.0, installed: 1.5.0]
  - setuptools [required: >=39.0, installed: 50.3.2]

Inventory

Check inventories/site for a sample inventory.

There are two special ansible groups:

• rke_rancher_clusters: Hosts in this group represent a Rancher Control Plane instance
• custom_k8s_clusters: Hosts in this group represent a custom kubernetes cluster added to a Rancher Control Plane

Members (Nodes) of the Rancher Control Plane and the Kubernetes cluster are managed with the following ansible groups.

Rancher Control Plane

For Rancher Control Plane: Assuming we have a Rancher Control Plane with the name cluster_rancher, we create the cluster_rancher host to the rke_rancher_clusters group and then add all nodes for this to the group rke_cluster_rancher, so the Rancher Control Plane name with a rke_ prefix.

[rke_rancher_clusters]
cluster_rancher # Belongs to Ansible Group rke_cluster_rancher

[rke_cluster_rancher]
rancher01
rancher02
rancher03

Make sure to set at least the following vars:

• For the cluster_rancher special host, you have to set rancher_hostname, rancher_admin_password and rancher_failover_ip with its sub-configurations (see roles/rke_rancher_clusters/README.md for more information). Check inventories/host_vars/cluster_rancher.yml and roles/rke_rancher_clusters/defaults/main.yml for more details.
• Set the k8s_roles each of the member should have (for a Rancher Control Plane this is normally controlplane, etcd, worker). See inventories/group_vars/rke_cluster_rancher.yml as an example.

Custom Kubernetes Cluster

For a custom Kubernetes cluster managed with a Rancher Control Plane: Assuming our cluster has the name mycluster we create a host rancher_mycluster in the custom_k8s_clusters group (so cluster name with a rancher_ prefix). The member nodes of this cluster are then added to a group with the name mycluster. To use some dedicated roles on some nodes you can use other ansible groups which are children of the mycluster group.

[custom_k8s_clusters]
rancher_mycluster

[mycluster:children]
mycluster_master
mycluster_worker

[mycluster_master]
master01

[mycluster_worker]
worker01

Make sure to set at least the following vars:

• For the ranchr_mycluster special host you have to set at least the custom_k8s_cluster_api_key & custom_k8s_cluster_rancher_host variable. Check roles/custom_k8s_cluster/defaults/main.yml for more details and variables.
• Set the k8s_roles each member should have. See inventories/group_vars/mycluster_master.yml and inventories/group_vars/mycluster_worker.yml as an example.

Playbooks

site.yml

Playbook to apply docker, firewalld, rke_rancher_clusters & custom_rk8s_cluster. Check plays/prepare_k8s_nodes.yml, plays/deploy_rancher.yml & plays/deploy_k8s_cluster.yml for details.

cleanup_k8snode.yml

With this playbook to can cleanup a node which was already added to a kubernetes cluster. Based on https://rancher.com/docs/rancher/v2.x/en/cluster-admin/cleaning-cluster-nodes/

Roles

docker

Simple role to install Docker. Check roles/docker/README.md for more details.

firewalld

The role only configures firewalld depending on the k8s_role the node has (this behaviour can also be disabled if you want to). Based on https://rancher.com/docs/rancher/v2.x/en/installation/options/firewall/

rke_rancher_clusters

Role to deploy a Rancher Control Plane with rke and helm. Check roles/rke_rancher_clusters/README.md for more details.

custom_rk8s_cluster

Role to create a custom Kubernetes cluster on a Rancher Control Plane and add nodes to the cluster. Check roles/custom_k8s_cluster/README.md for more details.

rancher_keepalived

Role to deploy keepalived Daemonsets on Rancher Control Plane and custom Kubernetes clusters. Provides one or multiple highly available virtual IPv4/IPv6 address(es) to the regarding cluster. Usually directly called from rke_rancher_clusters and custom_rk8s_cluster.

License

GPLv3

Author Information

• Sebastian Plattner
• Philip Schmid