Ansible role: K8s

This role renders an arbitrary number of Jinja2 templates and deploys or removes them to/from Kubernetes cluster.

Requirements

• Ansible 2.7
• openshift Python package

Command line variables

Additional variables that can be used (either as host_vars/group_vars or via command line args):

Variable	Description
k8s_create	If set with any value, only deployments to create are executed.
k8s_remove	If set with any value, only deployments to remove are executed.
k8s_context	Global cluster context (can be overwritten by each array item).
k8s_tag	Only deployments (create or remove) which have this tag specified in their definition are executed.
k8s_force	Force deployment. The existing object will be replaced.

Example

For all examples below, we will use the following Ansible playbook:

playbook.yml

---
- hosts: all
  roles:
    - k8s
  tags:
    - k8s

1. Usage of variables

Required files:

create-k8s-namespace.yml.j2

---
kind: Namespace
apiVersion: v1
metadata:
  name: {{ my_namespace }}
  labels:
    name: {{ my_namespace }}

group_vars/all.yml

---
# Custom variables for usage in templates
my_namespace: frontend

# Role variables
k8s_templates_create:
  - template: path/to/create-k8s-namespace.yml.j2

How to execute:

# Deploy namespace
$ ansible-playbook playbook.yml

# Overwrite namespace name
$ ansible-playbook playbook.yml -e my_namespace=backend

2. Usage of tags per item

Required files:

group_vars/all.yml

---
k8s_templates_create:
  - template: path/to/pod1.yml.j2
    tag: stage1
  - template: path/to/pod2.yml.j2
    tags:
      - pod
      - stage2

k8s_templates_remove:
  - template: path/to/ds1.yml.j2
    tag: stage1
  - template: path/to/ds2.yml.j2
    tags:
      - pod
      - stage2

How to execute:

# Remove and deploy all files
$ ansible-playbook playbook.yml

# Only deploy files
$ ansible-playbook playbook.yml -e k8s_create=1

# Only deploy files with tag stage1
$ ansible-playbook playbook.yml -e k8s_create=1 -e k8s_tag=stage1

3. Usage of context per item

Required files:

group_vars/all.yml

---
# context is global for all deployment files
k8s_context: minikube

k8s_templates_create:
  - template: path/to/pod1.yml.j2
  - template: path/to/pod2.yml.j2
  # The next item uses a different context (takes precedence over global context)
  - template: path/to/pod3.yml.j2
    context: dev-cluster

How to execute:

# IMPORTANT:
# When a context is attached to an item (as with pod3.yml)
# it will take precedence over any globally specified context.
# So this example will deploy everything into the cluster specified by the global context,
# except pod3.yml, which will always go into dev-cluster

# Deploy everything into minikube (pod3.yml will however be deployed into dev-cluster)
$ ansible-playbook playbook.yml -e k8s_create=1

# Deploy everything into a different cluster (pod3.yml will however be deployed into dev-cluster)
$ ansible-playbook playbook.yml -e k8s_create=1 -e k8s_context=prod-cluster

Testing

Requirements

• Docker
• yamllint
• openshift Python package

Run tests

# Lint the source files
make lint

# Run integration tests with default Ansible version
make test

# Run integration tests with custom Ansible version
make test ANSIBLE_VERSION=2.7