Dynamic Ansible Inventory for Rancher

Query a Rancher management cluster to know about available nodes, that belong to this cluster and also to imported Kubernetes clusters. See the documentation on dynamic inventory for more details on the 'dynamic inventory' concept.

Prerequisites

The Ansible dynamic inventory script for Rancher was tested with:

• Ansible 2.7+
• Rancher 2.4.x
• Python 3

Other Rancher versions might work as well depending on API changes.

Getting started

inventory.ini

First you have to provide the API url and the credentials by creating the inventory.ini file

[main]
rancher_url = https://rancher.example.com
rancher_token = token-abc:key1234567890

inventory.py

The inventory.py script queries the Rancher management cluster API to present the results to Ansible as an inventory. There is currently no caching implemented. Make sure to make the file executable.

ansible all -m ping -i inventory.py

For debugging reasons the inventory.py can also started without Ansible:

./inventory.py --list

Inventory example output

The local cluster inventory should look like this. This inventory script also supports imported clusters.

{
  "_meta": {
    "hostvars": {
      "node1": {
        "roles": [
          "controlplane",
          "worker",
          "etcd"
        ],
        "host_state": "active",
        "host_id": "local:machine-v9bcn",
        "cluster_name": "local",
        "cluster_id": "local",
        "labels": {
          "beta.kubernetes.io/arch": "amd64",
          "beta.kubernetes.io/os": "linux",
          "kubernetes.io/arch": "amd64",
          "kubernetes.io/hostname": "node1",
          "kubernetes.io/os": "linux",
          "node-role.kubernetes.io/controlplane": "true",
          "node-role.kubernetes.io/etcd": "true",
          "node-role.kubernetes.io/worker": "true",
          "persistence": "statefull"
        }
      },
      "node2": {
        "roles": [
          "controlplane",
          "worker",
          "etcd"
        ],
        "host_state": "active",
        "host_id": "local:machine-v9bcn",
        "cluster_name": "local",
        "cluster_id": "local",
        "labels": {
          "beta.kubernetes.io/arch": "amd64",
          "beta.kubernetes.io/os": "linux",
          "kubernetes.io/arch": "amd64",
          "kubernetes.io/hostname": "node2",
          "kubernetes.io/os": "linux",
          "node-role.kubernetes.io/controlplane": "true",
          "node-role.kubernetes.io/etcd": "true",
          "node-role.kubernetes.io/worker": "true",
          "persistence": "statefull"
        }
      },
      "node3": {
        "roles": [
          "controlplane",
          "worker",
          "etcd"
        ],
        "host_state": "active",
        "host_id": "local:machine-v9bcn",
        "cluster_name": "local",
        "cluster_id": "local",
        "labels": {
          "beta.kubernetes.io/arch": "amd64",
          "beta.kubernetes.io/os": "linux",
          "kubernetes.io/arch": "amd64",
          "kubernetes.io/hostname": "node3",
          "kubernetes.io/os": "linux",
          "node-role.kubernetes.io/controlplane": "true",
          "node-role.kubernetes.io/etcd": "true",
          "node-role.kubernetes.io/worker": "true",
          "persistence": "statefull"
        }
      }
    }
  },
  "all": {
    "vars": {
      "api_url_base": "https://rancher.example.com/v3"
    }
  },
  "local": {
    "hosts": [
      "node1",
      "node2",
      "node3"
    ],
    "vars": {
      "controller_manager_healthy": true,
      "etcd_0_healthy": true,
      "etcd_1_healthy": true,
      "etcd_2_healthy": true,
      "description": "",
      "driver": "imported",
      "id": "local",
      "istioEnabled": false,
      "nodeCount": 3,
      "state": "active"
    }
  }
}