README.md

sap_maintain_etc_hosts Ansible Role

Description

The Ansible role sap_maintain_etc_hosts is used to maintain the /etc/hosts file..

Execution

Execution Flow

1. Assert that required inputs were provided.
2. Verify duplicate entries and conflicts;
3. Update /etc/hosts file.

Example

Example playbook will update /etc/hosts:

• Remove node with IP 10.10.10.10.
• Remove node with name host2.
• Add node with IP 10.10.10.11, name host1, aliases alias1, alias2 and comment host1 comment.

- name: Ansible Play for add entry in /etc/hosts
  hosts: all
  become: true
  tasks:
    - name: Execute Ansible Role sap_sap_maintain_etc_hosts
      ansible.builtin.include_role:
        name: community.sap_install.sap_sap_maintain_etc_hosts
      vars:
        sap_maintain_etc_hosts_list:
        - node_ip: 10.10.10.10
          state: absent
        - node_name: host2
          state: absent
        - node_ip: 10.10.10.11
          node_name: host1
          aliases:
            - alias1
            - alias2
          node_comment: "host1 comment"  # Comment is created after hash sign (defaults to hana_site)
          state: present

Example playbook when executed together with sap_ha_pacemaker_cluster role which uses either sap_ha_pacemaker_cluster_cluster_nodes or sap_hana_cluster_nodes.

- name: Ansible Play for add entry in /etc/hosts
  hosts: all
  become: true
  tasks:
    - name: Execute Ansible Role sap_sap_maintain_etc_hosts
      ansible.builtin.include_role:
        name: community.sap_install.sap_sap_maintain_etc_hosts
      vars:
        sap_maintain_etc_hosts_list: "{{ sap_ha_pacemaker_cluster_cluster_nodes }}"

Further Information

For more examples on how to use this role in different installation scenarios, refer to the ansible.playbooks_for_sap playbooks.

License

Apache 2.0

Maintainers

• Markus Koch
• Bernd Finger

Role Variables

This role requires the dictionary sap_maintain_etc_hosts_list which contains the parameters for the /etc/hosts file.

The default value is the definition of the cluster nodes like in the role sap_ha_pacemaker_cluster.
If the value sap_hana_cluster_nodesor sap_ha_pacemaker_cluster_cluster_nodes is not defined, then the role creates a default value from ansible_facts.

NOTE: If you want to use this role to remove entries from /etc/hosts it is a good practice to do this before adding entries. The adding/removal is done in the order the entries are listed.

sap_maintain_etc_hosts_list

• Type: list with elements of type dict

Mandatory list of nodes in form of dictionaries to be added or removed in /etc/hosts file.

Following dictionary keys can be defined:

• node_ip
  IP address of the managed node.
  Required for adding new entries to /etc/hosts.
  Optional for removing entries, where node_name and node_domain can be used instead.

  • Type: string

• node_name
  Hostname of the managed node.
  Required for adding new entries to /etc/hosts.
  Optional for removing entries, when node_ip is not used.

  • Type: string

• node_domain
  Domain name of the managed node. Defaults to sap_domain if set or ansible_facts['domain'].
  Required for adding new entries to /etc/hosts.
  Optional for removing entries, when node_name is used.

  • Type: string
  • Default: sap_domain

• aliases
  List of aliases for the managed node.
  Optional for adding new entries to /etc/hosts.

  • Type: list with elements of type string

• alias_mode
  Select method of updating /etc/hosts file:
  - merge : merges the list of aliases with the exiting aliases of the node.
  - overwrite : overwrites the aliases of the node. Optional for adding new entries to /etc/hosts.

  • Type: string
  • Default: merge

• node_comment
  Node comment is appended at end of line of managed node.
  Optional for adding new entries to /etc/hosts.

  • Type: string
  • Default: managed by ansible sap_maintain_etc_hosts role

• hana_site
  Used by sap_ha_pacemaker_cluster and it is appended to node_comment
  Optional for adding new entries to /etc/hosts.

  • Type: string

• node_role
  Not used, but mentioned for compatibility reasons for sap_ha_pacemaker_cluster role.
  

  • Type: string

• state
  Select present for adding new entries, absent for removing them.
  Required for removing entries, otherwise default present is used.

  • Type: string
  • Default: present