pcs_resource: clone resource group feature

[chenwangkai]

Hello @OndrejHome
As you mentioned in issue #1 ,cloned resources cannot be part of resource group.
Do we have any plan to support this? Thanks in advanced.

My Ansible Task Sample

- name: Create PCS resource skyform_nginx
  pcs_resource:
    name: "skyform_nginx"
    resource_class: systemd
    resource_type: "systemd:nginx"
    options: "op monitor interval=0s timeout=30s --group skyform_group"
  run_once: true

- name: Create PCS resource skyform_appspace
  pcs_resource:
    name: "skyform_appspace"
    resource_class: systemd
    resource_type: "systemd:appspace"
    options: "op monitor interval=0s timeout=100s --group skyform_group"
  run_once: true

- name: Create resource clone group skyform_group-clone
  command: >
    pcs resource clone skyform_group meta clone-max=2 notify=true
  ignore_errors: yes
  run_once: true

[OndrejHome]

Hello @chenwangkai,

I wish I had time to have a look at this, but this particular feature is not easy for me to implement.
Also there were no recent requests for it nor need on my side, this may not be supported in short term.

While not as pretty as cloned group, you can achieve similar functionality just with cloned resources that are then ordered and colocated with constraints. From the example that you have provided that would look like this and it should work with current version of pcs-modules-2:

- name: Create cloned PCS resource skyform_nginx
  pcs_resource:
    name: "skyform_nginx"
    resource_class: systemd
    resource_type: "systemd:nginx"
    options: "op monitor interval=0s timeout=30s clone"
  run_once: true

- name: Create cloned PCS resource skyform_appspace
  pcs_resource:
    name: "skyform_appspace"
    resource_class: systemd
    resource_type: "systemd:appspace"
    options: "op monitor interval=0s timeout=100s clone"
  run_once: true

- name: Create resource ordering so resources start after each other
  pcs_constraint_order:
    resource1: 'skyform_nginx-clone'
    resource2: 'skyform_appspace-clone'
  run_once: true

- name: Create colocation of resources on same node
  pcs_constraint_colocation:
    resource1: 'skyform_appspace-clone'
    resource2: 'skyform_nginx-clone'
  run_once: true

NOTE 1: If the cloned resources will run on all nodes in cluster, then you probably don't need to 'colocation' constraint which is really useful when resources only run on some, but not all cluster nodes.
NOTE 2: When using constraint_colocation you should specify resources in opposite order as you would do with 'constraint_order' due to logic used by pacemaker.

Please let me know if you have any questions to above approach.

--
Ondrej