F #91: Improve ds "generic" and "simple" modes

- Assume true if "managed" attribute is undefined.
- Assert that all symlink targets must exist.
- Provide rationale for manual "generic" ds id management.

roles/datastore/frontend/README.md

@@ -33,7 +33,7 @@ Example Playbook
   # Configure OpenNebula to use "ssh" datastores.
   # Create symlinks accordingly.
   # NOTE: In case of HA OpenNebula, image and file datastores
-  # should be shared among all Frontends.
+  #  should be shared among all Frontends.
   ds:
   mode: ssh
   config:
@@ -68,6 +68,11 @@ Example Playbook
   vars:
   # Configure OpenNebula to use "shared" image and system datastores.
   # Create new datastores and symlinks accordingly.
+  # NOTE: 1. In OpenNebula all user-created datastores start from ID=100.
+  # 2. If the 'id' attribute refers to an existing datastore, then one-deploy tries to update it.
+  # 3. If 2. is false, then a new datastore is created using the next available ID.
+  # 4. Users *MUST* provide the 'id' attribute for each new entry in the 'ds.config' dict
+  # (starting from 100, then incrementing by 1 further down the line).
   ds:
   mode: generic
   config:

roles/datastore/generic/defaults/main.yml

@@ -11,7 +11,7 @@ ds_defaults:
  enabled: true
  symlink:
  groups: [node]
- src: /var/lib/one/datastores/
+ src: /var/lib/one/datastores/ # this skips symlinking
  template:
  TYPE: SYSTEM_DS
  TM_MAD: ssh
@@ -21,7 +21,7 @@ ds_defaults:
  managed: true
  symlink:
  groups: [frontend, node]
- src: /var/lib/one/datastores/
+ src: /var/lib/one/datastores/ # this skips symlinking
  template:
  TYPE: IMAGE_DS
  DS_MAD: fs
@@ -32,7 +32,7 @@ ds_defaults:
  managed: true
  symlink:
  groups: [frontend]
- src: /var/lib/one/datastores/
+ src: /var/lib/one/datastores/ # this skips symlinking
  template:
  TYPE: FILE_DS
  DS_MAD: fs

roles/datastore/generic/tasks/common.yml

@@ -7,14 +7,13 @@
  {{ _items | items2dict }}
  vars:
  _ds: >-
- {{ ds_defaults | combine(ds.config | default({}), recursive=true) }}
+ {{ ds_defaults | combine(ds.config | d({}), recursive=true) }}
  _items: >-
  {{ _ds | dict2items
  | map(attribute='value')
  | map('dict2items')
  | flatten
- | selectattr('value.managed', 'true')
- | list }}
+ | rejectattr('value.managed', 'false') }}
 
 - name: Ensure /var/lib/one/datastores/ exists
  ansible.builtin.file:
@@ -31,26 +30,43 @@
 
  if [[ -L '{{ _base_path }}' ]]; then exit 0; fi
 
- if [[ -d '{{ _base_path }}/' ]] && ! rmdir '{{ _base_path }}/'; then exit 1; fi
+ if ! [[ -d '{{ _mount_path }}' ]]; then
+ echo "Symlink target does not exist or is not a directory." >&2
+ exit 1
+ fi
 
- if ! ln -s '{{ _mount_path }}/' '{{ _base_path }}'; then exit 1; fi
+ if [[ -d '{{ _base_path }}' ]] && ! rmdir '{{ _base_path }}'; then exit 1; fi
+
+ if ! ln -s '{{ _mount_path }}' '{{ _base_path }}'; then exit 1; fi
 
  exit 78
  executable: /bin/bash
- when: inventory_hostname in _hosts and _mount_path != '/var/lib/one/datastores'
+ when:
+ - inventory_hostname in _hosts
+ # NOTE: It doesn't really make sense to symlink /var/lib/one/datastores/,
+ # so we use that as a skip condition.
+ - _mount_path != '/var/lib/one/datastores'
  vars:
+ # This isn't strictly a "mountpoint" (that's completely irrelevant).
  _mount_path: >-
- {{ ds_dict[item].symlink.src | normpath }}
+ {{ ds_dict[item].symlink.src | d('/var/lib/one/datastores/') | normpath }}
+ # NOTE: 1. In OpenNebula all user-created datastores start from ID=100.
+ # 2. If the ds_dict[item].id refers to an existing datastore, then one-deploy tries to update it (later).
+ # 3. If 2. is false, then a new datastore is created using the next available ID (later).
+ # 4. If 3. is true, then at this exact point in time one-deploy does *NOT* know the ID.
+ # 5. The 'generic' mode has been specifically designed in such a way that reduces code complexity.
+ # Users *MUST* provide the 'id' attribute for each new entry in the 'ds.config' dict
+ # (starting from 100, then incrementing by 1 further down the line).
  _base_path: >-
  /var/lib/one/datastores/{{ ds_dict[item].id }}
  _hosts: >-
- {{ ds_dict[item].symlink.groups | map('extract', groups)
+ {{ ds_dict[item].symlink.groups | d([])
+ | map('extract', groups)
  | flatten
- | unique
- | list }}
- loop: "{{ ds_names }}"
+ | unique }}
  register: shell
  changed_when:
  - shell.rc == 78 # EREMCHG "Remote address changed" 8^)
  failed_when:
  - shell.rc != 0 and shell.rc != 78
+ loop: "{{ ds_names }}"

roles/datastore/generic/tasks/frontend.yml

@@ -25,9 +25,9 @@
  _document: >-
  {{ shell.stdout | from_json }}
  _datastores: >-
- {{ [_document.DATASTORE_POOL.DATASTORE | default([])] | flatten | list }}
+ {{ [_document.DATASTORE_POOL.DATASTORE | d([])] | flatten }}
  _names: >-
- {{ _datastores | map(attribute='NAME') | default([]) | list }}
+ {{ _datastores | map(attribute='NAME') | d([]) | list }}
 
 - when: inventory_hostname == leader
  block:

roles/datastore/simple/tasks/frontend.yml

@@ -9,9 +9,14 @@
 
  if [[ -L '{{ _base_path }}' ]]; then exit 0; fi
 
- if [[ -d '{{ _base_path }}/' ]] && ! rmdir '{{ _base_path }}/'; then exit 1; fi
+ if ! [[ -d '{{ _mount_path }}' ]]; then
+ echo "Symlink target does not exist or is not a directory." >&2
+ exit 1
+ fi
 
- if ! ln -s '{{ _mount_path }}/' '{{ _base_path }}'; then exit 1; fi
+ if [[ -d '{{ _base_path }}' ]] && ! rmdir '{{ _base_path }}'; then exit 1; fi
+
+ if ! ln -s '{{ _mount_path }}' '{{ _base_path }}'; then exit 1; fi
 
  exit 78
  executable: /bin/bash

roles/datastore/simple/tasks/node.yml

@@ -11,9 +11,14 @@
 
  if [[ -L '{{ _base_path }}' ]]; then exit 0; fi
 
- if [[ -d '{{ _base_path }}/' ]] && ! rmdir '{{ _base_path }}/'; then exit 1; fi
+ if ! [[ -d '{{ _mount_path }}' ]]; then
+ echo "Symlink target does not exist or is not a directory." >&2
+ exit 1
+ fi
 
- if ! ln -s '{{ _mount_path }}/' '{{ _base_path }}'; then exit 1; fi
+ if [[ -d '{{ _base_path }}' ]] && ! rmdir '{{ _base_path }}'; then exit 1; fi
+
+ if ! ln -s '{{ _mount_path }}' '{{ _base_path }}'; then exit 1; fi
 
  exit 78
  executable: /bin/bash