Looping through a product of two arrays - ansible

Question

I have this vars file in Ansible:
for_create:
client: ["VK","SB"]
folders: ["toula","tina"]
for_delete:
client: ["VK","SB"]
folders: ["invoices","scripts"]
for_rename:
client: ["VK", "SB"]
old_name: ["home"]
new_name: ["town"]
Is it possible to do something like that in YAML? The following code in Ruby
clients = ["VK", "SB"]
folders = ["toula","tina"]
clients.each do |client|
folders.each do |folder|
puts "folder #{folder} for client #{client} created"
end
end
To sum up I want each client to create the folders ["toula", "tina"]
I have tried a lot but I can't manage to make it loop twice for each folder.
The output of the above code
folder toula for client VK created
folder tina for client VK created
folder toula for client SB created
folder tina for client SB created

Answer 1

Iterate the lists with_nested. For example,
- debug:
msg: "folder {{ item.1 }} for client {{ item.0 }} created"
with_nested:
- "{{ for_create.client }}"
- "{{ for_create.folders }}"
vars:
for_create:
client: [VK, SB]
folders: [toula, tina]
gives (abridged)
msg: folder toula for client VK created
msg: folder tina for client VK created
msg: folder toula for client SB created
msg: folder tina for client SB created
To rename folders zip the lists
- debug:
msg: "folder {{ item.1 }} renamed to {{ item.2 }} for client {{ item.0 }}"
with_nested:
- "{{ for_rename.client }}"
- "{{ for_rename.old_name|zip(for_rename.new_name) }}"
vars:
for_rename:
client: [VK, SB]
old_name: [home]
new_name: [town]
gives (abridged)
msg: folder home renamed to town for client VK
msg: folder home renamed to town for client SB
Q: "Is it possible to check if the folder exists inside the loop?"
A: Yes. It is. Use the parameters creates or removes. For example, given the tree
shell> tree /tmp/home/
/tmp/home/
├── SB
│   └── home
└── VK
└── home
The playbook below
shell: cat pb.yml
- hosts: localhost
tasks:
- command:
cmd: "mv {{ main_path }}/{{ item.1 }} {{ main_path }}/{{ item.2 }}"
removes: "{{ main_path }}/{{ item.1 }}"
with_nested:
- "{{ for_rename.client }}"
- "{{ for_rename.old_name|zip(for_rename.new_name) }}"
vars:
main_path: "/tmp/home/{{ item.0 }}"
for_rename:
client: [VK, SB]
old_name: [home]
new_name: [town]
moves the files only if exist
shell> ansible-playbook pb.yml
PLAY [localhost] *****************************************************************************
TASK [command] *******************************************************************************
changed: [localhost] => (item=['VK', 'home', 'town'])
changed: [localhost] => (item=['SB', 'home', 'town'])
PLAY RECAP ***********************************************************************************
localhost: ok=1 changed=1 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
shell> tree /tmp/home/
/tmp/home/
├── SB
│   └── town
└── VK
└── town
2 directories, 2 files
The playbook is idempotent. The commands will not execute if the files are missing
shell> ansible-playbook pb.yml
PLAY [localhost] *****************************************************************************
TASK [command] *******************************************************************************
ok: [localhost] => (item=['VK', 'home', 'town'])
ok: [localhost] => (item=['SB', 'home', 'town'])
PLAY RECAP ***********************************************************************************
localhost: ok=1 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
You can use the module command the same way also to create or remove files. The next option is using the module file. For example, the playbook below
shell> cat pb.yml
- hosts: localhost
tasks:
- file:
state: touch
path: "{{ main_path }}/{{ item.1 }}"
with_nested:
- "{{ for_create.client }}"
- "{{ for_create.folders }}"
vars:
main_path: "/tmp/home/{{ item.0 }}"
for_create:
client: [VK, SB]
folders: [toula, tina]
creates the files
shell> ansible-playbook pb.yml
PLAY [localhost] *****************************************************************************
TASK [file] **********************************************************************************
changed: [localhost] => (item=['VK', 'toula'])
changed: [localhost] => (item=['VK', 'tina'])
changed: [localhost] => (item=['SB', 'toula'])
changed: [localhost] => (item=['SB', 'tina'])
PLAY RECAP ***********************************************************************************
localhost: ok=1 changed=1 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
shell> tree /tmp/home/
/tmp/home/
├── SB
│   ├── tina
│   ├── toula
│   └── town
└── VK
├── tina
├── toula
└── town
This task is not idempotent because the files will receive updated file access and modification times (similar to the way touch works from the command line). Preserve access_time and modification_time to make the task idempotent
- file:
state: touch
path: "{{ main_path }}/{{ item.1 }}"
access_time: preserve
modification_time: preserve
...