Ansible "apt cache update failed" during postgresql repo install - ansible

Question

I'm trying to install postgresql on my remote host using Ansible.
I have 2 solutions, but both work only half as I expect them to work/turn out.
1. Solution one (using Ansible apt_repository module);
- name: Get Postgres latest repository release
become: yes
apt_repository:
repo: deb https://apt.postgresql.org/pub/repos/apt/ $(lsb_release -cs)-pgdg main
state: present
filename: pgdg.list
This option first looks like it's successful on execution, but eventually gives an error (apt cache update failed):
2. Solution two (use shell module)
- name: Get Postgres latest repository release
become: yes
shell: sh -c 'echo "deb http://apt.postgresql.org/pub/repos/apt/ $(lsb_release -cs)-pgdg main" > /etc/apt/sources.list.d/pgdg.list'
This accomplishes exactly the same (correct me if I'm wrong) and later gives some other exception (No package matching):
So I'm not getting any further with my playbook, any tips?
My play to install postgresql-13 (or 14):
- name: Install Postgres dependencies (if not installed)
become: yes
apt:
name:
- postgresql-{{ postgres_version }}
- postgresql-doc-{{ postgres_version }}
- postgresql-contrib
- zabbix-sql-scripts
when:
- "not 'postgresql-13' in ansible_facts.packages"
- "not 'postgresql-doc-13' in ansible_facts.packages"
- "not 'postgresql-contrib' in ansible_facts.packages"
- "not 'zabbix-sql-scripts' in ansible_facts.packages"
Repository keys are provided in another play and performs without errors.
This is executed on a host with Ubuntu 20.04LTS, Ansible version 2.9.6, Python version 3.8.10
I have searched for both individual problems but did not find a specific answer that solved my problem.
If if perform the same as Ansible manually, it all installs fine (commands used):
sudo sh -c ‘echo “deb http://apt.postgresql.org/pub/repos/apt $(lsb_release -cs)-pgdg main” > /etc/apt/sources.list.d/pgdg.list’
wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | sudo apt-key add -
sudo apt-get update
sudo apt-get -y install postgresql-13 postgresql-doc-13
Edit:
Seemed I also had a quote (") missing at the start of my repo link (before deb https://...).
I had: repo: deb https://apt.postgresql.org/pub/repos/apt/ $(lsb_release -cs)-pgdg main"
Should be: "repo: deb https://apt.postgresql.org/pub/repos/apt/ $(lsb_release -cs)-pgdg main"

Answer 1

Basically, it must be said that an Ansible module, such as apt_repository is generally preferable to the shell module.
However, you have a few mistakes in your approach.
As you can see, apt_repository automatically updates the package sources, i.e. the repository key must already exist. You can add the repository key with the apt_key module, but you need to have the gpg package installed, which you should ensure first.
From this follows:
install gpg
- name: Ensure gpg is installed
apt:
name: gpg
add repository key
- name: Add repository signing key
apt_key:
url: "https://www.postgresql.org/media/keys/ACCC4CF8.asc"
state: present
add repository source
- name: Add postgresql repository
apt_repository:
repo: "deb https://apt.postgresql.org/pub/repos/apt/ {{ ansible_distribution_release }}-pgdg main"
state: present
filename: pgdg
When using apt_repository one of your problems was that you left $(lsb_release -cs) unchanged, but this only works via the shell, instead you have to use the variable ansible_distribution_release when using Ansible. Also, the filename parameter does not need an extension (.list), as the documentation tells you: "The .list extension will be automatically added." Your specification creates the file pgdg.list.list.
Again, as a whole playbook:
- name: Database Server
hosts: databaseserver
become: yes
tasks:
- name: Ensure gpg is installed
apt:
name: gpg
- name: Add repository signing key
apt_key:
url: "https://www.postgresql.org/media/keys/ACCC4CF8.asc"
state: present
- name: Add postgresql repository
apt_repository:
repo: "deb https://apt.postgresql.org/pub/repos/apt/ {{ ansible_distribution_release }}-pgdg main"
state: present
filename: pgdg
Now you should be able to install the desired packages, if they are provided by the included repository.

Answer 2

Maybe this is what cause your problem: answer
Before to add the repository you need to:
Add the APT Key.
Add Repository.
Install Packages.