From e8016be334a49dc225e9a8a70d1ec412f95397ad Mon Sep 17 00:00:00 2001 From: Rich Megginson Date: Fri, 18 Oct 2024 16:15:51 -0600 Subject: [PATCH] refactor: Use vars/RedHat_N.yml symlink for CentOS, Rocky, Alma wherever possible We have a lot of requests to support Rocky and Alma in various system roles. The first part of adding support is adding `vars/` files for these platforms. In almost every case, for a given major version N, the vars file RedHat_N.yml can be used for CentOS, Rocky, and Alma. Rather than making a copy of the RedHat_N.yml file, just use a symlink to reduce size and maintenance burden, and standardize this across all system roles for consistency. NOTE: OracleLinux is not a strict clone, so we are not going to do this for OracleLinux at this time. Support for OracleLinux will need to be done in separate PRs. For more information, see https://github.com/linux-system-roles/cockpit/issues/130 **Question**: Why not just use `ansible_facts["os_family"] == "RedHat"`? **Answer**: This is what Ansible uses as the RedHat os_family: https://github.com/ansible/ansible/blob/1e6ffc1d02559a26def6c9c3b07baf27032865a2/lib/ansible/module_utils/facts/system/distribution.py#L511 There are a lot of distributions in there. I know that Fedora is not a clone of RHEL, but it is very closely related. Most of the others are not clones, and it would generally not work to replace ansible_distribution in ['CentOS', 'Fedora', 'RedHat'] with ansible_facts['os_family'] == 'RedHat' (but it would probably work in specific cases with specific distributions). For example, OracleLinux is in there, and we know that doesn't generally work. The only ones we can be pretty sure about are `RedHat`, `CentOS`, `Fedora`, `AlmaLinux`, and `Rocky`. **Question**: Does my role really need this because it should already work on RHEL clones? **Answer**: Maybe not - but: * it doesn't hurt anything * it's there if we need it in the future * the role will be inconsistent with the other system roles if we don't have this **Question**: Why do I need the `tests/vars/rh_distros_vars.yml` file? Doesn't the test load the vars from the role? **Answer**: No, the test does not load the vars from the role until the role is included, and many tests use version and distribution before including the role. **Question**: Do we need to change the code now to use the new variables? **Answer**: No, not now, in subsequent PRs, hopefully by Alma and Rocky users. Note that there may be more work to be done to the role to fully support Rocky and Alma. Many roles have conditionals like this: ```yaml some_var: "{{ 'some value' if ansible_distribution in ['CentOS', 'RedHat'] else 'other value' }}" another_var: "{{ 'some value' if ansible_distribution in ['CentOS', 'Fedora', 'RedHat'] else 'other value' }}" ... - name: Do something when: ansible_distribution in ['CentOS', 'RedHat'] ... - name: Do something else when: ansible_distribution in ['CentOS', 'Fedora', 'RedHat'] ... ``` Adding Rocky and AlmaLinux to these conditionals will have to be done separately. In order to simplify the task, some new variables are being introduced: ```yaml __$rolename_rh_distros: - AlmaLinux - CentOS - RedHat - Rocky __$rolename_rh_distros_fedora: "{{ __$rolename_rh_distros + ['Fedora'] }}" __$rolename_is_rh_distro: "{{ ansible_distribution in __$rolename_rh_distros }}" __$rolename_is_rh_distro_fedora: "{{ ansible_distribution in __$rolename_rh_distros_fedora }}" ``` Then the conditionals can be rewritten as: ```yaml some_var: "{{ 'some value' if __$rolename_is_rh_distro else 'other value' }}" another_var: "{{ 'some value' if __$rolename_is_rh_distro_fedora else 'other value' }}" ... - name: Do something when: __$rolename_is_rh_distro | bool ... - name: Do something else when: __$rolename_is_rh_distro_fedora | bool ... ``` For tests - tests that use such conditionals will need to use `vars_files` or `include_vars` to load the variables that are defined in `tests/vars/rh_distros_vars.yml`: ```yaml vars_files: - vars/rh_distros_vars.yml ``` We don't currently have CI testing for Rocky or Alma, so someone wanting to run tests on those platforms would need to change the test code to use these. Signed-off-by: Rich Megginson --- tests/vars/rh_distros_vars.yml | 18 ++++++++++++++++++ vars/main.yml | 18 ++++++++++++++++++ 2 files changed, 36 insertions(+) create mode 100644 tests/vars/rh_distros_vars.yml diff --git a/tests/vars/rh_distros_vars.yml b/tests/vars/rh_distros_vars.yml new file mode 100644 index 0000000..7895e3f --- /dev/null +++ b/tests/vars/rh_distros_vars.yml @@ -0,0 +1,18 @@ +# vars for handling conditionals for RedHat and clones +# DO NOT EDIT - file is auto-generated +--- +# Ansible distribution identifiers that the role treats like RHEL +__tlog_rh_distros: + - AlmaLinux + - CentOS + - RedHat + - Rocky + +# Same as above but includes Fedora +__tlog_rh_distros_fedora: "{{ __tlog_rh_distros + ['Fedora'] }}" + +# Use this in conditionals to check if distro is Red Hat or clone +__tlog_is_rh_distro: "{{ ansible_distribution in __tlog_rh_distros }}" + +# Use this in conditionals to check if distro is Red Hat or clone, or Fedora +__tlog_is_rh_distro_fedora: "{{ ansible_distribution in __tlog_rh_distros_fedora }}" diff --git a/vars/main.yml b/vars/main.yml index b137790..13bb58d 100644 --- a/vars/main.yml +++ b/vars/main.yml @@ -24,3 +24,21 @@ __tlog_required_facts: # the 'gather_subset' parameter of the 'setup' module __tlog_required_facts_subsets: "{{ ['!all', '!min'] + __tlog_required_facts }}" + +# BEGIN - DO NOT EDIT THIS BLOCK - rh distros variables +# Ansible distribution identifiers that the role treats like RHEL +__tlog_rh_distros: + - AlmaLinux + - CentOS + - RedHat + - Rocky + +# Same as above but includes Fedora +__tlog_rh_distros_fedora: "{{ __tlog_rh_distros + ['Fedora'] }}" + +# Use this in conditionals to check if distro is Red Hat or clone +__tlog_is_rh_distro: "{{ ansible_distribution in __tlog_rh_distros }}" + +# Use this in conditionals to check if distro is Red Hat or clone, or Fedora +__tlog_is_rh_distro_fedora: "{{ ansible_distribution in __tlog_rh_distros_fedora }}" +# END - DO NOT EDIT THIS BLOCK - rh distros variables