diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 16:04:56 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 16:04:56 +0000 |
commit | d964cec5e6aa807b75c7a4e7cdc5f11e54b2eda2 (patch) | |
tree | 794bc3738a00b5e599f06d1f2f6d79048d87ff8e /src/ansiblelint/rules/key_order.md | |
parent | Initial commit. (diff) | |
download | ansible-lint-upstream.tar.xz ansible-lint-upstream.zip |
Adding upstream version 6.13.1.upstream/6.13.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/ansiblelint/rules/key_order.md')
-rw-r--r-- | src/ansiblelint/rules/key_order.md | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/src/ansiblelint/rules/key_order.md b/src/ansiblelint/rules/key_order.md new file mode 100644 index 0000000..378d8a5 --- /dev/null +++ b/src/ansiblelint/rules/key_order.md @@ -0,0 +1,63 @@ +# key-order + +This rule recommends reordering key names in ansible content to make +code easier to maintain and less prone to errors. + +Here are some examples of common ordering checks done for tasks and handlers: + +- `name` must always be the first key for plays, tasks and handlers +- on tasks, the `block`, `rescue` and `always` keys must be the last keys, + as this would avoid accidental miss-indentation errors between the last task + and the parent level. + +## Problematic code + +```yaml +--- +- hosts: localhost + name: This is a playbook # <-- name key should be the first one + tasks: + - name: A block + block: + - name: Display a message + debug: + msg: "Hello world!" + when: true # <-- when key should be before block +``` + +## Correct code + +```yaml +--- +- name: This is a playbook + hosts: localhost + tasks: + - name: A block + when: true + block: + - name: Display a message + debug: + msg: "Hello world!" +``` + +## Reasoning + +Making decisions about the optimal order of keys for ansible tasks or plays is +no easy task, as we had a huge number of combinations to consider. This is also +the reason why we started with a minimal sorting rule (name to be the first), +and aimed to gradually add more fields later, and only when we find the proofs +that one approach is likely better than the other. + +### Why I no longer can put `when` after a `block`? + +Try to remember that in real life, `block/rescue/always` have the habit to +grow due to the number of tasks they host inside, making them exceed what a single screen. This would move the `when` task further away from the rest of the task properties. A `when` from the last task inside the block can +easily be confused as being at the block level, or the reverse. When tasks are +moved from one location to another, there is a real risk of moving the block +level when with it. + +By putting the `when` before the `block`, we avoid that kind of risk. The same risk applies to any simple property at the task level, so that is why +we concluded that the block keys must be the last ones. + +Another common practice was to put `tags` as the last property. Still, for the +same reasons, we decided that they should not be put after block keys either. |