Create project_shared_children files if they do not exist

[fullyint]

Fixes this discourse thread.

The "Ensure shared sources are present" task uses the file module to create directories or files in the shared directory.

The comments for project_shared_children in the deploy/defaults indicates that items in the list "are created if they don't exist." The problem is that if a user specifies type: file, this is fed to the state option for the file module, but when state is "file, the file will NOT be created if it does not exist."

In addition, the file module will not create the subdirectories a file may be in, if they are missing.

This PR splits the "Ensure shared sources are present" task in two. The first task creates all the shared directories, including the parent directories of shared files. The second task touches the files.

If touch (new in 1.4), an empty file will be created if the path does not exist, while an existing file or directory will receive updated file access and modification times -- ref

Touch is necessary if we actually want to create files, but unfortunately it is never idempotent.

This approach should still allow for type/state values such as absent.

[fullyint]

Thank you @swalkinshaw for pointing out that the symlink creation will fail if the parent directory of project_shared_children[*].path doesn't exist in the new_release_path. I added a commit to create the parent directory.

I also added the lower filter to prevent the file module from failing if a user defines type: File.

I also added a comment in roles/deploy/defaults/main.yml...

Use `type: absent` to remove an item from `/shared`.

I also made it explicit that the mode value should be quoted to avoid the potential confusion around how "python and yaml (pyyaml) work with each other in regards to octal values" (discussion).

[swalkinshaw]

Shouldn't we enforce the path here? Items set to absent aren't included here anyway.

[fullyint]

The absent option allows an easy way for someone to remove something from /shared if it will no longer be used in the next deployment(s). Although it is not necessary to remove items, and although people could remove them manually, facilitating this absent option requires no extra tasks, so I thought it was convenient.

However, the absent option does require the the two tasks you've marked to include when conditions and item.path | default(''). Yes these two tasks will skip for items set to absent, but Ansible still attempts to template all the variables in the task. So, without a default for item.path, the task would fail when people omit path for items set to absent.

If we keep this absent option, I would like people to be able to omit path because an item to be removed from /shared will have no path in the release directory, so the path parameter doesn't make sense to include.

[swalkinshaw]

Same with here

[fullyint]

Latest commit Simplify handling ...

• removes the absent feature
• splits the first "ensure shared directories are present" task in two:
  • first create directories for items with type: directory
  • next create parent directories for items with type: file

These changes favor "more tasks that are simple" over "fewer tasks that are complex." I routinely have to fight my inclination toward the latter.

If/when merged, probably ought to be a "squash and merge."

[swalkinshaw]

🚀 squash, changelog, merge :)