[libvirt-ci PATCH 10/13] lcitool: Use d.update() on extra_vars for options coming from the config

[Andrea Bolognani]

On Wed, 2020-04-22 at 15:28 +0200, Erik Skultety wrote:
> +            # start with generic items not coming from the config
>              extra_vars = {
>                  "base": base,
>                  "playbook_base": playbook_base,
> -                "root_password": self._config.dict["install"]["root_password"],
> -                "flavor": self._config.dict["install"]["flavor"],
>                  "selected_projects": selected_projects,
>                  "git_remote": git_remote,
>                  "git_branch": git_branch,
> -                "gitlab_url": self._config.dict["gitlab"]["url"],
> -                "gitlab_runner_secret": self._config.dict["gitlab"]["token"],
>              }
> +
> +            # now add the config vars
> +            extra_vars.update(self._config.dict["install"])
> +
> +            if extra_vars["flavor"] == "gitlab":
> +                extra_vars.update(self._config.dict["gitlab"])
> +

Mh, I don't think I like this.

First of all, it forces you to replicate the "if gitlab" conditional
in one additional place, and most importantly it completely flattens
the resulting dictionary, eg.

  config.dict["gitlab"]["url"] -> extra_vars["url"]

Both of these issues will disappear if you follow the suggestion I
made in 6/13 and load the default config.toml first: at that point,
you can unconditionally copy entire sections from the TOML into
extra_vars, and later in the playbook you can simply refer to them
along the lines of

  - shell: gitlab-runner {{ gitlab.url }} {{ gitlab.runner_secret }}
    when:
      - install.flavor == "gitlab"

which is much nicer.

In fact, we should use the same approach for values in the
inventory, eg.

  os_name: "Debian"
  os_version: "10"

should become

  os:
    name: "Debian"
    version: "10"

Given that both Python and Ansible support proper dictionaries, we
might very well use them instead of using prefix notation to emulate
a worse version of them :)

-- 
Andrea Bolognani / Red Hat / Virtualization