# [Best practices] Extend an occupied hook

**URL:** https://discourse.roots.io/t/best-practices-extend-an-occupied-hook/9253
**Category:** trellis
**Created:** 2017-03-30T17:47:19Z
**Posts:** 9

## Post 1 by @strarsis — 2017-03-30T17:47:20Z

It doesn’t seem to be possible using an ansible list for a hook file path.

I want to extend the `deploy_build_after` hook file, adding new functionality while preserving the original one (from Trellis). I want to avoid editing the file directly for better pulling+merging further Trellis updates (I use trellis as normal git repository and pull from GitHub).

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## Post 2 by @swalkinshaw — 2017-03-30T20:24:54Z

There really isn’t one right now unfortunately. Which kind of defeats the purpose of hooks a bit :frowning:

We might be able to use Jinja inheritance for them. Want to create an issue for this?

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## Post 3 by @fullyint — 2017-03-30T20:38:54Z

I haven’t tried, but how about overriding [`deploy_build_after`](https://github.com/roots/trellis/blob/41b7f641d650af26d51800943045b5a412763168/deploy.yml#L20) with your own include?

```
# deploy.yml
- deploy_build_after: "{{ playbook_dir }}/roles/deploy/hooks/build-after.yml"
+ deploy_build_after: "{{ playbook_dir }}/deploy-hooks/build-after.yml"
```

Then in your custom `build-after.yml`, just include the original

```
# deploy-hooks/build-after.yml

- name: some task
  command: stuff

# original tasks
- include: "{{ playbook_dir }}/roles/deploy/hooks/build-after.yml"

- name: some task
  command: more stuff
```

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## Post 4 by @strarsis — 2017-03-31T00:07:33Z

Created a new issue: [https://github.com/roots/trellis/issues/814](https://github.com/roots/trellis/issues/814)

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## Post 5 by @mockey — 2017-04-01T01:37:36Z

> [@fullyint](#):
>
> Then in your custom build-after.yml, just include the original

That would be good, but it doesn’t seem to work, does it? In my test deployment just stopped before doing the build\_after stuff, no error message or so.

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## Post 6 by @fullyint — 2017-04-01T06:32:54Z

@mockey Thanks for trying and reporting back. Trying just now, I get the same result. It’s baffling that the play just stops with no errors.

I think a “task include” parses and loads things a little differently than regular and has a problem with the usage of a `default` containing a quoted string. Here’s an example of changes Trellis might make to enable the nested include strategy above to succeed.

Remove [this default](https://github.com/roots/trellis/blob/41b7f641d650af26d51800943045b5a412763168/roles/deploy/tasks/build.yml#L23) . . .

```
# roles/deploy/tasks/build.yml
- - include: "{{ deploy_build_after | default('../hooks/example.yml') }}"
+ - include: "{{ deploy_build_after }}"
```

. . . placing the default in `roles/deploy/defaults/main.yml` instead:

```
# roles/deploy/defaults/main.yml
+ deploy_build_after: ../hooks/example.yml
```

There may be something Ansible needs to fix upstream, but perhaps Trellis could make this implementation adjustment for all deploy hooks in order to facilitate nested includes.

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## Post 7 by @mockey — 2017-04-01T12:49:43Z

> [@fullyint](#):
>
> Trying just now, I get the same result. It’s baffling that the play just stops with no errors.

Yes, this whole `include` stuff seems a bit weird to me in Ansible.

> [@fullyint](#):
>
> Here’s an example of changes Trellis might make to enable the nested include strategy above to succeed.

It’s pretty cool that you figured that out, might really make sense to implement it this way.

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## Post 8 by @strarsis — 2017-04-02T14:53:46Z

Wouldn’t this be then an [issue in ansible](https://github.com/ansible/ansible/issues)?

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## Post 9 by @fullyint — 2017-04-02T19:02:45Z

A fix proposed to Ansible upstream in [ansible/ansible#23202](https://github.com/ansible/ansible/pull/23202)