localurl:/docs/codefresh-yaml/deployment-environments/

-title:Hooks

localurl:/docs/codefresh-yaml/hooks/

-title:Plugins

localurl:/docs/codefresh-yaml/steps/#creating-your-own-step

-title:Examples

localurl:/docs/yaml-examples/examples/

For simple commands we suggest you use a small image such as`alpine`, but any Docker image can be used in hooks.

Also, Hooks can use[steps/plugins](https://steps.codefresh.io) and need to define:

1. The type field for the step/plugin.

1. The arguments needed for the step/plugin.

Codefresh allows you to run a specific step before each pipeline as well as after it has finished.

1. The`on_finish` segment always executes at the end

Hooks can use[steps/plugins](https://steps.codefresh.io). With plugin you have to specify:

- The type field for the step/plugin.

- The arguments needed for the step/plugin.

{% highlight yaml %}

{% raw %}

version: "1.0"

hooks: #run slack-notifier hook on build completion

on_finish:

steps:

exec:

type: slack-notifier

arguments:

SLACK_HOOK_URL: '${{SLACK_WEBHOOK_URL}}'

SLACK_TEXT: '${{SLACK_TEXT}}'

steps:

step1:

title: "Freestyle step"

type: "freestyle"

image: alpine

commands:

- echo "Codefresh"

hooks: #run slack-notifier hook on step completion

on_finish:

steps:

exec:

type: slack-notifier

arguments:

SLACK_HOOK_URL: '${{SLACK_WEBHOOK_URL}}'

SLACK_TEXT: '${{SLACK_TEXT}}'

{% endraw %}

{% endhighlight %}

By default if a step fails within a pipeline, the whole pipeline will stop and be marked as failed. This is also true for`on_elected` segments as well. If they fail, then the whole pipeline will fail (regardless of the position of the segment in a pipeline or step).