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Version: 2025-09-11

Assets and templates

Asset templates​

To allow users to have different resources (defined by actions.rb files) within the same Git repository, OpsChain allows you to define asset templates. Asset templates in OpsChain can be seen as a way of referring to different actions.rb files within the same Git repository.

For example, if you have a Git repository with the following structure:

my-project/
  db_server/
    actions.rb
  web_server/
    actions.rb

You can create two asset templates, one for db_server and one for web_server. The actions in db_server will be available for the assets using the db_server template and the actions in web_server will be available for the assets using the web_server template.

More than that, asset templates are also used to:

Documented template actions​

The actions available in the actions.rb for an asset can be documented via an opschain.yaml file in the asset's repository. Any actions listed in the opschain.yaml file will be available in the dropdown list on the asset's create change dialog.

Below is an example of an opschain.yaml:

actions:
  - name: provision
    description: Provision an instance on existing infrastructure
  - name: destroy
    description: Destroy the installation (but not the infrastructure)
  - name: soa:apply_patches
    description: Apply patches listed in the ERB file to each of the SOA installations
note

It is not necessary to document an action to use it. Undocumented actions can be run by manually entering the action via the advanced mode option when creating a change for the asset.

Asset template versions​

To stay in control of the changes made to an asset template, OpsChain allows you to create template versions to lock the source code for a given template to a specific Git revision. A template version always refers directly to a single Git revision in the asset template's Git repository.

Whenever a template version is created or updated, OpsChain will fetch the Git revision and try to identify the actions available for the given template version, making them available for any asset that switches to the new version.

If OpsChain is unable to fetch the provided Git revision or resolve the template actions, the version will be marked as "broken" and it will not be usable until the issue is resolved.

You can only update a template version if no assets are using it. If you have a version being used by multiple assets, it is recommended to create a new template version instead and promote each asset as needed.

info

Creating new template versions will not automatically update the assets using the template. You will need to intentionally promote the assets to use the new template version, or create new assets using the new template version. This is done to ensure you are in control of the changes made to your assets and avoids unexpected or unintended changes.

Asset templates with a MintModel​

When creating a template version, if the relevant Git revision contains an ERB file at MintModel/templates/assets/<template_code>.json.erb, then the template version will be marked as having a MintModel. If the asset's template version includes a MintModel ERB file, then the MintModel actions will be available in the dropdown list on the asset's create change dialog, along with any action in the actions.rb file.

Each time a change is run for an asset with a MintModel ERB, a concrete MintModel JSON will be generated from the asset's converged properties and the ERB. The MintModel JSON will be linked to the change so it can be viewed via the change details screen in the GUI. Each distinct MintModel created by an asset's changes will also be available to view via the asset's MintModel tab, where it can be viewed and compared with other MintModel JSONs generated for the asset.

info

When running an action that is defined both in the actions.rb file and through the MintModel associated with the asset, the MintModel action will take precedence over the one defined in the actions.rb file.

We suggest not naming any actions in the actions.rb file with a name that matches a MintModel action name.

Assets​

Assets are the inner-most level of OpsChain's structure. They are used to represent a specific instance of an asset template. Assets can be created inside projects or environments.

Assigning an asset template version to an asset​

Once an asset has been created its template cannot be changed. To alter the asset's configuration, update the asset's properties or create a new version of the asset template and assign it to the desired assets.

Running changes on an asset​

The create change button, available from the asset's activity tab allows you to run any of the template version's MintModel or documented actions by selecting it from the dropdown list. In addition, you can use the advanced mode option to manually enter an action from the actions.rb to run.