prefetching-dependencies: Add one shared procedure section

Signed-off-by: Michal Šoltis <[email protected]>

docs/modules/ROOT/pages/how-tos/configuring/prefetching-dependencies.adoc

@@ -448,6 +448,54 @@ spec:
 ----
 <1> The `*prefetch-input*` parameter specifies the path to the directory that has the lockfile. In this example, the `.` indicates that the lockfile is in the repository root. Additionally, if you have multiple directories, you can provide the path to those directories in the JSON array format. For example, `[{"path": ".", "type": "generic"}, {"path": "subpath/to/the/other/directory", "type": "generic"}]`. Alternatively, if your lockfile is generated as part of your pipeline and is not commited to the repository, you can specify an absolute path to it, like this: `{"type": "generic", "path": ".", "lockfile": "/absolute/path/to/artifacts.lock.yaml"}`.
 
+== Procedure
+To prefetch dependencies for a component build, complete the following steps:
+
+. Go to the `.tekton` directory and find the `.yaml` files related to the `*pull request*` and `*push*` processes.
+
+. Configure the hermetic pipeline by adding the following parameters in both `.yaml` files:
+
++
+[source,yaml]
+----
+pipelineSpec:
+  params:
+    ...
+    - name: hermetic
+      type: string
+      description: Execute the build with network isolation
+      default: "true"
+----
+
++
+[source,yaml]
+----
+spec:
+  params:
+    ...
+    - name: prefetch-input
+      value: '{"type": "<package_manager>", "path": "."}' <1>
+----
+NOTE: The prefetch-input parameter specifies the path to the directory of the project. In this example, the `.` indicates the repository root. If you have multiple directories, you can provide the path to those directories in the JSON array format: `[{"type": "<package_manager>", "path": "."}, {"type": "<package_manager>", "path": "subpath/to/the/other/directory"}]`.
+
+. Additionally, pass an extra parameter to the `prefetch-dependencies` task in the `spec.pipelineSpec.tasks` section to indicate that "dev package managers" should be enabled.
+
++
+[source,yaml]
+----
+tasks:
+  ...
+  - name: prefetch-dependencies
+    params:
+    ...
+    - name: dev-package-managers
+      value: "true"
+----
+NOTE: You won't find `dev-package-managers` as a param on the `prefetch-dependencies` task. You have to add it, and set it to true. This is because Cachi2 hasn't declared stable support for the feature yet. Use it at your own risk.
+
+. Create a pull request by committing your changes to the repository of the component.
+
+. Review and merge the pull request.
 
 == Verification
 * From the {ProductName} *Applications* view, go to *Activity > Pipeline runs*.