spec changes for system buildpacks

Signed-off-by: Joe Kutner <jpkutner@gmail.com>
buildpacks · Feb 3, 2022 · 2e17f87 · 2e17f87
1 parent eac4899
commit 2e17f87
Showing 1 changed file with 20 additions and 13 deletions.
diff --git a/text/0000-system-buildpacks-in-builder.md b/text/0000-system-buildpacks-in-builder.md
@@ -57,8 +57,6 @@ The exit code of detection by system buildpacks MUST NOT influence the selected
 
 System buildpacks may require/provide in the build plan following standard buildpack API specification.
 
-A new flag to the lifecycle `detector`, `--disable-system-buildpacks`, will disable system buildpacks.
-
 ## Build
 
 System buildpacks that have passed detection will be added to `group.toml` and treated like any other buildpack for the remainder of the build.
@@ -114,19 +112,28 @@ Instead of a new `[system]` table, we could put `pre` and `post` in the `[[order
 # Spec. Changes (OPTIONAL)
 [spec-changes]: #spec-changes
 
-## `detector` in Platform specifiction
+#### `order.toml` (TOML)
 
-This proposal introduces a `--pre-buildpacks` and `--post-buildpacks` option on the `detector`.
+```toml
+[system]
+[[system.pre.buildpacks]]
+id = "<buildpack ID>"
+version = "<buildpack version>"
 
+[[system.post.buildpacks]]
+id = "<buildpack ID>"
+version = "<buildpack version>"
+
+[[order]]
+[[order.group]]
+id = "<buildpack ID>"
+version = "<buildpack version>"
+optional = false
 ```
-/cnb/lifecycle/detector \
-  [--pre-buildpacks <group>]\
-  [--post-buildpacks <group>]\
-```
-
-The lifecycle:
-
-* SHALL merge the `<pre-buildpacks>` group with each group from `<order>` such that the `pre` buildpacks are placed at the beginning of each group before running detection.
-* SHALL merge the `<post-buildpacks>` group with each group from `<order>` such that the `post` buildpacks are placed at the end of each group before running detection.
 
+Where:
 
+- Both `id` and `version` MUST be present for each buildpack object in a group.
+- The value of `optional` MUST default to false if not specified.
+- The lifecycle MUST add the buildpacks in `system.pre.buildpacks` to the begining of each group in the order.
+- The lifecycle MUST add the buildpacks in `system.post.buildpacks` to the end of each group in the order.