Fix apidiff CI (#15617)

#### Description
Running [the "Inform Incompatible PRs"
CI](https://github.com/open-telemetry/opentelemetry-collector/blob/main/.github/workflows/api-compatibility.yml)
locally, it seems it only checks for API breakage for the packages
inside the root module. This PR rewrites the relevant Makefiles to
actually check all non-internal packages inside all stable Collector
modules, and updates the CI check to match.

#### Testing
I briefly tested the `make` commands on #15589, confirming that the
expected breaking change is now correctly flagged.

#### Authorship

- [x] I, a human, wrote this pull request description myself.

Author: jade-guiton-dd

.github/workflows/api-compatibility.yml

@@ -56,17 +56,15 @@ jobs:
       # Compare apidiff states of Main with PR
       - name: Compare-States
         env:
-          CI: true
-          COMPARE_OPTS: -d "../${{ github.base_ref }}/internal/data/apidiff"
+          APIDIFF_DATA_DIR: "../${{ github.base_ref }}/internal/data/apidiff"
         run: |
           cd $HEAD_REF
           make apidiff-compare
 
       # Fail GitHub Action if there are incompatible changes
       - name: Check-States
         env:
-          CI: true
-          COMPARE_OPTS: -d "../${{ github.base_ref }}/internal/data/apidiff" -c
+          APIDIFF_DATA_DIR: "../${{ github.base_ref }}/internal/data/apidiff"
         run: |
           cd $HEAD_REF
-          make apidiff-compare
+          make apidiff-check

Makefile

@@ -270,22 +270,26 @@ checkapi:
 checkdoc:
 	$(GO_TOOL) checkfile --project-path $(CURDIR) --component-rel-path $(COMP_REL_PATH) --module-name $(MOD_NAME) --file-name "README.md"
 
+# Extract the relative path of every module listed between "stable:" and "beta:" in versions.yaml
+STABLE_MODULES := $(shell sed -n -e '/stable:/,/beta:/ s/.*- go.opentelemetry.io\/collector/./p' versions.yaml)
+
+.PHONY: for-all-stable-target
+for-all-stable-target: $(STABLE_MODULES)
+
 # Construct new API state snapshots
 .PHONY: apidiff-build
 apidiff-build:
-	@$(foreach pkg,$(ALL_PKGS),$(call exec-command,./internal/buildscripts/gen-apidiff.sh -p $(pkg)))
-
-# If we are running in CI, change input directory
-ifeq ($(CI), true)
-APICOMPARE_OPTS=$(COMPARE_OPTS)
-else
-APICOMPARE_OPTS=-d "./internal/data/apidiff"
-endif
+	@$(MAKE) --silent for-all-stable-target TARGET="apidiff-build-mod"
 
-# Compare API state snapshots
+# Compare API state snapshots and log differences
 .PHONY: apidiff-compare
 apidiff-compare:
-	@$(foreach pkg,$(ALL_PKGS),$(call exec-command,./internal/buildscripts/compare-apidiff.sh -p $(pkg)))
+	@$(MAKE) --silent for-all-stable-target TARGET="apidiff-compare-mod"
+
+# Compare API state snapshots and fail if there are differences
+.PHONY: apidiff-check
+apidiff-check:
+	@$(MAKE) --silent for-all-stable-target TARGET="apidiff-check-mod"
 
 .PHONY: multimod-verify
 multimod-verify:

Makefile.Common

@@ -110,3 +110,24 @@ FLAGS ?= '-o=$(CURDIR)/'
 schemagen:
 	@echo "Running schemagen with filepath='$(SRC)' and flags='$(FLAGS)'"
 	cd $(SRC_ROOT)/cmd/schemagen && go run . $(FLAGS) $(SRC)
+
+EXTERNAL_PKGS := $(shell go list ./... | grep -v -E '/internal($|/)')
+APIDIFF_DATA_DIR ?= internal/data/apidiff
+
+.PHONY: apidiff-build-mod
+apidiff-build-mod:
+	@for pkg in $(EXTERNAL_PKGS); do \
+		$(SRC_ROOT)/internal/buildscripts/gen-apidiff.sh -p $$pkg -o $(SRC_ROOT)/$(APIDIFF_DATA_DIR) || exit 1; \
+	done
+
+.PHONY: apidiff-compare-mod
+apidiff-compare-mod:
+	@for pkg in $(EXTERNAL_PKGS); do \
+		$(SRC_ROOT)/internal/buildscripts/compare-apidiff.sh -p $$pkg -d $(SRC_ROOT)/$(APIDIFF_DATA_DIR) || exit 1; \
+	done
+
+.PHONY: apidiff-check-mod
+apidiff-check-mod:
+	@for pkg in $(EXTERNAL_PKGS); do \
+		$(SRC_ROOT)/internal/buildscripts/compare-apidiff.sh -p $$pkg -d $(SRC_ROOT)/$(APIDIFF_DATA_DIR) -c || exit 1; \
+	done

internal/buildscripts/compare-apidiff.sh

@@ -57,4 +57,6 @@ if [ -e "$input_dir"/"$package"/apidiff.state ]; then
       echo "$changes"
     fi
   fi
+else
+  echo "WARNING: No snapshot exists for package $package; either it is newly stable or snapshot creation failed"
 fi

internal/buildscripts/gen-apidiff.sh

@@ -42,7 +42,7 @@ if [ -z "$package" ]; then
   usage
 fi
 
-set -ex
+set -e
 
 # Create temp dir for generated files.
 # Source: https://unix.stackexchange.com/a/84980
@@ -67,4 +67,5 @@ if [ $dry_run = false ]; then
   mkdir -p "$output_dir/$package" && \
   cp "$tmp_dir/$package/apidiff.state" \
      "$output_dir/$package"
+  echo "Wrote snapshot to $output_dir/$package"
 fi

internal/data/apidiff/.gitignore

@@ -0,0 +1 @@
+*