🌱 Add a make target and check in CI to verify CRD compatibility

.bingo/Variables.mk

@@ -29,6 +29,12 @@ $(CONTROLLER_GEN): $(BINGO_DIR)/controller-gen.mod
 	@echo "(re)installing $(GOBIN)/controller-gen-v0.16.1"
 	@cd $(BINGO_DIR) && GOWORK=off $(GO) build -mod=mod -modfile=controller-gen.mod -o=$(GOBIN)/controller-gen-v0.16.1 "sigs.k8s.io/controller-tools/cmd/controller-gen"
 
+CRD_DIFF := $(GOBIN)/crd-diff-v0.1.0
+$(CRD_DIFF): $(BINGO_DIR)/crd-diff.mod
+	@# Install binary/ries using Go 1.14+ build command. This is using bwplotka/bingo-controlled, separate go module with pinned dependencies.
+	@echo "(re)installing $(GOBIN)/crd-diff-v0.1.0"
+	@cd $(BINGO_DIR) && GOWORK=off $(GO) build -mod=mod -modfile=crd-diff.mod -o=$(GOBIN)/crd-diff-v0.1.0 "github.com/everettraven/crd-diff"
+
 CRD_REF_DOCS := $(GOBIN)/crd-ref-docs-v0.1.0
 $(CRD_REF_DOCS): $(BINGO_DIR)/crd-ref-docs.mod
 	@# Install binary/ries using Go 1.14+ build command. This is using bwplotka/bingo-controlled, separate go module with pinned dependencies.

.bingo/crd-diff.mod

@@ -0,0 +1,5 @@
+module _ // Auto generated by https://github.com/bwplotka/bingo. DO NOT EDIT
+
+go 1.22.5
+
+require github.com/everettraven/crd-diff v0.1.0

.bingo/variables.env

@@ -12,6 +12,8 @@ BINGO="${GOBIN}/bingo-v0.9.0"
 
 CONTROLLER_GEN="${GOBIN}/controller-gen-v0.16.1"
 
+CRD_DIFF="${GOBIN}/crd-diff-v0.1.0"
+
 CRD_REF_DOCS="${GOBIN}/crd-ref-docs-v0.1.0"
 
 GOLANGCI_LINT="${GOBIN}/golangci-lint-v1.61.0"

.github/workflows/crd-diff.yaml

@@ -0,0 +1,18 @@
+name: crd-diff
+on:
+  pull_request:
+jobs:
+  crd-diff:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+
+      - name: Run make verify-crd-compatibility
+        run: make verify-crd-compatibility CRD_DIFF_ORIGINAL_REF=${{ github.event.pull_request.base.sha }} CRD_DIFF_UPDATED_REF=${{ github.event.pull_request.head.sha }}
+

Makefile

@@ -130,6 +130,13 @@ bingo-upgrade: $(BINGO) #EXHELP Upgrade tools
 		$(BINGO) get "$$pkg@latest"; \
 	done
 
+.PHONY: verify-crd-compatibility
+CRD_DIFF_ORIGINAL_REF := main
+CRD_DIFF_UPDATED_REF  := HEAD
+CRD_DIFF_CONFIG := crd-diff-config.yaml
+verify-crd-compatibility: $(CRD_DIFF)
+	$(CRD_DIFF) --config="${CRD_DIFF_CONFIG}" "git://${CRD_DIFF_ORIGINAL_REF}?path=config/base/crd/bases/olm.operatorframework.io_clusterextensions.yaml" "git://${CRD_DIFF_UPDATED_REF}?path=config/base/crd/bases/olm.operatorframework.io_clusterextensions.yaml"
+
 .PHONY: test
 test: manifests generate fmt vet test-unit test-e2e #HELP Run all tests.
 

crd-diff-config.yaml

@@ -0,0 +1,109 @@
+checks:
+  crd:
+    scope:
+      enabled: true
+    existingFieldRemoval:
+      enabled: true
+    storedVersionRemoval:
+      enabled: true
+  version:
+    sameVersion:
+      enabled: true
+      unhandledFailureMode: "Closed"
+      enum:
+        enabled: true
+        removalEnforcement: "Strict"
+        additionEnforcement: "Strict"
+      default:
+        enabled: true
+        changeEnforcement: "Strict"
+        removalEnforcement: "Strict"
+        additionEnforcement: "Strict"
+      required:
+        enabled: true
+        newEnforcement: "Strict"
+      type:
+        enabled: true
+        changeEnforcement: "Strict"
+      maximum:
+        enabled: true
+        additionEnforcement: "Strict"
+        decreaseEnforcement: "Strict"
+      maxItems:
+        enabled: true
+        additionEnforcement: "Strict"
+        decreaseEnforcement: "Strict"
+      maxProperties:
+        enabled: true
+        additionEnforcement: "Strict"
+        decreaseEnforcement: "Strict"
+      maxLength:
+        enabled: true
+        additionEnforcement: "Strict"
+        decreaseEnforcement: "Strict"
+      minimum:
+        enabled: true
+        additionEnforcement: "Strict"
+        increaseEnforcement: "Strict"
+      minItems:
+        enabled: true
+        additionEnforcement: "Strict"
+        increaseEnforcement: "Strict"
+      minProperties:
+        enabled: true
+        additionEnforcement: "Strict"
+        increaseEnforcement: "Strict"
+      minLength:
+        enabled: true
+        additionEnforcement: "Strict"
+        increaseEnforcement: "Strict"
+    servedVersion:
+      enabled: true
+      unhandledFailureMode: "Closed"
+      enum:
+        enabled: true
+        removalEnforcement: "Strict"
+        additionEnforcement: "Strict"
+      default:
+        enabled: true
+        changeEnforcement: "Strict"
+        removalEnforcement: "Strict"
+        additionEnforcement: "Strict"
+      required:
+        enabled: true
+        newEnforcement: "Strict"
+      type:
+        enabled: true
+        changeEnforcement: "Strict"
+      maximum:
+        enabled: true
+        additionEnforcement: "Strict"
+        decreaseEnforcement: "Strict"
+      maxItems:
+        enabled: true
+        additionEnforcement: "Strict"
+        decreaseEnforcement: "Strict"
+      maxProperties:
+        enabled: true
+        additionEnforcement: "Strict"
+        decreaseEnforcement: "Strict"
+      maxLength:
+        enabled: true
+        additionEnforcement: "Strict"
+        decreaseEnforcement: "Strict"
+      minimum:
+        enabled: true
+        additionEnforcement: "Strict"
+        increaseEnforcement: "Strict"
+      minItems:
+        enabled: true
+        additionEnforcement: "Strict"
+        increaseEnforcement: "Strict"
+      minProperties:
+        enabled: true
+        additionEnforcement: "Strict"
+        increaseEnforcement: "Strict"
+      minLength:
+        enabled: true
+        additionEnforcement: "Strict"
+        increaseEnforcement: "Strict"