refactor: migrate to golangci-lint v2 and fix all lint issues

Adapt config to v2 format, fix indent-error-flow/superfluous-else,
add package comments, remove unused code, fix deprecated API usage,
and correct error string capitalization.

Author: enriqueavindi

.golangci.yml

@@ -1,50 +1,45 @@
+version: "2"
+
 run:
   timeout: 5m
   allow-parallel-runners: true
+  tests: false
 
-issues:
-  # don't skip warning about doc comments
-  # don't exclude the default set of lint
-  exclude-use-default: false
-  # restore some of the defaults
-  # (fill in the rest as needed)
-  exclude-rules:
-    - path: "api/*"
-      linters:
-        - lll
-    - path: "internal/*"
-      linters:
-        - dupl
-        - lll
-    - path: "cmd/*"
-      linters:
-        - lll
 linters:
-  disable-all: true
+  default: none
   enable:
-    - dupl
     - errcheck
-    - exportloopref
     - ginkgolinter
     - goconst
-    - gocyclo
-    - gofmt
-    - goimports
-    - gosimple
     - govet
     - ineffassign
-    - lll
     - misspell
     - nakedret
-    - prealloc
     - revive
     - staticcheck
-    - typecheck
     - unconvert
     - unparam
     - unused
-
-linters-settings:
-  revive:
+  settings:
+    revive:
+      rules:
+        - name: comment-spacings
+        - name: indent-error-flow
+        - name: superfluous-else
+        - name: package-comments
+        - name: exported
+          disabled: true
+        - name: unused-parameter
+          disabled: true
+        - name: var-naming
+          disabled: true
+  exclusions:
     rules:
-      - name: comment-spacings
+      - linters:
+          - staticcheck
+        text: "SA1019"
+
+formatters:
+  enable:
+    - gofmt
+    - goimports

Dockerfile

@@ -14,7 +14,7 @@ RUN go mod download
 # Copy the go source
 COPY cmd/main.go cmd/main.go
 COPY api/ api/
-COPY internal// internal//
+COPY internal/ internal/
 COPY pkg/ pkg/
 
 # Build

Makefile

@@ -128,11 +128,11 @@ test-e2e:
 
 .PHONY: lint
 lint: golangci-lint ## Run golangci-lint linter
-	$(GOLANGCI_LINT) --tests=false --config=.golangci.yml --exclude=type run
+	$(GOLANGCI_LINT) run --config=.golangci.yml
 
 .PHONY: lint-fix
 lint-fix: golangci-lint ## Run golangci-lint linter and perform fixes
-	$(GOLANGCI_LINT) --tests=false --config=.golangci.yml --exclude=type run --fix
+	$(GOLANGCI_LINT) run --config=.golangci.yml --fix
 
 ##@ Build
 
@@ -219,7 +219,7 @@ GOLANGCI_LINT = $(LOCALBIN)/golangci-lint
 KUSTOMIZE_VERSION ?= v5.4.3
 CONTROLLER_TOOLS_VERSION ?= v0.17.2
 ENVTEST_VERSION ?= release-0.19
-GOLANGCI_LINT_VERSION ?= v1.59.1
+GOLANGCI_LINT_VERSION ?= v2.11.4
 
 .PHONY: kustomize
 kustomize: $(KUSTOMIZE) ## Download kustomize locally if necessary.
@@ -239,7 +239,7 @@ $(ENVTEST): $(LOCALBIN)
 .PHONY: golangci-lint
 golangci-lint: $(GOLANGCI_LINT) ## Download golangci-lint locally if necessary.
 $(GOLANGCI_LINT): $(LOCALBIN)
-	$(call go-install-tool,$(GOLANGCI_LINT),github.com/golangci/golangci-lint/cmd/golangci-lint,$(GOLANGCI_LINT_VERSION))
+	$(call go-install-tool,$(GOLANGCI_LINT),github.com/golangci/golangci-lint/v2/cmd/golangci-lint,$(GOLANGCI_LINT_VERSION))
 
 # go-install-tool will 'go install' any package with custom target and name of binary, if it doesn't exist
 # $1 - target path with name of binary

api/v1alphav1/groupversion_info.go

@@ -3,7 +3,7 @@
 //
 // SPDX-License-Identifier: Apache-2.0
 
-// Package v1 contains API Schema definitions for the overcommit v1 API group
+// Package v1alphav1 contains API Schema definitions for the overcommit v1alphav1 API group
 // +kubebuilder:object:generate=true
 // +groupName=overcommit.inditex.dev
 package v1alphav1

api/v1alphav1/webhook_validations.go

@@ -17,10 +17,10 @@ import (
 
 func validateSpecOvercommit(class OvercommitClass) error {
 	if class.Spec.CpuOvercommit <= 0 || class.Spec.CpuOvercommit > 1 {
-		return errors.New("Error: cpuOvercommit must be greater than 0 and equal or lower than 1, failed creating " + class.ObjectMeta.Name + " class ")
+		return errors.New("Error: cpuOvercommit must be greater than 0 and equal or lower than 1, failed creating " + class.Name + " class ")
 	}
 	if class.Spec.MemoryOvercommit <= 0 || class.Spec.MemoryOvercommit > 1 {
-		return errors.New("Error: memoryOvercommit must be greater than 0 and equal or lower than 1, failed creating " + class.ObjectMeta.Name + " class ")
+		return errors.New("Error: memoryOvercommit must be greater than 0 and equal or lower than 1, failed creating " + class.Name + " class ")
 	}
 	return nil
 }
@@ -32,12 +32,12 @@ func checkDecimals(class OvercommitClass) error {
 	roundedCpu := math.Round(cpu*precision) / precision
 
 	if math.Abs(cpu-roundedCpu) > 1e-9 {
-		return errors.New("Error: the CPU value must have 4 decimals max")
+		return errors.New("the CPU value must have 4 decimals max")
 	}
 
 	roundedMemory := math.Round(memory*precision) / precision
 	if math.Abs(memory-roundedMemory) > 1e-9 {
-		return errors.New("Error: the memory value must have 4 decimals max")
+		return errors.New("the memory value must have 4 decimals max")
 	}
 	return nil
 }
@@ -63,7 +63,7 @@ func isClassDefault(class OvercommitClass, client client.Client) error {
 	}
 
 	if existsDefault {
-		return fmt.Errorf("error: only one OvercommitClass can be default, failed creating %s class", class.ObjectMeta.Name)
+		return fmt.Errorf("error: only one OvercommitClass can be default, failed creating %s class", class.Name)
 	}
 
 	return nil

cmd/main.go

@@ -3,6 +3,7 @@
 //
 // SPDX-License-Identifier: Apache-2.0
 
+// Package main is the entrypoint for the k8s-overcommit-operator.
 package main
 
 import (