fix(ci): fix linter issues and use deterministic golangci-lint version used both locally and in CI

.github/workflows/golangci-lint.yml

@@ -21,16 +21,16 @@ jobs:
     name: lint
     runs-on: ubuntu-latest
     steps:
-      - name: Checkout repository
-        uses: actions/checkout@v4
-      - name: Setup go
-        uses: actions/setup-go@v5
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
         with:
           go-version-file: go.mod
-      - name: Setup golangci-lint
-        uses: golangci/golangci-lint-action@v6
+      - run: |
+          echo "YQ_VERSION=$(yq -r '.golangci-lint' < .tools_versions.yaml)" >> $GITHUB_ENV
+      - uses: golangci/golangci-lint-action@v6
         with:
           # actions/setup-go@v5 introduced automatic cache handling so skip cache here
           skip-cache: true
+          version: "v${{ env.YQ_VERSION }}"
       - name: Verify Codegen
         run: make verify-codegen

.golangci.yml

@@ -14,21 +14,21 @@ linters:
   - errname
   - errorlint
   - exhaustive
-  - exportloopref
+  # TODO: enable when we set minimal Go version to 1.23
+  # - copyloopvar
   - gci
   - gochecknoinits
   - gofmt
   - gofumpt
   - goimports
-  - gomnd
+  - mnd
   - gomodguard
   - gosec
   - gosimple
   - govet
   - importas
   - ineffassign
   - lll
-  - megacheck
   - misspell
   - nakedret
   - nilerr

.tools_versions.yaml

@@ -0,0 +1,2 @@
+# renovate: datasource=github-releases depName=golangci/golangci-lint
+golangci-lint: "1.60.2"

Makefile

@@ -3,19 +3,32 @@
 # ------------------------------------------------------------------------------
 
 PROJECT_DIR := $(shell dirname $(abspath $(lastword $(MAKEFILE_LIST))))
+TOOLS_VERSIONS_FILE = $(PROJECT_DIR)/.tools_versions.yaml
+export MISE_DATA_DIR = $(PROJECT_DIR)/bin/
 
-.PHONY: _download_tool
-_download_tool:
-	(cd third_party && go mod tidy && \
-		GOBIN=$(PROJECT_DIR)/bin go generate -tags=third_party ./$(TOOL).go )
+MISE := $(shell which mise)
+.PHONY: mise
+mise:
+	@mise -V >/dev/null || (echo "mise - https://github.com/jdx/mise - not found. Please install it." && exit 1)
 
 .PHONY: tools
-tools: golangci-lint
-
-GOLANGCI_LINT = $(PROJECT_DIR)/bin/golangci-lint
+tools: golangci-lint yq
+
+# Do not store yq's version in .tools_versions.yaml as it is used to get tool versions.
+# renovate: datasource=github-releases depName=mikefarah/yq
+YQ_VERSION = 4.43.1
+YQ = $(PROJECT_DIR)/bin/installs/yq/$(YQ_VERSION)/bin/yq
+.PHONY: yq
+yq: mise # Download yq locally if necessary.
+	@$(MISE) plugin install --yes -q yq
+	@$(MISE) install -q yq@$(YQ_VERSION)
+
+GOLANGCI_LINT_VERSION = $(shell $(YQ) -r '.golangci-lint' < $(TOOLS_VERSIONS_FILE))
+GOLANGCI_LINT = $(PROJECT_DIR)/bin/installs/golangci-lint/$(GOLANGCI_LINT_VERSION)/bin/golangci-lint
 .PHONY: golangci-lint
-golangci-lint: ## Download golangci-lint locally if necessary.
-	@$(MAKE) _download_tool TOOL=golangci-lint
+golangci-lint: mise yq ## Download golangci-lint locally if necessary.
+	@$(MISE) plugin install --yes -q golangci-lint
+	@$(MISE) install -q golangci-lint@$(GOLANGCI_LINT_VERSION)
 
 # ------------------------------------------------------------------------------
 # Testing

go.mod

@@ -18,6 +18,7 @@ require (
 	github.com/imdario/mergo v0.3.12
 	github.com/kong/semver/v4 v4.0.1
 	github.com/mitchellh/mapstructure v1.5.0
+	github.com/samber/lo v1.47.0
 	github.com/stretchr/testify v1.9.0
 	github.com/tidwall/gjson v1.17.3
 	k8s.io/code-generator v0.30.3
@@ -38,8 +39,10 @@ require (
 	github.com/spf13/pflag v1.0.5 // indirect
 	github.com/tidwall/match v1.1.1 // indirect
 	github.com/tidwall/pretty v1.2.0 // indirect
-	golang.org/x/mod v0.15.0 // indirect
-	golang.org/x/tools v0.18.0 // indirect
+	golang.org/x/mod v0.17.0 // indirect
+	golang.org/x/sync v0.7.0 // indirect
+	golang.org/x/text v0.16.0 // indirect
+	golang.org/x/tools v0.21.1-0.20240508182429-e35e4ccd0d2d // indirect
 	google.golang.org/protobuf v1.33.0 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect

go.sum

@@ -51,6 +51,8 @@ github.com/onsi/gomega v1.19.0 h1:4ieX6qQjPP/BfC3mpsAtIGGlxTWPeA3Inl/7DtXw1tw=
 github.com/onsi/gomega v1.19.0/go.mod h1:LY+I3pBVzYsTBU1AnDwOSxaYi9WoWiqgwooUqq9yPro=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/samber/lo v1.47.0 h1:z7RynLwP5nbyRscyvcD043DWYoOcYRv3mV8lBeqOCLc=
+github.com/samber/lo v1.47.0/go.mod h1:RmDH9Ct32Qy3gduHQuKJ3gW1fMHAnE/fAzQuf6He5cU=
 github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
 github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
@@ -68,18 +70,18 @@ github.com/tidwall/match v1.1.1 h1:+Ho715JplO36QYgwN9PGYNhgZvoUSc9X2c80KVTi+GA=
 github.com/tidwall/match v1.1.1/go.mod h1:eRSPERbgtNPcGhD8UCthc6PmLEQXEWd3PRB5JTxsfmM=
 github.com/tidwall/pretty v1.2.0 h1:RWIZEg2iJ8/g6fDDYzMpobmaoGh5OLl4AXtGUGPcqCs=
 github.com/tidwall/pretty v1.2.0/go.mod h1:ITEVvHYasfjBbM0u2Pg8T2nJnzm8xPwvNhhsoaGGjNU=
-golang.org/x/mod v0.15.0 h1:SernR4v+D55NyBH2QiEQrlBAnj1ECL6AGrA5+dPaMY8=
-golang.org/x/mod v0.15.0/go.mod h1:hTbmBsO62+eylJbnUtE2MGJUyE7QWk4xUqPFrRgJ+7c=
-golang.org/x/net v0.21.0 h1:AQyQV4dYCvJ7vGmJyKki9+PBdyvhkSd8EIx/qb0AYv4=
-golang.org/x/net v0.21.0/go.mod h1:bIjVDfnllIU7BJ2DNgfnXvpSvtn8VRwhlsaeUTyUS44=
-golang.org/x/sync v0.6.0 h1:5BMeUDZ7vkXGfEr1x9B4bRcTH4lpkTkpdh0T/J+qjbQ=
-golang.org/x/sync v0.6.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
-golang.org/x/sys v0.17.0 h1:25cE3gD+tdBA7lp7QfhuV+rJiE9YXTcS3VG1SqssI/Y=
-golang.org/x/sys v0.17.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-golang.org/x/text v0.14.0 h1:ScX5w1eTa3QqT8oi6+ziP7dTV1S2+ALU0bI+0zXKWiQ=
-golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
-golang.org/x/tools v0.18.0 h1:k8NLag8AGHnn+PHbl7g43CtqZAwG60vZkLqgyZgIHgQ=
-golang.org/x/tools v0.18.0/go.mod h1:GL7B4CwcLLeo59yx/9UWWuNOW1n3VZ4f5axWfML7Lcg=
+golang.org/x/mod v0.17.0 h1:zY54UmvipHiNd+pm+m0x9KhZ9hl1/7QNMyxXbc6ICqA=
+golang.org/x/mod v0.17.0/go.mod h1:hTbmBsO62+eylJbnUtE2MGJUyE7QWk4xUqPFrRgJ+7c=
+golang.org/x/net v0.25.0 h1:d/OCCoBEUq33pjydKrGQhw7IlUPI2Oylr+8qLx49kac=
+golang.org/x/net v0.25.0/go.mod h1:JkAGAh7GEvH74S6FOH42FLoXpXbE/aqXSrIQjXgsiwM=
+golang.org/x/sync v0.7.0 h1:YsImfSBoP9QPYL0xyKJPq0gcaJdG3rInoqxTWbfQu9M=
+golang.org/x/sync v0.7.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
+golang.org/x/sys v0.20.0 h1:Od9JTbYCk261bKm4M/mw7AklTlFYIa0bIp9BgSm1S8Y=
+golang.org/x/sys v0.20.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/text v0.16.0 h1:a94ExnEXNtEwYLGJSIUxnWoxoRz/ZcCsV63ROupILh4=
+golang.org/x/text v0.16.0/go.mod h1:GhwF1Be+LQoKShO3cGOHzqOgRrGaYc9AvblQOmPVHnI=
+golang.org/x/tools v0.21.1-0.20240508182429-e35e4ccd0d2d h1:vU5i/LfpvrRCpgM/VPfJLg5KjxD3E+hfT1SH+d9zLwg=
+golang.org/x/tools v0.21.1-0.20240508182429-e35e4ccd0d2d/go.mod h1:aiJjzUbINMkxbQROHiO6hDPo2LHcIPhhQsa9DLh0yGk=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 google.golang.org/protobuf v1.33.0 h1:uNO2rsAINq/JlFpSdYEKIZ0uKD/R9cpdv0T+yoGwGmI=
 google.golang.org/protobuf v1.33.0/go.mod h1:c6P6GXX6sHbq/GpV6MGZEdwhWPcYBgnhAHhKbcUYpos=

kong/custom/entity_crud.go

@@ -53,8 +53,7 @@ func render(template string, entity Entity) (string, error) {
 		if v := entity.GetRelation(m[1]); v != "" {
 			result = strings.Replace(result, m[0], v, 1)
 		} else {
-			return "", fmt.Errorf("cannot substitute '" + m[1] +
-				"' in URL: " + template)
+			return "", fmt.Errorf("cannot substitute '%s' in URL: %s", m[1], template)
 		}
 	}
 	return result, nil

kong/custom_entity_service.go

@@ -36,8 +36,7 @@ func (s *CustomEntityService) Get(ctx context.Context,
 ) (custom.Entity, error) {
 	def := s.client.Lookup(entity.Type())
 	if def == nil {
-		return nil, fmt.Errorf("entity '" + string(entity.Type()) +
-			"' not registered")
+		return nil, fmt.Errorf("entity '%s' not registered", entity.Type())
 	}
 
 	queryPath, err := def.GetEndpoint(entity)
@@ -66,8 +65,7 @@ func (s *CustomEntityService) Create(ctx context.Context,
 ) (custom.Entity, error) {
 	def := s.client.Lookup(entity.Type())
 	if def == nil {
-		return nil, fmt.Errorf("entity '" + string(entity.Type()) +
-			"' not registered")
+		return nil, fmt.Errorf("entity '%s' not registered", entity.Type())
 	}
 
 	method := "POST"
@@ -111,8 +109,7 @@ func (s *CustomEntityService) Update(ctx context.Context,
 ) (custom.Entity, error) {
 	def := s.client.Lookup(entity.Type())
 	if def == nil {
-		return nil, fmt.Errorf("entity '" + string(entity.Type()) +
-			"' not registered")
+		return nil, fmt.Errorf("entity '%s' not registered", entity.Type())
 	}
 
 	queryPath, err := def.PatchEndpoint(entity)
@@ -146,8 +143,7 @@ func (s *CustomEntityService) Delete(ctx context.Context,
 ) error {
 	def := s.client.Lookup(entity.Type())
 	if def == nil {
-		return fmt.Errorf("entity '" + string(entity.Type()) +
-			"' not registered")
+		return fmt.Errorf("entity '%s' not registered", entity.Type())
 	}
 
 	queryPath, err := def.PatchEndpoint(entity)
@@ -170,8 +166,7 @@ func (s *CustomEntityService) List(ctx context.Context, opt *ListOpt,
 ) ([]custom.Entity, *ListOpt, error) {
 	def := s.client.Lookup(entity.Type())
 	if def == nil {
-		return nil, nil, fmt.Errorf("entity '" + string(entity.Type()) +
-			"' not registered")
+		return nil, nil, fmt.Errorf("entity '%s' not registered", entity.Type())
 	}
 
 	queryPath, err := def.ListEndpoint(entity)

kong/plugin_service_test.go

@@ -730,7 +730,7 @@ func TestFillPluginDefaults(T *testing.T) {
 			require.NoError(t, FillPluginsDefaults(p, fullSchema))
 
 			if diff := cmp.Diff(p, tc.expected); diff != "" {
-				t.Errorf(diff)
+				t.Errorf("unexpected diff:\n%s", diff)
 			}
 		})
 	}
@@ -795,7 +795,7 @@ func TestFillPluginDefaultsArbitraryMap(T *testing.T) {
 			// https://github.com/Kong/kong/commit/9df893f6aff98cd51f27f1c27fa30fdcf13fcf48 changes a number of other
 			// fields for 3.3, so this test only checks the relevant field to avoid needing a version split
 			if diff := cmp.Diff(p.Config["custom_fields_by_lua"], tc.expected.Config["custom_fields_by_lua"]); diff != "" {
-				t.Errorf(diff)
+				t.Errorf("unexpected diff:\n%s", diff)
 			}
 		})
 	}