Configuration File .golangci.yml for golangci-lint Runs (#1921)

* Linter: Run default linters from .golangci.yaml

Move the default linter's config to .golangci.yaml file.
The 7 default linters: errcheck, gosimple, govet,
ineffassign, staticcheck, typecheck & unused.

Signed-off-by: Bhargav Ravuri <bhargav.ravuri@infracloud.io>

* Linter: Run gofmt from .golangci.yaml

Move gofmt linter run to .golangci.yaml file.

Signed-off-by: Bhargav Ravuri <bhargav.ravuri@infracloud.io>

* Linter: Run custom linters from .golangci.yaml

Move custom linters to .golangci.yaml file.
4 custom linters: maligned, whitespace, gocognit & unparam

Signed-off-by: Bhargav Ravuri <bhargav.ravuri@infracloud.io>

* Linter: Remove linter maligned

Reasons:
- Linter maligned is archived by owner and deprecated
  from golangci-lint.
- maligned (or it's replacement: govet's fieldalignment)
  recommends >50 struct's field alignment. Too many changes
  for much less value.
- Struct fields might be ordered per their similarities.
  Rearranging for saving few bytes is not reasonable.

Signed-off-by: Bhargav Ravuri <bhargav.ravuri@infracloud.io>

---------

Signed-off-by: Bhargav Ravuri <bhargav.ravuri@infracloud.io>

.golangci.yml

@@ -0,0 +1,31 @@
+linters:
+  disable-all: false                    # This enabled 7 default linters as of golangci-lint@v1.50.0:
+                                        #   1. errcheck
+                                        #   2. gosimple
+                                        #   3. govet
+                                        #   4. ineffassign
+                                        #   5. staticcheck
+                                        #   6. typecheck
+                                        #   7. unused
+  enable:
+    - gofmt
+    - whitespace
+    - gocognit
+    - unparam
+
+run:
+  timeout: 10m                          # golangci-lint run's timeout.
+
+  build-tags:                           # All linters will run with below mentioned build tags.
+    - "integration"
+
+issues:
+  exclude-rules:
+    - path: '_test.go'
+      linters:
+        - errcheck                      # Errors may be ignored in tests.
+        - unparam                       # Tests might have unused function parameters.
+
+    - text: "`ctx` is unused"           # Context might not be in use in places, but for consistency, we pass it.
+      linters:
+        - unparam

build/golint.sh

@@ -17,19 +17,10 @@
 set -o errexit
 set -o nounset
 
-SKIP_DIR_REGEX="pkg/client"
-TIMEOUT="10m"
+CONFIG_FILE=".golangci.yml"
 
-echo "Running golangci-lint..."
-
-golangci-lint run --timeout ${TIMEOUT} --skip-dirs ${SKIP_DIR_REGEX} -E maligned,whitespace,gocognit,unparam -e '`ctx` is unused'
-
-# gofmt should run everywhere, including
-#   1. Skipped directories in previous step
-#   2. Build exempted files using build tags
-#      Note: Future build tags should be included.
-echo "Running gofmt..."
-golangci-lint run --timeout ${TIMEOUT} --disable-all --enable gofmt --build-tags integration
+echo "Running golangci-lint from config file: ${CONFIG_FILE}"
+golangci-lint run --config=${CONFIG_FILE}
 
 echo "PASS"
 echo

pkg/testing/integration_test.go

@@ -169,7 +169,7 @@ func newSecretProfile() *secretProfile {
 
 func (s *IntegrationSuite) SetUpSuite(c *C) {
 	ctx := context.Background()
-	ctx, s.cancel = context.WithCancel(ctx)
+	_, s.cancel = context.WithCancel(ctx)
 
 	// Instantiate Client SDKs
 	cfg, err := kube.LoadConfig()