lint by golangci-lint (#3080)

.golangci.yml

@@ -0,0 +1,141 @@
+service:
+  # When updating this, also update the version stored in docker/build-tools/Dockerfile in the istio/tools repo.
+  golangci-lint-version: 1.49.x # use the fixed version to not introduce new linters unexpectedly
+  
+run:
+  concurrency: 4
+  # timeout for analysis, e.g. 30s, 5m, default is 1m
+  deadline: 20m
+  build-tags:
+  - integ
+  - integfuzz
+  # which dirs to skip: they won't be analyzed;
+  # can use regexp here: generated.*, regexp is applied on full path;
+  # default value is empty list, but next dirs are always skipped independently
+  # from this option's value:
+  #       vendor$, third_party$, testdata$, examples$, Godeps$, builtin$
+  skip-dirs:
+    - genfiles$
+    - vendor$
+    - bin$
+
+  # which files to skip: they will be analyzed, but issues from them
+  # won't be reported. Default value is empty list, but there is
+  # no need to include all autogenerated files, we confidently recognize
+  # autogenerated files. If it's not please let us know.
+  skip-files:
+    - ".*\\.pb\\.go"
+    - ".*\\.gen\\.go"
+
+linters:
+  disable-all: true
+  enable:
+  - unused
+  - errcheck
+  - exportloopref
+  - gocritic
+  - gofumpt
+  - goimports
+  - revive
+  - gosimple
+  - govet
+  - ineffassign
+  - lll
+  - misspell
+  - staticcheck
+  - stylecheck
+  - typecheck
+  - unconvert
+  - unparam
+  - gci
+  - bodyclose
+  - gosec
+  - asciicheck
+  - prealloc
+  - predeclared
+  - makezero
+  fast: false
+
+linters-settings:
+  errcheck:
+    # report about not checking of errors in type assetions: `a := b.(MyStruct)`;
+    # default is false: such cases aren't reported by default.
+    check-type-assertions: false
+
+    # report about assignment of errors to blank identifier: `num, _ := strconv.Atoi(numStr)`;
+    # default is false: such cases aren't reported by default.
+    check-blank: false
+  govet:
+    # report about shadowed variables
+    check-shadowing: false
+  maligned:
+    # print struct with more effective memory layout or not, false by default
+    suggest-new: true
+  misspell:
+    # Correct spellings using locale preferences for US or UK.
+    # Default is to use a neutral variety of English.
+    # Setting locale to US will correct the British spelling of 'colour' to 'color'.
+    locale: US
+    ignore-words:
+    - cancelled
+    - marshalled
+  lll:
+    # max line length, lines longer will be reported. Default is 120.
+    # '\t' is counted as 1 character by default, and can be changed with the tab-width option
+    line-length: 160
+    # tab width in spaces. Default to 1.
+    tab-width: 1
+  gocritic:
+    disabled-checks:
+    - exitAfterDefer
+  unused:
+    check-exported: false
+  unparam:
+    # Inspect exported functions, default is false. Set to true if no external program/library imports your code.
+    # XXX: if you enable this setting, unparam will report a lot of false-positives in text editors:
+    # if it's called for subdir of a project it can't find external interfaces. All text editor integrations
+    # with golangci-lint call it on a directory with the changed file.
+    check-exported: false
+  gci:
+    sections:
+    - standard
+    - default
+    - prefix(github.com/fatedier/frp/)
+  gosec:
+    severity: "low"
+    confidence: "low"
+    excludes:
+    - G102
+    - G112
+    - G306
+    - G401
+    - G402
+    - G404
+    - G501
+
+issues:
+  # List of regexps of issue texts to exclude, empty list by default.
+  # But independently from this option we use default exclude patterns,
+  # it can be disabled by `exclude-use-default: false`. To list all
+  # excluded by default patterns execute `golangci-lint run --help`
+  # exclude:
+  #  - composite literal uses unkeyed fields
+
+  exclude-rules:
+    # Exclude some linters from running on test files.
+    - path: _test\.go$|^tests/|^samples/
+      linters:
+        - errcheck
+        - maligned
+
+  # Independently from option `exclude` we use default exclude patterns,
+  # it can be disabled by this option. To list all
+  # excluded by default patterns execute `golangci-lint run --help`.
+  # Default value for this option is true.
+  exclude-use-default: true
+
+  # Maximum issues count per one linter. Set to 0 to disable. Default is 50.
+  max-per-linter: 0
+
+  # Maximum count of issues with the same text. Set to 0 to disable. Default is 3.
+  max-same-issues: 0