A good base to start with for Go linting

.golangci.yaml

# This file contains all available configuration options
# with their default values.

# options for analysis running
run:
  # default concurrency is a available CPU number
  concurrency: 4

  # timeout for analysis, e.g. 30s, 5m, default is 1m
  timeout: 1m

  # exit code when at least one issue was found, default is 1
  issues-exit-code: 1

  # include test files or not, default is true
  tests: true

  # default is true. Enables skipping of directories:
  #   vendor$, third_party$, testdata$, examples$, Godeps$, builtin$
  skip-dirs-use-default: true

  # by default isn't set. If set we pass it to "go list -mod={option}". From "go help modules":
  # If invoked with -mod=readonly, the go command is disallowed from the implicit
  # automatic updating of go.mod described above. Instead, it fails when any changes
  # to go.mod are needed. This setting is most useful to check that go.mod does
  # not need updates, such as in a continuous integration and testing system.
  # If invoked with -mod=vendor, the go command assumes that the vendor
  # directory holds the correct copies of dependencies and ignores
  # the dependency descriptions in go.mod.
  #modules-download-mode: mod

  # Allow multiple parallel golangci-lint instances running.
  # If false (default) - golangci-lint acquires file lock on start.
  allow-parallel-runners: false


# output configuration options
output:
  # colored-line-number|line-number|json|tab|checkstyle|code-climate|junit-xml|github-actions
  # default is "colored-line-number"
  format: colored-line-number

  # print lines of code with issue, default is true
  print-issued-lines: true

  # print linter name in the end of issue text, default is true
  print-linter-name: true

  # make issues output unique by line, default is true
  uniq-by-line: true

  # sorts results by: filepath, line and column
  sort-results: true


# all available settings of specific linters
linters-settings:
  errcheck:
    # report about not checking of errors in type assertions: `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

    # [deprecated] comma-separated list of pairs of the form pkg:regex
    # the regex is used to ignore names within pkg. (default "fmt:.*").
    # see https://github.com/kisielk/errcheck#the-deprecated-method for details
    ignore: fmt:.*,io/ioutil:^Read.*

    # [deprecated] use exclude-functions instead.
    # path to a file containing a list of functions to exclude from checking
    # see https://github.com/kisielk/errcheck#excluding-functions for details
    #exclude: /path/to/file.txt

    # list of functions to exclude from checking, where each entry is a single function to exclude.
    # see https://github.com/kisielk/errcheck#excluding-functions for details
    #exclude-functions:
    #  - io/ioutil.ReadFile
    #  - io.Copy(*bytes.Buffer)
    #  - io.Copy(os.Stdout)

  errorlint:
    # Check whether fmt.Errorf uses the %w verb for formatting errors. See the readme for caveats
    errorf: true
    # Check for plain type assertions and type switches
    asserts: true
    # Check for plain error comparisons
    comparison: true

  goconst:
    # minimal length of string constant, 3 by default
    min-len: 3
    # minimum occurrences of constant string count to trigger issue, 3 by default
    min-occurrences: 3
    # ignore test files, false by default
    ignore-tests: false
    # look for existing constants matching the values, true by default
    match-constant: true
    # search also for duplicated numbers, false by default
    numbers: false
    # minimum value, only works with goconst.numbers, 3 by default
    min: 3
    # maximum value, only works with goconst.numbers, 3 by default
    max: 3
    # ignore when constant is not used as function argument, true by default
    ignore-calls: true

  gocritic:
    # Which checks should be enabled; can't be combined with 'disabled-checks';
    # See https://go-critic.github.io/overview#checks-overview
    # To check which checks are enabled run `GL_DEBUG=gocritic golangci-lint run`
    # By default list of stable checks is used.
    enabled-checks:
      - nestingReduce
      - unnamedresult
      - ruleguard
      - truncateCmp

    # Which checks should be disabled; can't be combined with 'enabled-checks'; default is empty
    disabled-checks:
      - regexpMust

    # Enable multiple checks by tags, run `GL_DEBUG=gocritic golangci-lint run` to see all tags and checks.
    # Empty list by default. See https://github.com/go-critic/go-critic#usage -> section "Tags".
    enabled-tags:
      - performance
    disabled-tags:
      - experimental

    # Settings passed to gocritic.
    # The settings key is the name of a supported gocritic checker.
    # The list of supported checkers can be find in https://go-critic.github.io/overview.
    settings:
      captLocal: # must be valid enabled check name
        # whether to restrict checker to params only (default true)
        paramsOnly: true
      elseif:
        # whether to skip balanced if-else pairs (default true)
        skipBalanced: true
      hugeParam:
        # size in bytes that makes the warning trigger (default 80)
        sizeThreshold: 80
      nestingReduce:
        # min number of statements inside a branch to trigger a warning (default 5)
        bodyWidth: 5
      rangeExprCopy:
        # size in bytes that makes the warning trigger (default 512)
        sizeThreshold: 512
        # whether to check test functions (default true)
        skipTestFuncs: true
      rangeValCopy:
        # size in bytes that makes the warning trigger (default 128)
        sizeThreshold: 32
        # whether to check test functions (default true)
        skipTestFuncs: true
      ruleguard:
        # Enable debug to identify which 'Where' condition was rejected.
        # The value of the parameter is the name of a function in a ruleguard file.
        #
        # When a rule is evaluated:
        # If:
        #   The Match() clause is accepted; and
        #   One of the conditions in the Where() clause is rejected,
        # Then:
        #   ruleguard prints the specific Where() condition that was rejected.
        #
        # The flag is passed to the ruleguard 'debug-group' argument.
        debug: 'emptyDecl'
        # Deprecated, use 'failOn' param.
        # If set to true, identical to failOn='all', otherwise failOn=''
        failOnError: false
        # Determines the behavior when an error occurs while parsing ruleguard files.
        # If flag is not set, log error and skip rule files that contain an error.
        # If flag is set, the value must be a comma-separated list of error conditions.
        # - 'all':    fail on all errors.
        # - 'import': ruleguard rule imports a package that cannot be found.
        # - 'dsl':    gorule file does not comply with the ruleguard DSL.
        failOn: dsl
        # Comma-separated list of file paths containing ruleguard rules.
        # If a path is relative, it is relative to the directory where the golangci-lint command is executed.
        # The special '${configDir}' variable is substituted with the absolute directory containing the golangci config file.
        # Glob patterns such as 'rules-*.go' may be specified.
        # rules: '${configDir}/ruleguard/rules-*.go,${configDir}/myrule1.go'
      truncateCmp:
        # whether to skip int/uint/uintptr types (default true)
        skipArchDependent: true
      underef:
        # whether to skip (*x).method() calls where x is a pointer receiver (default true)
        skipRecvDeref: true
      unnamedResult:
        # whether to check exported functions
        checkExported: true

  gofmt:
    # simplify code: gofmt with `-s` option, true by default
    simplify: true

  gomoddirectives:
    # Allow local `replace` directives. Default is false.
    replace-local: false
    # List of allowed `replace` directives. Default is empty.
    replace-allow-list:
      - launchpad.net/gocheck
    # Allow to not explain why the version has been retracted in the `retract` directives. Default is false.
    retract-allow-no-explanation: false
    # Forbid the use of the `exclude` directives. Default is false.
    exclude-forbidden: false

  gosec:
    # To select a subset of rules to run.
    # Available rules: https://github.com/securego/gosec#available-rules
    includes:
      - G401
      - G306
      - G101
    # To specify a set of rules to explicitly exclude.
    # Available rules: https://github.com/securego/gosec#available-rules
    excludes:
      - G204
    # Exclude generated files
    exclude-generated: true
    # Filter out the issues with a lower severity than the given value. Valid options are: low, medium, high.
    severity: "low"
    # Filter out the issues with a lower confidence than the given value. Valid options are: low, medium, high.
    confidence: "low"
    # To specify the configuration of rules.
    # The configuration of rules is not fully documented by gosec:
    # https://github.com/securego/gosec#configuration
    # https://github.com/securego/gosec/blob/569328eade2ccbad4ce2d0f21ee158ab5356a5cf/rules/rulelist.go#L60-L102
    config:
      G306: "0600"
      G101:
        pattern: "(?i)example"
        ignore_entropy: false
        entropy_threshold: "80.0"
        per_char_threshold: "3.0"
        truncate: "32"

  gosimple:
    # Select the Go version to target. The default is '1.13'.
    go: "1.15"
    # https://staticcheck.io/docs/options#checks
    checks: [ "all" ]

  govet:
    # report about shadowed variables
    check-shadowing: true

    # settings per analyzer
    settings:
      printf: # analyzer name, run `go tool vet help` to see all analyzers
        funcs: # run `go tool vet help printf` to see available settings for `printf` analyzer
          - (github.com/golangci/golangci-lint/pkg/logutils.Log).Infof
          - (github.com/golangci/golangci-lint/pkg/logutils.Log).Warnf
          - (github.com/golangci/golangci-lint/pkg/logutils.Log).Errorf
          - (github.com/golangci/golangci-lint/pkg/logutils.Log).Fatalf

    # enable or disable analyzers by name
    # run `go tool vet help` to see all analyzers
    enable:
      - atomicalign
    enable-all: false
    disable:
      - shadow
    disable-all: false

  importas:
    # if set to `true`, force to use alias.
    no-unaliased: true
    # List of aliases
    alias:
      # using `servingv1` alias for `knative.dev/serving/pkg/apis/serving/v1` package
      - pkg: knative.dev/serving/pkg/apis/serving/v1
        alias: servingv1
      # using `autoscalingv1alpha1` alias for `knative.dev/serving/pkg/apis/autoscaling/v1alpha1` package
      - pkg: knative.dev/serving/pkg/apis/autoscaling/v1alpha1
        alias: autoscalingv1alpha1
      # You can specify the package path by regular expression,
      # and alias by regular expression expansion syntax like below.
      # see https://github.com/julz/importas#use-regular-expression for details
      - pkg: knative.dev/serving/pkg/apis/(\w+)/(v[\w\d]+)
        alias: $1$2

  nakedret:
    # make an issue if func has more lines of code than this setting and it has naked returns; default is 30
    max-func-lines: 0

  nolintlint:
    # Disable to ensure that all nolint directives actually have an effect. Default is false.
    allow-unused: false
    # Disable to ensure that nolint directives don't have a leading space. Default is true.
    allow-leading-space: true
    # Exclude following linters from requiring an explanation.  Default is [].
    allow-no-explanation: [ ]
    # Enable to require an explanation of nonzero length after each nolint directive. Default is false.
    require-explanation: true
    # Enable to require nolint directives to mention the specific linter being suppressed. Default is false.
    require-specific: true

  prealloc:
    # XXX: we don't recommend using this linter before doing performance profiling.
    # For most programs usage of prealloc will be a premature optimization.

    # Report preallocation suggestions only on simple loops that have no returns/breaks/continues/gotos in them.
    # True by default.
    simple: true
    range-loops: true # Report preallocation suggestions on range loops, true by default
    for-loops: false # Report preallocation suggestions on for loops, false by default

  whitespace:
    multi-if: false   # Enforces newlines (or comments) after every multi-line if statement
    multi-func: false # Enforces newlines (or comments) after every multi-line function signature

  wsl:
    # See https://github.com/bombsimon/wsl/blob/master/doc/configuration.md for
    # documentation of available settings. These are the defaults for
    # `golangci-lint`.
    allow-assign-and-anything: false
    allow-assign-and-call: true
    allow-cuddle-declarations: false
    allow-multiline-assign: true
    allow-separated-leading-comment: false
    allow-trailing-comment: false
    force-case-trailing-whitespace: 0
    force-err-cuddling: false
    force-short-decl-cuddling: false
    strict-append: true

linters:
  disable-all: true
  enable:
    - bodyclose
    - deadcode
    - errcheck
    - errname
    - errorlint
    - exportloopref
    - goconst
    - gocritic
    - godot
    - gofmt
    - gosec
    - gosimple
    - govet
    - govet
    - importas
    - ineffassign
    - nakedret
    - noctx
    - nolintlint
    - paralleltest
    - prealloc
    - rowserrcheck
    - sqlclosecheck
    - tparallel
    - unconvert
    - unused
    - varcheck
    - whitespace
    - wsl

issues:
  exclude:
    - "undeclared name"
    - "undefined \\(type .*? has no field or method .*?\\)"
    - "only one cuddle assignment allowed before defer statement"
    - "only cuddled expressions if assigning variable or using from line above"
    - "declarations should never be cuddled"