golangci-lint

Golangci-lint is a fast, comprehensive linters runner for Go that provides a unified interface to over 100 different Go linters. It's designed to be the ultimate Go code quality tool, combining multiple linters into a single, efficient, and highly configurable solution.

Key features:

⚡ Extremely Fast: Runs linters in parallel, reuses Go build cache, and caches analysis results for optimal performance
📦 100+ Linters Included: Comprehensive collection of linters covering all aspects of Go code quality - no need to install them separately
⚙️ YAML Configuration: Flexible configuration system with sensible defaults and extensive customization options
🥇 Minimal False Positives: Carefully tuned default settings to reduce noise and focus on real issues
🔥 Rich Output Formats: Multiple output formats including text with colors, JSON, SARIF, HTML, JUnit-XML, and more

Comprehensive linting coverage:

Code Quality: Detects bugs, performance issues, and maintainability problems
Style Enforcement: Ensures consistent formatting and coding conventions
Security Analysis: Identifies potential security vulnerabilities and unsafe patterns
Performance Optimization: Finds inefficient code patterns and suggests improvements
Complexity Analysis: Measures and controls code complexity and cognitive load
Error Handling: Validates proper error handling patterns in Go

Popular included linters:

staticcheck: Advanced static analysis for Go
govet: Official Go static analyzer
errcheck: Checks for unchecked errors
gosimple: Suggests code simplifications
ineffassign: Detects ineffectual assignments
misspell: Finds commonly misspelled words
gocyclo: Cyclomatic complexity analysis
gosec: Security-focused static analysis

Advanced capabilities:

Smart Caching: Dramatically speeds up repeated runs by caching results
Incremental Analysis: Can analyze only changed files for faster analysis
Custom Rules: Support for custom linters and configuration
Issue Filtering: Sophisticated filtering and suppression of false positives
Parallel Execution: Concurrent linter execution for maximum speed

Golangci-lint is the industry standard for Go code quality and is used by thousands of Go projects for maintaining high code standards and catching issues early in the development process.

golangci-lint documentation

Version in MegaLinter: 2.11.4
Visit Official Web Site
See How to configure golangci-lint rules
- If custom .golangci.yml config file isn't found, .golangci.yml will be used
See How to disable golangci-lint rules in files
See Index of problems detected by golangci-lint

Configuration in MegaLinter

Enable golangci-lint by adding GO_GOLANGCI_LINT in ENABLE_LINTERS variable
Disable golangci-lint by adding GO_GOLANGCI_LINT in DISABLE_LINTERS variable

Enable autofixes by adding GO_GOLANGCI_LINT in APPLY_FIXES variable

Variable	Description	Default value
GO_GOLANGCI_LINT_ARGUMENTS	User custom arguments to add in linter CLI call Ex: `-s --foo "bar"`
GO_GOLANGCI_LINT_COMMAND_REMOVE_ARGUMENTS	User custom arguments to remove from command line before calling the linter Ex: `-s --foo "bar"`
GO_GOLANGCI_LINT_CLI_LINT_MODE	Override default CLI lint mode ⚠️ As default value is project, overriding might not work - `file`: Calls the linter for each file - `list_of_files`: Call the linter with the list of files as argument - `project`: Call the linter from the root of the project	`project`
GO_GOLANGCI_LINT_FILE_EXTENSIONS	Allowed file extensions. `"*"` matches any extension, `""` matches empty extension. Empty list excludes all files Ex: `[".py", ""]`	`[".go"]`
GO_GOLANGCI_LINT_FILE_NAMES_REGEX	File name regex filters. Regular expression list for filtering files by their base names using regex full match. Empty list includes all files Ex: `["Dockerfile(-.+)?", "Jenkinsfile"]`	Include every file
GO_GOLANGCI_LINT_PRE_COMMANDS	List of bash commands to run before the linter	None
GO_GOLANGCI_LINT_POST_COMMANDS	List of bash commands to run after the linter	None
GO_GOLANGCI_LINT_UNSECURED_ENV_VARIABLES	List of env variables explicitly not filtered before calling GO_GOLANGCI_LINT and its pre/post commands	None
GO_GOLANGCI_LINT_CONFIG_FILE	golangci-lint configuration file name Use `LINTER_DEFAULT` to let the linter find it	`.golangci.yml`
GO_GOLANGCI_LINT_RULES_PATH	Path where to find linter configuration file	Workspace folder, then MegaLinter default rules
GO_GOLANGCI_LINT_DISABLE_ERRORS	Run linter but consider errors as warnings	`false`
GO_GOLANGCI_LINT_DISABLE_ERRORS_IF_LESS_THAN	Maximum number of errors allowed	`0`
GO_GOLANGCI_LINT_CLI_EXECUTABLE	Override CLI executable	`['golangci-lint']`

IDE Integration

Use golangci-lint in your favorite IDE to catch errors before MegaLinter !

IDE	Extension Name	Install
Emacs	flycheck-golandci-lint	Visit Web Site
Emacs	SpaceMacs	Visit Web Site
goland	goland	Visit Web Site
Sublime Text	SublimeLinter-contrib-golang-cilint	Visit Web Site
vim	vim-go	Visit Web Site
Visual Studio Code	vscode.Go

MegaLinter Flavors

This linter is available in the following flavors

Flavor	Description	Embedded linters
all	Default MegaLinter Flavor	136
cupcake	MegaLinter for the most commonly used languages	92
go	Optimized for GO based projects	54

Behind the scenes

How are identified applicable files

File extensions: .go

How the linting is performed

golangci-lint is called once on the whole project directory (project CLI lint mode)

filtering can not be done using MegaLinter configuration variables,it must be done using golangci-lint configuration or ignore file (if existing)
VALIDATE_ALL_CODEBASE: false doesn't make golangci-lint analyze only updated files

Example calls

golangci-lint run myfile.go

golangci-lint run -c .golangci.yml myfile.go

Help content

Smart, fast linters runner.

Usage:
  golangci-lint [flags]
  golangci-lint [command]

Available Commands:
  cache       Cache control and information.
  completion  Generate the autocompletion script for the specified shell
  config      Configuration file information and verification.
  custom      Build a version of golangci-lint with custom linters.
  fmt         Format Go source files.
  formatters  List current formatters configuration.
  help        Display extra help
  linters     List current linters configuration.
  migrate     Migrate configuration file from v1 to v2.
  run         Lint the code.
  version     Display the golangci-lint version.

Flags:
      --color string   Use color when printing; can be 'always', 'auto', or 'never' (default "auto")
  -h, --help           Help for a command
  -v, --verbose        Verbose output
      --version        Print version

Use "golangci-lint [command] --help" for more information about a command.

Installation on mega-linter Docker image

Dockerfile commands :

# Parent descriptor install
# renovate: datasource=repology depName=alpine_edge/go versioning=loose
ARG GO_ALPINE_VERSION=1.26.3-r0
RUN apk add --no-cache \
    --repository=https://dl-cdn.alpinelinux.org/alpine/edge/main \
    --repository=https://dl-cdn.alpinelinux.org/alpine/edge/community \
    go=${GO_ALPINE_VERSION}
# Linter install
# renovate: datasource=github-tags depName=golangci/golangci-lint
ARG GO_GOLANGCI_LINT_VERSION=2.11.4
RUN wget -O- -nv https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s "v${GO_GOLANGCI_LINT_VERSION}" \
    && golangci-lint --version

Known errors and resolutions

When this linter fails for a known non-lint reason (remote service unavailable, malformed config, missing credentials, etc.), MegaLinter detects the pattern below in the linter output and surfaces the matching guidance.

GO_GOLANGCI_LINT_ERROR_MODULE_DOWNLOAD

Detection pattern (regex):

(go: .*: (reading|module .*: Get) .*: (dial tcp|TLS handshake|connection refused)|module lookup disabled by GOPROXY=off|verifying .*: checksum mismatch)

Resolution guidance:

golangci-lint could not download Go module dependencies before typechecking.
This is a network/proxy issue, not a lint finding.
Resolutions:
  - Retry the run; module proxy outages are usually transient.
  - If your project uses a private Go module proxy, set `GOPROXY` / `GOPRIVATE` and whitelist them for this linter in your .mega-linter.yml:
      GO_GOLANGCI_LINT_UNSECURED_ENV_VARIABLES:
        - GOPROXY
        - GOPRIVATE
        - GOSUMDB
        - GONOSUMCHECK
  - Pre-populate `$GOPATH/pkg/mod` in CI cache to avoid downloads on each run.

GO_GOLANGCI_LINT_ERROR_CONFIG_INVALID

Detection pattern (regex):

(can't load config:|failed to load config|unsupported version of the configuration|is not a linter, it cannot be enabled or disabled|is a formatter)

Resolution guidance:

golangci-lint could not load the `.golangci.yml` configuration file.
Resolutions:
  - Validate the YAML syntax and indentation of `.golangci.yml`.
  - Ensure all linter names referenced under `enable:` / `disable:` exist in the installed golangci-lint version (some linters were renamed/removed across major versions).
  - Run `golangci-lint config verify` locally to reproduce.

GO_GOLANGCI_LINT_ERROR_TYPECHECK

Detection pattern (regex):

(typecheck.*could not (import|load)|level=error.*build (failed|error)|# .*\n.*: undefined:)

Resolution guidance:

golangci-lint's typecheck stage failed to build the Go program. golangci-lint requires the code to compile in order to run most analyzers.
Resolutions:
  - Run `go build ./...` locally; fix the underlying compilation errors first.
  - Ensure all required packages are in `go.mod` and the module cache is reachable.

GO_GOLANGCI_LINT_ERROR_OUT_OF_MEMORY

Detection pattern (regex):

(runtime: out of memory|fatal error: runtime: out of memory|signal: killed)

Resolution guidance:

golangci-lint was killed (OOM) while analyzing a large Go project.
Resolutions:
  - Increase the memory available to the MegaLinter container/runner.
  - Reduce scope by setting `GO_GOLANGCI_LINT_FILTER_REGEX_INCLUDE` / `..._EXCLUDE` or by enabling fewer linters in `.golangci.yml`.
  - Temporarily mark the linter as non-blocking by adding to your .mega-linter.yml:
      DISABLE_ERRORS_LINTERS:
        - GO_GOLANGCI_LINT