GolangCI-Lint is a linters aggregator. It's fast: on average 5 times faster than gometalinter. It's easy to integrate and use, has nice output and has a minimum number of false positives. It supports go modules.
GolangCI-Lint has integrations with VS Code, GNU Emacs, Sublime Text.
Follow the news and releases on our twitter and our blog.
Sponsored by GolangCI.com: SaaS service for running linters on Github pull requests. Free for Open Source.
- Demo
- Install
- Trusted By
- Quick Start
- Editor Integration
- Comparison
- Performance
- Internals
- Supported Linters
- Configuration
- False Positives
- FAQ
- Thanks
- Changelog
- Future Plans
- Contact Information
Short 1.5 min video demo of analyzing beego.
Most installations are done for CI (travis, circleci etc). It's important to have reproducible CI:
don't start to fail all builds at the same time. With golangci-lint this can happen if you
use --enable-all
and a new linter is added or even without --enable-all
: when one upstream linter is upgraded.
It's highly recommended to install a fixed version of golangci-lint. Releases are available on the releases page.
The recommended way to install golangci-lint (replace vX.Y.Z
with the latest
version from the releases page):
# binary will be $(go env GOPATH)/bin/golangci-lint
curl -sfL https://install.goreleaser.com/github.com/golangci/golangci-lint.sh | sh -s -- -b $(go env GOPATH)/bin vX.Y.Z
# or install it into ./bin/
curl -sfL https://install.goreleaser.com/github.com/golangci/golangci-lint.sh | sh -s vX.Y.Z
# In alpine linux (as it does not come with curl by default)
wget -O - -q https://install.goreleaser.com/github.com/golangci/golangci-lint.sh | sh -s vX.Y.Z
golangci-lint --version
As a fallback you can also use raw.githubusercontent.com
# binary will be $(go env GOPATH)/bin/golangci-lint
curl -sfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh| sh -s -- -b $(go env GOPATH)/bin vX.Y.Z
# or install it into ./bin/
curl -sfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh| sh -s vX.Y.Z
# In alpine linux (as it does not come with curl by default)
wget -O - -q https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh| sh -s vX.Y.Z
golangci-lint --version
Periodically update version of golangci-lint: the project is under active development and is constantly being improved. But please always check for newly found issues and update if needed.
Local installation is not recommended for your CI pipeline. Only install the linter this way in a local development environment.
go get -u github.com/golangci/golangci-lint/cmd/golangci-lint
cd $(go env GOPATH)/src/github.com/golangci/golangci-lint/cmd/golangci-lint
go install -ldflags "-X 'main.version=$(git describe --tags)' -X 'main.commit=$(git rev-parse --short HEAD)' -X 'main.date=$(date)'"
(On Windows, you can run the above commands with Git Bash, which comes with Git for Windows. Or you can run just go get -u github.com/golangci/golangci-lint/cmd/golangci-lint
.)
You can also install it on MacOS using brew:
brew install golangci/tap/golangci-lint
brew upgrade golangci/tap/golangci-lint
The following companies/products use golangci-lint:
- Red Hat OpenShift
- Yahoo
- IBM
- Xiaomi
- Samsung
- Arduino
- Eclipse Foundation
- WooCart
- Percona
- Serverless
- ScyllaDB
- NixOS
- The New York Times
- Istio
The following great projects use golangci-lint:
- goreleaser/goreleaser
- tsuru/tsuru
- xenolf/lego
- go-swagger/go-swagger
- kubernetes-sigs/kustomize
- virtual-kubelet/virtual-kubelet
- alecthomas/participle
- asobti/kube-monkey
- getantibody/antibody
- banzaicloud/pipeline
- posener/complete
- y0ssar1an/q
- segmentio/terraform-docs
To run golangci-lint execute:
golangci-lint run
It's an equivalent of executing:
golangci-lint run ./...
You can choose which directories and files to analyze:
golangci-lint run dir1 dir2/... dir3/file1.go
Directories are NOT analyzed recursively. To analyze them recursively append /...
to their path.
GolangCI-Lint can be used with zero configuration. By default the following linters are enabled:
$ golangci-lint help linters
{{.LintersCommandOutputEnabledOnly}}
and the following linters are disabled by default:
$ golangci-lint help linters
...
{{.LintersCommandOutputDisabledOnly}}
Pass -E/--enable
to enable linter and -D/--disable
to disable:
golangci-lint run --disable-all -E errcheck
-
Go for Visual Studio Code. Recommended settings for VS Code are:
"go.lintTool":"golangci-lint", "go.lintFlags": [ "--fast" ]
Using it in an editor without
--fast
can freeze your editor. Golangci-lint automatically discovers.golangci.yml
config for edited file: you don't need to configure it in VS Code settings. -
Sublime Text - plugin for SublimeLinter.
-
GoLand
- Configure File Watcher with arguments
run --print-issued-lines=false $FileDir$
. - Predefined File Watcher will be added in issue.
- Configure File Watcher with arguments
-
GNU Emacs
-
Vim
- vim-go open issue
- syntastic merged pull request with golangci-lint support
- ale merged pull request with golangci-lint support
-
Atom - go-plus supports golangci-lint.
GolangCI-Lint was created to fix the following issues with gometalinter
:
- Slow work:
gometalinter
usually works for minutes in average projects. GolangCI-Lint works 2-7x times faster by reusing work. - Huge memory consumption: parallel linters don't share the same program representation and can consume
n
times more memory (n
- concurrency). GolangCI-Lint fixes it by sharing representation and consumes 26% less memory. - Doesn't use real bounded concurrency: if you set it to
n
it can take up ton*n
threads because of forced threads in specific linters.gometalinter
can't do anything about it because it runs linters as black boxes in forked processes. In GolangCI-Lint we run all linters in one process and completely control them. Configured concurrency will be correctly bounded. This issue is important because you often want to set concurrency to the CPUs count minus one to ensure you do not freeze your PC and be able to work on it while analyzing code. - Lack of nice output. We like how the
gcc
andclang
compilers format their warnings: using colors, printing warning lines and showing the position in line. - Too many issues. GolangCI-Lint cuts a lot of issues by using default exclude list of common false-positives. By default, it has enabled smart issues processing: merge multiple issues for one line, merge issues with the same text or from the same linter. All of these smart processors can be configured by the user.
- Integration into large codebases. A good way to start using linters in a large project is not to fix a plethora
of existing issues, but to set up CI and fix only issues in new commits. You can use
revgrep
for it, but it's yet another utility to install and configure. Withgolangci-lint
it's much easier:revgrep
is already built intogolangci-lint
and you can use it with one option (-n, --new
or--new-from-rev
). - Installation. With
gometalinter
, you need to run a linters installation step. It's easy to forget this step and end up with stale linters. It also complicates CI setup. GolangCI-Lint requires no installation of linters. - Yaml or toml config. Gometalinter's JSON isn't convenient for config files.
- It will be much slower because
golangci-lint
runs all linters in parallel and shares 50-80% of linters work. - It will have less control and more false-positives: some linters can't be properly configured without hacks.
- It will take more time because of different usages and need of tracking of versions of
n
linters.
Benchmarks were executed on MacBook Pro (Retina, 13-inch, Late 2013), 2,4 GHz Intel Core i5, 8 GB 1600 MHz DDR3.
It has 4 cores and concurrent linting as a default consuming all cores.
Benchmark was run (and measured) automatically, see the code
here (BenchmarkWithGometalinter
).
We measure peak memory usage (RSS) by tracking of processes RSS every 5 ms.
We compare golangci-lint and gometalinter in default mode, but explicitly enable all linters because of small differences in the default configuration.
$ golangci-lint run --no-config --issues-exit-code=0 --deadline=30m \
--disable-all --enable=deadcode --enable=gocyclo --enable=golint --enable=varcheck \
--enable=structcheck --enable=maligned --enable=errcheck --enable=dupl --enable=ineffassign \
--enable=interfacer --enable=unconvert --enable=goconst --enable=gosec --enable=megacheck
$ gometalinter --deadline=30m --vendor --cyclo-over=30 --dupl-threshold=150 \
--exclude=<default golangci-lint excludes> --skip=testdata --skip=builtin \
--disable-all --enable=deadcode --enable=gocyclo --enable=golint --enable=varcheck \
--enable=structcheck --enable=maligned --enable=errcheck --enable=dupl --enable=ineffassign \
--enable=interfacer --enable=unconvert --enable=goconst --enable=gosec --enable=megacheck
./...
Repository | GolangCI Time | GolangCI Is Faster than Gometalinter | GolangCI Memory | GolangCI eats less memory than Gometalinter |
---|---|---|---|---|
gometalinter repo, 4 kLoC | 6s | 6.4x | 0.7GB | 33% |
self-repo, 4 kLoC | 12s | 7.5x | 1.2GB | 41% |
beego, 50 kLoC | 10s | 4.2x | 1.4GB | 9% |
hugo, 70 kLoC | 15s | 6.1x | 1.6GB | 44% |
consul, 127 kLoC | 58s | 4x | 2.7GB | 41% |
terraform, 190 kLoC | 2m13s | 1.6x | 4.8GB | 0% |
go-ethereum, 250 kLoC | 33s | 5x | 3.6GB | 0% |
go source ($GOROOT/src ), 1300 kLoC |
2m45s | 2x | 4.7GB | 0% |
On average golangci-lint is 4.6 times faster than gometalinter. Maximum difference is in the self-repo: 7.5 times faster, minimum difference is in terraform source code repo: 1.8 times faster.
On average golangci-lint consumes 26% less memory.
Golangci-lint directly calls linters (no forking) and reuses 80% of work by parsing program only once. Read this section for details.
-
Work sharing The key difference with gometalinter is that golangci-lint shares work between specific linters (golint, govet, ...). We don't fork to call specific linter but use its API. For small and medium projects 50-90% of work between linters can be reused.
-
load
[]*packages.Package
bygo/packages
onceWe load program (parsing all files and type-checking) only once for all linters. For the most of linters it's the most heavy operation: it takes 5 seconds on 8 kLoC repo and 11 seconds on
$GOROOT/src
. -
build
ssa.Program
onceSome linters (megacheck, interfacer, unparam) work on SSA representation. Building of this representation takes 1.5 seconds on 8 kLoC repo and 6 seconds on
$GOROOT/src
. -
parse source code and build AST once
Parsing one source file takes 200 us on average. Parsing of all files in
$GOROOT/src
takes 2 seconds. Currently we parse each file more than once because it's not the bottleneck. But we already save a lot of extra parsing. We're planning to parse each file only once. -
walk files and directories once
It takes 300-1000 ms for
$GOROOT/src
.
-
-
Smart linters scheduling
We schedule linters by a special algorithm which takes estimated execution time into account. It allows to save 10-30% of time when one of heavy linters (megacheck etc) is enabled.
-
Don't fork to run shell commands
All linters are vendored in the /vendor
folder: their version is fixed, they are builtin
and you don't need to install them separately.
To see a list of supported linters and which linters are enabled/disabled:
golangci-lint help linters
{{.EnabledByDefaultLinters}}
{{.DisabledByDefaultLinters}}
The config file has lower priority than command-line options. If the same bool/string/int option is provided on the command-line and in the config file, the option from command-line will be used. Slice options (e.g. list of enabled/disabled linters) are combined from the command-line and config file.
To see a list of enabled by your configuration linters:
golangci-lint linters
golangci-lint run -h
{{.RunHelpText}}
GolangCI-Lint looks for config files in the following paths from the current working directory:
.golangci.yml
.golangci.toml
.golangci.json
GolangCI-Lint also searches for config files in all directories from the directory of the first analyzed path up to the root.
To see which config file is being used and where it was sourced from run golangci-lint with -v
option.
Config options inside the file are identical to command-line options. You can configure specific linters' options only within the config file (not the command-line).
There is a .golangci.example.yml
example
config file with all supported options, their description and default value:
{{.GolangciYamlExample}}
It's a .golangci.yml config file of this repo: we enable more linters than the default and have more strict settings:
{{.GolangciYaml}}
False positives are inevitable, but we did our best to reduce their count. For example, we have a default enabled set of exclude patterns. If a false positive occurred you have the following choices:
- Exclude issue by text using command-line option
-e
or config optionissues.exclude
. It's helpful when you decided to ignore all issues of this type. - Exclude this one issue by using special comment
//nolint[:linter1,linter2,...]
on issued line. Comment//nolint
disables all issues reporting on this line. Comment e.g.//nolint:govet
disables only govet issues for this line. If you would like to completely exclude all issues for some function prepend this comment above function:
//nolint
func f() {
...
}
Please create GitHub Issues here if you find any false positives. We will add it to the default exclude list if it's common or we will fix underlying linter.
How do you add a custom linter?
You can integrate it yourself, see this wiki page with documentation. Or you can create a GitHub Issue and we will integrate when time permits.
It's cool to use golangci-lint
when starting a project, but what about existing projects with large codebase? It will take days to fix all found issues
We are sure that every project can easily integrate golangci-lint
, even the large one. The idea is to not fix all existing issues. Fix only newly added issue: issues in new code. To do this setup CI (or better use GolangCI) to run golangci-lint
with option --new-from-rev=HEAD~1
. Also, take a look at option --new
, but consider that CI scripts that generate unstaged files will make --new
only point out issues in those files and not in the last commit. In that regard --new-from-rev=HEAD~1
is safer.
By doing this you won't create new issues in your code and can choose fix existing issues (or not).
How to use golangci-lint
in CI (Continuous Integration)?
You have 2 choices:
- Use GolangCI: this service is highly integrated with GitHub (issues are commented in the pull request) and uses a
golangci-lint
tool. For configuration use.golangci.yml
(or toml/json). - Use custom CI: just run
golangci-lint
in CI and check the exit code. If it's non-zero - fail the build. The main disadvantage is that you can't see issues in pull request code and would need to view the build log, then open the referenced source file to see the context.
We don't recommend vendoring golangci-lint
in your repo: you will get troubles updating golangci-lint
. Please, use recommended way to install with the shell script: it's very fast.
Do I need to run go install
?
No, you don't need to do it anymore.
Which go versions are supported Short answer: go 1.10 and newer are supported.
Long answer: golangci-lint > 1.10.2 supports Go 1.10 and 1.11; golangci-lint <= v1.10.2 supports Go 1.9, 1.10, 1.11.
golangci-lint
doesn't work
- Update it:
go get -u github.com/golangci/golangci-lint/cmd/golangci-lint
- Run it with
-v
option and check the output. - If it doesn't help create a GitHub issue with the output from the error and #2 above.
Why running with --fast
is slow on the first run?
Because the first run caches type information. All subsequent runs will be fast.
Usually this options is used during development on local machine and compilation was already performed.
Thanks to all contributors! Thanks to alecthomas/gometalinter for inspiration and amazing work. Thanks to bradleyfalzon/revgrep for cool diff tool.
Thanks to developers and authors of used linters: {{.ThanksList}}
Follow the news and releases on our twitter and our blog. There is the most valuable changes log:
- Update
megacheck
(staticcheck
) to the latest version: it consumes much less memory. - Support the new
stylecheck
linter. - Update
go-critic
to the latest version. - Support of
enabled-tags
options forgo-critic
. - Make rich debugging for
go-critic
and meticulously validatego-critic
checks config. - Update and use upstream versions of
unparam
andinterfacer
instead of forked ones. - Improve handling of unknown linter names in
//nolint
directives. - Speedup
typecheck
on large project with compilation errors. - Add support for searching for
errcheck
exclude file. - Fix
go-misc
checksum.
- Update
goimports
: the new version creates named imports for name/path mismatches. - Update
go-critic
to the latest version. - Sync default
go-critic
checks list with thego-critic
. - Support
pre-commit.com
hooks. - Rework and simplify
--skip-dirs
for some edge cases. - Add
modules-download-mode
option: it's useful in CI. - Better validate commands.
- Fix working with absolute paths.
- Fix
errcheck.ignore
option.
- Support new linters:
- gocritic
- scopelint
- gochecknointis
- gochecknoglobals
- Update CLA
- Update goimports formatting
- Use go/packages
-
A lot of linters became "fast": they are enabled by --fast now and work in 1-2 seconds. Only unparam, interfacer and megacheck are "slow" linters now.
-
Average project is analyzed 20-40% faster than before if all linters are enabled! If we enable all linters except unparam, interfacer and megacheck analysis is 10-20x faster!
-
- Support goimports.local-prefix option for goimports
- Change license from AGPL to GPL
- Rename GAS to gosec
- Drop go1.9 support
- Support installation of golangci-lint via go modules
- Update dockerfile to use golang 1.11
- Add support for ignore/exclude flags in errcheck
- Improve lll parsing for very long lines
- Update Depguard with a Glob support
- Silent output by default
- Disable GAS (gosec) by default
- Build golangci-lint on go1.11
- Add
golangci-lint linters
command - Fix work with symlinks
- Add support of the next linters:
- unparam
- misspell
- prealloc
- nakedret
- lll
- depguard
- Smart generated files detector
- Full
//nolint
support - Implement
--skip-files
and--skip-dirs
options - Checkstyle output format support
- Support GitHub Releases
- Installation via Homebrew and Docker
- Upstream all changes of forked linters.
- Make it easy to write own linter/checker: it should take a minimum code, have perfect documentation, debugging and testing tooling.
- Speed up SSA loading: on-disk cache and existing code profiling-optimizing.
- Analyze (don't only filter) only new code: analyze only changed files and dependencies, make incremental analysis, caches.
- Smart new issues detector: don't print existing issues on changed lines.
- Minimize false-positives by fixing linters and improving testing tooling.
- Automatic issues fixing (code rewrite, refactoring) where it's possible.
- Documentation for every issue type.
You can contact the author of GolangCI-Lint by denis@golangci.com. Follow the news and releases on our twitter and our blog.