gaper
Used to build and restart a Go project when it crashes or some watched file changes
Aimed to be used in development only.
Changelog
See Releases for detailed history changes.
Installation
Using go tooling:
go get -u github.com/maxcnunes/gaper/cmd/gaper
Or, downloading the binary instead (example for version 1.0.3, make sure you are using the latest version though):
curl -SL https://github.com/maxcnunes/gaper/releases/download/v1.0.3/gaper_1.0.3_linux_amd64.tar.gz | tar -xvzf - -C "${GOPATH}/bin"
Usage
NAME:
gaper - Used to build and restart a Go project when it crashes or some watched file changes
USAGE:
gaper [global options] command [command options] [arguments...]
VERSION:
version
COMMANDS:
help, h Shows a list of commands or help for one command
GLOBAL OPTIONS:
--bin-name value name for the binary built by gaper for the executed program (default current directory name)
--build-path value path to the program source code (default: ".")
--build-args value arguments used on building the program
--program-args value arguments used on executing the program
--verbose turns on the verbose messages from gaper
--disable-default-ignore turns off default ignore for hidden files and folders, "*_test.go" files, and vendor folder
--watch value, -w value list of folders or files to watch for changes
--ignore value, -i value list of folders or files to ignore for changes
--poll-interval value, -p value how often in milliseconds to poll watched files for changes (default: 500)
--extensions value, -e value extensions to watch for changes (default: "go")
--no-restart-on value, -n value don't automatically restart the supervised program if it ends:
if "error", an exit code of 0 will still restart.
if "exit", no restart regardless of exit code.
if "success", no restart only if exit code is 0.
--help, -h show help
--version, -v print the version
Watch and Ignore paths
For those options Gaper supports static paths (e.g. build/, seed.go) or glob paths (e.g. migrations/**/up.go, *_test.go).
On using a path to a directory please add a / at the end (e.g. build/) to make sure Gaper won't include other matches that starts with that same value (e.g. build/, build_settings.go).
Default ignore settings
Since in most projects there is no need to watch changes of:
- hidden files and folders
- test files (
*_test.go) - vendor folder
Gaper by default ignores those cases already. Although, if you need Gaper to watch those files anyway it is possible to disable this setting with --disable-default-ignore argument.
Watch method
Currently Gaper uses polling to watch file changes. We have plans to support fs events though in a near future.
Examples
Using all defaults provided by Gaper:
gaper
Example providing a few custom configurations:
gaper \
--bin-name build/api-dev \
--build-path cmd/server \
--build-args "-ldflags=\"-X 'main.Version=dev'" \
-w 'public/**' -w '*.go' \
-e js -e css -e html \
--watch .
Example to ignore watching over all test files:
no need for this if you have not disabled the default ignore settings
--disable-default-ignore
--ignore './**/*_test.go'
Contributing
See the Contributing guide for steps on how to contribute to this project.
Reference
This package was heavily inspired by gin and node-supervisor.
Basically, Gaper is a mixing of those projects above. It started from gin code base and I rewrote it aiming to get
something similar to node-supervisor (but simpler). A big thanks for those projects and for the people behind it!
How is Gaper different of Gin
The main difference is that Gaper removes a layer of complexity from Gin which has a proxy running on top of the executed server. It allows to postpone a build and reload the server when the first call hits it. With Gaper we don't care about that feature, it just restarts your server whenever a change is made.