Watches your .go files in a directory and invokes go build
if
a file changed. Nothing more.
Usage:
$ ./CompileDaemon -directory=yourproject/
Installation
You can use the go
tool to install CompileDaemon
:
go get github.com/githubnemo/CompileDaemon
Development
You need to use Go 1.16 or higher to build Compile Daemon, and you need to set
the env var GO111MODULE=on
, which enables you to develop outside of
$GOPATH/src
.
Command Line Options
Option | Default | Description |
---|---|---|
actions | ||
-build=… |
go build | Specify the command to run when rebuilding is required. |
-command=… |
none | Specify the command to run after a succesful build. The default is to run nothing. This command is issued with the working directory set to -directory. |
file selection | ||
-directory=… |
. | Which directory to watch. |
-recursive=… |
true | Recurse down the specified directory |
-exclude-dir=… |
none | Do not watch directories matching this glob pattern, e.g. ".git". You may have multiples of this flag. |
-exclude=… |
none | Exclude files matching this glob pattern, e.g. ".#*" ignores emacs temporary files. You may have multiples of this flag. |
-include=… |
none | Include files whose last path component matches this glob pattern. You may have multiples of this flag. |
-pattern=… |
(.+\.go|.+\.c)$ | A regular expression which matches the files to watch. The default watches .go and .c files. |
file watch | ||
-polling=… |
false | Use polling instead of FS notifications to detect changes. Default is false |
-polling-interval=… |
100 | Milliseconds of interval between polling file changes when polling option is selected |
misc | ||
-color=_ |
false | Colorize the output of the daemon's status messages. |
-log-prefix=_ |
true | Prefix all child process output with stdout/stderr labels and log timestamps. |
-graceful-kill=_ |
false | On supported platforms, send the child process a SIGTERM to allow it to exit gracefully if possible. |
Examples
In its simplest form, the defaults will do. With the current working directory set to the source directory you can simply…
$ CompileDaemon
… and it will recompile your code whenever you save a source file.
If you want it to also run your program each time it builds you might add…
$ CompileDaemon -command="./MyProgram -my-options"
… and it will also keep a copy of your program running. Killing the old one and starting a new one each time you build.
You may find that you need to exclude some directories and files from monitoring, such as a .git repository or emacs temporary files…
$ CompileDaemon -exclude-dir=.git -exclude=".#*" …
If you want to monitor files other than .go and .c files you might…
$ CompileDaemon -include=Makefile -include="*.less" -include="*.tmpl"
Security Considerations
Beware that, in case you are using CompileDaemon
in production to rebuild a
binary (please explain to me why you would do this, but carry on), an attacker
with write access is able to insert arbitrary code into your binary. So make
sure that you secure write access to the file system appropriately.
Common Issues
Too many open files
If you get an error for too many open files, you might wish to exclude your .git, .hg, or similar VCS directories using -exclude-dir=…
. This is common on OS X and BSD platforms where each watched file consumes a file descriptor.
If you still have too many open files, then you need to raise your process's file limit using the ulimit
command. Something like ulimit -n 1024
will probably take care of it. There is also a sysctl based limit which you may reach and need to adjust.
filepath.Walk() no space left on device
As described in this issue it might happen that you run out of inotify watchers which are limited by your system configuration. Please consider increasing them as is documented here.
Docker + Mac OS X
Some issues (here and here) report that changes on Docker volumes under Mac OS X are not reported.
There seem to be issues with either the implementation of the bind file
system mount between Mac OS X hosts and Docker containers or in
fsnotify/fsnotify
or a combination of both. As long as this is not
resolved, a possible workaround is to use polling:
CompileDaemon -polling
This will actively watch for changes, so it naturally uses more CPU
resources. You can tune the polling interval to your liking using the
-polling-interval=N
parameter but be advised: you should never use
this in production as it is simply too wasteful.
Project Details
Credits
CompileDaemon was written by githubnemo.
Code and documentation was contributed by jimstudt.
Repository
CompileDaemon is kept at https://github.com/githubnemo/CompileDaemon
License
CompileDaemon is licensed under the BSD Two Clause License