Tychus is a command line utility for live reloading applications. Tychus serves your application through a proxy. Anytime the proxy receives an HTTP request, it will automatically rerun your command if the filesystem has changed.
tychus is language agnostic - it can be configured to work with just about
anything: Go, Rust, Ruby, Python, scripts & arbitrary commands.
brew tap devlocker/tap
brew install tychus
Assuming you have a working Go environment and GOPATH/bin is in your PATH
go get github.com/devlocker/tychus
Currently isn't supported :(
Usage is simple, tychus and then your command. That will start a proxy on port
4000. When an HTTP request comes in and the filesystem has changed, your
command will be rerun.
tychus go run main.go
Tychus has a few options. In most cases the defaults should be sufficient. See below for a few examples.
-a, --app-port int port your application runs on, overwritten by ENV['PORT'] (default 3000)
-p, --proxy-port int proxy port (default 4000)
-x, --ignore stringSlice comma separated list of directories to ignore file changes in. (default [node_modules,log,tmp,vendor])
--wait Wait for command to finish before proxying a request.
-t, --timeout int timeout for proxied requests (default 10)
-h, --help help for tychus
--debug print debug output
--version version for tychusNote: Tychus will not look for file system changes any hidden directories
(those beginning with .).
Example: Web Servers
// Go - Hello World Server
$ tychus go run main.go
[tychus] Proxing requests on port 4000 to 3000
[Go App] App Starting
// Make a request
$ curl localhost:4000
Hello World
$ curl localhost:4000
Hello World
// Save a file, next request will restart your webapp
$ curl localhost:4000
[Go App] App Starting
Hello World
This can work with any webserver:
// Rust
tychus cargo run
// Ruby
tychus ruby myapp.rb
Need to pass flags? Stick the command in quotes
tychus "ruby myapp.rb -e development"
Complicated command? Stick it in quotes
tychus "go build -o my-bin && echo 'Built Binary' && ./my-bin"
Example: Scripts + Commands
Scenario: You have a webserver running on port 3005, and it serves static
files from the /public directory. In the /docs folder are some markdown
files. Should they change, you want them rebuilt and placed into the public
directory so the server can pick them up.
tychus "multimarkdown docs/index.md > public/index.html" --wait --app-port=3005
Now, when you make a request to the proxy on localhost:4000, tychus will
pause the request (that's what the --wait flag is for) until multimarkdown
finishes. Then it will forward the request to the server on port 3005.
multimarkdown will only be run if the filesystem has changed.
Advanced Example: Reload Scripts and Webserver
Like the scenario above, but you also want your server to autoreload as files
change. You can chain tychus together, by setting the app-port equal to the
proxy-port of the previous tychus. An example:
The first instance of tychus will run a Go webserver that serves assets out of
public/. We only want it to restart when the app folder changes, so ignore
docs and public directories.
$ tychus go run main.go --app-port=3000 --proxy-port=4000 --ignore=docs,public
[tychus] Proxing requests on port 4000 to 3000
...
...
In order to serve upto date docs, multimarkdown needs to be invoked to
transform markdown into servable html. So we start another tychus process to
and point its app-port to server's proxy port.
$ tychus "multimarkdown docs/index.md > public/index.html" --wait --app-port=4000 --proxy-port=4001
Now, there is a proxy running on 4001 pointing at a proxy on 4000 pointing
at a webserver on 3000. If you save docs/index.html, and then make a request
to localhost:4001, that will pause the request while multimarkdown runs.
Once it is finished, the requests gets forwarded to localhost:4000, which in
turn forwards it our websever on 3000. The request gets sent all the way back,
with the correctly updated html!
Had our server code been modified in the app/ folder, then after
multimarkdown finished, and the request got passed on to 4000, that would
have also triggered a restart of our websever.
Other Proxy Goodies
Error messages
If you make a syntax error, or your program won't build for some reason, stderr will be returned by the proxy. Handy for the times you can't see you server (its in another pane / tab / tmux split).