138 lines
4.0 KiB
Markdown
138 lines
4.0 KiB
Markdown
graceful [](http://godoc.org/github.com/tylerb/graceful) [](https://drone.io/github.com/tylerb/graceful/latest) [](https://coveralls.io/r/tylerb/graceful?branch=dronedebug) [](https://gitter.im/tylerb/graceful?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge)
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========
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Graceful is a Go 1.3+ package enabling graceful shutdown of http.Handler servers.
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## Installation
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To install, simply execute:
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```
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go get gopkg.in/tylerb/graceful.v1
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```
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I am using [gopkg.in](http://labix.org/gopkg.in) to control releases.
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## Usage
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Using Graceful is easy. Simply create your http.Handler and pass it to the `Run` function:
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```go
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package main
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import (
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"gopkg.in/tylerb/graceful.v1"
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"net/http"
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"fmt"
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"time"
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)
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func main() {
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mux := http.NewServeMux()
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mux.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) {
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fmt.Fprintf(w, "Welcome to the home page!")
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})
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graceful.Run(":3001",10*time.Second,mux)
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}
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```
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Another example, using [Negroni](https://github.com/codegangsta/negroni), functions in much the same manner:
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```go
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package main
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import (
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"github.com/codegangsta/negroni"
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"gopkg.in/tylerb/graceful.v1"
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"net/http"
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"fmt"
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"time"
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)
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func main() {
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mux := http.NewServeMux()
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mux.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) {
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fmt.Fprintf(w, "Welcome to the home page!")
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})
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n := negroni.Classic()
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n.UseHandler(mux)
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//n.Run(":3000")
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graceful.Run(":3001",10*time.Second,n)
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}
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```
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In addition to Run there are the http.Server counterparts ListenAndServe, ListenAndServeTLS and Serve, which allow you to configure HTTPS, custom timeouts and error handling.
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Graceful may also be used by instantiating its Server type directly, which embeds an http.Server:
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```go
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mux := // ...
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srv := &graceful.Server{
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Timeout: 10 * time.Second,
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Server: &http.Server{
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Addr: ":1234",
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Handler: mux,
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},
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}
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srv.ListenAndServe()
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```
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This form allows you to set the ConnState callback, which works in the same way as in http.Server:
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```go
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mux := // ...
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srv := &graceful.Server{
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Timeout: 10 * time.Second,
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ConnState: func(conn net.Conn, state http.ConnState) {
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// conn has a new state
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},
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Server: &http.Server{
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Addr: ":1234",
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Handler: mux,
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},
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}
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srv.ListenAndServe()
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```
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## Behaviour
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When Graceful is sent a SIGINT or SIGTERM (possibly from ^C or a kill command), it:
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1. Disables keepalive connections.
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2. Closes the listening socket, allowing another process to listen on that port immediately.
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3. Starts a timer of `timeout` duration to give active requests a chance to finish.
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4. When timeout expires, closes all active connections.
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5. Closes the `stopChan`, waking up any blocking goroutines.
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6. Returns from the function, allowing the server to terminate.
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## Notes
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If the `timeout` argument to `Run` is 0, the server never times out, allowing all active requests to complete.
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If you wish to stop the server in some way other than an OS signal, you may call the `Stop()` function.
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This function stops the server, gracefully, using the new timeout value you provide. The `StopChan()` function
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returns a channel on which you can block while waiting for the server to stop. This channel will be closed when
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the server is stopped, allowing your execution to proceed. Multiple goroutines can block on this channel at the
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same time and all will be signalled when stopping is complete.
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## Contributing
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If you would like to contribute, please:
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1. Create a GitHub issue regarding the contribution. Features and bugs should be discussed beforehand.
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2. Fork the repository.
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3. Create a pull request with your solution. This pull request should reference and close the issues (Fix #2).
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All pull requests should:
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1. Pass [gometalinter -t .](https://github.com/alecthomas/gometalinter) with no warnings.
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2. Be `go fmt` formatted.
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