Valentin TjonckeandSoam Vasani
1665235c14
Minimal golang runtime. Functions are built as Go plugins, and the plugin is uploaded to fission. See `environments/go/README.md` for instructions and `examples/go` for a usage example. For now, we're re-using the 'code' field of the function to store the binary plugin. With v2 environments, this will be stored separately as a binary package.
84 lines
1.6 KiB
Go
84 lines
1.6 KiB
Go
package main
|
|
|
|
import (
|
|
"fmt"
|
|
"net/http"
|
|
"os"
|
|
"plugin"
|
|
|
|
"github.com/fission/fission/environments/go/context"
|
|
)
|
|
|
|
const (
|
|
CODE_PATH = "/userfunc/user"
|
|
)
|
|
|
|
var userFunc http.HandlerFunc
|
|
|
|
func loadPlugin() http.HandlerFunc {
|
|
p, err := plugin.Open(CODE_PATH)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
sym, err := p.Lookup("Handler")
|
|
if err != nil {
|
|
panic("Entry point not found")
|
|
}
|
|
|
|
switch h := sym.(type) {
|
|
case *http.Handler:
|
|
return (*h).ServeHTTP
|
|
case *http.HandlerFunc:
|
|
return *h
|
|
case func(http.ResponseWriter, *http.Request):
|
|
return h
|
|
case func(context.Context, http.ResponseWriter, *http.Request):
|
|
return func(w http.ResponseWriter, r *http.Request) {
|
|
c := context.New()
|
|
h(c, w, r)
|
|
}
|
|
default:
|
|
panic("Entry point not found: bad type")
|
|
}
|
|
}
|
|
|
|
func specializeHandler(w http.ResponseWriter, r *http.Request) {
|
|
if userFunc != nil {
|
|
w.WriteHeader(400)
|
|
w.Write([]byte("Not a generic container"))
|
|
return
|
|
}
|
|
|
|
_, err := os.Stat(CODE_PATH)
|
|
if err != nil {
|
|
if os.IsNotExist(err) {
|
|
w.WriteHeader(http.StatusNotFound)
|
|
w.Write([]byte(CODE_PATH + ": not found"))
|
|
return
|
|
} else {
|
|
panic(err)
|
|
}
|
|
}
|
|
|
|
fmt.Println("Specializing ...")
|
|
userFunc = loadPlugin()
|
|
fmt.Println("Done")
|
|
}
|
|
|
|
func main() {
|
|
http.HandleFunc("/specialize", specializeHandler)
|
|
|
|
// Generic route -- all http requests go to the user function.
|
|
http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
|
|
if userFunc == nil {
|
|
w.WriteHeader(http.StatusInternalServerError)
|
|
w.Write([]byte("Generic container: no requests supported"))
|
|
return
|
|
}
|
|
userFunc(w, r)
|
|
})
|
|
|
|
fmt.Println("Listening on 8888 ...")
|
|
http.ListenAndServe(":8888", nil)
|
|
}
|