hashicorp/faas-nomad

package handlers

import (
    "context"
    "fmt"
    "net/http"
)

// FunctionNameCTXKey is a context key which points to the location of the function
// name set bu the ExtractFunction middleware
var FunctionNameCTXKey = struct{}{}

// MakeExtractFunctionMiddleWare returns a middleware handler which validates
// the presence of the function name in the URI query.
func MakeExtractFunctionMiddleWare(
    getVars func(*http.Request) map[string]string,
    next http.HandlerFunc) http.HandlerFunc {

    return func(rw http.ResponseWriter, r *http.Request) {
        vars := getVars(r)
        functionName := vars["name"]

        if functionName == "" {
            rw.WriteHeader(http.StatusBadRequest)
            fmt.Fprint(rw, fmt.Errorf("No function name"))
            return
        }

        r = r.WithContext(context.WithValue(r.Context(), FunctionNameCTXKey, functionName))
        next(rw, r)
    }
}