├── .travis.yml ├── Dockerfile ├── LICENSE ├── README.md ├── call.go ├── docker-compose.yml ├── handle.go ├── handle_test.go └── script └── test /.travis.yml: -------------------------------------------------------------------------------- 1 | language: go 2 | versions: 3 | - 1.6 4 | 5 | script: 6 | - go fmt ./... 7 | - go vet ./... 8 | - go test -v -race -cover ./... 9 | -------------------------------------------------------------------------------- /Dockerfile: -------------------------------------------------------------------------------- 1 | FROM golang:1.6-onbuild 2 | RUN go get -t . 3 | -------------------------------------------------------------------------------- /LICENSE: -------------------------------------------------------------------------------- 1 | 2 | Apache License 3 | Version 2.0, January 2004 4 | http://www.apache.org/licenses/ 5 | 6 | TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 7 | 8 | 1. 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In no event and under no legal theory, 155 | whether in tort (including negligence), contract, or otherwise, 156 | unless required by applicable law (such as deliberate and grossly 157 | negligent acts) or agreed to in writing, shall any Contributor be 158 | liable to You for damages, including any direct, indirect, special, 159 | incidental, or consequential damages of any character arising as a 160 | result of this License or out of the use or inability to use the 161 | Work (including but not limited to damages for loss of goodwill, 162 | work stoppage, computer failure or malfunction, or any and all 163 | other commercial damages or losses), even if such Contributor 164 | has been advised of the possibility of such damages. 165 | 166 | 9. Accepting Warranty or Additional Liability. While redistributing 167 | the Work or Derivative Works thereof, You may choose to offer, 168 | and charge a fee for, acceptance of support, warranty, indemnity, 169 | or other liability obligations and/or rights consistent with this 170 | License. However, in accepting such obligations, You may act only 171 | on Your own behalf and on Your sole responsibility, not on behalf 172 | of any other Contributor, and only if You agree to indemnify, 173 | defend, and hold each Contributor harmless for any liability 174 | incurred by, or claims asserted against, such Contributor by reason 175 | of your accepting any such warranty or additional liability. 176 | 177 | END OF TERMS AND CONDITIONS 178 | 179 | Copyright 2016 Docker, Inc. 180 | 181 | Licensed under the Apache License, Version 2.0 (the "License"); 182 | you may not use this file except in compliance with the License. 183 | You may obtain a copy of the License at 184 | 185 | http://www.apache.org/licenses/LICENSE-2.0 186 | 187 | Unless required by applicable law or agreed to in writing, software 188 | distributed under the License is distributed on an "AS IS" BASIS, 189 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 190 | See the License for the specific language governing permissions and 191 | limitations under the License. 192 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # Funker for Go 2 | 3 | A Go implementation of [Funker](https://github.com/bfirsh/funker). 4 | 5 | ## Usage 6 | 7 | Defining functions: 8 | 9 | ```go 10 | package main 11 | 12 | import "github.com/bfirsh/funker-go" 13 | 14 | type addArgs struct { 15 | X int `json:"x"` 16 | Y int `json:"y"` 17 | } 18 | 19 | func main() { 20 | err := funker.Handle(func(args *addArgs) int { 21 | return args.X + args.Y; 22 | }); 23 | if err != nil { 24 | panic(err); 25 | } 26 | } 27 | ``` 28 | 29 | Calling functions: 30 | 31 | ```go 32 | ret, err := funker.Call(addArgs{X: 1, Y: 2}); 33 | if err != nil { 34 | panic(err); 35 | } 36 | fmt.PrintLn(ret); 37 | ``` 38 | -------------------------------------------------------------------------------- /call.go: -------------------------------------------------------------------------------- 1 | package funker 2 | 3 | import ( 4 | "encoding/json" 5 | "io/ioutil" 6 | "net" 7 | "time" 8 | ) 9 | 10 | // Call a Funker function 11 | func Call(name string, args interface{}) (interface{}, error) { 12 | argsJSON, err := json.Marshal(args) 13 | if err != nil { 14 | return nil, err 15 | } 16 | 17 | addr, err := net.ResolveTCPAddr("tcp", name+":9999") 18 | if err != nil { 19 | return nil, err 20 | } 21 | 22 | conn, err := net.DialTCP("tcp", nil, addr) 23 | if err != nil { 24 | return nil, err 25 | } 26 | // Keepalive is a workaround for docker/docker#29655 . 27 | // The implementation of FIN_WAIT2 seems weird on Swarm-mode. 28 | // It seems always refuseing any packet after 60 seconds. 29 | // 30 | // TODO: remove this workaround if the issue gets resolved on the Docker side 31 | if err := conn.SetKeepAlive(true); err != nil { 32 | return nil, err 33 | } 34 | if err := conn.SetKeepAlivePeriod(30 * time.Second); err != nil { 35 | return nil, err 36 | } 37 | if _, err = conn.Write(argsJSON); err != nil { 38 | return nil, err 39 | } 40 | if err = conn.CloseWrite(); err != nil { 41 | return nil, err 42 | } 43 | retJSON, err := ioutil.ReadAll(conn) 44 | if err != nil { 45 | return nil, err 46 | } 47 | var ret interface{} 48 | err = json.Unmarshal(retJSON, &ret) 49 | return ret, err 50 | } 51 | -------------------------------------------------------------------------------- /docker-compose.yml: -------------------------------------------------------------------------------- 1 | version: "2" 2 | services: 3 | funker: 4 | build: . 5 | -------------------------------------------------------------------------------- /handle.go: -------------------------------------------------------------------------------- 1 | package funker 2 | 3 | import ( 4 | "encoding/json" 5 | "fmt" 6 | "io/ioutil" 7 | "net" 8 | "reflect" 9 | ) 10 | 11 | // Handle a Funker function. 12 | func Handle(handler interface{}) error { 13 | handlerValue := reflect.ValueOf(handler) 14 | handlerType := handlerValue.Type() 15 | if handlerType.Kind() != reflect.Func || handlerType.NumIn() != 1 || handlerType.NumOut() != 1 { 16 | return fmt.Errorf("Handler must be a function with a single parameter and single return value.") 17 | } 18 | argsValue := reflect.New(handlerType.In(0)) 19 | 20 | listener, err := net.Listen("tcp", ":9999") 21 | if err != nil { 22 | return err 23 | } 24 | conn, err := listener.Accept() 25 | if err != nil { 26 | return err 27 | } 28 | // We close listener, because we only allow single request. 29 | // Note that TCP "backlog" cannot be used for that purpose. 30 | // http://www.perlmonks.org/?node_id=940662 31 | if err = listener.Close(); err != nil { 32 | return err 33 | } 34 | argsJSON, err := ioutil.ReadAll(conn) 35 | if err != nil { 36 | return err 37 | } 38 | err = json.Unmarshal(argsJSON, argsValue.Interface()) 39 | if err != nil { 40 | return err 41 | } 42 | 43 | ret := handlerValue.Call([]reflect.Value{argsValue.Elem()})[0].Interface() 44 | retJSON, err := json.Marshal(ret) 45 | if err != nil { 46 | return err 47 | } 48 | 49 | if _, err = conn.Write(retJSON); err != nil { 50 | return err 51 | } 52 | 53 | return conn.Close() 54 | } 55 | -------------------------------------------------------------------------------- /handle_test.go: -------------------------------------------------------------------------------- 1 | package funker 2 | 3 | import ( 4 | "github.com/stretchr/testify/assert" 5 | "testing" 6 | "time" 7 | ) 8 | 9 | func TestSimpleFunction(t *testing.T) { 10 | type addArgs struct { 11 | X int `json:"x"` 12 | Y int `json:"y"` 13 | } 14 | 15 | done := make(chan bool, 1) 16 | errors := make(chan error, 1) 17 | 18 | go func() { 19 | err := Handle(func(args *addArgs) int { 20 | return args.X + args.Y 21 | }) 22 | if err != nil { 23 | errors <- err 24 | } 25 | }() 26 | 27 | time.Sleep(100 * time.Millisecond) 28 | 29 | go func() { 30 | ret, err := Call("localhost", addArgs{X: 1, Y: 2}) 31 | if err != nil { 32 | errors <- err 33 | return 34 | } 35 | assert.Equal(t, ret, 3.0) 36 | close(done) 37 | }() 38 | 39 | select { 40 | case <-done: 41 | case err := <-errors: 42 | t.Fatal(err) 43 | } 44 | } 45 | 46 | func TestSecondRequest(t *testing.T) { 47 | type data struct { 48 | X string `json:"x"` 49 | } 50 | handlerTakes := 3 * time.Second 51 | epsilon := 100 * time.Millisecond 52 | go func() { 53 | err := Handle(func(args *data) *data { 54 | t.Logf("Handling %+v (takes %s)", args, handlerTakes) 55 | time.Sleep(handlerTakes) 56 | return args 57 | }) 58 | if err != nil { 59 | t.Fatal(err) 60 | } 61 | }() 62 | 63 | call1Done := make(chan interface{}, 1) 64 | t.Logf("1st call begins in background, this should pass") 65 | go func() { 66 | res, err := Call("localhost", data{X: "shouldPass"}) 67 | if err != nil { 68 | t.Fatal(err) 69 | 70 | } 71 | call1Done <- res 72 | }() 73 | t.Logf("sleeping for %s, so that make sure the 1st call request is received", epsilon) 74 | time.Sleep(epsilon) 75 | 76 | t.Logf("2nd call begins in foreground, this should fail immediately") 77 | call2Begin := time.Now() 78 | res, err := Call("localhost", data{X: "call2"}) 79 | if err == nil { 80 | t.Fatalf("2nd call should fail, got %v", res) 81 | } 82 | call2Took := time.Now().Sub(call2Begin) 83 | t.Logf("2nd call took %s, got err %v", call2Took, err) 84 | if call2Took > epsilon { 85 | t.Fatalf("2nd call should have failed immediately (%s), took %s", 86 | epsilon, call2Took) 87 | } 88 | 89 | res = <-call1Done 90 | t.Logf("1st call done, got %+v", res) 91 | } 92 | -------------------------------------------------------------------------------- /script/test: -------------------------------------------------------------------------------- 1 | #!/bin/bash 2 | set -e 3 | docker-compose build 4 | exec docker-compose run funker go test -test.timeout 1s . 5 | --------------------------------------------------------------------------------