simplify configuration, semantic version, multi-worker

AMQP had several options in the config which should not be altered.
The version gets its own endpoint and uses semver. Starting
the background workers now supports the flag "-n X" to start X
workers within process to avoid having multiple detached screens.

.drone.yml

@@ -23,7 +23,7 @@ steps:
   pull: default
   image: golang
   commands:
-  - sed -i 's/"X-INFOMARK-VERSION", "0.0.1"/"X-INFOMARK-VERSION", "${DRONE_COMMIT_SHA}"/g' api/app/router.go
+  - sed -i 's/"YXZ"/"${DRONE_COMMIT_SHA}"/g' symbol/version.go
   - go version
   - go build infomark.go
   environment:
@@ -126,6 +126,6 @@ services:
 
 ---
 kind: signature
-hmac: bec11f987bcc8b10e923674bbb63e983c274ee5b007d2f2ae9a703f8f6e829cd
+hmac: 79461cde6a81a50bc7e6ad292872f4a10b9126d206196430cd4accaa4f6a61b9
 
 ...

.infomark.example.yml

@@ -2,9 +2,6 @@
 # ------------------------------------------------------------------------------
 
 rabbitmq_connection: amqp://user:password@localhost:5672/
-rabbitmq_exchange: test-exchange
-rabbitmq_exchangeType: direct
-rabbitmq_queue: test-queue
 rabbitmq_key: test-key
 
 # backend

.infomark.yml.ci

@@ -2,9 +2,6 @@
 # ------------------------------------------------------------------------------
 
 rabbitmq_connection: amqp://user:password@localhost:5672/
-rabbitmq_exchange: test-exchange
-rabbitmq_exchangeType: direct
-rabbitmq_queue: test-queue
 rabbitmq_key: test-key
 
 

api/app/common.go

@@ -52,6 +52,22 @@ func (rs *CommonResource) PingHandler(w http.ResponseWriter, r *http.Request) {
 	w.Write([]byte("pong"))
 }
 
+// VersionHandler is public endpoint for
+// URL: /version
+// METHOD: get
+// TAG: common
+// RESPONSE: 200,versionResponse
+// SUMMARY:  all version information
+func (rs *CommonResource) VersionHandler(w http.ResponseWriter, r *http.Request) {
+	// render JSON reponse
+	if err := render.Render(w, r, newVersionResponse()); err != nil {
+		render.Render(w, r, ErrRender(err))
+		return
+	}
+
+	render.Status(r, http.StatusOK)
+}
+
 // PrivacyStatementHandler is public endpoint for
 // URL: /privacy_statement
 // METHOD: get

api/app/common_responses.go

@@ -20,14 +20,16 @@ package app
 
 import (
 	"net/http"
+
+	"github.com/cgtuebingen/infomark-backend/symbol"
 )
 
-// courseResponse is the response payload for course management.
+// rawResponse is the response payload for course management.
 type rawResponse struct {
 	Text string `json:"text" example:"some text"`
 }
 
-// Render post-processes a courseResponse.
+// Render post-processes a rawResponse.
 func (body *rawResponse) Render(w http.ResponseWriter, r *http.Request) error {
 	return nil
 }
@@ -38,3 +40,22 @@ func newRawResponse(text string) *rawResponse {
 		Text: text,
 	}
 }
+
+// versionResponse is the response payload for course management.
+type versionResponse struct {
+	Commit  string `json:"commit" example:"d725269a8a7498aae1dbb07786bed4c88b002661"`
+	Version string `json:"version" example:"1"`
+}
+
+// newVersionResponse creates a response from a course model.
+func newVersionResponse() *versionResponse {
+	return &versionResponse{
+		Commit:  symbol.GitCommit,
+		Version: symbol.Version.String(),
+	}
+}
+
+// Render post-processes a versionResponse.
+func (body *versionResponse) Render(w http.ResponseWriter, r *http.Request) error {
+	return nil
+}

api/app/router.go

@@ -30,6 +30,7 @@ import (
 
 	"github.com/cgtuebingen/infomark-backend/auth/authenticate"
 	"github.com/cgtuebingen/infomark-backend/auth/authorize"
+	"github.com/cgtuebingen/infomark-backend/symbol"
 	"github.com/go-chi/chi"
 	"github.com/go-chi/chi/middleware"
 	"github.com/go-chi/cors"
@@ -74,21 +75,24 @@ func LoggingMiddleware(next http.Handler) http.Handler {
 		start := time.Now()
 		next.ServeHTTP(w, r)
 		end := time.Now()
-		log.WithFields(logrus.Fields{
-			"method": r.Method,
-			// "proto":   r.Proto,
-			"agent":   r.UserAgent(),
-			"remote":  r.RemoteAddr,
-			"latency": end.Sub(start),
-			"time":    end.Format(time.RFC3339),
-		}).Info(r.RequestURI)
+		if r.RequestURI != "/metrics" {
+			log.WithFields(logrus.Fields{
+				"method": r.Method,
+				// "proto":   r.Proto,
+				"agent":   r.UserAgent(),
+				"remote":  r.RemoteAddr,
+				"latency": end.Sub(start),
+				"time":    end.Format(time.RFC3339),
+			}).Info(r.RequestURI)
+		}
 	})
 }
 
 // VersionMiddleware writes the current API version to the headers.
 func VersionMiddleware(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		w.Header().Set("X-INFOMARK-VERSION", "0.0.1")
+		w.Header().Set("X-INFOMARK-VERSION", symbol.Version.String())
+		w.Header().Set("X-INFOMARK-Commit", symbol.GitCommit)
 		next.ServeHTTP(w, r)
 	})
 }
@@ -171,6 +175,7 @@ func New(db *sqlx.DB, log bool) (*chi.Mux, error) {
 				r.Post("/auth/confirm_email", appAPI.Auth.ConfirmEmailHandler)
 				r.Post("/account", appAPI.Account.CreateHandler)
 				r.Get("/ping", appAPI.Common.PingHandler)
+				r.Get("/version", appAPI.Common.VersionHandler)
 				r.Get("/privacy_statement", appAPI.Common.PrivacyStatementHandler)
 			})
 

api/app/submission_producer.go

@@ -44,9 +44,9 @@ func init() {
 
 	cfg := &service.Config{
 		Connection:   viper.GetString("rabbitmq_connection"),
-		Exchange:     viper.GetString("rabbitmq_exchange"),
-		ExchangeType: viper.GetString("rabbitmq_exchangeType"),
-		Queue:        viper.GetString("rabbitmq_queue"),
+		Exchange:     "infomark-worker-exchange",
+		ExchangeType: "direct",
+		Queue:        "infomark-worker-submissions",
 		Key:          viper.GetString("rabbitmq_key"),
 		Tag:          "SimpleSubmission",
 	}

api/worker.go

@@ -24,16 +24,19 @@ import (
 
 	background "github.com/cgtuebingen/infomark-backend/api/worker"
 	"github.com/cgtuebingen/infomark-backend/service"
+	"github.com/sirupsen/logrus"
 	"github.com/spf13/viper"
 )
 
 // Worker provides a background worker
-type Worker struct{}
+type Worker struct {
+	NumInstances int
+}
 
 // NewWorker creates and configures an background worker
-func NewWorker() (*Worker, error) {
+func NewWorker(numInstances int) (*Worker, error) {
 	log.Println("configuring worker...")
-	return &Worker{}, nil
+	return &Worker{NumInstances: numInstances}, nil
 }
 
 // Start runs ListenAndServe on the http.Worker with graceful shutdown.
@@ -42,25 +45,34 @@ func (srv *Worker) Start() {
 
 	cfg := &service.Config{
 		Connection:   viper.GetString("rabbitmq_connection"),
-		Exchange:     viper.GetString("rabbitmq_exchange"),
-		ExchangeType: viper.GetString("rabbitmq_exchangeType"),
-		Queue:        viper.GetString("rabbitmq_queue"),
+		Exchange:     "infomark-worker-exchange",
+		ExchangeType: "direct",
+		Queue:        "infomark-worker-submissions",
 		Key:          viper.GetString("rabbitmq_key"),
 		Tag:          "SimpleSubmission",
 	}
 
-	consumer, _ := service.NewConsumer(cfg, background.DefaultSubmissionHandler.Handle)
-	deliveries, err := consumer.Setup()
-	if err != nil {
-		panic(err)
-	}
+	consumers := []*service.Consumer{}
 
-	go consumer.HandleLoop(deliveries)
+	for i := 0; i < srv.NumInstances; i++ {
+		log.WithFields(logrus.Fields{"instance": i}).Info("start")
+		consumer, _ := service.NewConsumer(cfg, background.DefaultSubmissionHandler.Handle, i)
+		deliveries, err := consumer.Setup()
+		if err != nil {
+			panic(err)
+		}
+		consumers = append(consumers, consumer)
+		go consumers[i].HandleLoop(deliveries)
+	}
 
 	quit := make(chan os.Signal, 1)
 	signal.Notify(quit, os.Interrupt)
 	sig := <-quit
 	log.Println("Shutting down Worker... Reason:", sig)
-	consumer.Shutdown()
+
+	for i := 0; i < srv.NumInstances; i++ {
+		consumers[i].Shutdown()
+	}
+
 	log.Println("Worker gracefully stopped")
 }

cmd/console/submission_cmd.go

@@ -75,9 +75,9 @@ var SubmissionTriggerCmd = &cobra.Command{
 
 		cfg := &service.Config{
 			Connection:   viper.GetString("rabbitmq_connection"),
-			Exchange:     viper.GetString("rabbitmq_exchange"),
-			ExchangeType: viper.GetString("rabbitmq_exchangeType"),
-			Queue:        viper.GetString("rabbitmq_queue"),
+			Exchange:     "infomark-worker-exchange",
+			ExchangeType: "direct",
+			Queue:        "infomark-worker-submissions",
 			Key:          viper.GetString("rabbitmq_key"),
 			Tag:          "SimpleSubmission",
 		}
@@ -242,9 +242,9 @@ This triggers all [kind]-tests again (private, public).
 
 		cfg := &service.Config{
 			Connection:   viper.GetString("rabbitmq_connection"),
-			Exchange:     viper.GetString("rabbitmq_exchange"),
-			ExchangeType: viper.GetString("rabbitmq_exchangeType"),
-			Queue:        viper.GetString("rabbitmq_queue"),
+			Exchange:     "infomark-worker-exchange",
+			ExchangeType: "direct",
+			Queue:        "infomark-worker-submissions",
 			Key:          viper.GetString("rabbitmq_key"),
 			Tag:          "SimpleSubmission",
 		}

cmd/root.go

@@ -31,10 +31,12 @@ import (
 var RootCmd = &cobra.Command{
 	Use:   "infomark",
 	Short: "A CI based course framework",
-	Long: `InfoMark distributes exercise sheets in an course management system and
-tests students homework submission for these exercises sheet automatically.
-
+	Long: `InfoMark is a a scalable, modern and open-source
+online course management system supporting auto-testing/grading of
+programming assignments and distributing exercise sheets.
 The infomark-server is the REST api backend for the course distributing system.
+
+Complete documentation is available at https://infomark.org/.
 	`,
 }
 

cmd/serve.go

@@ -28,7 +28,7 @@ import (
 // serveCmd represents the serve command
 var serveCmd = &cobra.Command{
 	Use:   "serve",
-	Short: "start http server with configured api",
+	Short: "start the infomark RESTful JSON backend server with configured api",
 	Long:  `Starts a http server and serves the configured api`,
 	Run: func(cmd *cobra.Command, args []string) {
 		server, err := api.NewServer()

cmd/work.go

@@ -22,24 +22,30 @@ import (
 	"log"
 
 	"github.com/cgtuebingen/infomark-backend/api"
+
 	"github.com/spf13/cobra"
 )
 
+var numWorkers = 1
+
 var workCmd = &cobra.Command{
 	Use:   "work",
 	Short: "start a worker",
-	Long:  `Starts a background worker which will use docker to test submissions`,
+	Long: `Starts a background worker which will use docker to test submissions.
+Can be used with the flag "-n" to start multiple workers within one process.
+`,
 	Run: func(cmd *cobra.Command, args []string) {
 
-		worker, err := api.NewWorker()
+		worker, err := api.NewWorker(numWorkers)
 		if err != nil {
 			log.Fatal(err)
 		}
 		worker.Start()
-
 	},
 }
 
 func init() {
+
+	workCmd.Flags().IntVarP(&numWorkers, "number", "n", 1, "number of workers within one routine")
 	RootCmd.AddCommand(workCmd)
 }

service/consumer.go

@@ -33,18 +33,22 @@ type Consumer struct {
 	channel *amqp.Channel
 	done    chan error
 
+	instanceID int
+
 	handleFunc func(body []byte) error
 }
 
 // NewConsumer creates new consumer which can act on AMPQ messages
-func NewConsumer(cfg *Config, handleFunc func(body []byte) error) (*Consumer, error) {
+func NewConsumer(cfg *Config, handleFunc func(body []byte) error, instanceID int) (*Consumer, error) {
 
 	consumer := &Consumer{
 		conn:       nil,
 		channel:    nil,
 		done:       make(chan error),
 		handleFunc: handleFunc,
 
+		instanceID: instanceID,
+
 		Config: cfg,
 	}
 
@@ -55,6 +59,7 @@ func NewConsumer(cfg *Config, handleFunc func(body []byte) error) (*Consumer, er
 func (c *Consumer) Setup() (<-chan amqp.Delivery, error) {
 	logger := log.WithFields(logrus.Fields{
 		// "connection":   c.Config.Connection,
+		"instance":     c.instanceID,
 		"exchange":     c.Config.Exchange,
 		"exchangetype": c.Config.ExchangeType,
 		"queue":        c.Config.Queue,

symbol/version.go

@@ -0,0 +1,47 @@
+// InfoMark - a platform for managing courses with
+//            distributing exercise sheets and testing exercise submissions
+// Copyright (C) 2019  ComputerGraphics Tuebingen
+// Authors: Patrick Wieschollek
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package symbol
+
+import (
+	"github.com/coreos/go-semver/semver"
+)
+
+var (
+	// GitCommit is the git commit that was compiled
+	GitCommit string = "YXZ"
+	// VersionMajor is for an API incompatible changes.
+	VersionMajor int64 = 0
+	// VersionMinor is for functionality in a backwards-compatible manner.
+	VersionMinor int64 = 0
+	// VersionPatch is for backwards-compatible bug fixes.
+	VersionPatch int64 = 1
+	// VersionPre indicates prerelease.
+	VersionPre = "beta"
+	// VersionDev indicates development branch. Releases will be empty string.
+	VersionDev string
+)
+
+// Version is the specification version that the package types support.
+var Version = semver.Version{
+	Major:      VersionMajor,
+	Minor:      VersionMinor,
+	Patch:      VersionPatch,
+	PreRelease: semver.PreRelease(VersionPre),
+	Metadata:   VersionDev,
+}