feat: rewrite python calculator service in golang (#395)

.github/workflows/pr-go.yaml

@@ -24,6 +24,12 @@ env:
 jobs:
   unit-test:
     runs-on: ubuntu-latest
+    services:
+      # setup httpstan container used to run unit test in experiment service
+      httpstan:
+        image: ghcr.io/bucketeer-io/bucketeer-httpstan:0.0.1
+        ports:
+          - 8080:8080
     steps:
       - uses: actions/checkout@v3
       - uses: actions/setup-go@v4

cmd/experimentcalculator/experimentcalculator.go

@@ -0,0 +1,42 @@
+// Copyright 2022 The Bucketeer Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package main
+
+import (
+	"log"
+
+	"github.com/bucketeer-io/bucketeer/pkg/cli"
+	"github.com/bucketeer-io/bucketeer/pkg/experimentcalculator/cmd/server"
+)
+
+var (
+	name    = "bucketeer-experiment-calculator"
+	version = ""
+	build   = ""
+)
+
+func main() {
+	app := cli.NewApp(name, "A/B Testing Microservice", version, build)
+	registerCommands(app)
+	err := app.Run()
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+func registerCommands(app *cli.App) {
+	server.RegisterCommand(app, app)
+}

go.mod

@@ -13,7 +13,9 @@ require (
 	github.com/aws/aws-sdk-go-v2/service/kms v1.21.1
 	github.com/blang/semver v3.5.1+incompatible
 	github.com/coreos/go-oidc v2.2.1+incompatible
+	github.com/go-gota/gota v0.12.0
 	github.com/go-redis/redis v6.15.9+incompatible
+	github.com/go-resty/resty/v2 v2.7.0
 	github.com/go-sql-driver/mysql v1.7.1
 	github.com/golang-migrate/migrate/v4 v4.11.0
 	github.com/golang/protobuf v1.5.3
@@ -36,6 +38,7 @@ require (
 	golang.org/x/sync v0.2.0
 	golang.org/x/text v0.9.0
 	golang.org/x/time v0.3.0
+	gonum.org/v1/gonum v0.11.0
 	google.golang.org/api v0.126.0
 	google.golang.org/genproto v0.0.0-20230530153820-e85fd2cbaebc
 	google.golang.org/genproto/googleapis/api v0.0.0-20230530153820-e85fd2cbaebc
@@ -107,6 +110,7 @@ require (
 	go.uber.org/atomic v1.9.0 // indirect
 	go.uber.org/multierr v1.6.0 // indirect
 	golang.org/x/crypto v0.9.0 // indirect
+	golang.org/x/exp v0.0.0-20220827204233-334a2380cb91 // indirect
 	golang.org/x/mod v0.8.0 // indirect
 	golang.org/x/net v0.10.0 // indirect
 	golang.org/x/sys v0.8.0 // indirect

pkg/experimentcalculator/api/api.go

@@ -0,0 +1,67 @@
+// Copyright 2022 The Bucketeer Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package api
+
+import (
+	"time"
+
+	"go.uber.org/zap"
+	"google.golang.org/grpc"
+
+	envclient "github.com/bucketeer-io/bucketeer/pkg/environment/client"
+	ecclient "github.com/bucketeer-io/bucketeer/pkg/eventcounter/client"
+	experimentclient "github.com/bucketeer-io/bucketeer/pkg/experiment/client"
+	"github.com/bucketeer-io/bucketeer/pkg/experimentcalculator/experimentcalc"
+	"github.com/bucketeer-io/bucketeer/pkg/experimentcalculator/stan"
+	"github.com/bucketeer-io/bucketeer/pkg/metrics"
+	"github.com/bucketeer-io/bucketeer/pkg/rpc"
+	"github.com/bucketeer-io/bucketeer/pkg/storage/v2/mysql"
+	calculator "github.com/bucketeer-io/bucketeer/proto/experimentcalculator"
+)
+
+type calculatorService struct {
+	calculator *experimentcalc.ExperimentCalculator
+	logger     *zap.Logger
+}
+
+func NewCalculatorService(
+	stan *stan.Stan,
+	environmentClient envclient.Client,
+	eventCounterClient ecclient.Client,
+	experimentClient experimentclient.Client,
+	mysqlClient mysql.Client,
+	metrics metrics.Registerer,
+	loc *time.Location,
+	logger *zap.Logger,
+) rpc.Service {
+	return &calculatorService{
+		calculator: experimentcalc.NewExperimentCalculator(
+			stan,
+			environmentClient,
+			eventCounterClient,
+			experimentClient,
+			mysqlClient,
+			metrics,
+			loc,
+			logger,
+		),
+		logger: logger,
+	}
+}
+
+func (c calculatorService) Register(server *grpc.Server) {
+	calculator.RegisterExperimentCalculatorServiceServer(server, c)
+}

pkg/experimentcalculator/api/calculator.go

@@ -0,0 +1,31 @@
+// Copyright 2022 The Bucketeer Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package api
+
+import (
+	"context"
+
+	calculator "github.com/bucketeer-io/bucketeer/proto/experimentcalculator"
+)
+
+func (c calculatorService) CalcExperiment(
+	ctx context.Context,
+	request *calculator.BatchCalcRequest,
+) (*calculator.BatchCalcResponse, error) {
+	resp := &calculator.BatchCalcResponse{}
+	c.calculator.Run(ctx, request)
+	return resp, nil
+}

pkg/experimentcalculator/cmd/server/server.go

@@ -0,0 +1,196 @@
+// Copyright 2022 The Bucketeer Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package server
+
+import (
+	"context"
+	"time"
+
+	"go.uber.org/zap"
+	"gopkg.in/alecthomas/kingpin.v2"
+
+	"github.com/bucketeer-io/bucketeer/pkg/cli"
+	envclient "github.com/bucketeer-io/bucketeer/pkg/environment/client"
+	ecclient "github.com/bucketeer-io/bucketeer/pkg/eventcounter/client"
+	experimentclient "github.com/bucketeer-io/bucketeer/pkg/experiment/client"
+	"github.com/bucketeer-io/bucketeer/pkg/experimentcalculator/api"
+	"github.com/bucketeer-io/bucketeer/pkg/experimentcalculator/stan"
+	"github.com/bucketeer-io/bucketeer/pkg/health"
+	"github.com/bucketeer-io/bucketeer/pkg/locale"
+	"github.com/bucketeer-io/bucketeer/pkg/metrics"
+	"github.com/bucketeer-io/bucketeer/pkg/rpc"
+	"github.com/bucketeer-io/bucketeer/pkg/rpc/client"
+	"github.com/bucketeer-io/bucketeer/pkg/storage/v2/mysql"
+)
+
+const command = "server"
+
+type server struct {
+	*kingpin.CmdClause
+
+	port     *int
+	stanHost *string
+	stanPort *string
+	timezone *string
+
+	mysqlUser   *string
+	mysqlPass   *string
+	mysqlHost   *string
+	mysqlPort   *int
+	mysqlDBName *string
+
+	environmentService  *string
+	experimentService   *string
+	eventCounterService *string
+
+	certPath         *string
+	keyPath          *string
+	serviceTokenPath *string
+}
+
+func RegisterCommand(r cli.CommandRegistry, p cli.ParentCommand) cli.Command {
+	cmd := p.Command(command, "Start calculator server")
+	server := &server{
+		CmdClause:   cmd,
+		port:        cmd.Flag("port", "Port to bind to.").Default("9090").Int(),
+		stanHost:    cmd.Flag("stan-host", "httpstan host.").Default("localhost").String(),
+		stanPort:    cmd.Flag("stan-port", "httpstan port.").Default("8080").String(),
+		timezone:    cmd.Flag("timezone", "Time zone").Required().String(),
+		mysqlUser:   cmd.Flag("mysql-user", "MySQL user.").Required().String(),
+		mysqlPass:   cmd.Flag("mysql-pass", "MySQL password.").Required().String(),
+		mysqlHost:   cmd.Flag("mysql-host", "MySQL host.").Required().String(),
+		mysqlPort:   cmd.Flag("mysql-port", "MySQL port.").Required().Int(),
+		mysqlDBName: cmd.Flag("mysql-db-name", "MySQL database name.").Required().String(),
+		environmentService: cmd.Flag(
+			"environment-service",
+			"bucketeer-environment-service address.",
+		).Default("environment:9090").String(),
+		experimentService: cmd.Flag(
+			"experiment-service",
+			"bucketeer-experiment-service address.",
+		).Default("experiment:9090").String(),
+		eventCounterService: cmd.Flag(
+			"event-counter-service",
+			"bucketeer-event-counter-service address.",
+		).Default("event-counter-server:9090").String(),
+		certPath:         cmd.Flag("cert", "Path to TLS certificate.").Required().String(),
+		keyPath:          cmd.Flag("key", "Path to TLS key.").Required().String(),
+		serviceTokenPath: cmd.Flag("service-token", "Path to service token.").Required().String(),
+	}
+	r.RegisterCommand(server)
+	return server
+}
+
+func (s server) Run(ctx context.Context, metrics metrics.Metrics, logger *zap.Logger) error {
+	registerer := metrics.DefaultRegisterer()
+
+	mysqlClient, err := s.createMySQLClient(ctx, registerer, logger)
+	if err != nil {
+		return err
+	}
+	defer mysqlClient.Close()
+
+	creds, err := client.NewPerRPCCredentials(*s.serviceTokenPath)
+	if err != nil {
+		return err
+	}
+
+	experimentClient, err := experimentclient.NewClient(*s.experimentService, *s.certPath,
+		client.WithPerRPCCredentials(creds),
+		client.WithDialTimeout(30*time.Second),
+		client.WithBlock(),
+		client.WithMetrics(registerer),
+		client.WithLogger(logger),
+	)
+	if err != nil {
+		return err
+	}
+
+	ecClient, err := ecclient.NewClient(*s.eventCounterService, *s.certPath,
+		client.WithPerRPCCredentials(creds),
+		client.WithDialTimeout(30*time.Second),
+		client.WithBlock(),
+		client.WithMetrics(registerer),
+		client.WithLogger(logger),
+	)
+	if err != nil {
+		return err
+	}
+
+	envClient, err := envclient.NewClient(*s.environmentService, *s.certPath,
+		client.WithPerRPCCredentials(creds),
+		client.WithDialTimeout(30*time.Second),
+		client.WithBlock(),
+		client.WithMetrics(registerer),
+		client.WithLogger(logger),
+	)
+	if err != nil {
+		return err
+	}
+
+	location, err := locale.GetLocation(*s.timezone)
+	if err != nil {
+		return err
+	}
+
+	service := api.NewCalculatorService(
+		stan.NewStan(*s.stanHost, *s.stanPort),
+		envClient,
+		ecClient,
+		experimentClient,
+		mysqlClient,
+		registerer,
+		location,
+		logger,
+	)
+
+	healthChecker := health.NewGrpcChecker(
+		health.WithTimeout(time.Second),
+		health.WithCheck("metrics", metrics.Check),
+	)
+	go healthChecker.Run(ctx)
+
+	server := rpc.NewServer(service, *s.certPath, *s.keyPath,
+		"experiment-calculator-server",
+		rpc.WithPort(*s.port),
+		rpc.WithMetrics(registerer),
+		rpc.WithLogger(logger),
+		rpc.WithService(healthChecker),
+		rpc.WithHandler("/health", healthChecker),
+	)
+	defer server.Stop(10 * time.Second)
+	go server.Run()
+
+	<-ctx.Done()
+	return nil
+}
+
+func (s server) createMySQLClient(
+	ctx context.Context,
+	registerer metrics.Registerer,
+	logger *zap.Logger,
+) (mysql.Client, error) {
+	ctx, cancel := context.WithTimeout(ctx, 10*time.Second)
+	defer cancel()
+	return mysql.NewClient(
+		ctx,
+		*s.mysqlUser, *s.mysqlPass, *s.mysqlHost,
+		*s.mysqlPort,
+		*s.mysqlDBName,
+		mysql.WithLogger(logger),
+		mysql.WithMetrics(registerer),
+	)
+}