feat: add basic http server (#6)

cmd/root.go

@@ -15,10 +15,13 @@
 package cmd
 
 import (
+	"context"
 	_ "embed"
+	"fmt"
 	"os"
 	"strings"
 
+	"github.com/googleapis/genai-toolbox/internal/server"
 	"github.com/spf13/cobra"
 )
 
@@ -55,6 +58,7 @@ func Execute() {
 // Command represents an invocation of the CLI.
 type Command struct {
 	*cobra.Command
+	cfg server.Config
 }
 
 // NewCommand returns a Command object representing an invocation of the CLI.
@@ -62,17 +66,27 @@ func NewCommand() *Command {
 	rootCmd := &cobra.Command{
 		Use:     "toolbox",
 		Version: versionString,
-		RunE:    root,
 	}
 
 	c := &Command{
 		Command: rootCmd,
+		cfg: server.Config{},
 	}
+	// wrap RunE command so that we have access to original Command object
+	rootCmd.RunE = func(*cobra.Command, []string) error { return run(c) }
 
 	return c
 }
 
-func root(cmd *cobra.Command, args []string) error {
-	cmd.Printf("Toolbox running v%s!", versionString)
+func run(cmd *Command) error {
+	ctx := context.Background()
+
+	// run server
+	s := server.NewServer(cmd.cfg)
+	err := s.ListenAndServe(ctx)
+	if err != nil {
+		return fmt.Errorf("Error while serving: %w", err)
+	}
+
 	return nil
 }

cmd/root_test.go

@@ -52,5 +52,4 @@ func TestVersion(t *testing.T) {
 	if !strings.Contains(got, want) {
 		t.Errorf("cli did not return correct version: want %q, got %q", want, got)
 	}
-
 }

go.mod

@@ -2,7 +2,10 @@ module github.com/googleapis/genai-toolbox
 
 go 1.22.2
 
-require github.com/spf13/cobra v1.8.1
+require (
+	github.com/go-chi/chi/v5 v5.1.0
+	github.com/spf13/cobra v1.8.1
+)
 
 require (
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect

go.sum

@@ -1,4 +1,6 @@
 github.com/cpuguy83/go-md2man/v2 v2.0.4/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
+github.com/go-chi/chi/v5 v5.1.0 h1:acVI1TYaD+hhedDJ3r54HyA6sExp3HfXq7QWEEY/xMw=
+github.com/go-chi/chi/v5 v5.1.0/go.mod h1:DslCQbL2OYiznFReuXYUmQ2hGd1aDpCnlMNITLSKoi8=
 github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
 github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
 github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=

internal/server/config.go

@@ -0,0 +1,29 @@
+// Copyright 2024 Google LLC
+//
+// 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
+
+type Config struct {
+	// Address is the address of the interface the server will listen on.
+	Address string
+	// Port is the port the server will listen on.
+	Port string
+}
+
+func NewConfig() Config {
+	c := Config{
+		Address: "127.0.0.1",
+		Port:    "5000",
+	}
+	return c
+}

internal/server/server.go

@@ -0,0 +1,63 @@
+// Copyright 2024 Google LLC
+//
+// 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"
+	"fmt"
+	"net"
+	"net/http"
+	"time"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/go-chi/chi/v5/middleware"
+)
+
+// Server contains info for running an instance of Toolbox. Should be instantiated with NewServer().
+type Server struct {
+	conf   Config
+	router chi.Router
+}
+
+// NewServer returns a Server object based on provided Config.
+func NewServer(conf Config) *Server {
+	r := chi.NewRouter()
+	r.Use(middleware.Logger)
+	r.Use(middleware.Recoverer)
+	r.Get("/", func(w http.ResponseWriter, r *http.Request) {
+		_, _ = w.Write([]byte("🧰 Hello world! 🧰"))
+	})
+
+	s := &Server{
+		conf:   conf,
+		router: r,
+	}
+	return s
+}
+
+// ListenAndServe starts an HTTP server for the given Server instance.
+func (s *Server) ListenAndServe(ctx context.Context) error {
+	ctx, cancel := context.WithCancel(ctx)
+	defer cancel()
+
+	addr := net.JoinHostPort(s.conf.Address, s.conf.Port)
+	lc := net.ListenConfig{KeepAlive: 30 * time.Second}
+	l, err := lc.Listen(ctx, "tcp", addr)
+	if err != nil {
+		return fmt.Errorf("failed to open listener for %q: %w", addr, err)
+	}
+
+	return http.Serve(l, s.router)
+}

internal/server/server_test.go

@@ -0,0 +1,62 @@
+// Copyright 2024 Google LLC
+//
+// 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_test
+
+import (
+	"context"
+	"net"
+	"testing"
+	"time"
+
+	"github.com/googleapis/genai-toolbox/internal/server"
+)
+
+// tryDial is a utility function that dials an address up to 'attempts' number of times.
+func tryDial(addr string, attempts int) bool {
+	for i := 0; i < attempts; i++ {
+		conn, err := net.Dial("tcp", addr)
+		if err != nil {
+			time.Sleep(100 * time.Millisecond)
+			continue
+		}
+		_ = conn.Close()
+		return true
+	}
+	return false
+}
+
+func TestListenAndServe(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	host, port := "127.0.0.1", "5000"
+	cfg := server.NewConfig()
+	s := server.NewServer(cfg)
+
+	// start server in background
+	errCh := make(chan error)
+	go func() {
+		err := s.ListenAndServe(ctx)
+		defer close(errCh)
+		if err != nil {
+			errCh <- err
+		}
+	}()
+
+	if !tryDial(net.JoinHostPort(host, port), 10) {
+		t.Fatalf("Unable to dial server!")
+	}
+
+}