feat(mysql): add source (#250)

Add `mysql` source.

go.mod

@@ -13,6 +13,7 @@ require (
 	github.com/go-chi/chi/v5 v5.1.0
 	github.com/go-chi/httplog/v2 v2.1.1
 	github.com/go-chi/render v1.0.3
+	github.com/go-sql-driver/mysql v1.8.1
 	github.com/goccy/go-yaml v1.15.13
 	github.com/google/go-cmp v0.6.0
 	github.com/google/uuid v1.6.0
@@ -55,7 +56,6 @@ require (
 	github.com/felixge/httpsnoop v1.0.4 // indirect
 	github.com/go-logr/logr v1.4.2 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
-	github.com/go-sql-driver/mysql v1.8.1 // indirect
 	github.com/golang-sql/civil v0.0.0-20220223132316-b832511892a9 // indirect
 	github.com/golang-sql/sqlexp v0.1.0 // indirect
 	github.com/golang/groupcache v0.0.0-20241129210726-2c02b8208cf8 // indirect

internal/server/config.go

@@ -25,6 +25,7 @@ import (
 	cloudsqlmssqlsrc "github.com/googleapis/genai-toolbox/internal/sources/cloudsqlmssql"
 	cloudsqlmysqlsrc "github.com/googleapis/genai-toolbox/internal/sources/cloudsqlmysql"
 	cloudsqlpgsrc "github.com/googleapis/genai-toolbox/internal/sources/cloudsqlpg"
+	mysqlsrc "github.com/googleapis/genai-toolbox/internal/sources/mysql"
 	neo4jrc "github.com/googleapis/genai-toolbox/internal/sources/neo4j"
 	postgressrc "github.com/googleapis/genai-toolbox/internal/sources/postgres"
 	spannersrc "github.com/googleapis/genai-toolbox/internal/sources/spanner"
@@ -163,6 +164,12 @@ func (c *SourceConfigs) UnmarshalYAML(unmarshal func(interface{}) error) error {
 				return fmt.Errorf("unable to parse as %q: %w", k.Kind, err)
 			}
 			(*c)[name] = actual
+		case mysqlsrc.SourceKind:
+			actual := mysqlsrc.Config{Name: name}
+			if err := u.Unmarshal(&actual); err != nil {
+				return fmt.Errorf("unable to parse as %q: %w", k.Kind, err)
+			}
+			(*c)[name] = actual
 		case spannersrc.SourceKind:
 			actual := spannersrc.Config{Name: name, Dialect: "googlesql"}
 			if err := u.Unmarshal(&actual); err != nil {

internal/sources/mysql/mysql.go

@@ -0,0 +1,95 @@
+// Copyright 2025 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 mysql
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+
+	_ "github.com/go-sql-driver/mysql"
+	"github.com/googleapis/genai-toolbox/internal/sources"
+	"go.opentelemetry.io/otel/trace"
+)
+
+const SourceKind string = "mysql"
+
+// validate interface
+var _ sources.SourceConfig = Config{}
+
+type Config struct {
+	Name     string `yaml:"name"`
+	Kind     string `yaml:"kind"`
+	Host     string `yaml:"host"`
+	Port     string `yaml:"port"`
+	User     string `yaml:"user"`
+	Password string `yaml:"password"`
+	Database string `yaml:"database"`
+}
+
+func (r Config) SourceConfigKind() string {
+	return SourceKind
+}
+
+func (r Config) Initialize(ctx context.Context, tracer trace.Tracer) (sources.Source, error) {
+	pool, err := initMySQLConnectionPool(ctx, tracer, r.Name, r.Host, r.Port, r.User, r.Password, r.Database)
+	if err != nil {
+		return nil, fmt.Errorf("unable to create pool: %w", err)
+	}
+
+	err = pool.PingContext(context.Background())
+	if err != nil {
+		return nil, fmt.Errorf("unable to connect successfully: %w", err)
+	}
+
+	s := &Source{
+		Name: r.Name,
+		Kind: SourceKind,
+		Pool: pool,
+	}
+	return s, nil
+}
+
+var _ sources.Source = &Source{}
+
+type Source struct {
+	Name string `yaml:"name"`
+	Kind string `yaml:"kind"`
+	Pool *sql.DB
+}
+
+func (s *Source) SourceKind() string {
+	return SourceKind
+}
+
+func (s *Source) MySQLPool() *sql.DB {
+	return s.Pool
+}
+
+func initMySQLConnectionPool(ctx context.Context, tracer trace.Tracer, name, host, port, user, pass, dbname string) (*sql.DB, error) {
+	//nolint:all // Reassigned ctx
+	ctx, span := sources.InitConnectionSpan(ctx, tracer, SourceKind, name)
+	defer span.End()
+
+	// Configure the driver to connect to the database
+	dsn := fmt.Sprintf("%s:%s@tcp(%s:%s)/%s?parseTime=true", user, pass, host, port, dbname)
+
+	// Interact with the driver directly as you normally would
+	pool, err := sql.Open("mysql", dsn)
+	if err != nil {
+		return nil, fmt.Errorf("sql.Open: %w", err)
+	}
+	return pool, nil
+}

internal/sources/mysql/mysql_test.go

@@ -0,0 +1,70 @@
+// Copyright 2025 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 mysql_test
+
+import (
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/googleapis/genai-toolbox/internal/server"
+	"github.com/googleapis/genai-toolbox/internal/sources/mysql"
+	"github.com/googleapis/genai-toolbox/internal/testutils"
+	"gopkg.in/yaml.v3"
+)
+
+func TestParseFromYamlCloudSQLMySQL(t *testing.T) {
+	tcs := []struct {
+		desc string
+		in   string
+		want server.SourceConfigs
+	}{
+		{
+			desc: "basic example",
+			in: `
+			sources:
+				my-mysql-instance:
+					kind: mysql
+					host: 0.0.0.0
+					port: my-host
+					database: my_db
+			`,
+			want: server.SourceConfigs{
+				"my-mysql-instance": mysql.Config{
+					Name:     "my-mysql-instance",
+					Kind:     mysql.SourceKind,
+					Host:     "0.0.0.0",
+					Port:     "my-host",
+					Database: "my_db",
+				},
+			},
+		},
+	}
+	for _, tc := range tcs {
+		t.Run(tc.desc, func(t *testing.T) {
+			got := struct {
+				Sources server.SourceConfigs `yaml:"sources"`
+			}{}
+			// Parse contents
+			err := yaml.Unmarshal(testutils.FormatYaml(tc.in), &got)
+			if err != nil {
+				t.Fatalf("unable to unmarshal: %s", err)
+			}
+			if !cmp.Equal(tc.want, got.Sources) {
+				t.Fatalf("incorrect parse: want %v, got %v", tc.want, got.Sources)
+			}
+		})
+	}
+
+}

internal/tools/mysqlsql/mysqlsql.go

@@ -22,6 +22,7 @@ import (
 
 	"github.com/googleapis/genai-toolbox/internal/sources"
 	"github.com/googleapis/genai-toolbox/internal/sources/cloudsqlmysql"
+	"github.com/googleapis/genai-toolbox/internal/sources/mysql"
 	"github.com/googleapis/genai-toolbox/internal/tools"
 )
 
@@ -33,8 +34,9 @@ type compatibleSource interface {
 
 // validate compatible sources are still compatible
 var _ compatibleSource = &cloudsqlmysql.Source{}
+var _ compatibleSource = &mysql.Source{}
 
-var compatibleSources = [...]string{cloudsqlmysql.SourceKind}
+var compatibleSources = [...]string{cloudsqlmysql.SourceKind, mysql.SourceKind}
 
 type Config struct {
 	Name         string           `yaml:"name"`