mdb/msql: implement basic MySQL connector

go.mod

@@ -3,6 +3,8 @@ module github.com/mediocregopher/mediocre-go-lib
 require (
 	cloud.google.com/go v0.36.0
 	github.com/boombuler/barcode v1.0.0 // indirect
+	github.com/go-sql-driver/mysql v1.4.0
+	github.com/jmoiron/sqlx v1.2.0
 	github.com/pquerna/otp v1.1.0
 	github.com/stretchr/testify v1.3.0
 	golang.org/x/net v0.0.0-20190213061140-3a22650c66bd

go.sum

@@ -23,6 +23,8 @@ github.com/flynn/go-shlex v0.0.0-20150515145356-3f9db97f8568/go.mod h1:xEzjJPgXI
 github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
 github.com/ghodss/yaml v1.0.0/go.mod h1:4dBDuWmgqj2HViK6kFavaiC9ZROes6MMH2rRYeMEF04=
 github.com/gliderlabs/ssh v0.1.1/go.mod h1:U7qILu1NlMHj9FlMhZLlkCdDnU1DBEAqr0aevW3Awn0=
+github.com/go-sql-driver/mysql v1.4.0 h1:7LxgVwFb2hIQtMm87NdgAVfXjnt4OePseqT1tKx+opk=
+github.com/go-sql-driver/mysql v1.4.0/go.mod h1:zAC/RDZ24gD3HViQzih4MyKcchzm+sOG5ZlKdlhCg5w=
 github.com/gogo/protobuf v1.1.1/go.mod h1:r8qH/GZQm5c6nD/R0oafs1akxWv10x8SbQlK7atdtwQ=
 github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b h1:VKtxabqXZkF25pY9ekfRL6a582T4P37/31XEstQ5p58=
 github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b/go.mod h1:SBH7ygxi8pfUlaOkMMuAQtPIUF8ecWP5IEl/CR7VP2Q=
@@ -48,11 +50,17 @@ github.com/gopherjs/gopherjs v0.0.0-20181017120253-0766667cb4d1/go.mod h1:wJfORR
 github.com/gregjones/httpcache v0.0.0-20180305231024-9cad4c3443a7/go.mod h1:FecbI9+v66THATjSRHfNgh1IVFe/9kFxbXtjV0ctIMA=
 github.com/grpc-ecosystem/grpc-gateway v1.5.0/go.mod h1:RSKVYQBd5MCa4OVpNdGskqpgL2+G+NZTnrVHpWWfpdw=
 github.com/jellevandenhooff/dkim v0.0.0-20150330215556-f50fe3d243e1/go.mod h1:E0B/fFc00Y+Rasa88328GlI/XbtyysCtTHZS8h7IrBU=
+github.com/jmoiron/sqlx v1.2.0 h1:41Ip0zITnmWNR/vHV+S4m+VoUivnWY5E4OJfLZjCJMA=
+github.com/jmoiron/sqlx v1.2.0/go.mod h1:1FEQNm3xlJgrMD+FBdI9+xvCksHtbpVBBw5dYhBSsks=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/pty v1.1.3/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/lib/pq v1.0.0 h1:X5PMW56eZitiTeO7tKzZxFCSpbFZJtkMMooicw2us9A=
+github.com/lib/pq v1.0.0/go.mod h1:5WUZQaWbwv1U+lTReE5YruASi9Al49XbQIvNi/34Woo=
+github.com/mattn/go-sqlite3 v1.9.0 h1:pDRiWfl+++eC2FEFRy6jXmQlvp4Yh3z1MJKg4UeYM/4=
+github.com/mattn/go-sqlite3 v1.9.0/go.mod h1:FPy6KqzDD04eiIsT53CuJW3U88zkxoIYsOqkbpncsNc=
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
 github.com/microcosm-cc/bluemonday v1.0.1/go.mod h1:hsXNsILzKxV+sX77C5b8FSuKF00vh2OMYv+xgHpAMF4=
 github.com/neelance/astrewrite v0.0.0-20160511093645-99348263ae86/go.mod h1:kHJEU3ofeGjhHklVoIGuVj85JJwZ6kWPaJwCIxgnFmo=

mdb/msql/sql.go

@@ -0,0 +1,58 @@
+// Package msql implements connecting to a MySQL/MariaDB instance (and possibly
+// others) and simplifies a number of interactions with it.
+package msql
+
+import (
+	"context"
+	"fmt"
+
+	// If something is importing msql it must need mysql, because that's all
+	// that is implemented at the moment
+	_ "github.com/go-sql-driver/mysql"
+	"github.com/jmoiron/sqlx"
+	"github.com/mediocregopher/mediocre-go-lib/mcfg"
+	"github.com/mediocregopher/mediocre-go-lib/mctx"
+	"github.com/mediocregopher/mediocre-go-lib/merr"
+	"github.com/mediocregopher/mediocre-go-lib/mlog"
+	"github.com/mediocregopher/mediocre-go-lib/mrun"
+)
+
+// SQL is a wrapper around a sqlx client which provides more functionality.
+type SQL struct {
+	*sqlx.DB
+	ctx context.Context
+}
+
+// WithMySQL returns a SQL instance which will be initialized and configured
+// when the start event is triggered on the returned Context (see mrun.Start).
+// The SQL instance will have Close called on it when the stop event is
+// triggered on the returned Context (see mrun.Stop).
+//
+// defaultDB indicates the name of the database in MySQL to use by default,
+// though it will be overwritable in the config.
+func WithMySQL(parent context.Context, defaultDB string) (context.Context, *SQL) {
+	ctx := mctx.NewChild(parent, "mysql")
+	sql := new(SQL)
+
+	ctx, addr := mcfg.WithString(ctx, "addr", "[::1]:3306", "Address where mysql server can be found")
+	ctx, user := mcfg.WithString(ctx, "user", "root", "User to authenticate to mysql server as")
+	ctx, pass := mcfg.WithString(ctx, "password", "", "Password to authenticate to mysql server with")
+	ctx, db := mcfg.WithString(ctx, "database", defaultDB, "mysql database to use")
+	ctx = mrun.WithStartHook(ctx, func(innerCtx context.Context) error {
+		sql.ctx = mctx.Annotate(sql.ctx, "addr", *addr, "user", *user)
+
+		dsn := fmt.Sprintf("%s:%s@tcp(%s)/%s", *user, *pass, *addr, *db)
+		mlog.Debug("constructed dsn", mctx.Annotate(sql.ctx, "dsn", dsn))
+		mlog.Info("connecting to mysql server", sql.ctx)
+		var err error
+		sql.DB, err = sqlx.ConnectContext(innerCtx, "mysql", dsn)
+		return merr.Wrap(sql.ctx, err)
+	})
+	ctx = mrun.WithStopHook(ctx, func(innerCtx context.Context) error {
+		mlog.Info("closing connection to sql server", sql.ctx)
+		return sql.Close()
+	})
+
+	sql.ctx = ctx
+	return mctx.WithChild(parent, ctx), sql
+}

mdb/msql/sql_test.go

@@ -0,0 +1,18 @@
+package msql
+
+import (
+	. "testing"
+
+	"github.com/mediocregopher/mediocre-go-lib/mtest"
+)
+
+func TestMySQL(t *T) {
+	ctx := mtest.Context()
+	ctx, sql := WithMySQL(ctx, "test")
+	mtest.Run(ctx, t, func() {
+		_, err := sql.Exec("CREATE TABLE IF NOT EXISTS msql_test (id INT);")
+		if err != nil {
+			t.Fatal(err)
+		}
+	})
+}