Add Oracle backend support

README.md

@@ -6,4 +6,17 @@ Kine is an etcdshim that translates etcd API to sqlite, Postgres, Mysql, and dql
 - Can be ran standalone so any k8s (not just k3s) can use Kine
 - Implements a subset of etcdAPI (not usable at all for general purpose etcd)
 - Translates etcdTX calls into the desired API (Create, Update, Delete)
-- Backend drivers for dqlite, sqlite, Postgres, MySQL
+- Backend drivers for dqlite, sqlite, Postgres, MySQL, Oracle (experimental)
+
+### Using Oracle Backend (experimental)
+
+The Oracle backend is backed by [godror/godror](https://github.com/godror/godror), that uses a C-based OCI wrapper,
+so native OCI drivers are still required to start Kine.
+However, as those drivers are proprietary and dynamically linked, you will have to manually download it yourself and 
+point your LD_LIBRARY_PATH to the right direction. 
+
+Oracle has outlined the procedure to use the drivers correctly. You can refer to their documentation 
+[here](https://docs.oracle.com/en/database/oracle/oracle-database/19/lnoci/instant-client.html#GUID-7D65474A-8790-4E81-B535-409010791C2F).
+
+To download the drivers, please go [here](https://www.oracle.com/hk/database/technologies/instant-client/downloads.html)
+and carefully read their licensing terms. (unless you want Oracle to send you the papers)

go.mod

@@ -6,12 +6,14 @@ require (
 	github.com/Rican7/retry v0.1.0
 	github.com/canonical/go-dqlite v1.5.1
 	github.com/go-sql-driver/mysql v1.4.1
+	github.com/godror/godror v0.17.0
 	github.com/lib/pq v1.1.1
 	github.com/mattn/go-sqlite3 v1.10.0
 	github.com/pkg/errors v0.8.1
 	github.com/rancher/wrangler v0.4.0
 	github.com/sirupsen/logrus v1.4.2
 	github.com/urfave/cli v1.21.0
 	go.etcd.io/etcd v0.0.0-20191023171146-3cf2f69b5738
+	golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543
 	google.golang.org/grpc v1.23.1
 )

go.sum

@@ -76,6 +76,8 @@ github.com/globalsign/mgo v0.0.0-20180905125535-1ca0a4f7cbcb/go.mod h1:xkRDCp4j0
 github.com/globalsign/mgo v0.0.0-20181015135952-eeefdecb41b8/go.mod h1:xkRDCp4j0OGD1HRkm4kmhM+pmpv3AKq5SU7GMg4oO/Q=
 github.com/go-kit/kit v0.8.0/go.mod h1:xBxKIO96dXMWWy0MnWVtmwkA9/13aqxPnvrjFYMA2as=
 github.com/go-logfmt/logfmt v0.3.0/go.mod h1:Qt1PoO58o5twSAckw1HlFXLmHsOX5/0LbT9GBnD5lWE=
+github.com/go-logfmt/logfmt v0.5.0 h1:TrB8swr/68K7m9CcGut2g3UOihhbcbiMAYiuTXdEih4=
+github.com/go-logfmt/logfmt v0.5.0/go.mod h1:wCYkCAKZfumFQihp8CzCvQ3paCTfi41vtzG1KdI/P7A=
 github.com/go-logr/logr v0.1.0/go.mod h1:ixOQHD9gLJUVQQ2ZOR7zLEifBX6tGkNJF4QyIY7sIas=
 github.com/go-openapi/analysis v0.0.0-20180825180245-b006789cd277/go.mod h1:k70tL6pCuVxPJOHXQ+wIac1FUrvNkHolPie/cLEU6hI=
 github.com/go-openapi/analysis v0.17.0/go.mod h1:IowGgpVeD0vNm45So8nr+IcQ3pxVtpRoBWb8PVZO0ik=
@@ -123,6 +125,8 @@ github.com/go-openapi/validate v0.19.5/go.mod h1:8DJv2CVJQ6kGNpFW6eV9N3JviE1C85n
 github.com/go-sql-driver/mysql v1.4.1 h1:g24URVg0OFbNUTx9qqY1IRZ9D9z3iPyi5zKhQZpNwpA=
 github.com/go-sql-driver/mysql v1.4.1/go.mod h1:zAC/RDZ24gD3HViQzih4MyKcchzm+sOG5ZlKdlhCg5w=
 github.com/go-stack/stack v1.8.0/go.mod h1:v0f6uXyyMGvRgIKkXu+yp6POWl0qKG85gN/melR3HDY=
+github.com/godror/godror v0.17.0 h1:ClVuKG0qCj6f182BruhwgHS8xCgfpQp35pTrefSq4NE=
+github.com/godror/godror v0.17.0/go.mod h1:DE94Br7LXn4dQGCexePriVrKotR9GkVzPPT5nnm8dj0=
 github.com/gogo/protobuf v1.1.1/go.mod h1:r8qH/GZQm5c6nD/R0oafs1akxWv10x8SbQlK7atdtwQ=
 github.com/gogo/protobuf v1.2.1 h1:/s5zKNz0uPFCZ5hddgPdo2TK2TVrUNMn0OOX8/aZMTE=
 github.com/gogo/protobuf v1.2.1/go.mod h1:hp+jE20tsWTFYpLwKvXlhS1hjn+gTNwPg2I6zVXpSg4=
@@ -146,6 +150,8 @@ github.com/google/btree v1.0.0 h1:0udJVsspx3VBr5FwtLhQQtuAsVc79tTq0ocGIPAU6qo=
 github.com/google/btree v1.0.0/go.mod h1:lNA+9X1NB3Zf8V7Ke586lFgjr2dZNuvo3lPJSGZ5JPQ=
 github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
 github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
+github.com/google/go-cmp v0.4.0 h1:xsAVV57WRhGj6kEIi8ReJzQlHHqcBYCElAvkovg3B/4=
+github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/gofuzz v0.0.0-20161122191042-44d81051d367/go.mod h1:HP5RmnzzSNb993RKQDq4+1A4ia9nllfqcQFTQJedwGI=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
 github.com/google/martian v2.1.0+incompatible/go.mod h1:9I4somxYTbIHy5NJKHRl3wXiIaQGbYVAs8BPL6v8lEs=
@@ -357,6 +363,8 @@ golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20190227155943-e225da77a7e6/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e h1:vcxGaoTs7kV8m5Np9uUNQin4BrLOthgV7252N8V+FwY=
+golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20170830134202-bb24a47a89ea/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
@@ -401,6 +409,8 @@ golang.org/x/tools v0.0.0-20190614205625-5aca471b1d59/go.mod h1:/rFqwRUd4F7ZHNgw
 golang.org/x/tools v0.0.0-20190617190820-da514acc4774/go.mod h1:/rFqwRUd4F7ZHNgwSSTFct+R/Kf4OFW1sUzUTQQTgfc=
 golang.org/x/tools v0.0.0-20190920225731-5eefd052ad72/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gonum.org/v1/gonum v0.0.0-20190331200053-3d26580ed485/go.mod h1:2ltnJ7xHfj0zHS40VVPYEAAMTa3ZGguvHGBSJeRWqE0=
 gonum.org/v1/netlib v0.0.0-20190313105609-8cb42192e0e0/go.mod h1:wa6Ws7BG/ESfp6dHfk7C6KdzKA7wR7u/rKwOGE66zvw=
 gonum.org/v1/netlib v0.0.0-20190331212654-76723241ea4e/go.mod h1:kS+toOQn6AQKjmKJ7gzohV1XkqsFehRA2FbsbkopSuQ=

pkg/drivers/generic/generic.go

@@ -53,7 +53,7 @@ var (
 			GROUP BY mkv.name) maxkv
 	    ON maxkv.id = kv.id
 		WHERE
-			  (kv.deleted = 0 OR ?)
+			  kv.deleted = 0 OR kv.deleted = ?
 		ORDER BY kv.id ASC
 		`, revSQL, compactRevSQL, columns)
 )
@@ -67,6 +67,7 @@ func (s Stripped) String() string {
 
 type ErrRetry func(error) bool
 type TranslateErr func(error) error
+type TranslateLimit func(num int64) string
 
 type ConnectionPoolConfig struct {
 	MaxIdle     int           // zero means defaultMaxIdleConns; negative means 0
@@ -77,23 +78,26 @@ type ConnectionPoolConfig struct {
 type Generic struct {
 	sync.Mutex
 
-	LockWrites            bool
-	LastInsertID          bool
-	DB                    *sql.DB
-	GetCurrentSQL         string
-	GetRevisionSQL        string
-	RevisionSQL           string
-	ListRevisionStartSQL  string
-	GetRevisionAfterSQL   string
-	CountSQL              string
-	AfterSQL              string
-	DeleteSQL             string
-	UpdateCompactSQL      string
-	InsertSQL             string
-	FillSQL               string
-	InsertLastInsertIDSQL string
-	Retry                 ErrRetry
-	TranslateErr          TranslateErr
+	LockWrites             bool
+	LastInsertID           bool
+	InsertReturningInto    bool
+	DB                     *sql.DB
+	GetCurrentSQL          string
+	GetRevisionSQL         string
+	RevisionSQL            string
+	ListRevisionStartSQL   string
+	GetRevisionAfterSQL    string
+	CountSQL               string
+	AfterSQL               string
+	DeleteSQL              string
+	UpdateCompactSQL       string
+	InsertSQL              string
+	FillSQL                string
+	InsertLastInsertIDSQL  string
+	InsertReturningIntoSQL string
+	Retry                  ErrRetry
+	TranslateErr           TranslateErr
+	TranslateLimit         TranslateLimit
 }
 
 func q(sql, param string, numbered bool) string {
@@ -113,17 +117,14 @@ func q(sql, param string, numbered bool) string {
 }
 
 func (d *Generic) Migrate(ctx context.Context) {
-	var (
-		count     = 0
-		countKV   = d.queryRow(ctx, "SELECT COUNT(*) FROM key_value")
-		countKine = d.queryRow(ctx, "SELECT COUNT(*) FROM kine")
-	)
+	var count int64
 
-	if err := countKV.Scan(&count); err != nil || count == 0 {
+	if err := d.queryRow(ctx, "SELECT COUNT(*) FROM key_value").Scan(&count); err != nil || count == 0 {
+		logrus.WithError(err).Debug("no migration request demanded")
 		return
 	}
 
-	if err := countKine.Scan(&count); err != nil || count != 0 {
+	if err := d.queryRow(ctx, "SELECT COUNT(*) FROM kine").Scan(&count); err != nil || count != 0 {
 		return
 	}
 
@@ -234,20 +235,52 @@ func Open(ctx context.Context, driverName, dataSourceName string, connPoolConfig
 
 		FillSQL: q(`INSERT INTO kine(id, name, created, deleted, create_revision, prev_revision, lease, value, old_value)
 			values(?, ?, ?, ?, ?, ?, ?, ?, ?)`, paramCharacter, numbered),
+
+		InsertReturningIntoSQL: q(`INSERT INTO kine(name, created, deleted, create_revision, prev_revision, lease, value, old_value)
+			values(?, ?, ?, ?, ?, ?, ?, ?) RETURNING id INTO ?`, paramCharacter, numbered),
 	}, err
 }
 
-func (d *Generic) query(ctx context.Context, sql string, args ...interface{}) (*sql.Rows, error) {
-	logrus.Tracef("QUERY %v : %s", args, Stripped(sql))
+var limitNum = regexp.MustCompile(`LIMIT[[:space:]]+(\d+)`)
+
+func (d *Generic) doTranslateLimit(sql string) string {
+	if d.TranslateLimit == nil {
+		return sql
+	}
+
+	return limitNum.ReplaceAllStringFunc(sql, func(s string) string {
+		// This should be a necessary condition
+		if n, err := strconv.ParseInt(limitNum.FindStringSubmatch(s)[1], 10, 64); err == nil {
+			return d.TranslateLimit(n)
+		} else {
+			// ???
+			panic(err)
+		}
+	})
+}
+
+func (d *Generic) query(ctx context.Context, sql string, args ...interface{}) (rows *sql.Rows, err error) {
+	sql = d.doTranslateLimit(sql)
+	logrus.
+		WithField("args", args).
+		WithField("sql", Stripped(sql)).
+		WithField("mode", nil).
+		Trace("query")
 	return d.DB.QueryContext(ctx, sql, args...)
 }
 
 func (d *Generic) queryRow(ctx context.Context, sql string, args ...interface{}) *sql.Row {
-	logrus.Tracef("QUERY ROW %v : %s", args, Stripped(sql))
+	sql = d.doTranslateLimit(sql)
+	logrus.
+		WithField("args", args).
+		WithField("sql", Stripped(sql)).
+		WithField("mode", "row").
+		Trace("query")
 	return d.DB.QueryRowContext(ctx, sql, args...)
 }
 
 func (d *Generic) execute(ctx context.Context, sql string, args ...interface{}) (result sql.Result, err error) {
+	sql = d.doTranslateLimit(sql)
 	if d.LockWrites {
 		d.Lock()
 		defer d.Unlock()
@@ -256,9 +289,17 @@ func (d *Generic) execute(ctx context.Context, sql string, args ...interface{})
 	wait := strategy.Backoff(backoff.Linear(100 + time.Millisecond))
 	for i := uint(0); i < 20; i++ {
 		if i > 2 {
-			logrus.Debugf("EXEC (try: %d) %v : %s", i, args, Stripped(sql))
+			logrus.
+				WithField("try", i).
+				WithField("args", args).
+				WithField("sql", Stripped(sql)).
+				Debug("exec")
 		} else {
-			logrus.Tracef("EXEC (try: %d) %v : %s", i, args, Stripped(sql))
+			logrus.
+				WithField("try", i).
+				WithField("args", args).
+				WithField("sql", Stripped(sql)).
+				Trace("exec")
 		}
 		result, err = d.DB.ExecContext(ctx, sql, args...)
 		if err != nil && d.Retry != nil && d.Retry(err) {
@@ -299,7 +340,13 @@ func (d *Generic) ListCurrent(ctx context.Context, prefix string, limit int64, i
 	if limit > 0 {
 		sql = fmt.Sprintf("%s LIMIT %d", sql, limit)
 	}
-	return d.query(ctx, sql, prefix, includeDeleted)
+	// don't ask me why, ask golang
+	return d.query(ctx, sql, prefix, func() int {
+		if includeDeleted {
+			return 1
+		}
+		return 0
+	}())
 }
 
 func (d *Generic) List(ctx context.Context, prefix, startKey string, limit, revision int64, includeDeleted bool) (*sql.Rows, error) {
@@ -308,14 +355,24 @@ func (d *Generic) List(ctx context.Context, prefix, startKey string, limit, revi
 		if limit > 0 {
 			sql = fmt.Sprintf("%s LIMIT %d", sql, limit)
 		}
-		return d.query(ctx, sql, prefix, revision, includeDeleted)
+		return d.query(ctx, sql, prefix, revision, func() int {
+			if includeDeleted {
+				return 1
+			}
+			return 0
+		}())
 	}
 
 	sql := d.GetRevisionAfterSQL
 	if limit > 0 {
 		sql = fmt.Sprintf("%s LIMIT %d", sql, limit)
 	}
-	return d.query(ctx, sql, prefix, revision, startKey, revision, includeDeleted)
+	return d.query(ctx, sql, prefix, revision, startKey, revision, func() int {
+		if includeDeleted {
+			return 1
+		}
+		return 0
+	}())
 }
 
 func (d *Generic) Count(ctx context.Context, prefix string) (int64, int64, error) {
@@ -382,6 +439,15 @@ func (d *Generic) Insert(ctx context.Context, key string, create, delete bool, c
 		return row.LastInsertId()
 	}
 
+	if d.InsertReturningInto {
+		_, err := d.execute(ctx, d.InsertReturningIntoSQL, key, cVal, dVal, createRevision, previousRevision, ttl, value, prevValue, sql.Out{Dest: &id})
+		if err != nil {
+			return 0, err
+		}
+		logrus.WithField("id", id).Debug("insert returning into")
+		return id, nil
+	}
+
 	row := d.queryRow(ctx, d.InsertSQL, key, cVal, dVal, createRevision, previousRevision, ttl, value, prevValue)
 	err = row.Scan(&id)
 	return id, err