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package postgres |
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|
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import ( |
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"encoding/json" |
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"fmt" |
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"os" |
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"time" |
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|
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"github.com/flynn/flynn/Godeps/_workspace/src/github.com/jackc/pgx" |
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"github.com/flynn/flynn/discoverd/client" |
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"github.com/flynn/flynn/pkg/attempt" |
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"github.com/flynn/flynn/pkg/dialer" |
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"github.com/flynn/flynn/pkg/shutdown" |
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"github.com/flynn/flynn/pkg/sirenia/state" |
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) |
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|
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const ( |
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InvalidTextRepresentation = "22P02" |
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CheckViolation = "23514" |
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UniqueViolation = "23505" |
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RaiseException = "P0001" |
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ForeignKeyViolation = "23503" |
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) |
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|
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type Conf struct { |
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Service string |
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User string |
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Password string |
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Database string |
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} |
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|
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var connectAttempts = attempt.Strategy{ |
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Min: 5, |
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Total: 5 * time.Minute, |
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Delay: 200 * time.Millisecond, |
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} |
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|
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func New(connPool *pgx.ConnPool, conf *Conf) *DB { |
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return &DB{connPool, conf} |
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} |
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|
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func Wait(conf *Conf, afterConn func(*pgx.Conn) error) *DB { |
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if conf == nil { |
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conf = &Conf{ |
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Service: os.Getenv("FLYNN_POSTGRES"), |
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User: os.Getenv("PGUSER"), |
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Password: os.Getenv("PGPASSWORD"), |
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Database: os.Getenv("PGDATABASE"), |
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} |
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} |
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events := make(chan *discoverd.Event) |
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stream, err := discoverd.NewService(conf.Service).Watch(events) |
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if err != nil { |
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shutdown.Fatal(err) |
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} |
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// wait for service meta that has sync or singleton primary |
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for e := range events { |
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if e.Kind&discoverd.EventKindServiceMeta == 0 || e.ServiceMeta == nil || len(e.ServiceMeta.Data) == 0 { |
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continue |
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} |
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state := &state.State{} |
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json.Unmarshal(e.ServiceMeta.Data, state) |
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if state.Singleton || state.Sync != nil { |
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break |
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} |
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} |
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stream.Close() |
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// TODO(titanous): handle discoverd disconnection |
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|
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// retry here as authentication may fail if DB is still |
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// starting up. |
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// TODO(jpg): switch this to use pgmanager to check if user |
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// exists, we can also check for r/w with pgmanager |
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var db *DB |
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err = connectAttempts.Run(func() error { |
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db, err = Open(conf, afterConn) |
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return err |
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}) |
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if err != nil { |
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panic(err) |
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} |
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for { |
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var readonly string |
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// wait until read-write transactions are allowed |
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if err := db.QueryRow("SHOW default_transaction_read_only").Scan(&readonly); err != nil || readonly == "on" { |
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time.Sleep(100 * time.Millisecond) |
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// TODO(titanous): add max wait here |
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continue |
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} |
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return db |
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} |
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} |
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|
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func Open(conf *Conf, afterConn func(*pgx.Conn) error) (*DB, error) { |
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connConfig := pgx.ConnConfig{ |
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Host: fmt.Sprintf("leader.%s.discoverd", conf.Service), |
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User: conf.User, |
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Database: conf.Database, |
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Password: conf.Password, |
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Dial: dialer.Retry.Dial, |
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} |
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connPool, err := pgx.NewConnPool(pgx.ConnPoolConfig{ |
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ConnConfig: connConfig, |
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AfterConnect: afterConn, |
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MaxConnections: 20, |
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}) |
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db := &DB{connPool, conf} |
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return db, err |
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} |
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|
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type DB struct { |
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*pgx.ConnPool |
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conf *Conf |
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} |
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|
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func (db *DB) Exec(query string, args ...interface{}) error { |
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_, err := db.ConnPool.Exec(query, args...) |
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return err |
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} |
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|
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func (db *DB) ExecRetry(query string, args ...interface{}) error { |
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retries := 0 |
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max := 30 |
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for { |
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_, err := db.ConnPool.Exec(query, args...) |
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if err == pgx.ErrDeadConn && retries < max { |
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retries++ |
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time.Sleep(1 * time.Second) |
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continue |
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} |
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return err |
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} |
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} |
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|
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type Scanner interface { |
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Scan(...interface{}) error |
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} |
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|
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func (db *DB) QueryRow(query string, args ...interface{}) Scanner { |
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return rowErrFixer{db.ConnPool.QueryRow(query, args...)} |
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} |
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|
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func (db *DB) Begin() (*DBTx, error) { |
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tx, err := db.ConnPool.Begin() |
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return &DBTx{tx}, err |
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} |
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|
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type DBTx struct{ *pgx.Tx } |
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|
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func (tx *DBTx) Exec(query string, args ...interface{}) error { |
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_, err := tx.Tx.Exec(query, args...) |
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return err |
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} |
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|
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func (tx *DBTx) QueryRow(query string, args ...interface{}) Scanner { |
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return rowErrFixer{tx.Tx.QueryRow(query, args...)} |
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} |
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|
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type rowErrFixer struct { |
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s Scanner |
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} |
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|
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func (f rowErrFixer) Scan(args ...interface{}) error { |
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err := f.s.Scan(args...) |
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if e, ok := err.(pgx.PgError); ok && e.Code == InvalidTextRepresentation && e.File == "uuid.c" && e.Routine == "string_to_uuid" { |
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// invalid input syntax for uuid |
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err = pgx.ErrNoRows |
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} |
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return err |
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} |
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|
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func IsUniquenessError(err error, constraint string) bool { |
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if e, ok := err.(pgx.PgError); ok && e.Code == UniqueViolation { |
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return constraint == "" || constraint == e.ConstraintName |
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} |
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return false |
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} |
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|
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func IsPostgresCode(err error, code string) bool { |
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if e, ok := err.(pgx.PgError); ok && e.Code == code { |
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return true |
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} |
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return false |
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} |
