func LockDBAndMigrate(logger lager.Logger, sqlDriver string, sqlDataSource string) (db.Conn, error) {
var err error
var dbLockConn db.Conn
var dbConn db.Conn
for {
dbLockConn, err = db.WrapWithError(sql.Open(sqlDriver, sqlDataSource))
if err != nil {
if strings.Contains(err.Error(), " dial ") {
logger.Error("failed-to-open-db-retrying", err)
time.Sleep(5 * time.Second)
continue
}
return nil, err
}
break
}
lockName := crc32.ChecksumIEEE([]byte(sqlDriver + sqlDataSource))
for {
_, err = dbLockConn.Exec(`select pg_advisory_lock($1)`, lockName)
if err != nil {
logger.Error("failed-to-acquire-lock-retrying", err)
time.Sleep(5 * time.Second)
continue
}
logger.Info("migration-lock-acquired")
migrations := Translogrifier(logger, Migrations)
dbConn, err = db.WrapWithError(migration.OpenWith(sqlDriver, sqlDataSource, migrations, safeGetVersion, safeSetVersion))
if err != nil {
logger.Fatal("failed-to-run-migrations", err)
}
_, err = dbLockConn.Exec(`select pg_advisory_unlock($1)`, lockName)
if err != nil {
logger.Error("failed-to-release-lock", err)
}
dbLockConn.Close()
break
}
return dbConn, nil
}
It("returns the return values from the underlying connection", func() {
underlyingConn.PingReturns(errors.New("disaster"))
err := countingConn.Ping()
Expect(err).To(MatchError("disaster"))
})
Describe("query counting", func() {
It("increments the global (;_;) counter", func() {
_, err := countingConn.Query("SELECT $1::int", 1)
Expect(err).NotTo(HaveOccurred())
Expect(metric.DatabaseQueries.Max()).To(Equal(1))
_, err = countingConn.Exec("SELECT $1::int", 1)
Expect(err).NotTo(HaveOccurred())
Expect(metric.DatabaseQueries.Max()).To(Equal(2))
countingConn.QueryRow("SELECT $1::int", 1)
Expect(metric.DatabaseQueries.Max()).To(Equal(3))
By("working in transactions")
underlyingTx := &fakes.FakeTx{}
underlyingConn.BeginReturns(underlyingTx, nil)
tx, err := countingConn.Begin()
Expect(err).NotTo(HaveOccurred())
})
It("logs the output of the explain", func() {
var i int
err := explainConn.QueryRow("SELECT $1::int", 1).Scan(&i)
Ω(err).ShouldNot(HaveOccurred())
Expect(logger).To(gbytes.Say("Result"))
Expect(logger).To(gbytes.Say("cost="))
Expect(logger).To(gbytes.Say("SELECT"))
})
})
Describe("Exec()", func() {
It("EXPLAINs the query", func() {
_, err := explainConn.Exec("SELECT $1::int", 1)
Ω(err).ShouldNot(HaveOccurred())
Ω(underlyingConn.ExecCallCount()).Should(Equal(1))
Ω(underlyingConn.QueryCallCount()).Should(Equal(1))
query, args := underlyingConn.ExecArgsForCall(0)
Ω(query).Should(Equal("SELECT $1::int"))
Ω(args).Should(Equal(varargs(1)))
query, args = underlyingConn.QueryArgsForCall(0)
Ω(query).Should(Equal("EXPLAIN SELECT $1::int"))
Ω(args).Should(Equal(varargs(1)))
})
It("logs the output of the explain", func() {