53 lines
1.3 KiB
Go
53 lines
1.3 KiB
Go
package main
|
|
|
|
import (
|
|
"time"
|
|
"database/sql"
|
|
_ "github.com/lib/pq"
|
|
"os"
|
|
)
|
|
|
|
func connectDB(retriesLeft int) error {
|
|
con := os.Getenv("POSTGRES")
|
|
logger.Infof("opening connection to postgres: %s", con)
|
|
|
|
var err error
|
|
db, err = sql.Open("postgres", con)
|
|
if err != nil {
|
|
logger.Errorf("cannot open connection to postgres: %v", err)
|
|
return err
|
|
}
|
|
|
|
err = db.Ping()
|
|
if err != nil {
|
|
if retriesLeft > 0 {
|
|
logger.Errorf("cannot talk to postgres, retrying in 10 seconds (%d attempts left): %v", retriesLeft-1, err)
|
|
time.Sleep(10 * time.Second)
|
|
return connectDB(retriesLeft - 1)
|
|
} else {
|
|
logger.Errorf("cannot talk to postgres, last attempt failed: %v", err)
|
|
return err
|
|
}
|
|
}
|
|
|
|
statement := `
|
|
CREATE TABLE IF NOT EXISTS migrations (
|
|
filename TEXT NOT NULL UNIQUE
|
|
);
|
|
`
|
|
_, err = db.Exec(statement)
|
|
if err != nil {
|
|
logger.Errorf("cannot create migrations table: %v", err)
|
|
return err
|
|
}
|
|
|
|
// At most 1000 database connections will be left open in the idle state. This
|
|
// was found to be important when benchmarking with `wrk`: if this was unset,
|
|
// too many open idle connections were present, resulting in dropped requests
|
|
// due to the limit on the number of file handles. On benchmarking, around
|
|
// 100 was found to be pretty optimal.
|
|
db.SetMaxIdleConns(100)
|
|
|
|
return nil
|
|
}
|