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