posterior.go

package main

import (
	"database/sql"
	"errors"
	"fmt"
	_ "github.com/lib/pq"
	_ "go.uber.org/zap"
	"os"
	"strconv"
)

const (
	host     = "localhost"
	port     = 5433
	user     = "herlighet"
	password = "herlighet"
	confdb   = "herlighet"
)

func openDb() *sql.DB {
	psqlInfo := getDbConfString()
	db, err := sql.Open("postgres", psqlInfo)
	if err != nil {
		logger.Error("Failed to connect to herlighet database")
		panic(err)
	}
	err = db.Ping()
	if err != nil {
		logger.Error("Failed to connect to herlighet database")
		panic(err)
	}
	return db
}

func smellTest() {
	var count int
	db := openDb()
	row := db.QueryRow("SELECT COUNT(*) FROM databases;")
	err := row.Scan(&count)
	if err != nil {
		panic(err)
	}
	logger.Info(fmt.Sprintf("%d databases in access list", count))
	db.Close()
}

func getDbConfField(key string, fallback string) string {
	if value, ok := os.LookupEnv(key); ok {
		return value
	}
	os.Setenv(key, fallback)
	logger.Info(fmt.Sprintf(`"%s" is not defined; using fallback value.`, key))
	return fallback
}

func getDbConfString() string {
	user := getDbConfField("HERLIGHET_DBUSER", "herlighet")
	pass := getDbConfField("HERLIGHET_DBPASS", "herlighet")
	host := getDbConfField("HERLIGHET_DBHOST", "localhost")
	port, _ := strconv.Atoi(getDbConfField("HERLIGHET_DBPORT", "5433"))
	dbname := getDbConfField("HERLIGHET_DBNAME", "herlighet")
	logger.Info(fmt.Sprintf("Connecting as %s to %s:%d/%s", user, host, port, dbname))
	return fmt.Sprintf("host=%s port=%d user=%s password=%s dbname=%s sslmode=disable",
		host, port, user, pass, dbname)
}

func getRearEnd(dbname string) (string, error) {
	db := openDb()
	defer db.Close()

	sqlStatement := `SELECT hostname, naisdevice FROM databases WHERE dbname=$1;`

	var hostname string
	var naisdevice bool

	row := db.QueryRow(sqlStatement, dbname)
	switch err := row.Scan(&hostname, &naisdevice); err {
	case sql.ErrNoRows:
		return "", errors.New("naisdevice access not configured for this database; please ask #postgres-på-laptop for help with updating database-iac.")
	case nil:
		if !naisdevice {
			return "", errors.New("naisdevice access disabled for this database; please update database-iac.")
		} else {
			return hostname, nil
		}
	default:
		return "", err
	}
}