kea-manage/ipv4/reservation/reservation.go

package reservation

import (
	"context"
	"errors"
	"log/slog"

	"git.staur.ca/stobbsm/kea-manage/lib/types"
	"github.com/jackc/pgx/v5"
)

const insertHostReservation = `INSERT INTO hosts (dhcp_identifier,
    dhcp_identifier_type,
    dhcp4_subnet_id,
    ipv4_address,
    hostname)
	VALUES (DECODE(REPLACE($1, ':', ''), 'hex'), $2, $3, (SELECT ($4::inet - '0.0.0.0'::inet)), $5);`

const getHostIDWithMacAddr = `SELECT host_id
	FROM hosts
	WHERE dhcp4_subnet_id = $1
	AND dhcp_identifier_type = $2
	AND dhcp_identifier = (DECODE(REPLACE($3, ':', ''), 'hex'));`

const insertIfNotExists = `INSERT INTO hosts (dhcp_identifier,
    dhcp_identifier_type,
    dhcp4_subnet_id,
    ipv4_address,
    hostname)
	SELECT DECODE(REPLACE($1, ':', ''), 'hex'), $2, $3, (SELECT ($4::inet - '0.0.0.0'::inet)), $5
	WHERE NOT EXISTS (
	SELECT host_id FROM hosts
	WHERE dhcp4_subnet_id = $3
	AND dhcp_identifier_type = $2
	AND dhcp_identifier = DECODE(REPLACE($1, ':', ''), 'hex'));`

type ReservationV4 struct {
	Type     int
	SubnetID int
	MacAddr  string
	Ipv4     string
	Hostname string
}

func ReserveV4MacAddr(mac string, addr string, hostname string, subnet int) *ReservationV4 {
	r := &ReservationV4{
		MacAddr:  mac,
		Type:     int(types.MacAddress),
		SubnetID: subnet,
		Ipv4:     addr,
		Hostname: hostname,
	}

	return r
}

func (r *ReservationV4) check(conn *pgx.Conn) error {
	rows, err := conn.Query(context.Background(), getHostIDWithMacAddr, r.SubnetID, r.Type, r.MacAddr)
	if err != nil {
		slog.Error("error during check query")
		return err
	}
	slog.Info("check result size")
	if rv, _ := rows.Values(); len(rv) > 0 {
		return errors.New("existing record found")
	}
	return nil
}

func (r *ReservationV4) Insert(conn *pgx.Conn) error {
	tx, err := conn.Begin(context.Background())
	if err != nil {
		return err
	}
	defer tx.Rollback(context.Background())

	if _, err = tx.Exec(context.Background(), insertIfNotExists, r.MacAddr, r.Type, r.SubnetID, r.Ipv4, r.Hostname); err != nil {
		return err
	}

	if err = tx.Commit(context.Background()); err != nil {
		return err
	}
	return nil
}