more work on fixing data access

cmd/root.go

@@ -90,17 +90,9 @@ func runMain(cmd *cobra.Command, args []string) {
 
 	pg := postgres.Open("10.1.0.6", 5432, "kea", "xGq42ZMeMUIWRK", "kea")
 
-	conn, err := pg.Connection(context.Background())
-	if err != nil {
-		slog.Error(err.Error())
-	} else {
-		slog.Info("connected to database")
-	}
-	defer conn.Close(context.Background())
-
 	for _, v := range reslist {
 		v := v
-		if err = v.Insert(conn); err != nil {
+		if err := pg.InsertResV4(v); err != nil {
 			slog.Error(err.Error())
 			continue
 		}

ipv4/reservation/reservation.go

@@ -1,12 +1,7 @@
 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,
@@ -53,33 +48,3 @@ func ReserveV4MacAddr(mac string, addr string, hostname string, subnet int) *Res
 
 	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
-}

lib/database/database.go

@@ -1 +1,9 @@
 package database
+
+import (
+	"git.staur.ca/stobbsm/kea-manage/ipv4/reservation"
+)
+
+type StoreV4 interface {
+	InsertResV4(*reservation.ReservationV4) error
+}

lib/database/postgres/postgres.go

@@ -4,13 +4,17 @@ import (
 	"context"
 	"fmt"
 
+	"git.staur.ca/stobbsm/kea-manage/ipv4/reservation"
 	"github.com/jackc/pgx/v5"
 )
 
 type Postgres struct {
 	connString string
+	conn       *pgx.Conn
 }
 
+// Open receives the host, port, username, password and database name of a postgresql
+// database, and manages connections to it.
 func Open(host string, port int, user string, password string, name string) *Postgres {
 	var p = &Postgres{
 		connString: fmt.Sprintf("postgres://%s:%s@%s:%d/%s", user, password, host, port, name),
@@ -18,6 +22,34 @@ func Open(host string, port int, user string, password string, name string) *Pos
 	return p
 }
 
-func (p *Postgres) Connection(ctx context.Context) (*pgx.Conn, error) {
-	return pgx.Connect(ctx, p.connString)
+func (p *Postgres) connect(ctx context.Context) error {
+	var err error
+	p.conn, err = pgx.Connect(ctx, p.connString)
+	return err
+}
+
+func (p *Postgres) close() {
+	p.conn.Close(context.Background())
+}
+
+func (p *Postgres) InsertResV4(r *reservation.ReservationV4) error {
+	if err := p.connect(context.Background()); err != nil {
+		return err
+	}
+	defer p.close()
+
+	tx, err := p.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
 }

lib/database/postgres/queries.go

@@ -0,0 +1,13 @@
+package postgres
+
+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'));`