PostgreSQL

/*

** Zabbix

** Copyright 2001-2024 Zabbix SIA

**

** Licensed under the Apache License, Version 2.0 (the "License");

** you may not use this file except in compliance with the License.

** You may obtain a copy of the License at

**

**     http://www.apache.org/licenses/LICENSE-2.0

**

** Unless required by applicable law or agreed to in writing, software

** distributed under the License is distributed on an "AS IS" BASIS,

** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

** See the License for the specific language governing permissions and

** limitations under the License.

**/

​

package plugin

​

import (

    "context"

    "database/sql"

    "errors"

    "strconv"

​

    "github.com/jackc/pgx/v4"

    "golang.zabbix.com/sdk/zbxerr"

)

​

// replicationHandler gets info about recovery state if all is OK or nil otherwise.

func replicationHandler(ctx context.Context, conn PostgresClient,

    key string, _ map[string]string, _ ...string) (interface{}, error) {

    var (

        replicationResult int64

        status            int

        query             string

        stringResult      sql.NullString

        inRecovery        bool

    )

​

    switch key {

    case keyReplicationStatus:

        row, err := conn.QueryRow(ctx, `SELECT pg_is_in_recovery()`)

        if err != nil {

            return nil, zbxerr.ErrorCannotFetchData.Wrap(err)

        }

​

        err = row.Scan(&inRecovery)

        if err != nil {

            return nil, zbxerr.ErrorCannotFetchData.Wrap(err)

        }

​

        if inRecovery {

            row, err = conn.QueryRow(ctx, `SELECT COUNT(*) FROM pg_stat_wal_receiver`)

            if err != nil {

                return nil, zbxerr.ErrorCannotFetchData.Wrap(err)

            }

​

            err = row.Scan(&status)

            if err != nil {

                if errors.Is(err, pgx.ErrNoRows) {

                    return nil, zbxerr.ErrorEmptyResult.Wrap(err)

                }