Zabbix

/*

** Zabbix

** Copyright (C) 2001-2022 Zabbix SIA

**

** This program is free software; you can redistribute it and/or modify

** it under the terms of the GNU General Public License as published by

** the Free Software Foundation; either version 2 of the License, or

** (at your option) any later version.

**

** This program is distributed in the hope that it will be useful,

** but WITHOUT ANY WARRANTY; without even the implied warranty of

** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

** GNU General Public License for more details.

**

** You should have received a copy of the GNU General Public License

** along with this program; if not, write to the Free Software

** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

**/

​

package postgres

​

import (

    "context"

    "encoding/json"

    "errors"

    "strings"

​

    "git.zabbix.com/ap/plugin-support/zbxerr"

    "github.com/jackc/pgx/v4"

)

​

// customQueryHandler executes custom user queries from *.sql files.

func customQueryHandler(ctx context.Context, conn PostgresClient,

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

    queryName := params["QueryName"]

​

    queryArgs := make([]interface{}, len(extraParams))

    for i, v := range extraParams {

        queryArgs[i] = v

    }

​

    rows, err := conn.QueryByName(ctx, queryName, queryArgs...)

    if err != nil {

        return nil, zbxerr.ErrorCannotFetchData.Wrap(err)

    }

    defer rows.Close()

​

    // JSON marshaling

    var data []string

​

    columns, err := rows.Columns()

    if err != nil {

        return nil, zbxerr.ErrorCannotFetchData.Wrap(err)

    }

​

    values := make([]interface{}, len(columns))

    valuePointers := make([]interface{}, len(values))

​

    for i := range values {

        valuePointers[i] = &values[i]

    }

​

    results := make(map[string]interface{})

​

    for rows.Next() {

        err = rows.Scan(valuePointers...)

        if err != nil {

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

                return nil, zbxerr.ErrorEmptyResult.Wrap(err)

            }

​

            return nil, zbxerr.ErrorCannotFetchData.Wrap(err)

        }

​

        setResult(results, values, columns)

​

        jsonRes, err := json.Marshal(results)

        if err != nil {

            return nil, err

        }

​

        data = append(data, strings.TrimSpace(string(jsonRes)))

    }

​

    // Any errors encountered by rows.Next or rows.Scan will be returned here

    if rows.Err() != nil {

        return nil, err

    }

​

    return "[" + strings.Join(data, ",") + "]", nil

}