Implement method for estimating SQL server database disk usage

mssql/utils.go

@@ -0,0 +1,87 @@
+/*
+Copyright AppsCode Inc. and Contributors
+
+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 mssql
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"k8s.io/klog/v2"
+	"xorm.io/xorm"
+)
+
+var (
+	diskUsageSafetyFactor = 0.10 // Add 10%
+	diskUsageDefaultMi    = 1024 // 1024 Mi
+)
+
+func (xc *XormClient) GetEstimateDatabaseDiskUsage(ctx context.Context, dbName string) (string, error) {
+	session := xc.NewSession().Context(ctx)
+	defer func(session *xorm.Session) {
+		err := session.Close()
+		if err != nil {
+			klog.Error(err)
+		}
+	}(session)
+
+	query := fmt.Sprintf(`USE %s; SELECT 
+        (SELECT SUM(used_log_space_in_bytes) FROM sys.dm_db_log_space_usage) +
+        (SELECT SUM(allocated_extent_page_count)*8*1024 FROM sys.dm_db_file_space_usage) AS total_size`, quoteName(dbName))
+
+	var result struct {
+		TotalSize int64 `xorm:"total_size"`
+	}
+	_, err := session.SQL(query).Get(&result)
+	if err != nil {
+		return "", fmt.Errorf("failed to execute query: %v", err)
+	}
+
+	totalDiskUsageInBytesWithExtra := result.TotalSize + int64(diskUsageSafetyFactor*float64(result.TotalSize))
+	totalDiskUsageInMib := totalDiskUsageInBytesWithExtra / (1024 * 1024)
+	if totalDiskUsageInMib < int64(diskUsageDefaultMi) {
+		totalDiskUsageInMib = int64(diskUsageDefaultMi)
+	}
+	return fmt.Sprintf("%dMi", totalDiskUsageInMib), nil
+}
+
+func quoteName(name string) string {
+	return "[" + strings.ReplaceAll(name, "]", "]]") + "]"
+}
+
+func (xc *XormClient) FetchNonSystemDatabases(ctx context.Context) ([]string, error) {
+	// Create a session from the mssqlClient
+	session := xc.NewSession().Context(ctx)
+	defer func(session *xorm.Session) {
+		err := session.Close()
+		if err != nil {
+			klog.Error(err)
+		}
+	}(session)
+
+	query := "SELECT name FROM sys.databases WHERE name NOT IN ('master', 'tempdb', 'model', 'msdb','kubedb_system')"
+	rows, err := session.Query(query)
+	if err != nil {
+		return nil, fmt.Errorf("failed to execute query: %v", err)
+	}
+
+	var databases []string
+	for _, row := range rows {
+		databases = append(databases, string(row["name"]))
+	}
+	return databases, nil
+}