func()

in plugins/inputs/sql/sql.go [299:428]

• 100 lines of code
• 27 McCabe index (conditional complexity)

func (s *SQL) Init() error {
	// Option handling
	if s.Driver == "" {
		return errors.New("missing SQL driver option")
	}

	if s.Dsn == "" {
		return errors.New("missing data source name (DSN) option")
	}

	if s.Timeout <= 0 {
		s.Timeout = config.Duration(5 * time.Second)
	}

	if s.MaxIdleConnections == magicIdleCount {
		// Determine the number by the number of queries + the golang default value
		s.MaxIdleConnections = len(s.Queries) + 2
	}

	for i, q := range s.Queries {
		if q.Query == "" && q.Script == "" {
			return errors.New("neither 'query' nor 'query_script' specified")
		}

		if q.Query != "" && q.Script != "" {
			return errors.New("only one of 'query' and 'query_script' can be specified")
		}

		// In case we got a script, we should read the query now.
		if q.Script != "" {
			query, err := os.ReadFile(q.Script)
			if err != nil {
				return fmt.Errorf("reading script %q failed: %v", q.Script, err)
			}
			s.Queries[i].Query = string(query)
		}

		// Time format
		if q.TimeFormat == "" {
			s.Queries[i].TimeFormat = "unix"
		}

		// Compile the tag-filter
		tagfilter, err := filter.NewIncludeExcludeFilterDefaults(q.TagColumnsInclude, q.TagColumnsExclude, false, false)
		if err != nil {
			return fmt.Errorf("creating tag filter failed: %v", err)
		}
		s.Queries[i].tagFilter = tagfilter

		// Compile the explicit type field-filter
		fieldfilterFloat, err := filter.NewIncludeExcludeFilterDefaults(q.FieldColumnsFloat, nil, false, false)
		if err != nil {
			return fmt.Errorf("creating field filter for float failed: %v", err)
		}
		s.Queries[i].fieldFilterFloat = fieldfilterFloat

		fieldfilterInt, err := filter.NewIncludeExcludeFilterDefaults(q.FieldColumnsInt, nil, false, false)
		if err != nil {
			return fmt.Errorf("creating field filter for int failed: %v", err)
		}
		s.Queries[i].fieldFilterInt = fieldfilterInt

		fieldfilterUint, err := filter.NewIncludeExcludeFilterDefaults(q.FieldColumnsUint, nil, false, false)
		if err != nil {
			return fmt.Errorf("creating field filter for uint failed: %v", err)
		}
		s.Queries[i].fieldFilterUint = fieldfilterUint

		fieldfilterBool, err := filter.NewIncludeExcludeFilterDefaults(q.FieldColumnsBool, nil, false, false)
		if err != nil {
			return fmt.Errorf("creating field filter for bool failed: %v", err)
		}
		s.Queries[i].fieldFilterBool = fieldfilterBool

		fieldfilterString, err := filter.NewIncludeExcludeFilterDefaults(q.FieldColumnsString, nil, false, false)
		if err != nil {
			return fmt.Errorf("creating field filter for string failed: %v", err)
		}
		s.Queries[i].fieldFilterString = fieldfilterString

		// Compile the field-filter
		fieldfilter, err := filter.NewIncludeExcludeFilter(q.FieldColumnsInclude, q.FieldColumnsExclude)
		if err != nil {
			return fmt.Errorf("creating field filter failed: %v", err)
		}
		s.Queries[i].fieldFilter = fieldfilter

		if q.Measurement == "" {
			s.Queries[i].Measurement = "sql"
		}
	}

	// Derive the sql-framework driver name from our config name. This abstracts the actual driver
	// from the database-type the user wants.
	aliases := map[string]string{
		"cockroach": "pgx",
		"tidb":      "mysql",
		"mssql":     "sqlserver",
		"maria":     "mysql",
		"postgres":  "pgx",
	}
	s.driverName = s.Driver
	if driver, ok := aliases[s.Driver]; ok {
		s.driverName = driver
	}

	availDrivers := dbsql.Drivers()
	if !choice.Contains(s.driverName, availDrivers) {
		for d, r := range aliases {
			if choice.Contains(r, availDrivers) {
				availDrivers = append(availDrivers, d)
			}
		}

		// Sort the list of drivers and make them unique
		sort.Strings(availDrivers)
		last := 0
		for _, d := range availDrivers {
			if d != availDrivers[last] {
				last++
				availDrivers[last] = d
			}
		}
		availDrivers = availDrivers[:last+1]

		return fmt.Errorf("driver %q not supported use one of %v", s.Driver, availDrivers)
	}

	return nil
}