94 lines
2.2 KiB
Go
94 lines
2.2 KiB
Go
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package sec
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import (
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// stdlib
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"errors"
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"log"
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"os"
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"reflect"
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"strconv"
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"strings"
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)
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var (
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// Errors.
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errNotPTR = errors.New("passed data is not a pointer")
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errNotStructure = errors.New("passed data is not a structure")
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// Debug flag.
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debugFlagEnvName = "SEC_DEBUG"
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debug bool
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// Parsed structure fields.
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parsedTree []*field
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// Options for current run.
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options *Options
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)
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// Parse parses environment variables into passed structure.
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func Parse(structure interface{}, config *Options) error {
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parsedTree = []*field{}
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options = config
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if config == nil {
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options = defaultOptions
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}
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// Set debug flag if defined in environment.
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debugFlagRaw, found := os.LookupEnv(debugFlagEnvName)
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if found {
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var err error
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debug, err = strconv.ParseBool(debugFlagRaw)
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if err != nil {
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log.Println("Invalid '" + debugFlagEnvName + "' environment variable data: '" + debugFlagRaw + "'. Error: " + err.Error())
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if options.ErrorsAreCritical {
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return err
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}
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} else {
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printDebug("Debug mode activated")
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}
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}
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printDebug("Parsing started with configuration: %+v", options)
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value := reflect.ValueOf(structure)
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// Figure out passed data type. We should accept ONLY pointers
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// to structure.
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printDebug("Passed structure kind: %s, want: %s", value.Type().Kind().String(), reflect.Ptr.String())
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// If passed data isn't a pointer - return error in any case because
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// we can't support anything except pointer.
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if value.Type().Kind() != reflect.Ptr {
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return errNotPTR
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}
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printDebug("Passed data kind: %s, want: %s", value.Elem().Type().Kind().String(), reflect.Struct.String())
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value = value.Elem()
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// Passed data should be a pointer to structure. Otherwise we should
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// return error in any case.
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if value.Type().Kind() != reflect.Struct {
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return errNotStructure
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}
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// Parse structure.
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composeTree(value, strings.ToUpper(value.Type().Name()))
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return parseEnv()
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}
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// Produces debug output into stdout using standard log module if debug
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// mode was activated by setting SEC_DEBUG environment variable to true.
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func printDebug(text string, params ...interface{}) {
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if debug {
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if len(params) == 0 {
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log.Println(text)
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} else {
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log.Printf(text, params...)
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}
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}
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}
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