Improve implementation around config (#1122)

* refactor config

* fix saas config

* feat(config): scanmodule for each server in config.toml

* feat(config): enable to specify containersOnly in config.toml

* add new keys of config.toml to discover.go

* fix summary output, logging

config/scanmodule.go

@@ -0,0 +1,97 @@
+package config
+
+import (
+	"strings"
+
+	"golang.org/x/xerrors"
+)
+
+// ScanModule has a type of scan module
+type ScanModule struct {
+	flag byte
+}
+
+const (
+	// OSPkg is scanmodule
+	OSPkg = byte(1 << iota)
+	// WordPress is scanmodule
+	WordPress
+	// Lockfile is scanmodule
+	Lockfile
+	// Port is scanmodule
+	Port
+
+	osPkgStr     = "ospkg"
+	wordPressStr = "wordpress"
+	lockfileStr  = "lockfile"
+	portStr      = "port"
+)
+
+var allModules = []string{osPkgStr, wordPressStr, lockfileStr, portStr}
+
+// Set module
+func (s *ScanModule) Set(f byte) {
+	s.flag |= f
+}
+
+// IsScanOSPkg return whether scanning os pkg
+func (s ScanModule) IsScanOSPkg() bool {
+	return s.flag&OSPkg == OSPkg
+}
+
+// IsScanWordPress return whether scanning wordpress
+func (s ScanModule) IsScanWordPress() bool {
+	return s.flag&WordPress == WordPress
+}
+
+// IsScanLockFile whether scanning lock file
+func (s ScanModule) IsScanLockFile() bool {
+	return s.flag&Lockfile == Lockfile
+}
+
+// IsScanPort whether scanning listening ports
+func (s ScanModule) IsScanPort() bool {
+	return s.flag&Port == Port
+}
+
+// IsZero return the struct value are all false
+func (s ScanModule) IsZero() bool {
+	return !(s.IsScanOSPkg() || s.IsScanWordPress() || s.IsScanLockFile() || s.IsScanPort())
+}
+
+func (s *ScanModule) ensure() error {
+	if s.IsZero() {
+		s.Set(OSPkg)
+		s.Set(WordPress)
+		s.Set(Lockfile)
+		s.Set(Port)
+	} else if !s.IsScanOSPkg() && s.IsScanPort() {
+		return xerrors.New("When specifying the Port, Specify OSPkg as well")
+	}
+	return nil
+}
+
+func setScanModules(server *ServerInfo, d ServerInfo) error {
+	if len(server.ScanModules) == 0 {
+		server.ScanModules = d.ScanModules
+	}
+	for _, m := range server.ScanModules {
+		switch strings.ToLower(m) {
+		case osPkgStr:
+			server.Module.Set(OSPkg)
+		case wordPressStr:
+			server.Module.Set(WordPress)
+		case lockfileStr:
+			server.Module.Set(Lockfile)
+		case portStr:
+			server.Module.Set(Port)
+		default:
+			return xerrors.Errorf("scanMode: %s of %s is invalid. Specify %s",
+				m, server.ServerName, allModules)
+		}
+	}
+	if err := server.Module.ensure(); err != nil {
+		return xerrors.Errorf("%s in %s", err, server.ServerName)
+	}
+	return nil
+}