package acquisition import ( "errors" "fmt" "io" "os" "strings" "github.com/antonmedv/expr" "github.com/antonmedv/expr/vm" "github.com/google/uuid" "github.com/prometheus/client_golang/prometheus" log "github.com/sirupsen/logrus" tomb "gopkg.in/tomb.v2" "gopkg.in/yaml.v2" "github.com/crowdsecurity/go-cs-lib/pkg/trace" "github.com/crowdsecurity/crowdsec/pkg/acquisition/configuration" cloudwatchacquisition "github.com/crowdsecurity/crowdsec/pkg/acquisition/modules/cloudwatch" dockeracquisition "github.com/crowdsecurity/crowdsec/pkg/acquisition/modules/docker" fileacquisition "github.com/crowdsecurity/crowdsec/pkg/acquisition/modules/file" journalctlacquisition "github.com/crowdsecurity/crowdsec/pkg/acquisition/modules/journalctl" kafkaacquisition "github.com/crowdsecurity/crowdsec/pkg/acquisition/modules/kafka" kinesisacquisition "github.com/crowdsecurity/crowdsec/pkg/acquisition/modules/kinesis" k8sauditacquisition "github.com/crowdsecurity/crowdsec/pkg/acquisition/modules/kubernetesaudit" s3acquisition "github.com/crowdsecurity/crowdsec/pkg/acquisition/modules/s3" syslogacquisition "github.com/crowdsecurity/crowdsec/pkg/acquisition/modules/syslog" wineventlogacquisition "github.com/crowdsecurity/crowdsec/pkg/acquisition/modules/wineventlog" "github.com/crowdsecurity/crowdsec/pkg/exprhelpers" "github.com/crowdsecurity/crowdsec/pkg/csconfig" "github.com/crowdsecurity/crowdsec/pkg/types" ) type DataSourceUnavailableError struct { Name string Err error } func (e *DataSourceUnavailableError) Error() string { return fmt.Sprintf("datasource '%s' is not available: %v", e.Name, e.Err) } func (e *DataSourceUnavailableError) Unwrap() error { return e.Err } // The interface each datasource must implement type DataSource interface { GetMetrics() []prometheus.Collector // Returns pointers to metrics that are managed by the module GetAggregMetrics() []prometheus.Collector // Returns pointers to metrics that are managed by the module (aggregated mode, limits cardinality) UnmarshalConfig([]byte) error // Decode and pre-validate the YAML datasource - anything that can be checked before runtime Configure([]byte, *log.Entry) error // Complete the YAML datasource configuration and perform runtime checks. ConfigureByDSN(string, map[string]string, *log.Entry, string) error // Configure the datasource GetMode() string // Get the mode (TAIL, CAT or SERVER) GetName() string // Get the name of the module OneShotAcquisition(chan types.Event, *tomb.Tomb) error // Start one shot acquisition(eg, cat a file) StreamingAcquisition(chan types.Event, *tomb.Tomb) error // Start live acquisition (eg, tail a file) CanRun() error // Whether the datasource can run or not (eg, journalctl on BSD is a non-sense) GetUuid() string // Get the unique identifier of the datasource Dump() interface{} } var AcquisitionSources = map[string]func() DataSource{ "file": func() DataSource { return &fileacquisition.FileSource{} }, "journalctl": func() DataSource { return &journalctlacquisition.JournalCtlSource{} }, "cloudwatch": func() DataSource { return &cloudwatchacquisition.CloudwatchSource{} }, "syslog": func() DataSource { return &syslogacquisition.SyslogSource{} }, "docker": func() DataSource { return &dockeracquisition.DockerSource{} }, "kinesis": func() DataSource { return &kinesisacquisition.KinesisSource{} }, "wineventlog": func() DataSource { return &wineventlogacquisition.WinEventLogSource{} }, "kafka": func() DataSource { return &kafkaacquisition.KafkaSource{} }, "k8s-audit": func() DataSource { return &k8sauditacquisition.KubernetesAuditSource{} }, "s3": func() DataSource { return &s3acquisition.S3Source{} }, } var transformRuntimes = map[string]*vm.Program{} func GetDataSourceIface(dataSourceType string) DataSource { source := AcquisitionSources[dataSourceType] if source == nil { return nil } return source() } // DataSourceConfigure creates and returns a DataSource object from a configuration, // if the configuration is not valid it returns an error. // If the datasource can't be run (eg. journalctl not available), it still returns an error which // can be checked for the appropriate action. func DataSourceConfigure(commonConfig configuration.DataSourceCommonCfg) (*DataSource, error) { // we dump it back to []byte, because we want to decode the yaml blob twice: // once to DataSourceCommonCfg, and then later to the dedicated type of the datasource yamlConfig, err := yaml.Marshal(commonConfig) if err != nil { return nil, fmt.Errorf("unable to marshal back interface: %w", err) } if dataSrc := GetDataSourceIface(commonConfig.Source); dataSrc != nil { /* this logger will then be used by the datasource at runtime */ clog := log.New() if err := types.ConfigureLogger(clog); err != nil { return nil, fmt.Errorf("while configuring datasource logger: %w", err) } if commonConfig.LogLevel != nil { clog.SetLevel(*commonConfig.LogLevel) } customLog := log.Fields{ "type": commonConfig.Source, } if commonConfig.Name != "" { customLog["name"] = commonConfig.Name } subLogger := clog.WithFields(customLog) /* check eventual dependencies are satisfied (ie. journald will check journalctl availability) */ if err := dataSrc.CanRun(); err != nil { return nil, &DataSourceUnavailableError{Name: commonConfig.Source, Err: err} } /* configure the actual datasource */ if err := dataSrc.Configure(yamlConfig, subLogger); err != nil { return nil, fmt.Errorf("failed to configure datasource %s: %w", commonConfig.Source, err) } return &dataSrc, nil } return nil, fmt.Errorf("cannot find source %s", commonConfig.Source) } // detectBackwardCompatAcquis: try to magically detect the type for backward compat (type was not mandatory then) func detectBackwardCompatAcquis(sub configuration.DataSourceCommonCfg) string { if _, ok := sub.Config["filename"]; ok { return "file" } if _, ok := sub.Config["filenames"]; ok { return "file" } if _, ok := sub.Config["journalctl_filter"]; ok { return "journalctl" } return "" } func LoadAcquisitionFromDSN(dsn string, labels map[string]string, transformExpr string) ([]DataSource, error) { var sources []DataSource frags := strings.Split(dsn, ":") if len(frags) == 1 { return nil, fmt.Errorf("%s isn't valid dsn (no protocol)", dsn) } dataSrc := GetDataSourceIface(frags[0]) if dataSrc == nil { return nil, fmt.Errorf("no acquisition for protocol %s://", frags[0]) } /* this logger will then be used by the datasource at runtime */ clog := log.New() if err := types.ConfigureLogger(clog); err != nil { return nil, fmt.Errorf("while configuring datasource logger: %w", err) } subLogger := clog.WithFields(log.Fields{ "type": dsn, }) uniqueId := uuid.NewString() if transformExpr != "" { vm, err := expr.Compile(transformExpr, exprhelpers.GetExprOptions(map[string]interface{}{"evt": &types.Event{}})...) if err != nil { return nil, fmt.Errorf("while compiling transform expression '%s': %w", transformExpr, err) } transformRuntimes[uniqueId] = vm } err := dataSrc.ConfigureByDSN(dsn, labels, subLogger, uniqueId) if err != nil { return nil, fmt.Errorf("while configuration datasource for %s: %w", dsn, err) } sources = append(sources, dataSrc) return sources, nil } // LoadAcquisitionFromFile unmarshals the configuration item and checks its availability func LoadAcquisitionFromFile(config *csconfig.CrowdsecServiceCfg) ([]DataSource, error) { var sources []DataSource for _, acquisFile := range config.AcquisitionFiles { log.Infof("loading acquisition file : %s", acquisFile) yamlFile, err := os.Open(acquisFile) if err != nil { return nil, err } dec := yaml.NewDecoder(yamlFile) dec.SetStrict(true) idx := -1 for { var sub configuration.DataSourceCommonCfg err = dec.Decode(&sub) idx += 1 if err != nil { if !errors.Is(err, io.EOF) { return nil, fmt.Errorf("failed to yaml decode %s: %w", acquisFile, err) } log.Tracef("End of yaml file") break } //for backward compat ('type' was not mandatory, detect it) if guessType := detectBackwardCompatAcquis(sub); guessType != "" { sub.Source = guessType } //it's an empty item, skip it if len(sub.Labels) == 0 { if sub.Source == "" { log.Debugf("skipping empty item in %s", acquisFile) continue } return nil, fmt.Errorf("missing labels in %s (position: %d)", acquisFile, idx) } if sub.Source == "" { return nil, fmt.Errorf("data source type is empty ('source') in %s (position: %d)", acquisFile, idx) } if GetDataSourceIface(sub.Source) == nil { return nil, fmt.Errorf("unknown data source %s in %s (position: %d)", sub.Source, acquisFile, idx) } uniqueId := uuid.NewString() sub.UniqueId = uniqueId src, err := DataSourceConfigure(sub) if err != nil { var dserr *DataSourceUnavailableError if errors.As(err, &dserr) { log.Error(err) continue } return nil, fmt.Errorf("while configuring datasource of type %s from %s (position: %d): %w", sub.Source, acquisFile, idx, err) } if sub.TransformExpr != "" { vm, err := expr.Compile(sub.TransformExpr, exprhelpers.GetExprOptions(map[string]interface{}{"evt": &types.Event{}})...) if err != nil { return nil, fmt.Errorf("while compiling transform expression '%s' for datasource %s in %s (position: %d): %w", sub.TransformExpr, sub.Source, acquisFile, idx, err) } transformRuntimes[uniqueId] = vm } sources = append(sources, *src) } } return sources, nil } func GetMetrics(sources []DataSource, aggregated bool) error { var metrics []prometheus.Collector for i := 0; i < len(sources); i++ { if aggregated { metrics = sources[i].GetMetrics() } else { metrics = sources[i].GetAggregMetrics() } for _, metric := range metrics { if err := prometheus.Register(metric); err != nil { if _, ok := err.(prometheus.AlreadyRegisteredError); !ok { return fmt.Errorf("could not register metrics for datasource %s: %w", sources[i].GetName(), err) } // ignore the error } } } return nil } func transform(transformChan chan types.Event, output chan types.Event, AcquisTomb *tomb.Tomb, transformRuntime *vm.Program, logger *log.Entry) { defer trace.CatchPanic("crowdsec/acquis") logger.Infof("transformer started") for { select { case <-AcquisTomb.Dying(): logger.Debugf("transformer is dying") return case evt := <-transformChan: logger.Tracef("Received event %s", evt.Line.Raw) out, err := expr.Run(transformRuntime, map[string]interface{}{"evt": &evt}) if err != nil { logger.Errorf("while running transform expression: %s, sending event as-is", err) output <- evt } if out == nil { logger.Errorf("transform expression returned nil, sending event as-is") output <- evt } switch v := out.(type) { case string: logger.Tracef("transform expression returned %s", v) evt.Line.Raw = v output <- evt case []interface{}: logger.Tracef("transform expression returned %v", v) //nolint:asasalint // We actually want to log the slice content for _, line := range v { l, ok := line.(string) if !ok { logger.Errorf("transform expression returned []interface{}, but cannot assert an element to string") output <- evt continue } evt.Line.Raw = l output <- evt } case []string: logger.Tracef("transform expression returned %v", v) for _, line := range v { evt.Line.Raw = line output <- evt } default: logger.Errorf("transform expression returned an invalid type %T, sending event as-is", out) output <- evt } } } } func StartAcquisition(sources []DataSource, output chan types.Event, AcquisTomb *tomb.Tomb) error { // Don't wait if we have no sources, as it will hang forever if len(sources) == 0 { return nil } for i := 0; i < len(sources); i++ { subsrc := sources[i] //ensure its a copy log.Debugf("starting one source %d/%d ->> %T", i, len(sources), subsrc) AcquisTomb.Go(func() error { defer trace.CatchPanic("crowdsec/acquis") var err error outChan := output log.Debugf("datasource %s UUID: %s", subsrc.GetName(), subsrc.GetUuid()) if transformRuntime, ok := transformRuntimes[subsrc.GetUuid()]; ok { log.Infof("transform expression found for datasource %s", subsrc.GetName()) transformChan := make(chan types.Event) outChan = transformChan transformLogger := log.WithFields(log.Fields{ "component": "transform", "datasource": subsrc.GetName(), }) AcquisTomb.Go(func() error { transform(outChan, output, AcquisTomb, transformRuntime, transformLogger) return nil }) } if subsrc.GetMode() == configuration.TAIL_MODE { err = subsrc.StreamingAcquisition(outChan, AcquisTomb) } else { err = subsrc.OneShotAcquisition(outChan, AcquisTomb) } if err != nil { //if one of the acqusition returns an error, we kill the others to properly shutdown AcquisTomb.Kill(err) } return nil }) } /*return only when acquisition is over (cat) or never (tail)*/ err := AcquisTomb.Wait() return err }