a910b7beca
This on the other hand, gives a new fatal error when there are no valid datasources. In the previous version, crowdsec kept running with just a warning if no acquisition yaml or dir were specified.
362 lines
13 KiB
Go
362 lines
13 KiB
Go
package acquisition
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import (
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"errors"
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"fmt"
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"io"
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"os"
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"strings"
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"github.com/antonmedv/expr"
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"github.com/antonmedv/expr/vm"
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"github.com/google/uuid"
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"github.com/prometheus/client_golang/prometheus"
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log "github.com/sirupsen/logrus"
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tomb "gopkg.in/tomb.v2"
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"gopkg.in/yaml.v2"
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"github.com/crowdsecurity/go-cs-lib/pkg/trace"
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"github.com/crowdsecurity/crowdsec/pkg/acquisition/configuration"
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cloudwatchacquisition "github.com/crowdsecurity/crowdsec/pkg/acquisition/modules/cloudwatch"
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dockeracquisition "github.com/crowdsecurity/crowdsec/pkg/acquisition/modules/docker"
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fileacquisition "github.com/crowdsecurity/crowdsec/pkg/acquisition/modules/file"
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journalctlacquisition "github.com/crowdsecurity/crowdsec/pkg/acquisition/modules/journalctl"
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kafkaacquisition "github.com/crowdsecurity/crowdsec/pkg/acquisition/modules/kafka"
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kinesisacquisition "github.com/crowdsecurity/crowdsec/pkg/acquisition/modules/kinesis"
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k8sauditacquisition "github.com/crowdsecurity/crowdsec/pkg/acquisition/modules/kubernetesaudit"
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s3acquisition "github.com/crowdsecurity/crowdsec/pkg/acquisition/modules/s3"
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syslogacquisition "github.com/crowdsecurity/crowdsec/pkg/acquisition/modules/syslog"
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wineventlogacquisition "github.com/crowdsecurity/crowdsec/pkg/acquisition/modules/wineventlog"
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"github.com/crowdsecurity/crowdsec/pkg/exprhelpers"
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"github.com/crowdsecurity/crowdsec/pkg/csconfig"
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"github.com/crowdsecurity/crowdsec/pkg/types"
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)
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type DataSourceUnavailableError struct {
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Name string
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Err error
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}
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func (e *DataSourceUnavailableError) Error() string {
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return fmt.Sprintf("datasource '%s' is not available: %v", e.Name, e.Err)
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}
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func (e *DataSourceUnavailableError) Unwrap() error {
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return e.Err
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}
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// The interface each datasource must implement
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type DataSource interface {
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GetMetrics() []prometheus.Collector // Returns pointers to metrics that are managed by the module
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GetAggregMetrics() []prometheus.Collector // Returns pointers to metrics that are managed by the module (aggregated mode, limits cardinality)
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UnmarshalConfig([]byte) error // Decode and pre-validate the YAML datasource - anything that can be checked before runtime
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Configure([]byte, *log.Entry) error // Complete the YAML datasource configuration and perform runtime checks.
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ConfigureByDSN(string, map[string]string, *log.Entry, string) error // Configure the datasource
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GetMode() string // Get the mode (TAIL, CAT or SERVER)
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GetName() string // Get the name of the module
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OneShotAcquisition(chan types.Event, *tomb.Tomb) error // Start one shot acquisition(eg, cat a file)
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StreamingAcquisition(chan types.Event, *tomb.Tomb) error // Start live acquisition (eg, tail a file)
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CanRun() error // Whether the datasource can run or not (eg, journalctl on BSD is a non-sense)
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GetUuid() string // Get the unique identifier of the datasource
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Dump() interface{}
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}
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var AcquisitionSources = map[string]func() DataSource{
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"file": func() DataSource { return &fileacquisition.FileSource{} },
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"journalctl": func() DataSource { return &journalctlacquisition.JournalCtlSource{} },
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"cloudwatch": func() DataSource { return &cloudwatchacquisition.CloudwatchSource{} },
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"syslog": func() DataSource { return &syslogacquisition.SyslogSource{} },
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"docker": func() DataSource { return &dockeracquisition.DockerSource{} },
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"kinesis": func() DataSource { return &kinesisacquisition.KinesisSource{} },
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"wineventlog": func() DataSource { return &wineventlogacquisition.WinEventLogSource{} },
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"kafka": func() DataSource { return &kafkaacquisition.KafkaSource{} },
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"k8s-audit": func() DataSource { return &k8sauditacquisition.KubernetesAuditSource{} },
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"s3": func() DataSource { return &s3acquisition.S3Source{} },
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}
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var transformRuntimes = map[string]*vm.Program{}
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func GetDataSourceIface(dataSourceType string) DataSource {
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source := AcquisitionSources[dataSourceType]
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if source == nil {
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return nil
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}
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return source()
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}
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// DataSourceConfigure creates and returns a DataSource object from a configuration,
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// if the configuration is not valid it returns an error.
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// If the datasource can't be run (eg. journalctl not available), it still returns an error which
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// can be checked for the appropriate action.
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func DataSourceConfigure(commonConfig configuration.DataSourceCommonCfg) (*DataSource, error) {
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// we dump it back to []byte, because we want to decode the yaml blob twice:
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// once to DataSourceCommonCfg, and then later to the dedicated type of the datasource
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yamlConfig, err := yaml.Marshal(commonConfig)
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if err != nil {
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return nil, fmt.Errorf("unable to marshal back interface: %w", err)
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}
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if dataSrc := GetDataSourceIface(commonConfig.Source); dataSrc != nil {
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/* this logger will then be used by the datasource at runtime */
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clog := log.New()
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if err := types.ConfigureLogger(clog); err != nil {
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return nil, fmt.Errorf("while configuring datasource logger: %w", err)
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}
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if commonConfig.LogLevel != nil {
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clog.SetLevel(*commonConfig.LogLevel)
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}
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customLog := log.Fields{
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"type": commonConfig.Source,
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}
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if commonConfig.Name != "" {
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customLog["name"] = commonConfig.Name
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}
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subLogger := clog.WithFields(customLog)
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/* check eventual dependencies are satisfied (ie. journald will check journalctl availability) */
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if err := dataSrc.CanRun(); err != nil {
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return nil, &DataSourceUnavailableError{Name: commonConfig.Source, Err: err}
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}
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/* configure the actual datasource */
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if err := dataSrc.Configure(yamlConfig, subLogger); err != nil {
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return nil, fmt.Errorf("failed to configure datasource %s: %w", commonConfig.Source, err)
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}
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return &dataSrc, nil
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}
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return nil, fmt.Errorf("cannot find source %s", commonConfig.Source)
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}
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// detectBackwardCompatAcquis: try to magically detect the type for backward compat (type was not mandatory then)
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func detectBackwardCompatAcquis(sub configuration.DataSourceCommonCfg) string {
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if _, ok := sub.Config["filename"]; ok {
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return "file"
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}
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if _, ok := sub.Config["filenames"]; ok {
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return "file"
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}
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if _, ok := sub.Config["journalctl_filter"]; ok {
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return "journalctl"
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}
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return ""
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}
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func LoadAcquisitionFromDSN(dsn string, labels map[string]string, transformExpr string) ([]DataSource, error) {
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var sources []DataSource
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frags := strings.Split(dsn, ":")
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if len(frags) == 1 {
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return nil, fmt.Errorf("%s isn't valid dsn (no protocol)", dsn)
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}
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dataSrc := GetDataSourceIface(frags[0])
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if dataSrc == nil {
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return nil, fmt.Errorf("no acquisition for protocol %s://", frags[0])
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}
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/* this logger will then be used by the datasource at runtime */
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clog := log.New()
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if err := types.ConfigureLogger(clog); err != nil {
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return nil, fmt.Errorf("while configuring datasource logger: %w", err)
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}
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subLogger := clog.WithFields(log.Fields{
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"type": dsn,
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})
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uniqueId := uuid.NewString()
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if transformExpr != "" {
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vm, err := expr.Compile(transformExpr, exprhelpers.GetExprOptions(map[string]interface{}{"evt": &types.Event{}})...)
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if err != nil {
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return nil, fmt.Errorf("while compiling transform expression '%s': %w", transformExpr, err)
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}
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transformRuntimes[uniqueId] = vm
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}
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err := dataSrc.ConfigureByDSN(dsn, labels, subLogger, uniqueId)
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if err != nil {
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return nil, fmt.Errorf("while configuration datasource for %s: %w", dsn, err)
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}
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sources = append(sources, dataSrc)
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return sources, nil
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}
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// LoadAcquisitionFromFile unmarshals the configuration item and checks its availability
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func LoadAcquisitionFromFile(config *csconfig.CrowdsecServiceCfg) ([]DataSource, error) {
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var sources []DataSource
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for _, acquisFile := range config.AcquisitionFiles {
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log.Infof("loading acquisition file : %s", acquisFile)
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yamlFile, err := os.Open(acquisFile)
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if err != nil {
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return nil, err
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}
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dec := yaml.NewDecoder(yamlFile)
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dec.SetStrict(true)
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idx := -1
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for {
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var sub configuration.DataSourceCommonCfg
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err = dec.Decode(&sub)
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idx += 1
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if err != nil {
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if !errors.Is(err, io.EOF) {
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return nil, fmt.Errorf("failed to yaml decode %s: %w", acquisFile, err)
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}
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log.Tracef("End of yaml file")
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break
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}
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//for backward compat ('type' was not mandatory, detect it)
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if guessType := detectBackwardCompatAcquis(sub); guessType != "" {
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sub.Source = guessType
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}
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//it's an empty item, skip it
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if len(sub.Labels) == 0 {
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if sub.Source == "" {
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log.Debugf("skipping empty item in %s", acquisFile)
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continue
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}
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return nil, fmt.Errorf("missing labels in %s (position: %d)", acquisFile, idx)
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}
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if sub.Source == "" {
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return nil, fmt.Errorf("data source type is empty ('source') in %s (position: %d)", acquisFile, idx)
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}
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if GetDataSourceIface(sub.Source) == nil {
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return nil, fmt.Errorf("unknown data source %s in %s (position: %d)", sub.Source, acquisFile, idx)
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}
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uniqueId := uuid.NewString()
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sub.UniqueId = uniqueId
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src, err := DataSourceConfigure(sub)
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if err != nil {
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var dserr *DataSourceUnavailableError
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if errors.As(err, &dserr) {
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log.Error(err)
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continue
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}
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return nil, fmt.Errorf("while configuring datasource of type %s from %s (position: %d): %w", sub.Source, acquisFile, idx, err)
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}
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if sub.TransformExpr != "" {
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vm, err := expr.Compile(sub.TransformExpr, exprhelpers.GetExprOptions(map[string]interface{}{"evt": &types.Event{}})...)
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if err != nil {
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return nil, fmt.Errorf("while compiling transform expression '%s' for datasource %s in %s (position: %d): %w", sub.TransformExpr, sub.Source, acquisFile, idx, err)
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}
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transformRuntimes[uniqueId] = vm
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}
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sources = append(sources, *src)
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}
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}
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return sources, nil
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}
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func GetMetrics(sources []DataSource, aggregated bool) error {
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var metrics []prometheus.Collector
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for i := 0; i < len(sources); i++ {
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if aggregated {
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metrics = sources[i].GetMetrics()
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} else {
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metrics = sources[i].GetAggregMetrics()
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}
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for _, metric := range metrics {
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if err := prometheus.Register(metric); err != nil {
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if _, ok := err.(prometheus.AlreadyRegisteredError); !ok {
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return fmt.Errorf("could not register metrics for datasource %s: %w", sources[i].GetName(), err)
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}
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// ignore the error
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}
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}
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}
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return nil
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}
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func transform(transformChan chan types.Event, output chan types.Event, AcquisTomb *tomb.Tomb, transformRuntime *vm.Program, logger *log.Entry) {
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defer trace.CatchPanic("crowdsec/acquis")
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logger.Infof("transformer started")
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for {
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select {
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case <-AcquisTomb.Dying():
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logger.Debugf("transformer is dying")
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return
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case evt := <-transformChan:
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logger.Tracef("Received event %s", evt.Line.Raw)
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out, err := expr.Run(transformRuntime, map[string]interface{}{"evt": &evt})
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if err != nil {
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logger.Errorf("while running transform expression: %s, sending event as-is", err)
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output <- evt
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}
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if out == nil {
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logger.Errorf("transform expression returned nil, sending event as-is")
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output <- evt
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}
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switch v := out.(type) {
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case string:
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logger.Tracef("transform expression returned %s", v)
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evt.Line.Raw = v
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output <- evt
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case []interface{}:
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logger.Tracef("transform expression returned %v", v) //nolint:asasalint // We actually want to log the slice content
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for _, line := range v {
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l, ok := line.(string)
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if !ok {
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logger.Errorf("transform expression returned []interface{}, but cannot assert an element to string")
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output <- evt
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continue
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}
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evt.Line.Raw = l
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output <- evt
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}
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case []string:
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logger.Tracef("transform expression returned %v", v)
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for _, line := range v {
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evt.Line.Raw = line
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output <- evt
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}
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default:
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logger.Errorf("transform expression returned an invalid type %T, sending event as-is", out)
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output <- evt
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}
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}
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}
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}
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func StartAcquisition(sources []DataSource, output chan types.Event, AcquisTomb *tomb.Tomb) error {
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// Don't wait if we have no sources, as it will hang forever
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if len(sources) == 0 {
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return nil
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}
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for i := 0; i < len(sources); i++ {
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subsrc := sources[i] //ensure its a copy
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log.Debugf("starting one source %d/%d ->> %T", i, len(sources), subsrc)
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AcquisTomb.Go(func() error {
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defer trace.CatchPanic("crowdsec/acquis")
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var err error
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outChan := output
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log.Debugf("datasource %s UUID: %s", subsrc.GetName(), subsrc.GetUuid())
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if transformRuntime, ok := transformRuntimes[subsrc.GetUuid()]; ok {
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log.Infof("transform expression found for datasource %s", subsrc.GetName())
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transformChan := make(chan types.Event)
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outChan = transformChan
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transformLogger := log.WithFields(log.Fields{
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"component": "transform",
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"datasource": subsrc.GetName(),
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})
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AcquisTomb.Go(func() error {
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transform(outChan, output, AcquisTomb, transformRuntime, transformLogger)
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return nil
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})
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}
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if subsrc.GetMode() == configuration.TAIL_MODE {
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err = subsrc.StreamingAcquisition(outChan, AcquisTomb)
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} else {
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err = subsrc.OneShotAcquisition(outChan, AcquisTomb)
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}
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if err != nil {
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//if one of the acqusition returns an error, we kill the others to properly shutdown
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AcquisTomb.Kill(err)
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}
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return nil
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})
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}
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/*return only when acquisition is over (cat) or never (tail)*/
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err := AcquisTomb.Wait()
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return err
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}
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