[processor/filter] Update processor to log errors (open-telemetry#18862)

* Log error

* add changelog

* fix lint

.chloggen/fp-log-errors.yaml

@@ -0,0 +1,16 @@
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: bug_fix
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: filterprocessor
+
+# A brief description of the change. Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Fixes issue where errors in the filterprocessor might not be logged
+
+# One or more tracking issues related to the change
+issues: [18862]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:

processor/filterprocessor/logs.go

@@ -22,6 +22,7 @@ import (
  "go.opentelemetry.io/collector/pdata/plog"
  "go.opentelemetry.io/collector/processor/processorhelper"
  "go.uber.org/multierr"
+ "go.uber.org/zap"
 
  "github.com/open-telemetry/opentelemetry-collector-contrib/internal/filter/expr"
  "github.com/open-telemetry/opentelemetry-collector-contrib/internal/filter/filterconfig"
@@ -32,16 +33,20 @@ import (
 
 type filterLogProcessor struct {
  skipExpr expr.BoolExpr[ottllog.TransformContext]
+ logger *zap.Logger
 }
 
 func newFilterLogsProcessor(set component.TelemetrySettings, cfg *Config) (*filterLogProcessor, error) {
+ flp := &filterLogProcessor{
+ logger: set.Logger,
+ }
  if cfg.Logs.LogConditions != nil {
  skipExpr, err := common.ParseLog(cfg.Logs.LogConditions, set)
  if err != nil {
  return nil, err
  }
-
- return &filterLogProcessor{skipExpr: skipExpr}, nil
+ flp.skipExpr = skipExpr
+ return flp, nil
  }
 
  cfgMatch := filterconfig.MatchConfig{}
@@ -57,8 +62,9 @@ func newFilterLogsProcessor(set component.TelemetrySettings, cfg *Config) (*filt
  if err != nil {
  return nil, fmt.Errorf("failed to build skip matcher: %w", err)
  }
+ flp.skipExpr = skipExpr
 
- return &filterLogProcessor{skipExpr: skipExpr}, nil
+ return flp, nil
 }
 
 func (flp *filterLogProcessor) processLogs(ctx context.Context, ld plog.Logs) (plog.Logs, error) {
@@ -87,6 +93,7 @@ func (flp *filterLogProcessor) processLogs(ctx context.Context, ld plog.Logs) (p
  })
 
  if errors != nil {
+ flp.logger.Error("failed processing logs", zap.Error(errors))
  return ld, errors
  }
  if ld.ResourceLogs().Len() == 0 {

processor/filterprocessor/metrics.go

@@ -39,11 +39,14 @@ type filterMetricProcessor struct {
  skipResourceExpr expr.BoolExpr[ottlresource.TransformContext]
  skipMetricExpr expr.BoolExpr[ottlmetric.TransformContext]
  skipDataPointExpr expr.BoolExpr[ottldatapoint.TransformContext]
+ logger *zap.Logger
 }
 
 func newFilterMetricProcessor(set component.TelemetrySettings, cfg *Config) (*filterMetricProcessor, error) {
  var err error
- fsp := &filterMetricProcessor{}
+ fsp := &filterMetricProcessor{
+ logger: set.Logger,
+ }
  if cfg.Metrics.MetricConditions != nil || cfg.Metrics.DataPointConditions != nil {
  if cfg.Metrics.MetricConditions != nil {
  fsp.skipMetricExpr, err = common.ParseMetric(cfg.Metrics.MetricConditions, set)
@@ -169,6 +172,7 @@ func (fmp *filterMetricProcessor) processMetrics(ctx context.Context, md pmetric
  })
 
  if errors != nil {
+ fmp.logger.Error("failed processing metrics", zap.Error(errors))
  return md, errors
  }
  if md.ResourceMetrics().Len() == 0 {

processor/filterprocessor/traces.go

@@ -33,11 +33,14 @@ import (
 type filterSpanProcessor struct {
  skipSpanExpr expr.BoolExpr[ottlspan.TransformContext]
  skipSpanEventExpr expr.BoolExpr[ottlspanevent.TransformContext]
+ logger *zap.Logger
 }
 
 func newFilterSpansProcessor(set component.TelemetrySettings, cfg *Config) (*filterSpanProcessor, error) {
  var err error
- fsp := &filterSpanProcessor{}
+ fsp := &filterSpanProcessor{
+ logger: set.Logger,
+ }
  if cfg.Traces.SpanConditions != nil || cfg.Traces.SpanEventConditions != nil {
  if cfg.Traces.SpanConditions != nil {
  fsp.skipSpanExpr, err = common.ParseSpan(cfg.Traces.SpanConditions, set)
@@ -117,6 +120,7 @@ func (fsp *filterSpanProcessor) processTraces(ctx context.Context, td ptrace.Tra
  })
 
  if errors != nil {
+ fsp.logger.Error("failed processing traces", zap.Error(errors))
  return td, errors
  }
  if td.ResourceSpans().Len() == 0 {