Generalize config converter

cmd/otelcol/main.go

@@ -31,6 +31,7 @@ import (
  "go.uber.org/zap"
 
  "github.com/signalfx/splunk-otel-collector/internal/components"
+ "github.com/signalfx/splunk-otel-collector/internal/configconverter"
  "github.com/signalfx/splunk-otel-collector/internal/configprovider"
  "github.com/signalfx/splunk-otel-collector/internal/configsources"
  "github.com/signalfx/splunk-otel-collector/internal/version"
@@ -67,7 +68,7 @@ func main() {
 
  // Allow dumping configuration locally by default
  // Used by support bundle script
- os.Setenv(configServerEnabledEnvVar, "true")
+ _ = os.Setenv(configServerEnabledEnvVar, "true")
 
  factories, err := components.Get()
  if err != nil {
@@ -79,30 +80,24 @@ func main() {
  Version: version.Version,
  }
 
+ cfgSourcePP := configprovider.NewConfigSourceParserProvider(
+ newBaseParserProvider(),
+ zap.NewNop(), // The service logger is not available yet, setting it to NoP.
+ info,
+ configsources.Get()...,
+ )
+ configConverterPP := configconverter.ParserProvider(cfgSourcePP, configconverter.RemoveBallastKey)
  serviceParams := service.CollectorSettings{
  BuildInfo: info,
  Factories: factories,
- ParserProvider: memLimitRemoverParserProvider(info),
+ ParserProvider: configConverterPP,
  }
 
  if err := run(serviceParams); err != nil {
  log.Fatal(err)
  }
 }
 
-// memLimitRemoverParserProvider removes a ballast_size_mib key from a memory
-// limiter processor, if it exists. Support for this key will be (or has been)
-// removed and will cause the Collector to not start.
-func memLimitRemoverParserProvider(info component.BuildInfo) parserprovider.ParserProvider {
- cfgSourcePP := configprovider.NewConfigSourceParserProvider(
- newBaseParserProvider(),
- zap.NewNop(), // The service logger is not available yet, setting it to NoP.
- info,
- configsources.Get()...,
- )
- return configprovider.NewMemLimitRemoverParserProvider(cfgSourcePP)
-}
-
 // Check whether a string exists in an array of CLI arguments
 // Support key/value with and without an equal sign
 func contains(arr []string, str string) bool {
@@ -263,7 +258,7 @@ func setMemoryBallast(memTotalSizeMiB int) int {
  if os.Getenv(ballastEnvVarName) != "" {
  log.Fatalf("Both %v and '--mem-ballast-size-mib' were specified, but only one is allowed", ballastEnvVarName)
  }
- os.Setenv(ballastEnvVarName, ballastSizeFlag)
+ _ = os.Setenv(ballastEnvVarName, ballastSizeFlag)
  }
 
  ballastSize := memTotalSizeMiB * defaultMemoryBallastPercentage / 100
@@ -275,7 +270,7 @@ func setMemoryBallast(memTotalSizeMiB int) int {
  }
  }
 
- os.Setenv(ballastEnvVarName, strconv.Itoa(ballastSize))
+ _ = os.Setenv(ballastEnvVarName, strconv.Itoa(ballastSize))
  log.Printf("Set ballast to %d MiB", ballastSize)
  return ballastSize
 }
@@ -289,7 +284,7 @@ func setMemoryLimit(memTotalSizeMiB int) int {
  memLimit = envVarAsInt(memLimitMiBEnvVarName)
  }
 
- os.Setenv(memLimitMiBEnvVarName, strconv.Itoa(memLimit))
+ _ = os.Setenv(memLimitMiBEnvVarName, strconv.Itoa(memLimit))
  log.Printf("Set memory limit to %d MiB", memLimit)
  return memLimit
 }
@@ -307,15 +302,15 @@ func setDefaultEnvVars() {
  for _, v := range testArgs {
  _, ok := os.LookupEnv(v[0])
  if !ok {
- os.Setenv(v[0], v[1])
+ _ = os.Setenv(v[0], v[1])
  }
  }
  }
  token, tokenOk := os.LookupEnv("SPLUNK_ACCESS_TOKEN")
  if tokenOk {
  _, ok := os.LookupEnv("SPLUNK_HEC_TOKEN")
  if !ok {
- os.Setenv("SPLUNK_HEC_TOKEN", token)
+ _ = os.Setenv("SPLUNK_HEC_TOKEN", token)
  }
  }
 }

internal/configprovider/mem_limit_ballast_remover_parser_provider.go → internal/configconverter/ballast_remover.go

@@ -12,15 +12,13 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package configprovider
+package configconverter
 
 import (
- "fmt"
  "log"
  "regexp"
 
  "go.opentelemetry.io/collector/config/configparser"
- "go.opentelemetry.io/collector/service/parserprovider"
 )
 
 var ballastKeyRegexp *regexp.Regexp
@@ -30,36 +28,18 @@ func init() {
  ballastKeyRegexp, _ = regexp.Compile(expr)
 }
 
-// memLimitBallastRemoverParserProvider implements ParserProvider, wraps a
-// ParserProvider, and removes any ballast_size_mib key from the memory_limiter
-// processor, if one exists, from the wrapped config. This is to ensure that the
-// Collector will still start when support for this key gets removed.
-type memLimitBallastRemoverParserProvider struct {
- pp parserprovider.ParserProvider
-}
-
-var _ parserprovider.ParserProvider = (*memLimitBallastRemoverParserProvider)(nil)
-
-func NewMemLimitRemoverParserProvider(pp parserprovider.ParserProvider) parserprovider.ParserProvider {
- return &memLimitBallastRemoverParserProvider{pp: pp}
-}
-
-func (mpp memLimitBallastRemoverParserProvider) Get() (*configparser.ConfigMap, error) {
- cfgMap, err := mpp.pp.Get()
- if err != nil {
- return nil, fmt.Errorf("memLimitBallastRemoverParserProvider.Get(): %w", err)
- }
+// RemoveBallastKey is a CfgMapFunc that removes a ballast_size_mib on a
+// memory_limiter processor config if it exists. This config key will go away at
+// some point (or already has) at which point its presence in a config will
+// prevent the Collector from starting.
+func RemoveBallastKey(cfgMap *configparser.ConfigMap) *configparser.ConfigMap {
  out := configparser.NewParser()
  for _, k := range cfgMap.AllKeys() {
- if isMemLimitBallastKey(k) {
+ if ballastKeyRegexp.MatchString(k) {
  log.Println("Deprecated memory_limiter processor `ballast_size_mib` key found. Removing from config.")
  } else {
  out.Set(k, cfgMap.Get(k))
  }
  }
- return out, nil
-}
-
-func isMemLimitBallastKey(k string) bool {
- return ballastKeyRegexp.MatchString(k)
+ return out
 }

internal/configconverter/parser_provider.go

@@ -0,0 +1,55 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package configconverter
+
+import (
+ "fmt"
+
+ "go.opentelemetry.io/collector/config/configparser"
+ "go.opentelemetry.io/collector/service/parserprovider"
+)
+
+// converterProvider wraps a ParserProvider and accepts a list of functions that
+// convert ConfigMaps. The idea is for this type to conform to the open-closed
+// principle.
+type converterProvider struct {
+ wrapped parserprovider.ParserProvider
+ cfgMapFuncs []CfgMapFunc
+}
+
+type CfgMapFunc func(*configparser.ConfigMap) *configparser.ConfigMap
+
+var _ parserprovider.ParserProvider = (*converterProvider)(nil)
+
+func ParserProvider(wrapped parserprovider.ParserProvider, funcs ...CfgMapFunc) parserprovider.ParserProvider {
+ return &converterProvider{wrapped: wrapped, cfgMapFuncs: funcs}
+}
+
+func (p converterProvider) Get() (*configparser.ConfigMap, error) {
+ cfgMap, err := p.wrapped.Get()
+ if err != nil {
+ return nil, fmt.Errorf("converterProvider.Get(): %w", err)
+ }
+
+ for _, cfgMapFunc := range p.cfgMapFuncs {
+ cfgMap = cfgMapFunc(cfgMap)
+ }
+
+ out := configparser.NewParser()
+ for _, k := range cfgMap.AllKeys() {
+ out.Set(k, cfgMap.Get(k))
+ }
+ return out, nil
+}

internal/configprovider/mem_limit_ballast_remover_parser_provider_test.go → internal/configconverter/parser_provider_test.go

@@ -12,21 +12,16 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package configprovider
+package configconverter
 
 import (
  "testing"
 
  "github.com/stretchr/testify/assert"
  "github.com/stretchr/testify/require"
+ "go.opentelemetry.io/collector/config/configparser"
 )
 
-func TestIsMemLimitBallastKey(t *testing.T) {
- assert.False(t, isMemLimitBallastKey("processors::ballast_size_mib"))
- assert.True(t, isMemLimitBallastKey("processors::memory_limiter::ballast_size_mib"))
- assert.True(t, isMemLimitBallastKey("processors::memory_limiter/foo::ballast_size_mib"))
-}
-
 func TestMemLimitBallastRemoverPP(t *testing.T) {
  tests := []struct {
  name string
@@ -46,8 +41,9 @@ func TestMemLimitBallastRemoverPP(t *testing.T) {
  }
  for _, test := range tests {
  t.Run(test.name, func(t *testing.T) {
- pp := &memLimitBallastRemoverParserProvider{
- &fileParserProvider{FileName: test.fname},
+ pp := &converterProvider{
+ wrapped: &fileParserProvider{fileName: test.fname},
+ cfgMapFuncs: []CfgMapFunc{RemoveBallastKey},
  }
  cfgMap, err := pp.Get()
  require.NoError(t, err)
@@ -56,3 +52,11 @@ func TestMemLimitBallastRemoverPP(t *testing.T) {
  })
  }
 }
+
+type fileParserProvider struct {
+ fileName string
+}
+
+func (fpp fileParserProvider) Get() (*configparser.ConfigMap, error) {
+ return configparser.NewParserFromFile(fpp.fileName)
+}