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Expose initial and effective config for debugging purposes (#325)
* Expose initial and effective config for debugging purposes (Still incomplete, just the initial ideas) * Add tests * Remove outdated test comment * Add 'token' to the redaction list * Require an env var to be defined before serving config
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3 files changed

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‎internal/configprovider/config_server.go

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// Copyright Splunk, Inc.
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// Copyright The OpenTelemetry Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package configprovider
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import (
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"net"
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"net/http"
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"os"
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"strings"
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"github.com/spf13/cast"
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"go.uber.org/zap"
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"gopkg.in/yaml.v2"
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)
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const (
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configServerEnabledEnvVar = "SPLUNK_DEBUG_CONFIG_SERVER"
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configServerPortEnvVar = "SPLUNK_DEBUG_CONFIG_SERVER_PORT"
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defaultConfigServerEndpoint = "localhost:55555"
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)
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type configServer struct {
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logger *zap.Logger
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initial map[string]interface{}
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effective map[string]interface{}
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server *http.Server
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doneCh chan struct{}
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}
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func newConfigServer(logger *zap.Logger, initial, effective map[string]interface{}) *configServer {
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return &configServer{
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logger: logger,
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initial: initial,
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effective: effective,
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}
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}
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func (cs *configServer) start() error {
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if enabled := os.Getenv(configServerEnabledEnvVar); enabled != "true" {
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// The config server needs to be explicitly enabled for the time being.
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return nil
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}
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endpoint := defaultConfigServerEndpoint
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if portOverride, ok := os.LookupEnv(configServerPortEnvVar); ok {
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if portOverride == "" {
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// If explicitly set to empty do not start the server.
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return nil
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}
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endpoint = "localhost:" + portOverride
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}
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listener, err := net.Listen("tcp", endpoint)
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if err != nil {
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return err
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}
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mux := http.NewServeMux()
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initialHandleFunc, err := cs.muxHandleFunc(cs.initial)
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if err != nil {
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return err
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}
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mux.HandleFunc("/debug/configz/initial", initialHandleFunc)
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effectiveHandleFunc, err := cs.muxHandleFunc(simpleRedact(cs.effective))
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if err != nil {
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return err
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}
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mux.HandleFunc("/debug/configz/effective", effectiveHandleFunc)
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cs.server = &http.Server{
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Handler: mux,
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}
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cs.doneCh = make(chan struct{})
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go func() {
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defer close(cs.doneCh)
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httpErr := cs.server.Serve(listener)
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if httpErr != http.ErrServerClosed {
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cs.logger.Error("config server error", zap.Error(err))
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}
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}()
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return nil
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}
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func (cs *configServer) shutdown() error {
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var err error
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if cs.server != nil {
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err = cs.server.Close()
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// If launched wait for Serve goroutine exit.
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<-cs.doneCh
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}
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return err
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}
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func (cs *configServer) muxHandleFunc(config map[string]interface{}) (func(http.ResponseWriter, *http.Request), error) {
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configYAML, err := yaml.Marshal(config)
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if err != nil {
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return nil, err
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}
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return func(writer http.ResponseWriter, request *http.Request) {
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if request.Method != "GET" {
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writer.WriteHeader(http.StatusMethodNotAllowed)
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return
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}
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_, _ = writer.Write(configYAML)
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}, nil
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}
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func simpleRedact(config map[string]interface{}) map[string]interface{} {
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redactedConfig := make(map[string]interface{})
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for k, v := range config {
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switch value := v.(type) {
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case string:
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if shouldRedactKey(k) {
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v = "<redacted>"
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}
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case map[string]interface{}:
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v = simpleRedact(value)
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case map[interface{}]interface{}:
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v = simpleRedact(cast.ToStringMap(value))
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}
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redactedConfig[k] = v
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}
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return redactedConfig
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}
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// shouldRedactKey applies a simple check to see if the contents of the given key
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// should be redacted or not.
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func shouldRedactKey(k string) bool {
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fragments := []string{
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"access",
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"api_key",
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"apikey",
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"auth",
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"credential",
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"creds",
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"login",
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"password",
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"pwd",
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"token",
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"user",
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}
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for _, fragment := range fragments {
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if strings.Contains(k, fragment) {
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return true
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}
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}
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return false
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}

‎internal/configprovider/config_server_test.go

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// Copyright Splunk, Inc.
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// Copyright The OpenTelemetry Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package configprovider
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import (
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"io/ioutil"
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"net/http"
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"os"
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"strconv"
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"testing"
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"github.com/stretchr/testify/assert"
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"github.com/stretchr/testify/require"
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"go.opentelemetry.io/collector/testutil"
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"go.uber.org/zap"
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"gopkg.in/yaml.v2"
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)
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func TestConfigServer_RequireEnvVar(t *testing.T) {
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initial := map[string]interface{}{
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"minimal": "config",
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}
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cs := newConfigServer(zap.NewNop(), initial, initial)
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require.NotNil(t, cs)
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require.NoError(t, cs.start())
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t.Cleanup(func() {
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require.NoError(t, cs.shutdown())
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})
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client := &http.Client{}
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path := "/debug/configz/initial"
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_, err := client.Get("http://" + defaultConfigServerEndpoint + path)
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assert.Error(t, err)
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}
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func TestConfigServer_EnvVar(t *testing.T) {
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alternativePort := strconv.FormatUint(uint64(testutil.GetAvailablePort(t)), 10)
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require.NoError(t, os.Setenv(configServerEnabledEnvVar, "true"))
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t.Cleanup(func() {
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assert.NoError(t, os.Unsetenv(configServerEnabledEnvVar))
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})
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tests := []struct {
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name string
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portEnvVar string
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endpoint string
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setPortEnvVar bool
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serverDown bool
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}{
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{
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name: "default",
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},
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{
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name: "disable_server",
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setPortEnvVar: true, // Explicitly setting it to empty to disable the server.
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serverDown: true,
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},
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{
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name: "change_port",
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portEnvVar: alternativePort,
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endpoint: "http://localhost:" + alternativePort,
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},
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}
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for _, tt := range tests {
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t.Run(tt.name, func(t *testing.T) {
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initial := map[string]interface{}{
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"key": "value",
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}
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if tt.portEnvVar != "" || tt.setPortEnvVar {
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require.NoError(t, os.Setenv(configServerPortEnvVar, tt.portEnvVar))
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defer func() {
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assert.NoError(t, os.Unsetenv(configServerPortEnvVar))
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}()
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}
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cs := newConfigServer(zap.NewNop(), initial, initial)
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require.NoError(t, cs.start())
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defer func() {
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assert.NoError(t, cs.shutdown())
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}()
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endpoint := tt.endpoint
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if endpoint == "" {
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endpoint = "http://" + defaultConfigServerEndpoint
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}
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path := "/debug/configz/initial"
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if tt.serverDown {
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client := &http.Client{}
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_, err := client.Get(endpoint + path)
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assert.Error(t, err)
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return
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}
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client := &http.Client{}
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resp, err := client.Get(endpoint + path)
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require.NoError(t, err)
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assert.Equal(t, http.StatusOK, resp.StatusCode, "unsuccessful zpage %q GET", path)
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})
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}
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}
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func TestConfigServer_Serve(t *testing.T) {
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require.NoError(t, os.Setenv(configServerEnabledEnvVar, "true"))
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t.Cleanup(func() {
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assert.NoError(t, os.Unsetenv(configServerEnabledEnvVar))
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})
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initial := map[string]interface{}{
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"field": "not_redacted",
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"api_key": "not_redacted_on_initial",
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"int": 42,
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"map": map[interface{}]interface{}{
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"k0": true,
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"k1": -1,
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"password": "$ENV_VAR",
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},
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}
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effective := map[string]interface{}{
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"field": "not_redacted",
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"api_key": "<redacted>",
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"int": 42,
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"map": map[interface{}]interface{}{
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"k0": true,
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"k1": -1,
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"password": "<redacted>",
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},
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}
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cs := newConfigServer(zap.NewNop(), initial, initial)
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require.NotNil(t, cs)
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require.NoError(t, cs.start())
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t.Cleanup(func() {
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require.NoError(t, cs.shutdown())
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})
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// Test for the pages to be actually valid YAML files.
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assertValidYAMLPages(t, initial, "/debug/configz/initial")
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assertValidYAMLPages(t, effective, "/debug/configz/effective")
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}
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func assertValidYAMLPages(t *testing.T, expected map[string]interface{}, path string) {
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url := "http://" + defaultConfigServerEndpoint + path
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client := &http.Client{}
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// Anything other the GET should return 405.
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resp, err := client.Head(url)
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assert.NoError(t, err)
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assert.Equal(t, http.StatusMethodNotAllowed, resp.StatusCode)
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assert.NoError(t, resp.Body.Close())
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resp, err = client.Get(url)
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if !assert.NoError(t, err, "error retrieving zpage at %q", path) {
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return
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}
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assert.Equal(t, http.StatusOK, resp.StatusCode, "unsuccessful zpage %q GET", path)
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t.Cleanup(func() {
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assert.NoError(t, resp.Body.Close())
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})
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respBytes, err := ioutil.ReadAll(resp.Body)
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require.NoError(t, err)
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var unmarshalled map[string]interface{}
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require.NoError(t, yaml.Unmarshal(respBytes, &unmarshalled))
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assert.Equal(t, expected, unmarshalled)
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}

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