Configuration client library for use by Go implementation of EdgeX micro services. This project contains the abstract Configuration API and an implementation for Consul. The API initializes a connection to the Configuration service and push/pull configuration values to/from the Configuration service.
- Initialize connection to a Configuration service
- Push a service's configuration in to the Configuration
- Pull service's configuration from the Configuration service into its configuration struct
- Listen for configuration updates
This library is used by Go programs for interacting with the Configuration service (i.e. Consul) and requires that a Configuration service be running somewhere that the Configuration Client can connect. The types.ServiceConfig struct is used to specify the service implementation details :
type ServiceConfig struct {
Protocol string
Host string
Port int
Type string
BasePath string
AccessToken string
}The following code snippets demonstrate how a service uses this Configuration module to store and load configuration, listen to for configuration updates.
This code snippet shows how to connect to the Configuration service, store and load the service's configuration from the Configuration service.
func initializeConfiguration(useConfigService bool, useProfile string) (*ConfigurationStruct, error) {
configuration := &ConfigurationStruct{}
err := config.LoadFromFile(useProfile, configuration)
if err != nil {
return nil, err
}
if useConfigService {
serviceConfig := types.Config{
Host: conf.Configuration.Host,
Port: conf.Configuration.Port,
Type: conf.Configuration.Type,
BasePath: internal.ConfigStem + internal.MyServiceKey,
AccessToken: <AccessTokenLoadedFromSecretFile>,
}
ConfigClient, err = configuration.NewConfigurationClient(serviceConfig)
if err != nil {
return fmt.Errorf("connection to Configuration service could not be made: %v", err.Error())
}
hasConfig, err := ConfigClient.HasConfiguration()
if hasConfig {
// Get the service's configuration from the Configuration service
rawConfig, err := ConfigClient.GetConfiguration(configuration)
if err != nil {
return fmt.Errorf("could not get configuration from Configuration: %v", err.Error())
}
actual, ok := rawConfig.(*ConfigurationStruct)
if !ok {
return fmt.Errorf("configuration from Configuration failed type check")
}
*configuration = actual
} else {
err = ConfigClient.PutConfiguration(configuration, true)
if err != nil {
return fmt.Errorf("could not push configuration into Configuration service: %v", err)
}
}
// Run as go func so doesn't block
go listenForConfigChanges()
}
This code snippet shows how to listen for configuration changes from the Configuration service after connecting above.
func listenForConfigChanges() {
if ConfigClient == nil {
LoggingClient.Error("listenForConfigChanges() configuration client not set")
return
}
ConfigClient.WatchForChanges(updateChannel, errChannel, &WritableInfo{}, internal.WritableKey)
signalChan := make(chan os.Signal)
signal.Notify(signalChan, syscall.SIGINT, syscall.SIGTERM)
for {
select {
case <- signalChan:
// Quietly and gracefully stop when SIGINT/SIGTERM received
return
case ex := <-errChannel:
LoggingClient.Error(ex.Error())
case raw, ok := <-updateChannel:
if !ok {
return
}
actual, ok := raw.(*WritableInfo)
if !ok {
LoggingClient.Error("listenForConfigChanges() type check failed")
return
}
Configuration.Writable = *actual
LoggingClient.Info("Writeable configuration has been updated")
LoggingClient.SetLogLevel(Configuration.Writable.LogLevel)
}
}
}
![dependabot[bot] avatar](https://avatars.githubusercontent.com/in/29110?v=4 "dependabot[bot]")
React
Typescript
Django
Laravel
Facebook
Microsoft
Google
Alibaba
D3
Tencent