Application Service Configuration
Similar to other EdgeX services, configuration is first determined by the configuration.yaml file in the /res folder. Once loaded any environment overrides are applied. If -cp is passed to the application on startup, the SDK will leverage the specific configuration provider (i.e Consul) to push the configuration into the provider and monitor Writeable configuration from there. You will find the configuration under the edgex/appservices/2.0/ key in the provider (i.e Consul). On re-restart the service will pull the configuration from the provider and apply any environment overrides.
This section describes the configuration elements that are unique to Application Services
Please first refer to the general Configuration documentation for configuration properties common across all EdgeX services.
Note
*indicates the configuration value can be changed on the fly if using a configuration provider (like Consul).
**indicates the configuration value can be changed but the service must be restarted.
Writable
The tabs below provide additional entries in the Writable section which are applicable to Application Services.
The section configures the Store and Forward capability. Please refer to Store and Forward documentation for more details.
| Configuration | Default Value | |
|---|---|---|
| Enabled | false* | Indicates whether the Store and Forward capability enabled or disabled |
| RetryInterval | "5m"* | Indicates the duration of time to wait before retries, aka Forward |
| MaxRetryCount | 10* | Indicates whether maximum number of retries of failed data. The failed data is removed after the maximum retries has been exceeded. A value of 0 indicates endless retries. |
The section configures the Configurable Function Pipeline which is used only by App Service Configurable. Please refer to App Service Configurable - Getting Started section for more details
This section defines Insecure Secrets that are used when running in non-secure mode, i.e. when Vault isn't available. This is a dynamic map of configuration, so can empty if no secrets are used or can have as many or few user define secrets. It simulates a Secret Store in non-secure mode. Below are a few examples that are need if using the indicated capabilities.
| Configuration | Default Value | Description |
|---|---|---|
| ` |
--- | This section defines a block of insecure secrets for some service specific need |
| SecretName | <name> |
Indicates the location in the simulated Secret Store where the secret resides. |
| SecretData | --- | This section is the collection of secret data. |
key |
value |
Secret data key value pairs |
| Property | <Default Value | Description |
|---|---|---|
See Writable.Telemetry at Common Configuration for the Telemetry configuration common to all services |
||
| Metrics | Service metrics that the application service collects. Boolean value indicates if reporting of the metric is enabled. Custom metrics are also included here for custom application services that define custom metrics | |
| Metrics.MessagesReceived | false | Enable/disable reporting of the built-in MessagesReceived metric |
| Metrics.InvalidMessagesReceived | false | Enable/disable reporting of the built-in InvalidMessagesReceived metric |
| Metrics.HttpExportSize | false | Enable/disable reporting of the built-in HttpExportSize metric |
| Metrics.MqttExportSize | false | Enable/disable reporting of the built-in MqttExportSize metric |
| Metrics.PipelineMessagesProcessed | false | Enable/disable reporting of the built-in PipelineMessagesProcessed metric |
| Metrics.PipelineProcessingErrors | false | Enable/disable reporting of the built-in PipelineProcessingErrors metric |
| Metrics.PipelineMessageProcessingTime | false | Enable/disable reporting of the built-in PipelineMessageProcessingTime metric |
Metrics.<CustomMetric> |
false | (Service Specific) Enable/disable reporting of custom application service's custom metric. See Custom Application Service Metrics for more detail |
| Tags | <empty> |
List of arbitrary service level tags to included with every metric that is reported. i.e. Gateway="my-iot-gateway" |
Not Writable
The tabs below provide additional configuration which are applicable to Application Services that require the service to be restarted after value(s) are changed.
This section contains the configuration for the internal Webserver. Only need if configuring the Webserver for HTTPS
| Configuration | Default Value | Description |
|---|---|---|
| Protocol | http** | Indicates the protocol for the webserver to use |
| SecretName | blank** | Indicates the name of the secret in the Secret Store where the HTTPS secret data resides |
| HTTPSCertName | blank** | Indicates the key name in the HTTPS secret data that contains the certificate data to use for HTTPS |
| HTTPSKeyName | blank** | Indicates the key name in the HTTPS secret data that contains the key data to use for HTTPS |
This service specific section defines the connection information for the EdgeX Clients and is the same as that used by all EdgeX services, just which clients are needed differs. Please refer to the Note about Clients section for more details.
This section defines the Trigger for incoming data. See the Triggers documentation for more details on the inner working of triggers.
| Configuration | Default Value | Description |
|---|---|---|
| Type | edgex-messagebus** | Indicates the Trigger binding type. valid values are edgex-messagebus, external-mqtt, http, or <custom> |
| SubscribeTopics | events/#** | Topic(s) to subscribe to. This is a comma separated list of topics. Supports filtering by subscribe topics. Only set when using edgex-messagebus or external-mqtt. See EdgeXMessageBus Trigger for more details. |
| PublishTopic | blank** | Indicates the topic in which to publish the function pipeline response data, if any. Supports dynamic topic places holders. Only set when using edgex-messagebus or external-mqtt. See EdgeXMessageBus Trigger for more details. |
This section defines the external MQTT Broker connect information.
Only used for external-mqtt trigger binding type
Note
external-mqtt is not the default Trigger type, so there are no default values for ExternalMqtt settings beyond those that the Go compiler gives to the empty struct. Some of those default values are not valid and must be specified, i.e. Authmode
| Configuration | Default Value | Description |
|---|---|---|
| Url | blank** | Fully qualified URL to connect to the MQTT broker, i.e. tcp://localhost:1883 |
| ClientId | blank** | ClientId to connect to the broker with |
| ConnectTimeout | blank** | Time duration indicating how long to wait before timing out broker connection, i.e "30s" |
| AutoReconnect | false** | Indicates whether or not to retry connection if disconnected |
| KeepAlive | 0** | Seconds between client ping when no active data flowing to avoid client being disconnected. Must be greater then 2 |
| QOS | 0** | Quality of Service 0 (At most once), 1 (At least once) or 2 (Exactly once) |
| Retain | false** | Retain setting for MQTT Connection |
| SkipCertVerify | false** | Indicates if the certificate verification should be skipped |
| SecretPath | blank** | Name of the path in secret provider to retrieve your secrets. Must be non-blank. |
| AuthMode | blank** | Indicates what to use when connecting to the broker. Must be one of "none", "cacert" , "usernamepassword", "clientcert". If a CA Cert exists in the SecretPath then it will be used for all modes except "none". |
| RetryDuration | 600 | Indicates how long (in seconds) to wait timing out on the MQTT client creation |
| RetryInterval | 5 | Indicates the time (in seconds) that will be waited between attempts to create MQTT client |
Note
Authmode=cacert is only needed when client authentication (e.g. usernamepassword) is not required, but a CA Cert is needed to validate the broker's SSL/TLS cert.
[ApplicationSettings] - Is used for custom application settings and is accessed via the ApplicationSettings() API. The ApplicationSettings API returns a map[string] string containing the contents on the ApplicationSetting section of the configuration.yaml file.
ApplicationSettings:
ApplicationName: "My Application Service"
Custom Application Services can now define their own custom structured configuration section in the configuration.yaml file. Any additional sections in the configuration file are ignore by the SDK when it parses the file for the SDK defined sections. See the Custom Configuration section of the SDK documentation for more details.