Etcd Watch

Since Camel 2.18

Only consumer is supported

The camel Etcd component allows you to work with Etcd, a distributed reliable key-value store.

URI Format

etcd-watch:path[?options]

URI Options

Configuring Options

Camel components are configured on two separate levels:

  • component level

  • endpoint level

Configuring Component Options

The component level is the highest level which holds general and common configurations that are inherited by the endpoints. For example a component may have security settings, credentials for authentication, urls for network connection and so forth.

Some components only have a few options, and others may have many. Because components typically have pre configured defaults that are commonly used, then you may often only need to configure a few options on a component; or none at all.

Configuring components can be done with the Component DSL, in a configuration file (application.properties|yaml), or directly with Java code.

Configuring Endpoint Options

Where you find yourself configuring the most is on endpoints, as endpoints often have many options, which allows you to configure what you need the endpoint to do. The options are also categorized into whether the endpoint is used as consumer (from) or as a producer (to), or used for both.

Configuring endpoints is most often done directly in the endpoint URI as path and query parameters. You can also use the Endpoint DSL as a type safe way of configuring endpoints.

A good practice when configuring options is to use Property Placeholders, which allows to not hardcode urls, port numbers, sensitive information, and other settings. In other words placeholders allows to externalize the configuration from your code, and gives more flexibility and reuse.

The following two sections lists all the options, firstly for the component followed by the endpoint.

Component Options

The Etcd Watch component supports 13 options, which are listed below.

Name Description Default Type

bridgeErrorHandler (consumer)

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored.

boolean

configuration (consumer)

Component configuration.

EtcdConfiguration

recursive (consumer)

To apply an action recursively.

boolean

servicePath (consumer)

The path to look for for service discovery.

String

timeout (consumer)

To set the maximum time an action could take to complete.

Long

uris (common)

To set the URIs the client connects.

String

sendEmptyExchangeOnTimeout (consumer)

To send an empty message in case of timeout watching for a key.

boolean

fromIndex (consumer (advanced))

The index to watch from.

long

autowiredEnabled (advanced)

Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc.

boolean

password (security)

The password to use for basic authentication.

String

sslContextParameters (security)

To configure security using SSLContextParameters.

SSLContextParameters

useGlobalSslContextParameters (security)

Enable usage of global SSL context parameters.

boolean

userName (security)

The user name to use for basic authentication.

String

Endpoint Options

The Etcd Watch endpoint is configured using URI syntax:

etcd-watch:path

with the following path and query parameters:

Path Parameters (1 parameters)

Name Description Default Type

path (common)

The path the endpoint refers to.

String

Query Parameters (12 parameters)

Name Description Default Type

bridgeErrorHandler (consumer)

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored.

boolean

recursive (consumer)

To apply an action recursively.

boolean

servicePath (consumer)

The path to look for for service discovery.

String

uris (common)

To set the URIs the client connects.

String

sendEmptyExchangeOnTimeout (consumer)

To send an empty message in case of timeout watching for a key.

boolean

timeout (consumer)

To set the maximum time an action could take to complete.

Long

exceptionHandler (consumer (advanced))

To let the consumer use a custom ExceptionHandler. Notice if the option bridgeErrorHandler is enabled then this option is not in use. By default the consumer will deal with exceptions, that will be logged at WARN or ERROR level and ignored.

ExceptionHandler

exchangePattern (consumer (advanced))

Sets the exchange pattern when the consumer creates an exchange.

Enum values:

  • InOnly

  • InOut

  • InOptionalOut

ExchangePattern

fromIndex (consumer (advanced))

The index to watch from.

long

password (security)

The password to use for basic authentication.

String

sslContextParameters (security)

To configure security using SSLContextParameters.

SSLContextParameters

userName (security)

The user name to use for basic authentication.

String

Spring Boot Auto-Configuration

When using etcd-watch with Spring Boot make sure to use the following Maven dependency to have support for auto configuration:

<dependency>
  <groupId>org.apache.camel.springboot</groupId>
  <artifactId>camel-etcd-starter</artifactId>
  <version>x.x.x</version>
  <!-- use the same version as your Camel core version -->
</dependency>

The component supports 43 options, which are listed below.

Name Description Default Type

camel.component.etcd-keys.autowired-enabled

Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc.

true

Boolean

camel.component.etcd-keys.configuration

Component configuration. The option is a org.apache.camel.component.etcd.EtcdConfiguration type.

EtcdConfiguration

camel.component.etcd-keys.enabled

Whether to enable auto configuration of the etcd-keys component. This is enabled by default.

Boolean

camel.component.etcd-keys.lazy-start-producer

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

Boolean

camel.component.etcd-keys.password

The password to use for basic authentication.

String

camel.component.etcd-keys.recursive

To apply an action recursively.

false

Boolean

camel.component.etcd-keys.service-path

The path to look for for service discovery.

/services/

String

camel.component.etcd-keys.ssl-context-parameters

To configure security using SSLContextParameters. The option is a org.apache.camel.support.jsse.SSLContextParameters type.

SSLContextParameters

camel.component.etcd-keys.time-to-live

To set the lifespan of a key in milliseconds.

Integer

camel.component.etcd-keys.timeout

To set the maximum time an action could take to complete. The option is a java.lang.Long type.

Long

camel.component.etcd-keys.uris

To set the URIs the client connects.

http://localhost:2379,http://localhost:4001

String

camel.component.etcd-keys.use-global-ssl-context-parameters

Enable usage of global SSL context parameters.

false

Boolean

camel.component.etcd-keys.user-name

The user name to use for basic authentication.

String

camel.component.etcd-stats.autowired-enabled

Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc.

true

Boolean

camel.component.etcd-stats.bridge-error-handler

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored.

false

Boolean

camel.component.etcd-stats.configuration

Component configuration. The option is a org.apache.camel.component.etcd.EtcdConfiguration type.

EtcdConfiguration

camel.component.etcd-stats.enabled

Whether to enable auto configuration of the etcd-stats component. This is enabled by default.

Boolean

camel.component.etcd-stats.from-index

The index to watch from.

0

Long

camel.component.etcd-stats.lazy-start-producer

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

Boolean

camel.component.etcd-stats.password

The password to use for basic authentication.

String

camel.component.etcd-stats.recursive

To apply an action recursively.

false

Boolean

camel.component.etcd-stats.send-empty-exchange-on-timeout

To send an empty message in case of timeout watching for a key.

false

Boolean

camel.component.etcd-stats.service-path

The path to look for for service discovery.

/services/

String

camel.component.etcd-stats.ssl-context-parameters

To configure security using SSLContextParameters. The option is a org.apache.camel.support.jsse.SSLContextParameters type.

SSLContextParameters

camel.component.etcd-stats.time-to-live

To set the lifespan of a key in milliseconds.

Integer

camel.component.etcd-stats.timeout

To set the maximum time an action could take to complete. The option is a java.lang.Long type.

Long

camel.component.etcd-stats.uris

To set the URIs the client connects.

http://localhost:2379,http://localhost:4001

String

camel.component.etcd-stats.use-global-ssl-context-parameters

Enable usage of global SSL context parameters.

false

Boolean

camel.component.etcd-stats.user-name

The user name to use for basic authentication.

String

camel.component.etcd-watch.autowired-enabled

Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc.

true

Boolean

camel.component.etcd-watch.bridge-error-handler

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored.

false

Boolean

camel.component.etcd-watch.configuration

Component configuration. The option is a org.apache.camel.component.etcd.EtcdConfiguration type.

EtcdConfiguration

camel.component.etcd-watch.enabled

Whether to enable auto configuration of the etcd-watch component. This is enabled by default.

Boolean

camel.component.etcd-watch.from-index

The index to watch from.

0

Long

camel.component.etcd-watch.password

The password to use for basic authentication.

String

camel.component.etcd-watch.recursive

To apply an action recursively.

false

Boolean

camel.component.etcd-watch.send-empty-exchange-on-timeout

To send an empty message in case of timeout watching for a key.

false

Boolean

camel.component.etcd-watch.service-path

The path to look for for service discovery.

/services/

String

camel.component.etcd-watch.ssl-context-parameters

To configure security using SSLContextParameters. The option is a org.apache.camel.support.jsse.SSLContextParameters type.

SSLContextParameters

camel.component.etcd-watch.timeout

To set the maximum time an action could take to complete. The option is a java.lang.Long type.

Long

camel.component.etcd-watch.uris

To set the URIs the client connects.

http://localhost:2379,http://localhost:4001

String

camel.component.etcd-watch.use-global-ssl-context-parameters

Enable usage of global SSL context parameters.

false

Boolean

camel.component.etcd-watch.user-name

The user name to use for basic authentication.

String