Chapter 2. AWS CloudWatch
Only producer is supported
The AWS2 Cloudwatch component allows messages to be sent to an Amazon CloudWatch metrics. The implementation of the Amazon API is provided by the AWS SDK.
Prerequisites
You must have a valid Amazon Web Services developer account, and be signed up to use Amazon CloudWatch. More information is available at Amazon CloudWatch.
2.1. URI Format
aws2-cw://namespace[?options]
The metrics will be created if they don’t already exists. You can append query options to the URI in the following format, ?options=value&option2=value&…
2.2. Configuring Options
Camel components are configured on two separate levels:
- component level
- endpoint level
2.2.1. 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.
2.2.2. 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.
2.3. Component Options
The AWS CloudWatch component supports 18 options, which are listed below.
| Name | Description | Default | Type |
|---|---|---|---|
| amazonCwClient (producer) | Autowired To use the AmazonCloudWatch as the client. | CloudWatchClient | |
| configuration (producer) | The component configuration. | Cw2Configuration | |
| lazyStartProducer (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 |
| name (producer) | The metric name. | String | |
| overrideEndpoint (producer) | Set the need for overidding the endpoint. This option needs to be used in combination with uriEndpointOverride option. | false | boolean |
| proxyHost (producer) | To define a proxy host when instantiating the CW client. | String | |
| proxyPort (producer) | To define a proxy port when instantiating the CW client. | Integer | |
| proxyProtocol (producer) | To define a proxy protocol when instantiating the CW client. Enum values:
| HTTPS | Protocol |
| region (producer) | The region in which CW client needs to work. When using this parameter, the configuration will expect the lowercase name of the region (for example ap-east-1) You’ll need to use the name Region.EU_WEST_1.id(). | String | |
| timestamp (producer) | The metric timestamp. | Instant | |
| trustAllCertificates (producer) | If we want to trust all certificates in case of overriding the endpoint. | false | boolean |
| unit (producer) | The metric unit. | String | |
| uriEndpointOverride (producer) | Set the overriding uri endpoint. This option needs to be used in combination with overrideEndpoint option. | String | |
| useDefaultCredentialsProvider (producer) | Set whether the S3 client should expect to load credentials through a default credentials provider or to expect static credentials to be passed in. | false | boolean |
| value (producer) | The metric value. | Double | |
| 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. | true | boolean |
| accessKey (security) | Amazon AWS Access Key. | String | |
| secretKey (security) | Amazon AWS Secret Key. | String |
2.4. Endpoint Options
The AWS CloudWatch endpoint is configured using URI syntax:
aws2-cw:namespace
with the following path and query parameters:
2.4.1. Path Parameters (1 parameters)
| Name | Description | Default | Type |
|---|---|---|---|
| namespace (producer) | Required The metric namespace. | String |
2.4.2. Query Parameters (16 parameters)
| Name | Description | Default | Type |
|---|---|---|---|
| amazonCwClient (producer) | Autowired To use the AmazonCloudWatch as the client. | CloudWatchClient | |
| lazyStartProducer (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 |
| name (producer) | The metric name. | String | |
| overrideEndpoint (producer) | Set the need for overidding the endpoint. This option needs to be used in combination with uriEndpointOverride option. | false | boolean |
| proxyHost (producer) | To define a proxy host when instantiating the CW client. | String | |
| proxyPort (producer) | To define a proxy port when instantiating the CW client. | Integer | |
| proxyProtocol (producer) | To define a proxy protocol when instantiating the CW client. Enum values:
| HTTPS | Protocol |
| region (producer) | The region in which CW client needs to work. When using this parameter, the configuration will expect the lowercase name of the region (for example ap-east-1) You’ll need to use the name Region.EU_WEST_1.id(). | String | |
| timestamp (producer) | The metric timestamp. | Instant | |
| trustAllCertificates (producer) | If we want to trust all certificates in case of overriding the endpoint. | false | boolean |
| unit (producer) | The metric unit. | String | |
| uriEndpointOverride (producer) | Set the overriding uri endpoint. This option needs to be used in combination with overrideEndpoint option. | String | |
| useDefaultCredentialsProvider (producer) | Set whether the S3 client should expect to load credentials through a default credentials provider or to expect static credentials to be passed in. | false | boolean |
| value (producer) | The metric value. | Double | |
| accessKey (security) | Amazon AWS Access Key. | String | |
| secretKey (security) | Amazon AWS Secret Key. | String |
Required CW component options
You have to provide the amazonCwClient in the Registry or your accessKey and secretKey to access the Amazon’s CloudWatch.
2.5. Usage
2.5.1. Static credentials vs Default Credential Provider
You have the possibility of avoiding the usage of explicit static credentials, by specifying the useDefaultCredentialsProvider option and set it to true.
- Java system properties - aws.accessKeyId and aws.secretKey
- Environment variables - AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY.
- Web Identity Token from AWS STS.
- The shared credentials and config files.
- Amazon ECS container credentials - loaded from the Amazon ECS if the environment variable AWS_CONTAINER_CREDENTIALS_RELATIVE_URI is set.
- Amazon EC2 Instance profile credentials.
For more information about this you can look at AWS credentials documentation
2.5.2. Message headers evaluated by the CW producer
| Header | Type | Description |
|---|---|---|
|
|
| The Amazon CW metric name. |
|
|
| The Amazon CW metric value. |
|
|
| The Amazon CW metric unit. |
|
|
| The Amazon CW metric namespace. |
|
|
| The Amazon CW metric timestamp. |
|
|
| The Amazon CW metric dimension name. |
|
|
| The Amazon CW metric dimension value. |
|
|
| A map of dimension names and dimension values. |
2.5.3. Advanced CloudWatchClient configuration
If you need more control over the CloudWatchClient instance configuration you can create your own instance and refer to it from the URI:
from("direct:start")
.to("aws2-cw://namespace?amazonCwClient=#client");
The #client refers to a CloudWatchClient in the Registry.
2.6. Dependencies
Maven users will need to add the following dependency to their pom.xml.
pom.xml
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-aws2-cw</artifactId>
<version>${camel-version}</version>
</dependency>
where {camel-version} must be replaced by the actual version of Camel.
2.7. Examples
2.7.1. Producer Example
from("direct:start")
.to("aws2-cw://http://camel.apache.org/aws-cw");and sends something like
exchange.getIn().setHeader(Cw2Constants.METRIC_NAME, "ExchangesCompleted"); exchange.getIn().setHeader(Cw2Constants.METRIC_VALUE, "2.0"); exchange.getIn().setHeader(Cw2Constants.METRIC_UNIT, "Count");
2.8. Spring Boot Auto-Configuration
When using aws2-cw 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-aws2-cw-starter</artifactId> </dependency>
The component supports 19 options, which are listed below.
| Name | Description | Default | Type |
|---|---|---|---|
| camel.component.aws2-cw.access-key | Amazon AWS Access Key. | String | |
| camel.component.aws2-cw.amazon-cw-client | To use the AmazonCloudWatch as the client. The option is a software.amazon.awssdk.services.cloudwatch.CloudWatchClient type. | CloudWatchClient | |
| camel.component.aws2-cw.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.aws2-cw.configuration | The component configuration. The option is a org.apache.camel.component.aws2.cw.Cw2Configuration type. | Cw2Configuration | |
| camel.component.aws2-cw.enabled | Whether to enable auto configuration of the aws2-cw component. This is enabled by default. | Boolean | |
| camel.component.aws2-cw.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.aws2-cw.name | The metric name. | String | |
| camel.component.aws2-cw.override-endpoint | Set the need for overidding the endpoint. This option needs to be used in combination with uriEndpointOverride option. | false | Boolean |
| camel.component.aws2-cw.proxy-host | To define a proxy host when instantiating the CW client. | String | |
| camel.component.aws2-cw.proxy-port | To define a proxy port when instantiating the CW client. | Integer | |
| camel.component.aws2-cw.proxy-protocol | To define a proxy protocol when instantiating the CW client. | Protocol | |
| camel.component.aws2-cw.region | The region in which CW client needs to work. When using this parameter, the configuration will expect the lowercase name of the region (for example ap-east-1) You’ll need to use the name Region.EU_WEST_1.id(). | String | |
| camel.component.aws2-cw.secret-key | Amazon AWS Secret Key. | String | |
| camel.component.aws2-cw.timestamp | The metric timestamp. The option is a java.time.Instant type. | Instant | |
| camel.component.aws2-cw.trust-all-certificates | If we want to trust all certificates in case of overriding the endpoint. | false | Boolean |
| camel.component.aws2-cw.unit | The metric unit. | String | |
| camel.component.aws2-cw.uri-endpoint-override | Set the overriding uri endpoint. This option needs to be used in combination with overrideEndpoint option. | String | |
| camel.component.aws2-cw.use-default-credentials-provider | Set whether the S3 client should expect to load credentials through a default credentials provider or to expect static credentials to be passed in. | false | Boolean |
| camel.component.aws2-cw.value | The metric value. | Double |
