The sample @SpringBootApplication above has a function that can be
+
The sample @SpringBootApplication above has a function that can be
decorated at runtime by Spring Cloud Function to be an HTTP endpoint,
or a Stream processor, for instance with RabbitMQ, Apache Kafka or
JMS.
The @Beans can be Function, Consumer or Supplier (all from
diff --git a/multi/multi__deploying_a_packaged_function.html b/multi/multi__deploying_a_packaged_function.html
index 32a805e89..e58324607 100644
--- a/multi/multi__deploying_a_packaged_function.html
+++ b/multi/multi__deploying_a_packaged_function.html
@@ -1,3 +1,3 @@
Spring Cloud Function provides a "deployer" library that allows you to launch a jar file (or exploded archive, or set of jar files) with an isolated class loader and expose the functions defined in it. This is quite a powerful tool that would allow you to, for instance, adapt a function to a range of different input-output adapters without changing the target jar file. Serverless platforms often have this kind of feature built in, so you could see it as a building block for a function invoker in such a platform (indeed the Riff Java function invoker uses this library).
The standard entry point of the API is the Spring configuration annotation @EnableFunctionDeployer. If that is used in a Spring Boot application the deployer kicks in and looks for some configuration to tell it where to find the function jar. At a minimum the user has to provide a function.location which is a URL or resource location for the archive containing the functions. It can optionally use a maven: prefix to locate the artifact via a dependency lookup (see FunctionProperties for complete details). A Spring Boot application is bootstrapped from the jar file, using the MANIFEST.MF to locate a start class, so that a standard Spring Boot fat jar works well, for example. If the target jar can be launched successfully then the result is a function registered in the main application’s FunctionCatalog. The registered function can be applied by code in the main application, even though it was created in an isolated class loader (by deault).
Spring Cloud Function provides a "deployer" library that allows you to launch a jar file (or exploded archive, or set of jar files) with an isolated class loader and expose the functions defined in it. This is quite a powerful tool that would allow you to, for instance, adapt a function to a range of different input-output adapters without changing the target jar file. Serverless platforms often have this kind of feature built in, so you could see it as a building block for a function invoker in such a platform (indeed the Riff Java function invoker uses this library).
The standard entry point of the API is the Spring configuration annotation @EnableFunctionDeployer. If that is used in a Spring Boot application the deployer kicks in and looks for some configuration to tell it where to find the function jar. At a minimum the user has to provide a function.location which is a URL or resource location for the archive containing the functions. It can optionally use a maven: prefix to locate the artifact via a dependency lookup (see FunctionProperties for complete details). A Spring Boot application is bootstrapped from the jar file, using the MANIFEST.MF to locate a start class, so that a standard Spring Boot fat jar works well, for example. If the target jar can be launched successfully then the result is a function registered in the main application’s FunctionCatalog. The registered function can be applied by code in the main application, even though it was created in an isolated class loader (by deault).
There is a sample app that uses the function compiler to create a +
There is a sample app that uses the function compiler to create a function from a configuration property. The vanilla "function-sample" also has that feature. And there are some scripts that you can run to see the compilation happening at run time. To run these examples, diff --git a/multi/multi__function_catalog_and_flexible_function_signatures.html b/multi/multi__function_catalog_and_flexible_function_signatures.html index f0404320b..d030be0d2 100644 --- a/multi/multi__function_catalog_and_flexible_function_signatures.html +++ b/multi/multi__function_catalog_and_flexible_function_signatures.html @@ -1,6 +1,6 @@
-One of the main features of Spring Cloud Function is to adapt and support a range of type signatures for user-defined functions, +
One of the main features of Spring Cloud Function is to adapt and support a range of type signatures for user-defined functions,
while providing a consistent execution model.
That’s why all user defined functions are transformed into a canonical representation by FunctionCatalog, using primitives
defined by the Project Reactor (i.e., Flux<T> and Mono<T>).
@@ -12,7 +12,7 @@ a plain old Java type (or primitive wrapper), then the function
catalog will wrap it to a Flux of the same type. If the user writes
a function using Message (from spring-messaging) it will receive and
transmit headers from any adapter that supports key-value metadata
-(e.g. HTTP headers). Here are the details.
| User Function | Catalog Registration | |
|---|---|---|
|
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
|
Consumer is a little bit special because it has a void return type,
+(e.g. HTTP headers). Here are the details.
| User Function | Catalog Registration | |
|---|---|---|
|
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
|
Consumer is a little bit special because it has a void return type,
which implies blocking, at least potentially. Most likely you will not
need to write Consumer<Flux<?>>, but if you do need to do that,
remember to subscribe to the input flux. If you declare a Consumer
diff --git a/multi/multi__getting_started.html b/multi/multi__getting_started.html
index eb4e3bef5..187512aae 100644
--- a/multi/multi__getting_started.html
+++ b/multi/multi__getting_started.html
@@ -1,6 +1,6 @@
Build from the command line (and "install" the samples):
$ ./mvnw clean install
(If you like to YOLO add -DskipTests.)
Run one of the samples, e.g.
$ java -jar spring-cloud-function-samples/function-sample/target/*.jar
This runs the app and exposes its functions over HTTP, so you can +
Build from the command line (and "install" the samples):
$ ./mvnw clean install
(If you like to YOLO add -DskipTests.)
Run one of the samples, e.g.
$ java -jar spring-cloud-function-samples/function-sample/target/*.jar
This runs the app and exposes its functions over HTTP, so you can convert a string to uppercase, like this:
$ curl -H "Content-Type: text/plain" localhost:8080/uppercase -d Hello HELLO
You can convert multiple strings (a Flux<String>) by separating them
with new lines
$ curl -H "Content-Type: text/plain" localhost:8080/uppercase -d 'Hello
diff --git a/multi/multi__introduction.html b/multi/multi__introduction.html
index c73a3e044..ecf88f8ae 100644
--- a/multi/multi__introduction.html
+++ b/multi/multi__introduction.html
@@ -1,6 +1,6 @@
- 1. Introduction Spring Cloud Function is a project with the following high-level goals:
- Promote the implementation of business logic via functions.
- Decouple the development lifecycle of business logic from any specific runtime target so that the same code can run as a web endpoint, a stream processor, or a task.
- Support a uniform programming model across serverless providers, as well as the ability to run standalone (locally or in a PaaS).
- Enable Spring Boot features (auto-configuration, dependency injection, metrics) on serverless providers.
It abstracts away all of the transport details and
+
1. Introduction Spring Cloud Function is a project with the following high-level goals:
- Promote the implementation of business logic via functions.
- Decouple the development lifecycle of business logic from any specific runtime target so that the same code can run as a web endpoint, a stream processor, or a task.
- Support a uniform programming model across serverless providers, as well as the ability to run standalone (locally or in a PaaS).
- Enable Spring Boot features (auto-configuration, dependency injection, metrics) on serverless providers.
It abstracts away all of the transport details and
infrastructure, allowing the developer to keep all the familiar tools
and processes, and focus firmly on business logic.
Here’s a complete, executable, testable Spring Boot application
(implementing a simple string manipulation):
@SpringBootApplication
diff --git a/multi/multi__serverless_platform_adapters.html b/multi/multi__serverless_platform_adapters.html
index 08e4d1070..5381445f3 100644
--- a/multi/multi__serverless_platform_adapters.html
+++ b/multi/multi__serverless_platform_adapters.html
@@ -1,6 +1,6 @@
- 9. Serverless Platform Adapters As well as being able to run as a standalone process, a Spring Cloud
+
9. Serverless Platform Adapters As well as being able to run as a standalone process, a Spring Cloud
Function application can be adapted to run one of the existing
serverless platforms. In the project there are adapters for
AWS
@@ -14,7 +14,7 @@ has its own Spring Cloud Function adapter. And
Java Function
Invoker acts natively is an adapter for Spring Cloud Function jars.
The AWS adapter takes a Spring Cloud Function app and converts it to a form that can run in AWS Lambda.
The adapter has a couple of generic request handlers that you can use. The most generic is SpringBootStreamHandler, which uses a Jackson ObjectMapper provided by Spring Boot to serialize and deserialize the objects in the function. There is also a SpringBootRequestHandler which you can extend, and provide the input and output types as type parameters (enabling AWS to inspect the class and do the JSON conversions itself).
If your app has more than one @Bean of type Function etc. then you can choose the one to use by configuring function.name (e.g. as FUNCTION_NAME environment variable in AWS). The functions are extracted from the Spring Cloud FunctionCatalog (searching first for Function then Consumer and finally Supplier).
You don’t need the Spring Cloud Function Web or Stream adapter at runtime in Lambda, so you might need to exclude those before you create the JAR you send to AWS. A Lambda application has to be shaded, but a Spring Boot standalone application does not, so you can run the same app using 2 separate jars (as per the sample). The sample app creates 2 jar files, one with an aws classifier for deploying in Lambda, and one executable (thin) jar that includes spring-cloud-function-web at runtime. Spring Cloud Function will try and locate a "main class" for you from the JAR file manifest, using the Start-Class attribute (which will be added for you by the Spring Boot tooling if you use the starter parent). If there is no Start-Class in your manifest you can use an environment variable MAIN_CLASS when you deploy the function to AWS.
Build the sample under spring-cloud-function-samples/function-sample-aws and upload the -aws jar file to Lambda. The handler can be example.Handler or org.springframework.cloud.function.adapter.aws.SpringBootStreamHandler (FQN of the class, not a method reference, although Lambda does accept method references).
./mvnw -U clean package
Using the AWS command line tools it looks like this:
aws lambda create-function --function-name Uppercase --role arn:aws:iam::[USERID]:role/service-role/[ROLE] --zip-file fileb://function-sample-aws/target/function-sample-aws-2.0.0.BUILD-SNAPSHOT-aws.jar --handler org.springframework.cloud.function.adapter.aws.SpringBootStreamHandler --description "Spring Cloud Function Adapter Example" --runtime java8 --region us-east-1 --timeout 30 --memory-size 1024 --publish
The input type for the function in the AWS sample is a Foo with a single property called "value". So you would need this to test it:
{
"value": "test"
-}AWS has some platform-specific data types, including batching of messages, which is much more efficient than processing each one individually. To make use of these types you can write a function that depends on those types. Or you can rely on Spring to extract the data from the AWS types and convert it to a Spring Message. To do this you tell AWS that the function is of a specific generic handler type (depending on the AWS service) and provide a bean of type Function<Message<S>,Message<T>>, where S and T are your business data types. If there is more than one bean of type Function you may also need to configure the Spring Boot property function.name to be the name of the target bean (e.g. use FUNCTION_NAME as an environment variable).
The supported AWS services and generic handler types are listed below:
Service AWS Types Generic Handler API Gateway
APIGatewayProxyRequestEvent, APIGatewayProxyResponseEvent
org.springframework.cloud.function.adapter.aws.SpringBootApiGatewayRequestHandler
Kinesis
KinesisEvent
org.springframework.cloud.function.adapter.aws.SpringBootKinesisEventHandler
For example, to deploy behind an API Gateway, use --handler org.springframework.cloud.function.adapter.aws.SpringBootApiGatewayRequestHandler in your AWS command line (in via the UI) and define a @Bean of type Function<Message<Foo>,Message<Bar>> where Foo and Bar are POJO types (the data will be marshalled and unmarshalled by AWS using Jackson).
The Azure adapter bootstraps a Spring Cloud Function context and channels function calls from the Azure framework into the user functions, using Spring Boot configuration where necessary. Azure Functions has quite a unique, but invasive programming model, involving annotations in user code that are specific to the platform. The easiest way to use it with Spring Cloud is to extend a base class and write a method in it with the @FunctionName annotation which delegates to a base class method.
This project provides an adapter layer for a Spring Cloud Function application onto Azure.
+}
AWS has some platform-specific data types, including batching of messages, which is much more efficient than processing each one individually. To make use of these types you can write a function that depends on those types. Or you can rely on Spring to extract the data from the AWS types and convert it to a Spring Message. To do this you tell AWS that the function is of a specific generic handler type (depending on the AWS service) and provide a bean of type Function<Message<S>,Message<T>>, where S and T are your business data types. If there is more than one bean of type Function you may also need to configure the Spring Boot property function.name to be the name of the target bean (e.g. use FUNCTION_NAME as an environment variable).
The supported AWS services and generic handler types are listed below:
Service AWS Types Generic Handler API Gateway
APIGatewayProxyRequestEvent, APIGatewayProxyResponseEvent
org.springframework.cloud.function.adapter.aws.SpringBootApiGatewayRequestHandler
Kinesis
KinesisEvent
org.springframework.cloud.function.adapter.aws.SpringBootKinesisEventHandler
For example, to deploy behind an API Gateway, use --handler org.springframework.cloud.function.adapter.aws.SpringBootApiGatewayRequestHandler in your AWS command line (in via the UI) and define a @Bean of type Function<Message<Foo>,Message<Bar>> where Foo and Bar are POJO types (the data will be marshalled and unmarshalled by AWS using Jackson).
The Azure adapter bootstraps a Spring Cloud Function context and channels function calls from the Azure framework into the user functions, using Spring Boot configuration where necessary. Azure Functions has quite a unique, but invasive programming model, involving annotations in user code that are specific to the platform. The easiest way to use it with Spring Cloud is to extend a base class and write a method in it with the @FunctionName annotation which delegates to a base class method.
This project provides an adapter layer for a Spring Cloud Function application onto Azure.
You can write an app with a single @Bean of type Function and it will be deployable in Azure if you get the JAR file laid out right.
There is an AzureSpringBootRequestHandler which you must extend, and provide the input and output types as annotated method parameters (enabling Azure to inspect the class and create JSON bindings). The base class has two useful methods (handleRequest and handleOutput) to which you can delegate the actual function call, so mostly the function will only ever have one line.
Example:
public class FooHandler extends AzureSpringBootRequestHandler<Foo, Bar> {
@FunctionName("uppercase")
public Bar execute(
diff --git a/multi/multi__standalone_streaming_applications.html b/multi/multi__standalone_streaming_applications.html
index 7936a9247..3b9229648 100644
--- a/multi/multi__standalone_streaming_applications.html
+++ b/multi/multi__standalone_streaming_applications.html
@@ -1,4 +1,4 @@
- 6. Standalone Streaming Applications To send or receive messages from a broker (such as RabbitMQ or Kafka) you can leverage spring-cloud-stream project and it’s integration with Spring Cloud Function.
+
6. Standalone Streaming Applications To send or receive messages from a broker (such as RabbitMQ or Kafka) you can leverage spring-cloud-stream project and it’s integration with Spring Cloud Function.
Please refer to Spring Cloud Function section of the Spring Cloud Stream reference manual for more details and examples.
\ No newline at end of file
diff --git a/multi/multi__standalone_web_applications.html b/multi/multi__standalone_web_applications.html
index 18fd54931..6677043ad 100644
--- a/multi/multi__standalone_web_applications.html
+++ b/multi/multi__standalone_web_applications.html
@@ -1,6 +1,6 @@
- 5. Standalone Web Applications The spring-cloud-function-web module has autoconfiguration that
+
5. Standalone Web Applications The spring-cloud-function-web module has autoconfiguration that
activates when it is included in a Spring Boot web application (with
MVC support). There is also a spring-cloud-starter-function-web to
collect all the optional dependnecies in case you just want a simple
@@ -8,4 +8,4 @@ getting started experience.
With the web configurations activated your app
endpoint (on "/" by default, but configurable with
spring.cloud.function.web.path) that can be used to access the
functions in the application context. The supported content types are
-plain text and JSON.
Method Path Request Response Status GET
/{supplier}
-
Items from the named supplier
200 OK
POST
/{consumer}
JSON object or text
Mirrors input and pushes request body into consumer
202 Accepted
POST
/{consumer}
JSON array or text with new lines
Mirrors input and pushes body into consumer one by one
202 Accepted
POST
/{function}
JSON object or text
The result of applying the named function
200 OK
POST
/{function}
JSON array or text with new lines
The result of applying the named function
200 OK
GET
/{function}/{item}
-
Convert the item into an object and return the result of applying the function
200 OK
As the table above shows the behaviour of the endpoint depends on the method and also the type of incoming request data. When the incoming data is single valued, and the target function is declared as obviously single valued (i.e. not returning a collection or Flux), then the response will also contain a single value. For multi-valued responses the client can ask for a server-sent event stream by sending `Accept: text/event-stream". If there is only one function (consumer etc.) then the name in the path is optional. Composite functions can be addressed using pipes or commas to separate function names (pipes are legal in URL paths, but a bit awkward to type on the command line).
Functions and consumers that are declared with input and output in Message<?> will see the request headers on the input messages, and the output message headers will be converted to HTTP headers.
When POSTing text the response format might be different with Spring Boot 2.0 and older versions, depending on the content negotiation (provide content type and accpt headers for the best results).
\ No newline at end of file
+plain text and JSON.Method Path Request Response Status GET
/{supplier}
-
Items from the named supplier
200 OK
POST
/{consumer}
JSON object or text
Mirrors input and pushes request body into consumer
202 Accepted
POST
/{consumer}
JSON array or text with new lines
Mirrors input and pushes body into consumer one by one
202 Accepted
POST
/{function}
JSON object or text
The result of applying the named function
200 OK
POST
/{function}
JSON array or text with new lines
The result of applying the named function
200 OK
GET
/{function}/{item}
-
Convert the item into an object and return the result of applying the function
200 OK
As the table above shows the behaviour of the endpoint depends on the method and also the type of incoming request data. When the incoming data is single valued, and the target function is declared as obviously single valued (i.e. not returning a collection or Flux), then the response will also contain a single value. For multi-valued responses the client can ask for a server-sent event stream by sending `Accept: text/event-stream". If there is only one function (consumer etc.) then the name in the path is optional. Composite functions can be addressed using pipes or commas to separate function names (pipes are legal in URL paths, but a bit awkward to type on the command line).
Functions and consumers that are declared with input and output in Message<?> will see the request headers on the input messages, and the output message headers will be converted to HTTP headers.
When POSTing text the response format might be different with Spring Boot 2.0 and older versions, depending on the content negotiation (provide content type and accpt headers for the best results).
\ No newline at end of file
diff --git a/multi/multi_pr01.html b/multi/multi_pr01.html
index 8500d459b..b198a8019 100644
--- a/multi/multi_pr01.html
+++ b/multi/multi_pr01.html
@@ -1,3 +1,3 @@
- Spring Cloud Function
\ No newline at end of file
+ Spring Cloud Function
\ No newline at end of file
diff --git a/single/spring-cloud-function.html b/single/spring-cloud-function.html
index 81d65d46e..5e400668f 100644
--- a/single/spring-cloud-function.html
+++ b/single/spring-cloud-function.html
@@ -1,6 +1,6 @@
- Spring Cloud Function Table of Contents
Spring Cloud Function is a project with the following high-level goals:
- Promote the implementation of business logic via functions.
- Decouple the development lifecycle of business logic from any specific runtime target so that the same code can run as a web endpoint, a stream processor, or a task.
- Support a uniform programming model across serverless providers, as well as the ability to run standalone (locally or in a PaaS).
- Enable Spring Boot features (auto-configuration, dependency injection, metrics) on serverless providers.
It abstracts away all of the transport details and
+
Spring Cloud Function Table of Contents
Spring Cloud Function is a project with the following high-level goals:
- Promote the implementation of business logic via functions.
- Decouple the development lifecycle of business logic from any specific runtime target so that the same code can run as a web endpoint, a stream processor, or a task.
- Support a uniform programming model across serverless providers, as well as the ability to run standalone (locally or in a PaaS).
- Enable Spring Boot features (auto-configuration, dependency injection, metrics) on serverless providers.
It abstracts away all of the transport details and
infrastructure, allowing the developer to keep all the familiar tools
and processes, and focus firmly on business logic.
Here’s a complete, executable, testable Spring Boot application
(implementing a simple string manipulation):
@SpringBootApplication
@@ -58,7 +58,7 @@ a plain old Java type (or primitive wrapper), then the function
catalog will wrap it to a Flux of the same type. If the user writes
a function using Message (from spring-messaging) it will receive and
transmit headers from any adapter that supports key-value metadata
-(e.g. HTTP headers). Here are the details.User Function Catalog Registration Function<S,T>
Function<Flux<S>, Flux<T>>
Function<Message<S>,Message<T>>
Function<Flux<Message<S>>, Flux<Message<T>>>
Function<Flux<S>, Flux<T>>
Function<Flux<S>, Flux<T>> (pass through)
Supplier<T>
Supplier<Flux<T>>
Supplier<Flux<T>>
Supplier<Flux<T>>
Consumer<T>
Function<Flux<T>, Mono<Void>>
Consumer<Message<T>>
Function<Flux<Message<T>>, Mono<Void>>
Consumer<Flux<T>>
Consumer<Flux<T>>
Consumer is a little bit special because it has a void return type,
+(e.g. HTTP headers). Here are the details.
User Function Catalog Registration Function<S,T>
Function<Flux<S>, Flux<T>>
Function<Message<S>,Message<T>>
Function<Flux<Message<S>>, Flux<Message<T>>>
Function<Flux<S>, Flux<T>>
Function<Flux<S>, Flux<T>> (pass through)
Supplier<T>
Supplier<Flux<T>>
Supplier<Flux<T>>
Supplier<Flux<T>>
Consumer<T>
Function<Flux<T>, Mono<Void>>
Consumer<Message<T>>
Function<Flux<Message<T>>, Mono<Void>>
Consumer<Flux<T>>
Consumer<Flux<T>>
Consumer is a little bit special because it has a void return type,
which implies blocking, at least potentially. Most likely you will not
need to write Consumer<Flux<?>>, but if you do need to do that,
remember to subscribe to the input flux. If you declare a Consumer
@@ -89,7 +89,7 @@ getting started experience.
With the web configurations activated your app
endpoint (on "/" by default, but configurable with
spring.cloud.function.web.path) that can be used to access the
functions in the application context. The supported content types are
-plain text and JSON.
Method Path Request Response Status GET
/{supplier}
-
Items from the named supplier
200 OK
POST
/{consumer}
JSON object or text
Mirrors input and pushes request body into consumer
202 Accepted
POST
/{consumer}
JSON array or text with new lines
Mirrors input and pushes body into consumer one by one
202 Accepted
POST
/{function}
JSON object or text
The result of applying the named function
200 OK
POST
/{function}
JSON array or text with new lines
The result of applying the named function
200 OK
GET
/{function}/{item}
-
Convert the item into an object and return the result of applying the function
200 OK
As the table above shows the behaviour of the endpoint depends on the method and also the type of incoming request data. When the incoming data is single valued, and the target function is declared as obviously single valued (i.e. not returning a collection or Flux), then the response will also contain a single value. For multi-valued responses the client can ask for a server-sent event stream by sending `Accept: text/event-stream". If there is only one function (consumer etc.) then the name in the path is optional. Composite functions can be addressed using pipes or commas to separate function names (pipes are legal in URL paths, but a bit awkward to type on the command line).
Functions and consumers that are declared with input and output in Message<?> will see the request headers on the input messages, and the output message headers will be converted to HTTP headers.
When POSTing text the response format might be different with Spring Boot 2.0 and older versions, depending on the content negotiation (provide content type and accpt headers for the best results).
To send or receive messages from a broker (such as RabbitMQ or Kafka) you can leverage spring-cloud-stream project and it’s integration with Spring Cloud Function.
+plain text and JSON.
Method Path Request Response Status GET
/{supplier}
-
Items from the named supplier
200 OK
POST
/{consumer}
JSON object or text
Mirrors input and pushes request body into consumer
202 Accepted
POST
/{consumer}
JSON array or text with new lines
Mirrors input and pushes body into consumer one by one
202 Accepted
POST
/{function}
JSON object or text
The result of applying the named function
200 OK
POST
/{function}
JSON array or text with new lines
The result of applying the named function
200 OK
GET
/{function}/{item}
-
Convert the item into an object and return the result of applying the function
200 OK
As the table above shows the behaviour of the endpoint depends on the method and also the type of incoming request data. When the incoming data is single valued, and the target function is declared as obviously single valued (i.e. not returning a collection or Flux), then the response will also contain a single value. For multi-valued responses the client can ask for a server-sent event stream by sending `Accept: text/event-stream". If there is only one function (consumer etc.) then the name in the path is optional. Composite functions can be addressed using pipes or commas to separate function names (pipes are legal in URL paths, but a bit awkward to type on the command line).
Functions and consumers that are declared with input and output in Message<?> will see the request headers on the input messages, and the output message headers will be converted to HTTP headers.
When POSTing text the response format might be different with Spring Boot 2.0 and older versions, depending on the content negotiation (provide content type and accpt headers for the best results).
To send or receive messages from a broker (such as RabbitMQ or Kafka) you can leverage spring-cloud-stream project and it’s integration with Spring Cloud Function.
Please refer to Spring Cloud Function section of the Spring Cloud Stream reference manual for more details and examples.
Spring Cloud Function provides a "deployer" library that allows you to launch a jar file (or exploded archive, or set of jar files) with an isolated class loader and expose the functions defined in it. This is quite a powerful tool that would allow you to, for instance, adapt a function to a range of different input-output adapters without changing the target jar file. Serverless platforms often have this kind of feature built in, so you could see it as a building block for a function invoker in such a platform (indeed the Riff Java function invoker uses this library).
The standard entry point of the API is the Spring configuration annotation @EnableFunctionDeployer. If that is used in a Spring Boot application the deployer kicks in and looks for some configuration to tell it where to find the function jar. At a minimum the user has to provide a function.location which is a URL or resource location for the archive containing the functions. It can optionally use a maven: prefix to locate the artifact via a dependency lookup (see FunctionProperties for complete details). A Spring Boot application is bootstrapped from the jar file, using the MANIFEST.MF to locate a start class, so that a standard Spring Boot fat jar works well, for example. If the target jar can be launched successfully then the result is a function registered in the main application’s FunctionCatalog. The registered function can be applied by code in the main application, even though it was created in an isolated class loader (by deault).
There is a sample app that uses the function compiler to create a
function from a configuration property. The vanilla "function-sample"
also has that feature. And there are some scripts that you can run to
@@ -124,7 +124,7 @@ has its own Spring Cloud Function adapter. And
Java Function
Invoker acts natively is an adapter for Spring Cloud Function jars.
The AWS adapter takes a Spring Cloud Function app and converts it to a form that can run in AWS Lambda.
The adapter has a couple of generic request handlers that you can use. The most generic is SpringBootStreamHandler, which uses a Jackson ObjectMapper provided by Spring Boot to serialize and deserialize the objects in the function. There is also a SpringBootRequestHandler which you can extend, and provide the input and output types as type parameters (enabling AWS to inspect the class and do the JSON conversions itself).
If your app has more than one @Bean of type Function etc. then you can choose the one to use by configuring function.name (e.g. as FUNCTION_NAME environment variable in AWS). The functions are extracted from the Spring Cloud FunctionCatalog (searching first for Function then Consumer and finally Supplier).
You don’t need the Spring Cloud Function Web or Stream adapter at runtime in Lambda, so you might need to exclude those before you create the JAR you send to AWS. A Lambda application has to be shaded, but a Spring Boot standalone application does not, so you can run the same app using 2 separate jars (as per the sample). The sample app creates 2 jar files, one with an aws classifier for deploying in Lambda, and one executable (thin) jar that includes spring-cloud-function-web at runtime. Spring Cloud Function will try and locate a "main class" for you from the JAR file manifest, using the Start-Class attribute (which will be added for you by the Spring Boot tooling if you use the starter parent). If there is no Start-Class in your manifest you can use an environment variable MAIN_CLASS when you deploy the function to AWS.
Build the sample under spring-cloud-function-samples/function-sample-aws and upload the -aws jar file to Lambda. The handler can be example.Handler or org.springframework.cloud.function.adapter.aws.SpringBootStreamHandler (FQN of the class, not a method reference, although Lambda does accept method references).
./mvnw -U clean package
Using the AWS command line tools it looks like this:
aws lambda create-function --function-name Uppercase --role arn:aws:iam::[USERID]:role/service-role/[ROLE] --zip-file fileb://function-sample-aws/target/function-sample-aws-2.0.0.BUILD-SNAPSHOT-aws.jar --handler org.springframework.cloud.function.adapter.aws.SpringBootStreamHandler --description "Spring Cloud Function Adapter Example" --runtime java8 --region us-east-1 --timeout 30 --memory-size 1024 --publish
The input type for the function in the AWS sample is a Foo with a single property called "value". So you would need this to test it:
{
"value": "test"
-}AWS has some platform-specific data types, including batching of messages, which is much more efficient than processing each one individually. To make use of these types you can write a function that depends on those types. Or you can rely on Spring to extract the data from the AWS types and convert it to a Spring Message. To do this you tell AWS that the function is of a specific generic handler type (depending on the AWS service) and provide a bean of type Function<Message<S>,Message<T>>, where S and T are your business data types. If there is more than one bean of type Function you may also need to configure the Spring Boot property function.name to be the name of the target bean (e.g. use FUNCTION_NAME as an environment variable).
The supported AWS services and generic handler types are listed below:
Service AWS Types Generic Handler API Gateway
APIGatewayProxyRequestEvent, APIGatewayProxyResponseEvent
org.springframework.cloud.function.adapter.aws.SpringBootApiGatewayRequestHandler
Kinesis
KinesisEvent
org.springframework.cloud.function.adapter.aws.SpringBootKinesisEventHandler
For example, to deploy behind an API Gateway, use --handler org.springframework.cloud.function.adapter.aws.SpringBootApiGatewayRequestHandler in your AWS command line (in via the UI) and define a @Bean of type Function<Message<Foo>,Message<Bar>> where Foo and Bar are POJO types (the data will be marshalled and unmarshalled by AWS using Jackson).
The Azure adapter bootstraps a Spring Cloud Function context and channels function calls from the Azure framework into the user functions, using Spring Boot configuration where necessary. Azure Functions has quite a unique, but invasive programming model, involving annotations in user code that are specific to the platform. The easiest way to use it with Spring Cloud is to extend a base class and write a method in it with the @FunctionName annotation which delegates to a base class method.
This project provides an adapter layer for a Spring Cloud Function application onto Azure.
+}
AWS has some platform-specific data types, including batching of messages, which is much more efficient than processing each one individually. To make use of these types you can write a function that depends on those types. Or you can rely on Spring to extract the data from the AWS types and convert it to a Spring Message. To do this you tell AWS that the function is of a specific generic handler type (depending on the AWS service) and provide a bean of type Function<Message<S>,Message<T>>, where S and T are your business data types. If there is more than one bean of type Function you may also need to configure the Spring Boot property function.name to be the name of the target bean (e.g. use FUNCTION_NAME as an environment variable).
The supported AWS services and generic handler types are listed below:
Service AWS Types Generic Handler API Gateway
APIGatewayProxyRequestEvent, APIGatewayProxyResponseEvent
org.springframework.cloud.function.adapter.aws.SpringBootApiGatewayRequestHandler
Kinesis
KinesisEvent
org.springframework.cloud.function.adapter.aws.SpringBootKinesisEventHandler
For example, to deploy behind an API Gateway, use --handler org.springframework.cloud.function.adapter.aws.SpringBootApiGatewayRequestHandler in your AWS command line (in via the UI) and define a @Bean of type Function<Message<Foo>,Message<Bar>> where Foo and Bar are POJO types (the data will be marshalled and unmarshalled by AWS using Jackson).
The Azure adapter bootstraps a Spring Cloud Function context and channels function calls from the Azure framework into the user functions, using Spring Boot configuration where necessary. Azure Functions has quite a unique, but invasive programming model, involving annotations in user code that are specific to the platform. The easiest way to use it with Spring Cloud is to extend a base class and write a method in it with the @FunctionName annotation which delegates to a base class method.
This project provides an adapter layer for a Spring Cloud Function application onto Azure.
You can write an app with a single @Bean of type Function and it will be deployable in Azure if you get the JAR file laid out right.
There is an AzureSpringBootRequestHandler which you must extend, and provide the input and output types as annotated method parameters (enabling Azure to inspect the class and create JSON bindings). The base class has two useful methods (handleRequest and handleOutput) to which you can delegate the actual function call, so mostly the function will only ever have one line.
Example:
public class FooHandler extends AzureSpringBootRequestHandler<Foo, Bar> {
@FunctionName("uppercase")
public Bar execute(
diff --git a/spring-cloud-function.html b/spring-cloud-function.html
index 3c15cae04..d2e71cb88 100644
--- a/spring-cloud-function.html
+++ b/spring-cloud-function.html
@@ -4,7 +4,7 @@
-
+
spring-cloud-function