Chapter 7. Customizing Fuse Online

After you upload an OpenAPI specification to Fuse Online, a connector to the REST API becomes available. You can select the connector to create a REST API client connection. You can then create a new integration and add the REST API client connection, or you can edit an existing integration to add the REST API client connection.

Fuse Online connectors support OAuth 2.0 and HTTP Basic Authorization. If access to the REST API requires Transport Layer Security (TLS) then the API needs to use a valid certificate that is issued by a recognized Certificate Authority (CA).

A REST API that uses OAuth must have an authorization URL that takes a client callback URL as input. After Fuse Online creates the connector and before you use the connector to create a connection, you must visit that URL to register your Fuse Online environment as a client of the REST API. This authorizes your Fuse Online environment to access the REST API. As part of registration, you provide the Fuse Online callback URL. The details for doing this are described in Connecting Fuse Online to Applications and Services, Register with REST APIs.

Fuse Online cannot create connectors for REST APIs that support the HTTP 2.0 protocol.

When Fuse Online creates a REST API client connector, it maps each resource operation in the OpenAPI specification to a connection action. The action name and action description come from documentation in the OpenAPI specification.

The more detail that the OpenAPI specification provides, the more support Fuse Online can offer when connecting to the API. For example, the API definition is not required to declare data types for requests and responses. Without type declarations, Fuse Online defines the corresponding connection action as typeless. However, in an integration, you cannot add a data mapping step immediately before or immediately after an API connection that performs a typeless action.

One remedy for this is to add more information to the OpenAPI specification. Identify the OpenAPI resource operations that will map to the actions you want the API connection to perform. In the OpenAPI specification, ensure that there is a JSON schema that specifies each operation’s request and response types.

After you upload the specification, Fuse Online gives you an opportunity to review and edit it in Apicurio Studio, which is a visual editor for designing APIs based on the OpenAPI specification. You can add more detail, save your updates, and Fuse Online creates an API client connector hat incorporates your updates.

If the OpenAPI specification for the API declares support for application/json content type and also application/xml content type then the connector uses the JSON format. If the OpenAPI specification specifies consumes or produces parameters that define both application/json and application/xml, then the connector uses the JSON format.

When Fuse Online tries to obtain authorization to access an OAuth2 application, it uses HTTP basic authentication to provide client credentials. If you need to, you can change this default behavior so that Fuse Online passes client credentials to the provider as parameters instead of using HTTP basic authentication. This affects the use of the tokenUrl endpoint that is used to obtain an OAuth access token.

To specify that Fuse Online should pass client credentials as parameters, in the securityDefinitions section of the OpenAPI specification, add the x-authorize-using-parameters vendor extension with a setting of true. In the example below, the last line specifies x-authorize-using-parameters:

securityDefinitions:
  concur_oauth2:
    type: 'oauth2'
    flow: 'accessCode'
    authorizationUrl: 'https://example.com/oauth/authorize'
    tokenUrl: 'https://example.com/oauth/token'
    scopes:
      LIST: Access List API
    x-authorize-using-parameters: true

The setting of the x-authorize-using-parameters vendor extension is true or false:

If an access token has an expiration date, then Fuse Online integrations that use that token to connect to an application stop running successfully when the taken expires. To obtain a new access token, you must either reconnect to the application or re-register with the application.

If you need to, you can change this default behavior so that Fuse Online automatically requests a new access token in the following situations:

To specify that Fuse Online should automatically try to obtain a new access token in the situations described, in the securityDefinitions section of the OpenAPI specification, add the x-refresh-token-retry-statuses vendor extension. The setting of this extension is a comma separated list that specifies HTTP response status codes. When an access token’s expiration date is reached or when Fuse Online receives a message from an OAuth2 provider and the message has one of these response status codes, then Fuse Online automatically tries to obtain a new access token. In the example below, the last line specifies x-refresh-token-retry-statuses:

securityDefinitions:
  concur_oauth2:
    type: 'oauth2'
    flow: 'accessCode'
    authorizationUrl: 'https://example.com/oauth/authorize'
    tokenUrl: 'https://example.com/oauth/token'
    scopes:
      LIST: Access List API
    x-refresh-token-retry-statuses: 401,402,403

To create an API client connector:

For details about using your new API connector, see Connecting Fuse Online to Applications and Services, Connecting to REST APIs.

You cannot update an API client connector. If there is an update to the API’s OpenAPI specification, then you must do one of the following:

To update integrations to use connections that are based on the updated OpenAPI specification:

You cannot delete a connector when there is a connection that was created from that connector and this connection is being used in an integration. After you delete an API client connector, you cannot use a connection that was created from that connector.

To delete an API client connector:

Before you start to develop an extension, become familiar with the tasks that you will need to accomplish.

An extension defines one of the following:

A business integrator shares requirements with a developer who codes the extension. The developer provides a .jar file that contains the extension. The business integrator uploads the .jar file in Fuse Online to make the custom connector, custom step(s), or library resource available for use within Fuse Online.

An extension .jar file that you upload to Fuse Online always contains exactly one extension.

For an example of uploading and using an extension that provides a step that operates on data between connections, see the AMQ to REST API sample integration tutorial.

An extension is a collection of classes, dependencies, and resources that are packaged in a .jar file.

Fuse Online uses Spring Boot to load an extension. Consequently, you must package an extension according to Spring Boot’s executable JAR format. For example, ensure that you use the ZipEntry.STORED() method to save a nested JAR file.

The structure of a .jar file that packages an extension is as follows:

extension.jar
|
+- META-INF
|  |
|  +- syndesis
|     |
|     +- syndesis-extension-definition.json 1
|
+- mycompany
|  |
|  +-project
|    |
|    +-YourClasses.class 2
|
+- lib 3
  |
  +-dependency1.jar
  |
  +-dependency2.jar

Each extension must have a .json file that defines the extension by specifying values for data structures such as name, description, supported actions, and dependencies. For each extension type, the following table indicates whether Maven can generate the extension definition JSON file and which data structures are required.

*While specification of dependencies is not strictly required, in practice, there are almost always dependencies that you need to specify.

Typically, an extension definition file has the following layout:

{
  "schemaVersion": "v1",
  "name": "",
  "description": "",
  "version": "",
  "extensionId": "",
  "extensionType": "",
  "properties": {
  },
  "actions": [
  ],
  "dependencies": [
  ],
}

The extension-maven-plugin supports extension development by packaging the extension as a valid Spring Boot module. For step extensions that you implement in Java, this plugin can generate the extension definition JSON file.

In your Maven project’s`pom.xml` file, add the following plugin declaration:

<plugin>
    <groupId>io.syndesis.extension</groupId>
    <artifactId>extension-maven-plugin</artifactId>
    <version>${syndesis.version}</version>
    <executions>
        <execution>
        <goals>
            <goal>generate-metadata</goal>
            <goal>repackage-extension</goal>
        </goals>
        </execution>
    </executions>
</plugin>

The extension-maven-plugin defines the following goals:

For example, suppose your Maven project has the following pom.xml file:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

  <modelVersion>4.0.0</modelVersion>
  <groupId>com.company</groupId>
  <artifactId>my-extension</artifactId>
  <version>1.0.0</version>
  <name>MyExtension</name>
  <description>A Sample Extension</description>
  <packaging>jar</packaging>

  <dependencyManagement>
    <dependencies>
      <dependency>
        <groupId>io.syndesis.extension</groupId>
        <artifactId>extension-bom</artifactId>
        <version>1.3.10</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
    </dependencies>
  </dependencyManagement>

  <dependencies>
    <dependency>
      <groupId>io.syndesis.extension</groupId>
      <artifactId>extension-api</artifactId>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>com.github.lalyos</groupId>
      <artifactId>jfiglet</artifactId>
      <version>0.0.8</version>
    </dependency>
  </dependencies>

  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>3.7.0</version>
        <configuration>
          <source>1.8</source>
          <target>1.8</target>
        </configuration>
      </plugin>
      <plugin>
        <groupId>io.syndesis.extension</groupId>
        <artifactId>extension-maven-plugin</artifactId>
        <version>1.3.10</version>
        <executions>
          <execution>
            <goals>
              <goal>generate-metadata</goal>
              <goal>repackage-extension</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
</project>

Based on this pom.xml file, the generated extension definition JSON file looks like this:

{
  "name": "MyExtension",
  "description": "A Sample Extension",
  "extensionId": "com.company:my-extension",
  "version": "1.0.0",
  "dependencies": [ {
    "type": "MAVEN",
    "id": "io.syndesis.extension:extension-api:jar:1.3.10"
  } ],
  "extensionType": "Libraries",
  "schemaVersion": "v1"
}

The generated archive has this structure and content:

my-extension-1.0.0.jar
|
+- lib
|  |
|  + jfiglet-0.0.8.jar
|
+- META-INF
  |
  +- MANIFEST.MF
     |
     +- syndesis
        |
        +- syndesis-extension-definition.json

A step extension implements one or more custom steps. Each custom step implements one action for processing integration data between connections. The following examples demonstrate the alternatives for developing step extensions:

Syndesis provides custom Java annotations that you can use in conjunction with the syndesis-extension-plugin. When you implement a step extension or a connector extension in Java, you can specify annotations that enable Maven to add action definitions to the extension definition JSON file. To enable annotation processing, add the following dependency to your Maven project:

<dependency>
  <groupId>io.syndesis.extension</groupId>
  <artifactId>extension-annotation-processor</artifactId>
  <optional>true</optional>
</dependency>

<?xml version="1.0" encoding="UTF-8"?>
<routes xmlns="http://camel.apache.org/schema/spring"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="
      http://camel.apache.org/schema/spring
      http://camel.apache.org/schema/spring/camel-spring.xsd">

  <route id="log-body-with-prefix">
    <from uri="direct:log"/>
    <choice>
      <when>
        <simple>${header.prefix} != ''</simple>
        <log message="${header.prefix} ${body}"/>
      </when>
      <otherwise>
        <log message="Output ${body}"/>
      </otherwise>
    </choice>
  </route>

</routes>

{
  "actionType": "step",
  "id": "log-body-with-prefix",
  "name": "Log body with prefix",
  "description": "A simple body log with a prefix",
  "descriptor": {
    "kind": "ENDPOINT", 1
    "entrypoint": "direct:log", 2
    "resource": "classpath:log-body-action.xml", 3
    "inputDataShape": {
      "kind": "none"
    },
    "outputDataShape": {
      "kind": "none"
    },
  "propertyDefinitionSteps": [ {
    "description": "extension-properties",
    "name": "extension-properties",
    "properties": { 4
      "prefix": {
        "componentProperty": false,
        "deprecated": false,
        "description": "The Log body prefix message",
        "displayName": "Log Prefix",
        "javaType": "String",
        "kind": "parameter",
        "required": false,
        "secret": false,
        "type": "string"
      }
    }
  } ]
  }
}

import org.apache.camel.builder.RouteBuilder;

import io.syndesis.extension.api.annotations.Action;
import io.syndesis.extension.api.annotations.ConfigurationProperty;

@Action( 1
    id = "log-body-with-prefix",
    name = "Log body with prefix",
    description = "A simple body log with a prefix",
    entrypoint = "direct:log")
public class LogAction extends RouteBuilder {
    @ConfigurationProperty( 2
        name = "prefix",
        description = "The Log body prefix message",
        displayName = "Log Prefix",
        type = "string")
    private String prefix;

    @Override
    public void configure() throws Exception {
        from("direct::start") 3
            .choice()
                .when(simple("${header.prefix} != ''"))
                    .log("${header.prefix} ${body}")
                .otherwise()
                    .log("Output ${body}")
            .endChoice();
    }
}

{
  "id": "log-body-with-prefix",
  "name": "Log body with prefix",
  "description": "A simple body log with a prefix",
  "descriptor": {
    "kind": "ENDPOINT", 1
    "entrypoint": "direct:log", 2
    "resource": "class:io.syndesis.extension.log.LogAction", 3
    "inputDataShape": {
      "kind": "none"
    },
    "outputDataShape": {
      "kind": "none"
    },
    "propertyDefinitionSteps": [ {
      "description": "extension-properties",
      "name": "extension-properties",
      "properties": { 4
        "prefix": {
          "componentProperty": false,
          "deprecated": false,
          "description": "The Log body prefix message",
          "displayName": "Log Prefix",
          "javaType": "java.lang.String",
          "kind": "parameter",
          "required": false,
          "secret": false,
          "type": "string",
          "raw": false
        }
      }
    } ]
  },
  "actionType": "step"
}

import org.apache.camel.Body;
import org.apache.camel.Handler;
import org.apache.camel.Header;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import io.syndesis.extension.api.annotations.Action;
import io.syndesis.extension.api.annotations.ConfigurationProperty;

@Action(
    id = "log-body-with-prefix",
    name = "Log body with prefix",
    description = "A simple body log with a prefix")
public class LogAction  {
    private static final Logger LOGGER = LoggerFactory.getLogger(LogAction.class);

    @ConfigurationProperty(
        name = "prefix",
        description = "The Log body prefix message",
        displayName = "Log Prefix",
        type = "string")
    private String prefix;

    @Handler 1
    public void process(@Header("prefix") String prefix, @Body Object body) {
        if (prefix == null) {
            LOGGER.info("Output {}", body);
        } else {
            LOGGER.info("{} {}", prefix, body);
        }
    }
}

{
  "id": "log-body-with-prefix",
  "name": "Log body with prefix",
  "description": "A simple body log with a prefix",
  "descriptor": {
    "kind": "BEAN", 1
    "entrypoint": "io.syndesis.extension.log.LogAction::process", 2
    "inputDataShape": {
      "kind": "none"
    },
    "outputDataShape": {
      "kind": "none"
    },
    "propertyDefinitionSteps": [ {
      "description": "extension-properties",
      "name": "extension-properties",
      "properties": {
        "prefix": { 3
          "componentProperty": false,
          "deprecated": false,
          "description": "The Log body prefix message",
          "displayName": "Log Prefix",
          "javaType": "java.lang.String",
          "kind": "parameter",
          "required": false,
          "secret": false,
          "type": "string",
          "raw": false
        }
      }
    } ]
  },
  "actionType": "step"
}

import org.apache.camel.Body;
import org.apache.camel.Handler;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import io.syndesis.extension.api.annotations.Action;
import io.syndesis.extension.api.annotations.ConfigurationProperty;

@Action(
    id = "log-body-with-prefix",
    name = "Log body with prefix",
    description = "A simple body log with a prefix")
public class LogAction  {
    private static final Logger LOGGER = LoggerFactory.getLogger(LogAction.class);

    @ConfigurationProperty(
        name = "prefix",
        description = "The Log body prefix message",
        displayName = "Log Prefix",
        type = "string")
    private String prefix;

    public void setPrefix(String prefix) { 1
        this.prefix = prefix;
    }

    public String getPrefix() { 2
        return prefix;
    }

    @Handler
    public void process(@Body Object body) {
        if (this.prefix == null) {
            LOGGER.info("Output {}", body);
        } else {
            LOGGER.info("{} {}", this.prefix, body);
        }
    }
}

import java.util.Map;
import java.util.Optional;

import io.syndesis.extension.api.Step;
import io.syndesis.extension.api.annotations.Action;
import io.syndesis.extension.api.annotations.ConfigurationProperty;
import org.apache.camel.CamelContext;
import org.apache.camel.model.ProcessorDefinition;
import org.apache.camel.util.ObjectHelper;
import org.apache.camel.Expression;
import org.apache.camel.builder.Builder;
import org.apache.camel.processor.aggregate.AggregationStrategy;
import org.apache.camel.processor.aggregate.UseOriginalAggregationStrategy;
import org.apache.camel.spi.Language;

@Action(id = "split", name = "Split", description = "Split your exchange")
public class SplitAction implements Step {

    @ConfigurationProperty(
        name = "language",
        displayName = "Language",
        description = "The language used for the expression")
    private String language;

    @ConfigurationProperty(
        name = "expression",
        displayName = "Expression",
        description = "The expression used to split the exchange")
    private String expression;

    public String getLanguage() {
        return language;
    }

    public void setLanguage(String language) {
        this.language = language;
    }

    public String getExpression() {
        return expression;
    }

    public void setExpression(String expression) {
        this.expression = expression;
    }

    @Override
    public Optional<ProcessorDefinition> configure(
            CamelContext context,
            ProcessorDefinition route,
            Map<String, Object> parameters) { 1

        String languageName = language;
        String expressionDefinition = expression;

        if (ObjectHelper.isEmpty(languageName) && ObjectHelper.isEmpty(expressionDefinition)) {
            route = route.split(Builder.body());
        } else if (ObjectHelper.isNotEmpty(expressionDefinition)) {

            if (ObjectHelper.isEmpty(languageName)) {
                languageName = "simple";
            }

            final Language splitLanguage = context.resolveLanguage(languageName);
            final Expression splitExpression = splitLanguage.createExpression(expressionDefinition);
            final AggregationStrategy aggreationStrategy = new UseOriginalAggregationStrategy(null, false);

            route = route.split(splitExpression).aggregationStrategy(aggreationStrategy);
        }

        return Optional.of(route);
    }
}

{
  "id": "split",
  "name": "Split",
  "description": "Split your exchange",
  "descriptor": {
    "kind": "STEP", 1
    "entrypoint": "io.syndesis.extension.split.SplitAction", 2
    "inputDataShape": {
      "kind": "none"
    },
    "outputDataShape": {
      "kind": "none"
    },
    "propertyDefinitionSteps": [ {
      "description": "extension-properties",
      "name": "extension-properties",
      "properties": {
        "language": {
          "componentProperty": false,
          "deprecated": false,
          "description": "The language used for the expression",
          "displayName": "Language",
          "javaType": "java.lang.String",
          "kind": "parameter",
          "required": false,
          "secret": false,
          "type": "string",
          "raw": false
        },
        "expression": {
          "componentProperty": false,
          "deprecated": false,
          "description": "The expression used to split the exchange",
          "displayName": "Expression",
          "javaType": "java.lang.String",
          "kind": "parameter",
          "required": false,
          "secret": false,
          "type": "string",
          "raw": false
        }
      }
    } ]
  },
  "tags": [],
  "actionType": "step"
}

If Fuse Online does not provide a connector for the application or service that you want to connect to in an integration, an experienced developer can code an extension that contributes a new connector to Fuse Online.

A connector is essentially a proxy for a Camel component. A connector configures the underlying component and creates endpoints according to options that are defined in the extension definition and in user-supplied options that the Fuse Online web interface collects.

The connector extension definition extends the extension definition that is required for step extensions with the following additional data structures:

You can set the above data structures at the action level or at the global level. Settings at the action level have precedence over the same items defined at global level.

public class DataSourceCustomizer implements ComponentProxyCustomizer, CamelContextAware {
    private final static Logger LOGGER = LoggerFactory.getLogger(DataSourceCustomizer.class);

    private CamelContext camelContext;

    @Override
    public void setCamelContext(CamelContext camelContext) { 1
        this.camelContext = camelContext;
    }

    @Override
    public CamelContext getCamelContext() { 2
        return this.camelContext;
    }

    @Override
    public void customize(ComponentProxyComponent component, Map<String, Object> options) {
        if (!options.containsKey("dataSource")) {
            if (options.containsKey("user") && options.containsKey("password") && options.containsKey("url")) {
                try {
                    BasicDataSource ds = new BasicDataSource();

                    consumeOption(camelContext, options, "user", String.class, ds::setUsername); 3
                    consumeOption(camelContext, options, "password", String.class, ds::setPassword); 4
                    consumeOption(camelContext, options, "url", String.class, ds::setUrl); 5

                    options.put("dataSource", ds);
                } catch (@SuppressWarnings("PMD.AvoidCatchingGenericException") Exception e) {
                    throw new IllegalArgumentException(e);
                }
            } else {
                LOGGER.debug("Not enough information provided to set-up the DataSource");
            }
        }
    }
}

public class DataSourceCustomizer implements ComponentProxyCustomizer, CamelContextAware {
    private final static Logger LOGGER = LoggerFactory.getLogger(DataSourceCustomizer.class);

    private CamelContext camelContext;
    private String userName;
    private String password;
    private String url;

    @Override
    public void setCamelContext(CamelContext camelContext) { 1
        this.camelContext = camelContext;
    }

    @Override
    public CamelContext getCamelContext() { 2
        return this.camelContext;
    }

    public void setUserName(String userName) { 3
      this.userName = userName;
    }

    public String getUserName() { 4
      return this.userName;
    }

    public void setPassword(String password) { 5
      this.password = password;
    }

    public String getPassword() { 6
      return this.password;
    }

    public void setUrl(String url) { 7
      this.url = url;
    }

    public String getUrl() { 8
      return this.url;
    }

    @Override
    public void customize(ComponentProxyComponent component, Map<String, Object> options) {
        if (!options.containsKey("dataSource")) {
            if (userName != null && password != null && url != null) {
                try {
                    BasicDataSource ds = new BasicDataSource();
                    ds.setUserName(userName);
                    ds.setPassword(password);
                    ds.setUrl(url);

                    options.put("dataSource", ds);
                } catch (@SuppressWarnings("PMD.AvoidCatchingGenericException") Exception e) {
                    throw new IllegalArgumentException(e);
                }
            } else {
                LOGGER.debug("Not enough information provided to set-up the DataSource");
            }
        }
    }
}

public class AWSS3DeleteObjectCustomizer implements ComponentProxyCustomizer {
  	private String filenameKey;

    public void setFilenameKey(String filenameKey) {
      this.filenameKey = filenameKey;
    }

    public String getFilenameKey() {
        return this.filenameKey;
    }

    @Override
    public void customize(ComponentProxyComponent component, Map<String, Object> options) {
      	component.setBeforeProducer(this::beforeProducer);
    }

    public void beforeProducer(final Exchange exchange) throws IOException {
      	exchange.getIn().setHeader(S3Constants.S3_OPERATION, S3Operations.deleteObject);

    	  if (filenameKey != null) {
    		    exchange.getIn().setHeader(S3Constants.KEY, filenameKey);
    	  }
    }
}

A library extension provides a resource that an integration requires at runtime. A library extension does not contribute steps or connectors to Fuse Online.

Support for library extensions is evolving. In this release, in the Fuse Online web interface:

See the following topics for information about creating library extensions:

{
  "schemaVersion" : "v1",
  "name" : "Example JDBC Driver Library",
  "description" : "Syndesis Extension for adding a custom JDBC Driver",
  "extensionId" : "io.syndesis.extensions:syndesis-library-jdbc-driver",
  "version" : "1.0.0",
  "tags" : [ "jdbc-driver" ],
  "extensionType" : "Libraries"
}

<dependency>
    <groupId>com.company</groupId>
    <artifactId>jdbc-driver</artifactId>
    <version>1.0</version>
    <scope>system</scope>
    <systemPath>${project.basedir}/lib/jdbc-driver-1.0.jar</systemPath>
</dependency>

To make a custom feature available for use in an integration, you upload the extension to Fuse Online as follows:

See also:

After you start using customizations provided in extensions, you can identify the integrations that use those customizations. This is helpful to do before you update or delete an extension.

For details, see: