Camel JBang

A JBang-based Camel app for easily running Camel routes.

Installation

First you must install JBang which is used for launching Camel. See instructions on JBang how to download and install.

After JBang is installed you can verify JBang is working by executing the following command from a command shell:

jbang version

Which should output the version of JBang.

To make it easier to use Camel JBang then install the following:

jbang app install camel@apache/camel

This will install Apache Camel as the camel command within JBang, meaning that you can run Camel from the command line by just executing camel (see more next).

Using Camel JBang

The Camel JBang supports multiple commands. Running the command below, will print all of them:

camel --help
The first time you run this command, it may cause dependencies to be cached, therefore taking a few extra seconds to run.

All the commands support the --help and will display the appropriate help if that flag is provided.

Enable shell completion

Camel JBang provides shell completion for bash and zsh out of the box. To enable shell completion for Camel JBang, run:

source <(camel completion)

To make it permanent, run:

echo 'source <(camel completion)' >> ~/.bashrc

Creating and running Camel routes

You can create a new basic routes with the init command.

For example to create an XML route you do:

camel init cheese.xml

Which creates the file cheese.xml (in the current directory) with a sample route.

To run the file, you simply do:

camel run cheese.xml
You can create and run any of the supported DSLs in Camel such as YAML, XML, Java, Groovy.

To create a new .java route, you simply do:

camel init foo.java

When using the init command then Camel will by default create the file in the current directory. However, you can use the --directory option to create the file in the specified directory. For example to create in a folder named foobar you can do:

camel init foo.java --directory=foobar
When using --directory then Camel will automatically clean this directory if already exists.

Running Routes from multiple files

You can run more than 1 file, for example to run two YAML files you can do:

camel run one.yaml two.yaml

You can also mix different DSLs such as yaml and Java:

camel run one.yaml hello.java

You can also use wildcards (i.e. *) to match multiple files, such as running all the yaml files:

camel run *.yaml

Or you can run all files starting with foo*

camel run foo*

And to run everything

camel run *
The run goal can also detect files that are properties, such as application.properties.

Dev mode with live reload

You can enable dev mode that comes with live reload of the route(s) when the source file is updated (saved), using the --dev options as shown:

camel run foo.yaml --dev

Then while the Camel integration is running, you can update the YAML route and update when saving.

This works for all DLS even java, so you can do:

camel run hello.java --dev
The live reload is meant for development purposes, and if you encounter problems with reloading such as JVM class loading issues, then you may need to restart the integration.

Developer Console

You can enable the developer console, which presents a variety of information to the developer.

camel run hello.java --console

The console is then accessible from a web browser at: http://localhost:8080/q/dev (by default). The link is also shown in the log when Camel is starting up.

The console can give you insights into your running Camel integration, such as reporting the top routes that takes the longest time to process messages. You can then drill down to pin-point, exactly which individual EIPs in these routes are the slowest.

The developer console can also output the data in JSon format, which for example can be used by 3rd-party tooling to scrape the information.

For example to output the top routes via curl, you can execute:

curl -s -H "Accept: application/json"  http://0.0.0.0:8080/q/dev/top/

And if you have jq installed which can format and output the JSon data in colour, then do:

curl -s -H "Accept: application/json"  http://0.0.0.0:8080/q/dev/top/ | jq

Using profiles

Camel JBang have the concept of profiles. A profile is essentially a name (id) that refers to which configuration to automatic load with Camel JBang. The default profile is named application which is a (smart default) to let Camel JBang automatic load application.properties (if present).

This means that creating profiles matching to a properties file with the same name.

For example having a profile named local, means that Camel JBang will load local.properties instead of application.properties.

To use a profile, you specify as command line option --profile such as:

camel run hello.java --profile=local

You can only specify one profile name, i.e. --profile=local,two is not valid.

In the properties files you can configure all the configurations from Camel Main.

For example to turn off Stream Caching and enable log masking you can specify:

camel.main.streamCaching=false
camel.main.logMask=true

And you can also configure Camel components such as camel-kafka to declare the URL to the brokers:

camel.component.kafka.brokers=broker1:9092,broker2:9092,broker3:9092
Keys starting with camel.jbang are reserved keys that are used by Camel JBang internally, and as well allow for pre-configuring arguments for Camel JBang commands.

Downloading JARs over the internet

By default, Camel JBang will automatically resolve dependencies needed to run Camel, which is done by JBang and Camel respectively. Camel itself detects at runtime if a component has a need for JARs that are not currently available on the classpath, and can then automatic download the JARs (incl transitive).

Camel will download these JARs in the following order:

  1. from local disk in ~/.m2/repository

  2. from internet in Maven Central

  3. from internet in custom 3rd-party Maven repositories

  4. from all the repositories found in active profiles of ~/.m2/settings.xml or a settings file specified using --maven-settings option.

If you do not want Camel JBang to download over the internet, you can turn this off with --download, as shown below:

camel run foo.java --download=false

Adding custom JARs

Camel JBang will automatically detect dependencies for Camel components, languages, data formats, etc. that from its own release. This means you often do not have to specify which JARs to use.

However, if you need to add 3rd-party custom JARs then you can specify these with --deps as CLI argument in Maven GAV syntax (groupId:artifactId:version), such as:

camel run foo.java --deps=com.foo:acme:1.0

In case you need to explicit add a Camel dependency you can use a shorthand syntax (starting with camel: or camel-) such as:

camel run foo.java --deps=camel-saxon

You can specify multiple dependencies separated by comma:

camel run foo.java --deps=camel-saxon,com.foo:acme:1.0

Using 3rd-party Maven repositories

Camel JBang will download from local repository first, and then online from Maven Central. To be able to download from 3rd-party Maven repositories then you need to specify this as CLI argument, ]or in application.properties

camel run foo.java --repos=https://packages.atlassian.com/maven-external
Multiple repositories can be separated by comma

The configuration for the 3rd-party Maven repositories can also be configured in application.properties with the key camel.jbang.repos as shown:

camel.jbang.repos=https://packages.atlassian.com/maven-external

And when running Camel then application.properties is automatically loaded:

camel run foo.java

However, you can also explicit specify the properties file to use:

camel run foo.java application.properties

And even better if you specify this as a profile:

camel run foo.java --profile=application

Where the profile id is the name of the properties file.

Configuration of Maven usage

By default, existing ~/.m2/settings.xml file is loaded, so it is possible to alter the behaviour of Maven resolution process. Maven settings file can provide information about Maven mirrors, credential configuration (potentially encrypted) or active profiles and additional repositories.

Maven repositories can use authentication and the Maven-way to configure credentials is through <server> elements, like this:

<server>
    <id>external-repository</id>
    <username>camel</username>
    <password>{SSVqy/PexxQHvubrWhdguYuG7HnTvHlaNr6g3dJn7nk=}</password>
</server>

While the password may be specified using plain text, it’s better to configure maven master password first and then use it to configure repository password:

$ mvn -emp
[INFO] BuildTimeEventSpy is registered.
Master password: camel
{hqXUuec2RowH8dA8vdqkF6jn4NU9ybOsDjuTmWvYj4U=}

The above password should be added to ~/.m2/settings-security.xml file like this:

<settingsSecurity>
  <master>{hqXUuec2RowH8dA8vdqkF6jn4NU9ybOsDjuTmWvYj4U=}</master>
</settingsSecurity>

Then a normal password can be configured like this:

$ mvn -ep
[INFO] BuildTimeEventSpy is registered.
Password: camel
{SSVqy/PexxQHvubrWhdguYuG7HnTvHlaNr6g3dJn7nk=}

Finally, such password can be used in <server>/<password> configuration.

By default, Maven reads the master password from ~/.m2/settings-security.xml file, but we can override it. Location of the settings.xml file itself can be specified as well:

camel run foo.java --maven-settings=/path/to/settings.xml --maven-settings-security=/path/to/settings-security.xml

If you want to run Camel application without assuming any location (even ~/.m2/settings.xml), use this option:

camel run foo.java --maven-settings=false

Running routes hosted on GitHub

You can run a route that is hosted on GitHub using Camels github resource loader.

For example to run one of the Camel K examples you can do:

camel run github:apache:camel-kamelets-examples:jbang/hello-java/Hey.java

You can also use the https URL for GitHub. For example, you can browse the examples from a web-browser and then copy the URL from the browser window and run the example with Camel JBang:

camel run https://github.com/apache/camel-kamelets-examples/tree/main/jbang/hello-java

You can also use wildcards (i.e. *) to match multiple files, such as running all the groovy files:

camel run https://github.com/apache/camel-kamelets-examples/tree/main/jbang/languages/*.groovy

Or you can run all files starting with rou*

camel run https://github.com/apache/camel-kamelets-examples/tree/main/jbang/languages/rou*

Running routes from GitHub gists

Using gists from GitHub is a quick way to share small Camel routes that you can easily run.

For example to run a gist you simply do:

camel run https://gist.github.com/davsclaus/477ddff5cdeb1ae03619aa544ce47e92

A gist can contain one or more files, and Camel JBang will gather all relevant files, so a gist can contain multiple routes, properties files, Java beans, etc.

Downloading routes hosted on GitHub

We have made it easy for Camel JBang to download existing examples from GitHub to local disk, which allows for modifying the example and to run locally.

All you need to do is to copy the https link from the web browser. For example, you can download the dependency injection example by:

camel init https://github.com/apache/camel-kamelets-examples/tree/main/jbang/dependency-injection

Then the files (not sub folders) are downloaded to the current directory. The example can then be run locally with:

camel run *

You can also download to a new folder using the --directory option, for example to download to a folder named myproject, you would do:

camel init https://github.com/apache/camel-kamelets-examples/tree/main/jbang/dependency-injection --directory=myproject
When using --directory then Camel will automatically clean this directory if already exists.

You can also run in dev mode, to hot-deploy on source code changes.

camel run * --dev

You can also download a single file, such as one of the Camel K examples:

camel init https://github.com/apache/camel-k-examples/blob/main/generic-examples/languages/simple.groovy

This is a groovy route, which you can run with (or use *):

camel run simple.groovy

Downloading routes form GitHub gists

You can also download files from gists easily as shown:

camel init https://gist.github.com/davsclaus/477ddff5cdeb1ae03619aa544ce47e92

This will then download the files to local disk, which you can run afterwards:

camel run *

You can also download to a new folder using the --directory option, for example to download to a folder named foobar, you would do:

camel init https://gist.github.com/davsclaus/477ddff5cdeb1ae03619aa544ce47e92 --directory=foobar
When using --directory then Camel will automatically clean this directory if already exists.

Using a specific Camel version

You can specify which Camel version to run as shown:

jbang run -Dcamel.jbang.version=3.17.0 camel@apache/camel [command]
Older versions of Camel may not work as well with Camel JBang as the newest versions. Starting from Camel 3.18 onwards is the versions that are recommended to be used onwards.

And you can also try bleeding edge development by using SNAPSHOT such as:

jbang run --fresh -Dcamel.jbang.version=3.20.0-SNAPSHOT camel@apache/camel [command]

Running Camel K integrations or bindings

Camel also supports running Camel K integrations and binding files, which are in CRD format (Kubernetes Custom Resource Definitions).

For example a kamelet binding file named joke.yaml:

#!/usr/bin/env jbang camel@apache/camel run
apiVersion: camel.apache.org/v1alpha1
kind: KameletBinding
metadata:
  name: joke
spec:
  source:
    ref:
      kind: Kamelet
      apiVersion: camel.apache.org/v1
      name: chuck-norris-source
    properties:
      period: 2000
  sink:
    ref:
      kind: Kamelet
      apiVersion: camel.apache.org/v1
      name: log-sink
    properties:
      show-headers: false

Can be run with camel:

camel run joke.yaml

Run from clipboard

You can also run Camel routes directly from the OS clipboard. This allows to copy some code, and then quickly run this.

The syntax is

camel run clipboard.<extension>

Where <extension> is what kind of file the content of the clipboard is, such as java, xml, or yaml etc.

For example. you can copy this to your clipboard and then run it afterwards:

<route>
  <from uri="timer:foo"/>
  <log message="Hello World"/>
</route>
camel run clipboard.xml

Controlling local Camel integrations

To list the currently running Camel integrations you use the ps command:

camel ps
  PID   NAME                          READY  STATUS    AGE
 61818  sample.camel.MyCamelApplica…   1/1   Running  26m38s
 62506  dude                           1/1   Running   4m34s

This lists the PID, the name and age of the integration.

You can use the stop command to stop any of these running Camel integrations. For example to stop dude, you can do

camel stop dude
Stopping running Camel integration (pid: 62506)

You can also stop by the PID:

camel stop 62506
Stopping running Camel integration (pid: 62506)
You do not have to type the full name, as the stop command will match using integrations that starts with the input, for example you can do camel stop d to stop all integrations starting with d.

To stop all integrations then you need to use the --all option as follows:

camel stop --all
Stopping running Camel integration (pid: 61818)
Stopping running Camel integration (pid: 62506)

Controlling Spring Boot and Quarkus integrations

The Camel JBang CLI will by default only control Camel integrations that are running using the CLI, eg camel run foo.java.

For the CLI to be able to control and manage Spring Boot or Quarkus applications, then you need to add a dependency to these projects to integrate with Camel CLI.

In Spring Boot you add the following dependency:

<dependency>
    <groupId>org.apache.camel.springboot</groupId>
    <artifactId>camel-cli-connector-starter</artifactId>
</dependency>

In Quarkus you need to add the following dependency:

<dependency>
    <groupId>org.apache.camel.quarkus</groupId>
    <artifactId>camel-quarkus-cli-connector</artifactId>
</dependency>

Getting status of Camel integrations

The get command in Camel JBang is used for getting Camel specific status for one or all of the running Camel integrations.

To display the status of the running Camel integrations:

camel get
  PID   NAME      CAMEL            PLATFORM            READY  STATUS    AGE    TOTAL  FAILED  INFLIGHT  SINCE-LAST
 61818  MyCamel   3.20.0-SNAPSHOT  Spring Boot v2.7.3   1/1   Running  28m34s    854       0         0     0s/0s/-
 63051  dude      3.20.0-SNAPSHOT  JBang                1/1   Running     18s     14       0         0     0s/0s/-
 63068  mygroovy  3.20.0-SNAPSHOT  JBang                1/1   Running      5s      2       0         0     0s/0s/-

The camel get command will default display integrations, which is equivalent to typing camel get integrations or camel get int.

This displays overall information for every Camel integration, where you can see the total number of messages processed. The column Since Last shows how long time ago the last processed message for 3 stages (started/completed/failed).

The value of 0s/0s/- means that the last started and completed message just happened (0 seconds ago), and that there has not been any failed message yet. And this example 9s/9s/1h3m means that last started and completed message is 9 seconds ago, and last failed is 1 hour and 3 minutes ago.

You can also see the status of every routes, from all the local Camel integrations with camel get route:

camel get route
  PID   NAME      ID      FROM                        STATUS    AGE   TOTAL  FAILED  INFLIGHT  MEAN  MIN  MAX  SINCE-LAST
 61818  MyCamel   hello   timer://hello?period=2000   Running  29m2s    870       0         0     0    0   14     0s/0s/-
 63051  dude      java    timer://java?period=1000    Running    46s     46       0         0     0    0    9     0s/0s/-
 63068  mygroovy  groovy  timer://groovy?period=1000  Running    34s     34       0         0     0    0    5     0s/0s/-
Use camel get --help to display all the available commands as additional will be added in upcoming releases.

Top status of Camel integrations

The camel top command is intended for getting top utilization statistics (highest to lowest heap used memory) of the running Camel integrations.

camel top
  PID   NAME     JAVA     CAMEL            PLATFORM            STATUS    AGE         HEAP        NON-HEAP     GC     THREADS   CLASSES
 22104  chuck    11.0.13  3.20.0-SNAPSHOT  JBang               Running   2m10s  131/322/4294 MB  70/73 MB  17ms (6)      7/8  7456/7456
 14242  MyCamel  11.0.13  3.20.0-SNAPSHOT  Spring Boot v2.7.3  Running  33m40s  115/332/4294 MB  62/66 MB  37ms (6)    16/16  8428/8428
 22116  bar      11.0.13  3.20.0-SNAPSHOT  JBang               Running    2m7s   33/268/4294 MB  54/58 MB  20ms (4)      7/8  6104/6104

The HEAP column shows the heap memory (used/committed/max) and the non-heap (used/committed). The GC column shows garbage collection information (time and total runs). The CLASSES column shows number of classes (loaded/total).

You can also see the top performing routes (highest to lowest mean processing time) of every routes, from all the local Camel integrations with camel top route:

camel top route
  PID   NAME     ID                     FROM                                 STATUS    AGE    TOTAL  FAILED  INFLIGHT  MEAN  MIN  MAX  SINCE-LAST
 22104  chuck    chuck-norris-source-1  timer://chuck?period=10000           Started     10s      1       0         0   163  163  163          9s
 22116  bar      route1                 timer://yaml2?period=1000            Started      7s      7       0         0     1    0   11          0s
 22104  chuck    chuck                  kamelet://chuck-norris-source        Started     10s      1       0         0     0    0    0          9s
 22104  chuck    log-sink-2             kamelet://source?routeId=log-sink-2  Started     10s      1       0         0     0    0    0          9s
 14242  MyCamel  hello                  timer://hello?period=2000            Started  31m41s    948       0         0     0    0    4          0s
Use camel top --help to display all the available commands as additional will be added in upcoming releases.

Starting and Stopping routes

The camel cmd is intended for executing miscellaneous commands in the running Camel integrations. For example there are commands to start and stop routes.

To stop all the routes in the chuck integration, you execute:

camel cmd stop-route chuck

And the status will then report the status as Stopped for the chuck integration:

camel get route
  PID   NAME     ID                     FROM                                 STATUS    AGE   TOTAL  FAILED  INFLIGHT  MEAN  MIN  MAX  SINCE-LAST
 81663  chuck    chuck                  kamelet://chuck-norris-source        Stopped           600       0         0     0    0    1          4s
 81663  chuck    chuck-norris-source-1  timer://chuck?period=10000           Stopped           600       0         0    65   52  290          4s
 81663  chuck    log-sink-2             kamelet://source?routeId=log-sink-2  Stopped           600       0         0     0    0    1          4s
 83415  bar      route1                 timer://yaml2?period=1000            Started  5m30s    329       0         0     0    0   10          0s
 83695  MyCamel  hello                  timer://hello?period=2000            Started  3m52s    116       0         0     0    0    9          1s

To start the routes, you can do:

camel cmd start-route chuck

To stop all routes in every Camel integration you need to use the --all flag as follows:

camel cmd stop-route --all

And you can start all routes using:

camel cmd start-route --all
You can stop one or more route by their ids by separating using comma such as: camel cmd start-route --id=route1,hello. Use camel cmd start-route --help for more details.

Configuring logging levels

You can see the current logging levels of the running Camel integrations by:

camel cmd logger
  PID   NAME   AGE   LOGGER  LEVEL
 90857  bar   2m48s  root    INFO
 91103  foo     20s  root    INFO

The logging level can be change at runtime, for example to change foo to DEBUG you execute:

camel cmd logger --level=DEBUG foo
You can use --all to change logging levels for all running integrations.

Listing services

Some Camel integrations may host a service which clients can call, such as REST, or SOAP-WS, or socket-level services using TCP protocols.

You can list the available services as shown in the example below:

camel get service
 PID   NAME       COMPONENT      PROTOCOL  SERVICE
 1912  netty      netty          tcp       tcp:localhost:4444
 2023  greetings  platform-http  rest      http://0.0.0.0:7777/camel/greetings/{name} (GET)
 2023  greetings  platform-http  http      http://0.0.0.0:7777/q/dev

Here you can see 2 Camel integrations. The netty integration hosts a TCP service that is available on port 4444. The other Camel integration hosts a REST service that can be called via GET only. And finally the integration comes with embedded web console (started with the --console option).

For a service to be listed then Camel components must be able to advertise the services using Camel Console.

Listing state of Circuit Breakers

If your Camel integration uses Circuit Breaker then you can output the status of the breakers with Camel JBang as follows:

camel get circuit-breaker
  PID   NAME  COMPONENT     ROUTE   ID               STATE      PENDING  SUCCESS  FAIL  REJECT
 56033  mycb  resilience4j  route1  circuitBreaker1  HALF_OPEN        5        2     3       0

Here we can see the circuit breaker is in half open state, i.e. a state where the breaker is attempting to transition back to closed, if the failures start to drop.

You can run the command with watch to keep showing the latest state watch camel get circuit-breaker.

Using Jolokia and Hawtio

The Hawtio web console allows inspecting running Camel integrations, such as all the JMX management information, and not but least to visualize the Camel routes with live performance metrics. Hawtio is a handy tool for many years, and we have made it easy to use Hawtio with Camel JBang.

To let Hawtio able to inspect the Camel integrations, then the Jolokia JVM Agent must be installed in the running integration, this can be done, either explicit as follows:

camel ps
  PID   NAME                          READY  STATUS    AGE
 61818  sample.camel.MyCamelApplica…   1/1   Running  26m38s
 62506  dude.java                      1/1   Running   4m34s

With the PID you can then attach Jolokia:

camel jolokia 62506
Started Jolokia for PID 62506
http://127.0.0.1:8778/jolokia/

Instead of using PID you can also attach by name pattern. In this example because the two Camel integrations have unique names (foo and dude), then you can also attach Jolokia without knowing the PID as follows:

camel jolokia du
Started Jolokia for PID 62506
http://127.0.0.1:8778/jolokia/

Then you can launch Hawtio using Camel JBang:

camel hawtio

This will automatically download and start Hawtio, and open in web browser.

See camel hawtio --help for options.

And when Hawtio launches in the web browser, click the Discover tab which should list all the local available Jolokia Agents (yes you can use camel jolokia PID to connect to multiple different Camel integrations and from this list select which to load).

Click the green lightning icon to connect to running Camel integration (of choice).

You can uninstall the Jolokia JVM Agent in a running Camel integration when no longer needed:

camel jolokia 62506 --stop
Stopped Jolokia for PID 62506

It is also possible to do this with only one command, as follows:

camel hawtio dude

Where dude is the name of the running Camel integration. When you stop Hawtio (using ctrl + c) then Camel will attempt to uninstall the Jolokia JVM Agent, however this may not be able to do this always, because the JVM is being terminated which can prevent camel-jbang from doing JVM process communication to the running Camel integration.

Scripting from terminal using pipes

You can also execute a Camel JBang file as a script that can be used for terminal scripting with pipes and filters.

Every time the script is executed a JVM is started with Camel. This is not very fast or low on memory usage, so use Camel JBang terminal scripting where using Camel makes sense. For example to use the many Camel components or Kamelets to more easily send or receive data from disparate IT systems.

This requires to add the following line in top of the file, for example as in the upper.yaml file below:

///usr/bin/env jbang --quiet camel@apache/camel pipe "$0" "$@" ; exit $?

# Will upper-case the input
- from:
    uri: "stream:in"
    steps:
      - setBody:
          simple: "${body.toUpperCase()}"
      - to: "stream:out"

To be able to execute this as a script, you need to set execute file permission:

chmod +x upper.yaml

Then you can then execute this as a script:

echo "Hello\nWorld" | ./upper.yaml

Which should output:

HELLO
WORLD

Logging can be turned on using --logging=true which then logs to .camel-jbang/camel-pipe.log file. The name of the logging file cannot be configured.

echo "Hello\nWorld" | ./upper.yaml --logging=true

Using stream:in with line vs raw mode

When using stream:in to read data from System in then the Stream component works in two modes:

  • line mode (default) - reads input as single lines (separated by line breaks). Message body is a String.

  • raw mode - reads the entire stream until end of stream. Message body is a byte[].

The default mode is due to historically how the stream component was created. Therefore, you may want to set stream:in?readLine=false to use raw mode.

Running local Kamelets

You can also use Camel JBang to try local Kamelets, without the need to publish them on GitHub or package them in a jar.

camel run --local-kamelet-dir=/path/to/local/kamelets earthquake.yaml

Using platform-http component

When a route is started from platform-http then Camel JBang will automatically include a VertX HTTP server running on port 8080. For example the following route in a file named server.yaml:

- from:
    uri: "platform-http:/hello"
    steps:
      - set-body:
          constant: "Hello World"

Can be run with

camel run server.yaml

And you can call the HTTP service with:

$ curl http://localhost:8080/hello
Hello World%

Using Java beans and processors

There is basic support for including regular Java source files together with Camel routes, and let Camel JBang runtime compile the Java source. This means you can include smaller utility classes, POJOs, Camel Processors and whatnot that the application needs.

The Java source files cannot use package names. This may change in the future.

Dependency Injection in Java classes

When running Camel integrations with camel-jbang, then the runtime is camel-main based. This means there is no Spring Boot, or Quarkus available. However, we have added support for using annotation based dependency injection in Java classes.

Using Camel dependency injection

You can use the following Camel annotations on Camel standalone:

  • @org.apache.camel.BindToRegistry on class level to create an instance of the class and register in the Registry.

  • @org.apache.camel.Configuration on class level to create an instance of the class and register in the Registry.

And these annotations should work on all runtimes (if target runtime is either Quarkus or Spring Boot then favour using their annotations):

  • @org.apache.camel.BeanInject to dependency inject a bean on a class field.

  • @org.apache.camel.PropertyInject to inject a property placeholder. Such as a property defined in application.properties.

  • @org.apache.camel.BindToRegistry on a method to create a bean by invoking the method.

  • @org.apache.camel.Converter on class level to auto-register the type converters from the class.

Using Spring Boot dependency injection

You can use the following Spring Boot annotations:

  • @org.springframework.stereotype.Component or @org.springframework.stereotype.Service on class level to create an instance of the class and register in the Registry.

  • @org.springframework.beans.factory.annotation.Autowired to dependency inject a bean on a class field. @org.springframework.beans.factory.annotation.Qualifier can be used to specify the bean id.

  • @org.springframework.beans.factory.annotation.Value to inject a property placeholder. Such as a property defined in application.properties.

  • @org.springframework.context.annotation.Bean on a method to create a bean by invoking the method.

Using Quarkus injection

You can use the following Quarkus annotations:

  • @javax.enterprise.context.ApplicationScoped or @javax.inject.Singleton on class level to create an instance of the class and register in the Registry. @javax.inject.Named can be used to specify the bean id.

  • @javax.inject.Inject to dependency inject a bean on a class field. @javax.inject.Named can be used to specify the bean id.

  • @org.eclipse.microprofile.config.inject.ConfigProperty to inject a property placeholder. Such as a property defined in application.properties.

  • @javax.enterprise.inject.Produces on a method to create a bean by invoking the method. @javax.inject.Named can be used to specify the bean id.

Debugging

There are two kinds of debugging:

  • Java debugging - Java code debugging (Standard Java)

  • Camel route debugging - Debugging Camel routes (requires Camel tooling plugins)

Java debugging

You can debug your integration scripts by making use of the --debug flag provided by JBang. However, due to Java debugging must be enabled when starting the JVM, then you must do this using the jbang command, instead of camel as shown:

jbang --debug  camel@apache/camel run hello.yaml
Listening for transport dt_socket at address: 4004

As you can see the default listening port is 4004 but can be configured as described in JBang Debugging.

This is a standard Java debug socket. You can then use the IDE of your choice. For instance, see the generic documentation for IntelliJ, VS Code and Eclipse Desktop. You will surely want to add Processor to be able to put breakpoints hit during route execution (as opposed to route definition creation).

Camel route debugging

The Camel route debugger is available by default (the camel-debug component is automatically added to the classpath). By default, it can be reached through JMX at the URL service:jmx:rmi:///jndi/rmi://localhost:1099/jmxrmi/camel.

You can then use the Integrated Development Environment (IDE) of your choice. For instance IntelliJ, VS Code or Eclipse Desktop.

A specific how-to is available for VS Code, see this video or this /blog/2022/05/start-camel-quarkus-application-with-camel-textual-debug-in-vscode/[blogpost].

Health Checks

The status of health checks can be accessed via Camel JBang from the CLI as follows:

camel get health
  PID   NAME    AGE  ID             RL  STATE  RATE    SINCE   MESSAGE
 61005  mybind   8s  camel/context   R   UP    2/2/-  1s/3s/-

Here we can see the Camel is UP. The application has just been running for 8 seconds, and the has been 2 health checks invoked.

The output is showing the default level of checks as:

  • CamelContext health check

  • Component specific health checks (such as from camel-kafka or camel-aws, …​)

  • Custom health checks

  • Any check which are not UP

The RATE column shows 3 numbers separated by /. So 2/2/- means 2 checks in total, 2 success, - no failures. The two last columns will reset when a health check changes state as this number is the number of consecutive checks that was successful or failure. So if the health check starts to fail then the numbers could be:

camel get health
  PID   NAME     AGE   ID             RL  STATE   RATE    SINCE    MESSAGE
 61005  mybind   3m2s  camel/context   R   UP    77/-/3  1s/-/17s  some kind of error

Here we can see the numbers is changed to 77/-/3. This means the total is 77. There is no success, but the check has been failing 3 times in a row. The SINCE column corresponds to the RATE. So in this case we can see the last check was 1 second ago, and that the check has been failing for 17 second in a row.

You can use --level=full to output every health checks; which will include consumer and route level checks as well.

A health check may often be failed due to an exception was thrown which can be shown via --trace flag:

camel get health --trace
  PID   NAME      AGE   ID                                      RL  STATE    RATE       SINCE     MESSAGE
 61038  mykafka  6m19s  camel/context                            R   UP    187/187/-  1s/6m16s/-
 61038  mykafka  6m19s  camel/kafka-consumer-kafka-not-secure…   R  DOWN   187/-/187  1s/-/6m16s  KafkaConsumer is not ready - Error: Invalid url in bootstrap.servers: value


------------------------------------------------------------------------------------------------------------------------
                                                       STACK-TRACE
------------------------------------------------------------------------------------------------------------------------
	PID: 61038
	NAME: mykafka
	AGE: 6m19s
	CHECK-ID: camel/kafka-consumer-kafka-not-secured-source-1
	STATE: DOWN
	RATE: 187
	SINCE: 6m16s
	METADATA:
		bootstrap.servers = value
		group.id = 7d8117be-41b4-4c81-b4df-cf26b928d38a
		route.id = kafka-not-secured-source-1
		topic = value
	MESSAGE: KafkaConsumer is not ready - Error: Invalid url in bootstrap.servers: value
	org.apache.kafka.common.KafkaException: Failed to construct kafka consumer
		at org.apache.kafka.clients.consumer.KafkaConsumer.<init>(KafkaConsumer.java:823)
		at org.apache.kafka.clients.consumer.KafkaConsumer.<init>(KafkaConsumer.java:664)
		at org.apache.kafka.clients.consumer.KafkaConsumer.<init>(KafkaConsumer.java:645)
		at org.apache.kafka.clients.consumer.KafkaConsumer.<init>(KafkaConsumer.java:625)
		at org.apache.camel.component.kafka.DefaultKafkaClientFactory.getConsumer(DefaultKafkaClientFactory.java:34)
		at org.apache.camel.component.kafka.KafkaFetchRecords.createConsumer(KafkaFetchRecords.java:241)
		at org.apache.camel.component.kafka.KafkaFetchRecords.createConsumerTask(KafkaFetchRecords.java:201)
		at org.apache.camel.support.task.ForegroundTask.run(ForegroundTask.java:123)
		at org.apache.camel.component.kafka.KafkaFetchRecords.run(KafkaFetchRecords.java:125)
		at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
		at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
		at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
		at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
		at java.base/java.lang.Thread.run(Thread.java:829)
	Caused by: org.apache.kafka.common.config.ConfigException: Invalid url in bootstrap.servers: value
		at org.apache.kafka.clients.ClientUtils.parseAndValidateAddresses(ClientUtils.java:59)
		at org.apache.kafka.clients.ClientUtils.parseAndValidateAddresses(ClientUtils.java:48)
		at org.apache.kafka.clients.consumer.KafkaConsumer.<init>(KafkaConsumer.java:730)
		... 13 more

Here we can easily see that the health check is failing because of the org.apache.kafka.common.config.ConfigException which is due to invalid configuration: Invalid url in bootstrap.servers: value.

Use camel get health --help to see all the various options.

Listing what Camel components is available

Camel comes with a lot of artifacts out of the box which comes as:

  • components

  • data formats

  • expression languages

  • miscellaneous components

  • kamelets

You can use the Camel CLI to list what Camel provides via the camel catalog command. For example to list all the components

camel catalog components

And to see which Kamelets are available:

camel catalog kamelets
Use camel catalog --help to see all possible commands.

Displaying component documentation

The doc goal can show quick documentation for every component, dataformat, kamelets etc. For example to see the kafka component you run:

camel doc kafka
The documentation is not the full documentation as shown on the website, as the Camel CLI does not have direct access to this information and can only show a basic description of the component, but include tables for every configuration option.

To see the documentation for jackson dataformat:

camel doc jackson

In some rare cases then there may be a component and dataformat with the same name, and the doc goal prioritizes components. In such a situation you can prefix the name with dataformat, i.e:

camel doc dataformat:thrift

You can also see the kamelet documentation such as shown:

camel doc aws-kinesis-sink

Browsing online documentation from the Camel website

You can use the doc command to quickly open the url in the web browser for the online documentation. For example to browse the kafka component, you use --open-url:

camel doc kafka --open-url

This also works for data formats, languages, kamelets etc.

camel doc aws-kinesis-sink --open-url
To just get the link to the online documentation, then use camel doc kafka --url.

Filtering options listed in the tables

Some components may have many options, and in such cases you may use --filter to only list options that match the filter in either name, description, or the group (producer, security, advanced etc).

For example to list only security related options:

camel doc kafka --filter=security

And to list only something about timeout:

camel doc kafka --filter=timeout

Open API

Camel JBang allows to quickly expose an Open API service using contract first approach, where you have an existing OpenAPI specification file.

Then Camel JBang is able to bridge each API endpoints from the OpenAPI specification to a Camel route with the naming convention direct:<operationId>.

This make it quick to implement a Camel route for a given operation.

See the open-api example for more details.

Gathering list of dependencies

When working with Camel JBang then dependencies are automatically resolved. This means that you do not have to use a build system like Maven or Gradle to add every Camel components as a dependency.

However, you may want to know what dependencies are required to run the Camel integration. To see this, you can use the dependencies command. The command output does not output a detailed tree, such as mvn dependencies:tree, as the output is intended to list which Camel components, and other JARs needed (when using Kamelets).

The dependency output by default is vanilla Apache Camel with the camel-main as runtime, as shown below:

camel dependencies
org.apache.camel:camel-dsl-modeline:3.20.0
org.apache.camel:camel-health:3.20.0
org.apache.camel:camel-kamelet:3.20.0
org.apache.camel:camel-log:3.20.0
org.apache.camel:camel-rest:3.20.0
org.apache.camel:camel-stream:3.20.0
org.apache.camel:camel-timer:3.20.0
org.apache.camel:camel-yaml-dsl:3.20.0
org.apache.camel.kamelets:camel-kamelets-utils:0.9.3
org.apache.camel.kamelets:camel-kamelets:0.9.3

The output is by default a line per maven dependency in GAV format (groupId:artifactId:version).

You can also specify the output should be in Maven format as shown:

camel dependencies --output=maven
<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-main</artifactId>
    <version>3.20.0</version>
</dependency>
<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-dsl-modeline</artifactId>
    <version>3.20.0</version>
</dependency>
<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-health</artifactId>
    <version>3.20.0</version>
</dependency>
<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-kamelet</artifactId>
    <version>3.20.0</version>
</dependency>
<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-log</artifactId>
    <version>3.20.0</version>
</dependency>
<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-rest</artifactId>
    <version>3.20.0</version>
</dependency>
<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-stream</artifactId>
    <version>3.20.0</version>
</dependency>
<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-timer</artifactId>
    <version>3.20.0</version>
</dependency>
<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-yaml-dsl</artifactId>
    <version>3.20.0</version>
</dependency>
<dependency>
    <groupId>org.apache.camel.kamelets</groupId>
    <artifactId>camel-kamelets-utils</artifactId>
    <version>0.9.3</version>
</dependency>
<dependency>
    <groupId>org.apache.camel.kamelets</groupId>
    <artifactId>camel-kamelets</artifactId>
    <version>0.9.3</version>
</dependency>

You can also choose the target runtime as either quarkus or spring-boot as shown:

camel dependencies --runtime=spring-boot
org.springframework.boot:spring-boot-starter-actuator:2.7.5
org.springframework.boot:spring-boot-starter-web:2.7.5
org.apache.camel.springboot:camel-spring-boot-engine-starter:3.20.0
org.apache.camel.springboot:camel-dsl-modeline-starter:3.20.0
org.apache.camel.springboot:camel-kamelet-starter:3.20.0
org.apache.camel.springboot:camel-log-starter:3.20.0
org.apache.camel.springboot:camel-rest-starter:3.20.0
org.apache.camel.springboot:camel-stream-starter:3.20.0
org.apache.camel.springboot:camel-timer-starter:3.20.0
org.apache.camel.springboot:camel-yaml-dsl-starter:3.20
org.apache.camel.kamelets:camel-kamelets-utils:0.9.3
org.apache.camel.kamelets:camel-kamelets:0.9.3

Creating Projects

You can export your Camel JBang integration to a traditional Java based project such as Spring Boot or Quarkus.

You may want to do this after you have built a prototype using Camel JBang, and are in need of a traditional Java based project with more need for Java coding, or wanting to use the powerful runtimes of Spring Boot, Quarkus or vanilla Camel Main.

Exporting to Camel Spring Boot

The command export --runtime=spring-boot will export your current Camel JBang file(s) to a Maven based Spring Boot project with files organized in src/main/ folder structure.

For example to export to Spring Boot using the Maven groupId com.foo and the artifactId acme and with version 1.0-SNAPSHOT you simply execute:

camel export --runtime=spring-boot --gav=com.foo:acme:1.0-SNAPSHOT
This will export to the current directory, meaning that files are moved into the needed folder structure.

To export to another directly (copies the files) you execute:

camel export --runtime=spring-boot --gav=com.foo:acme:1.0-SNAPSHOT --directory=../myproject

When exporting to Spring Boot then the Camel version defined in the pom.xml or build.gradle is the same version as Camel JBang uses. However, you can specify the Camel version as shown below:

camel export --runtime=spring-boot --gav=com.foo:acme:1.0-SNAPSHOT --directory=../myproject --camel-spring-boot-version=3.18.3
See the possible options by running: camel export --help for more details.

Exporting to Camel Quarkus

The command export --runtime=quarkus will export your current Camel JBang file(s) to a Maven based Quarkus project with files organized in src/main/ folder structure.

For example to export to Quarkus using the Maven groupId com.foo and the artifactId acme and with version 1.0-SNAPSHOT you simply execute:

camel export --runtime=quarkus --gav=com.foo:acme:1.0-SNAPSHOT
This will export to the current directory, meaning that files are moved into the needed folder structure.

To export to another directly (copies the files) you execute:

camel export --runtime=quarkus --gav=com.foo:acme:1.0-SNAPSHOT --directory=../myproject
See the possible options by running: camel export --help for more details.

Exporting to Camel Main

The command export --runtime=camel-main will export your current Camel JBang file(s) to a Maven based vanilla Camel Main project with files organized in src/main/ folder structure.

For example to export to Camel Main using the Maven groupId com.foo and the artifactId acme and with version 1.0-SNAPSHOT you simply execute:

camel export --runtime=camel-main --gav=com.foo:acme:1.0-SNAPSHOT
This will export to the current directory, meaning that files are moved into the needed folder structure.

To export to another directly (copies the files) you execute:

camel export --runtime=camel-main --gav=com.foo:acme:1.0-SNAPSHOT --directory=../myproject
See the possible options by running: camel export --help for more details.

Exporting as Gradle Project

Camel JBang exports by default as a Maven based project. To use Gradle instead, you can specify the --build-tool=gradle when exporting, such as:

camel export --build-tool=gradle --runtime=spring-boot --gav=com.foo:acme:1.0-SNAPSHOT --directory=../myproject

Exporting with JMX management included

Usually when exporting to Spring Boot, Quarkus or Camel Main, then JMX management is not included out of the box. To include JMX, you need to add camel:management in the --deps option, as shown below:

camel export --runtime=quarkus --gav=com.foo:acme:1.0-SNAPSHOT --deps=camel:management --directory=../myproject

Exporting with Camel CLI included

Usually when exporting to Spring Boot, Quarkus or Camel Main, then Camel JBang CLI is not included out of the box. To be able to continue to use Camel CLI (i.e. camel), you need to add camel:cli-connector in the --deps option, as shown below:

camel export --runtime=quarkus --gav=com.foo:acme:1.0-SNAPSHOT --deps=camel:cli-connector --directory=../myproject

Configuring exporting

The export command will by default load configuration from application.properties which also can be used to specific parameters for export such as selecting the runtime and java version.

The follow options related to exporting, can be configured in application.properties:

Option Description

camel.jbang.runtime

Runtime (spring-boot, quarkus, or camel-main)

camel.jbang.gav

The Maven group:artifact:version

camel.jbang.dependencies

Additional dependencies (Use commas to separate multiple dependencies). See more details at Adding custom JARs.

camel.jbang.javaVersion

Java version (11 or 17)

camel.jbang.kameletsVersion

Apache Camel Kamelets version

camel.jbang.localKameletDir

Local directory for loading Kamelets

camel.jbang.camelSpringBootVersion

Camel version to use with Spring Boot

camel.jbang.springBootVersion

Spring Boot version

camel.jbang.quarkusGroupId

Quarkus Platform Maven groupId

camel.jbang.quarkusArtifactId

Quarkus Platform Maven artifactId

camel.jbang.quarkusVersion

Quarkus Platform version

camel.jbang.mavenWrapper

Include Maven Wrapper files in exported project

camel.jbang.gradleWrapper

Include Gradle Wrapper files in exported project

camel.jbang.buildTool

Build tool to use (maven or gradle)

camel.jbang.repos

Additional maven repositories for download on-demand (Use commas to separate multiple repositories)

camel.jbang.mavenSettings

Optional location of maven setting.xml file to configure servers, repositories, mirrors and proxies. If set to false, not even the default ~/.m2/settings.xml will be used.

camel.jbang.mavenSettingsSecurity

Optional location of maven settings-security.xml file to decrypt settings.xml

camel.jbang.exportDir

Directory where the project will be exported

These are options from the export command, so you can see mor details and default values using camel export --help.

Troubleshooting

When using JBang then JBang stores state in ~/.jbang directory. This is also the location where JBang stores downloaded JARs.

Camel JBang also downloads needed dependencies while running. However, these dependencies are downloaded to your local Maven repository ~/.m2.

So if you find problems with running Camel JBang using what is seems like an outdated JAR, then you can try to delete these directories, or parts of it.