[[contributing]]
= Contributing to Camel K

We love contributions!

The https://github.com/apache/camel-k/[main project] is written in https://golang.org/[go] and contains some parts written in Java for the https://github.com/apache/camel-k-runtime/[integration runtime].
Camel K is built on top of Kubernetes through *Custom Resource Definitions*.

[[how]]
== How can I contribute?

There are many ways you can contribute to Camel K, not only software development, as well as with the rest of Camel community:

* Contribute actively to development (see the section below)
* Use it and report any feedback, improvement or bug you may find via https://github.com/apache/camel-k/[Github], link:/community/mailing-list/[mailing list] or https://camel.zulipchat.com[chat].
* Contribute by writing missing documentation or blog posts about the features around Camel K
* https://twitter.com/ApacheCamel[Tweet], like and socialize Camel K in your preferred social network
* Enjoy the talks that the contributors submit in various conferences around the world

[[requirements]]
== Requirements

In order to build the project, you need to comply with the following requirements:

* **Go version 1.15+**: needed to compile and test the project. Refer to the https://golang.org/[Go website] for the installation.
* **GNU Make**: used to define composite build actions. This should be already installed or available as a package if you have a good OS (https://www.gnu.org/software/make/).

The Camel K Java runtime (camel-k-runtime) requires:

* **Java 11**: needed for compilation
* **Maven**: needed for building

[[checks]]
== Running checks
Checks rely on `golangci-lint` being installed, to install it look at the https://github.com/golangci/golangci-lint#local-installation[Local Installation] instructions.

You can run checks via `make lint`, or you can install a GIT pre-commit hook and have the checks run via https://pre-commit.com[pre-commit]; then make sure to install the pre-commit hooks after installing pre-commit by running:

 $ pre-commit install

[[checking-out]]
== Checking Out the Sources

You can create a fork of https://github.com/apache/camel-k[this project] from GitHub, then clone your fork with the `git` command line tool.

[[structure]]
== Structure

This is a high-level overview of the project structure:

.Structure
[options="header"]
|=======================
| Path						| Content
| https://github.com/apache/camel-k/tree/main/build[/build]			| Contains the Docker and Maven build configuration.
| https://github.com/apache/camel-k/tree/main/cmd[/cmd]			| Contains the entry points (the *main* functions) for the **camel-k** binary (manager) and the **kamel** client tool.
| https://github.com/apache/camel-k/tree/main/config[/config]		| Contains Kubernetes resource files, specifically for use with the operator-sdk, that are used by the **kamel** client during installation. The `/pkg/resources/resources.go` file is kept in sync with the content of the directory (`make build-resources`), so that resources can be used from within the go code.
| https://github.com/apache/camel-k/tree/main/deploy[/deploy]		| Contains Kubernetes resource files, used by the **kamel** client during installation. The `/pkg/resources.go` file is kept in sync with the content of the directory (`make build-resources`), so that resources can be used from within the go code.
| https://github.com/apache/camel-k/tree/main/docs[/docs]			| Contains the documentation website based on https://antora.org/[Antora].
| https://github.com/apache/camel-k/tree/main/e2e[/e2e]			| Include integration tests to ensure that the software interacts correctly with Kubernetes and OpenShift.
| https://github.com/apache/camel-k/tree/main/examples[/examples]			| Various examples of Camel K usage.
| https://github.com/apache/camel-k/tree/main/pkg[/pkg]			| This is where the code resides. The code is divided in multiple subpackages.
| https://github.com/apache/camel-k/tree/main/script[/script]		| Contains scripts used during make operations for building the project.
|=======================

[[building]]
== Building

To build the whole project you now need to run:

[source]
----
make
----

This executes a full build of the Go code. If you need to build the components separately you can execute:

* `make build-operator`: to build the operator binary only.
* `make build-kamel`: to build the `kamel` client tool only.

After a successful build, if you're connected to a Docker daemon, you can build the operator Docker image by running:

[source]
----
make images
----

The above command produces a `camel-k` image with the name `docker.io/apache/camel-k`. Sometimes you might need to produce `camel-k` images that need to be pushed to the custom repository e.g. `docker.io/myrepo/camel-k`, to do that you can pass a parameter `STAGING_IMAGE_NAME` to `make` as shown below:

[source]
----
make STAGING_IMAGE_NAME='docker.io/myrepo/camel-k' images-push-staging
----

[[testing]]
== Testing

Unit tests are executed automatically as part of the build. They use the standard go testing framework.

Integration tests (aimed at ensuring that the code integrates correctly with Kubernetes and OpenShift), need special care.
Integration tests are all in the https://github.com/apache/camel-k/tree/main/e2e[/e2e] dir.

For more detail on integration testing, refer to the following documentation:

- xref:contributing/e2e.adoc[End To End local integration test]

[[running]]
== Running

If you want to install everything you have in your source code and see it running on Kubernetes, you need to run the following command:

=== For Red Hat CodeReady Containers (CRC)

* You need to have https://docs.docker.com/get-docker/[Docker] installed and running (or connected to a Docker daemon)
* You need to set up Docker daemon to https://docs.docker.com/registry/insecure/[trust] CRC's insecure Docker registry which is exposed by default through the route `default-route-openshift-image-registry.apps-crc.testing`. One way of doing that is to instruct the Docker daemon to trust the certificate:
** `oc extract secret/router-ca --keys=tls.crt -n openshift-ingress-operator`: to extract the certificate
** `sudo cp tls.crt /etc/docker/certs.d/default-route-openshift-image-registry.apps-crc.testing/ca.crt`: to copy the certificate for Docker daemon to trust
** `docker login -u kubeadmin -p $(oc whoami -t) default-route-openshift-image-registry.apps-crc.testing`: to test that the certificate is trusted
* Run `make install-crc`: to build the project and install it in the current namespace on CRC
* You can specify a different namespace with `make install-crc project=myawesomeproject`
* To uninstall Camel K, run `kamel uninstall --all --olm=false`

The commands assume you have an already running CRC instance and logged in correctly.

=== For Minikube

* Run `make install-minikube`: to build the project and install it in the current namespace on Minikube

This command assumes you have an already running Minikube instance with registry enabled (can be enabled with `minikube addons enable registry`) and no previous Camel K instance installed.

=== For remote Kubernetes/OpenShift clusters

If you have changed anything locally and want to apply the changes to a remote cluster, first push your `camel-k` image to a custom repository (see <<building>>) and run the following command (the image name `docker.io/myrepo/camel-k:1.5.0-SNAPSHOT` should be changed accordingly):

[source]
----
kamel install --operator-image=docker.io/myrepo/camel-k:1.5.0-SNAPSHOT --operator-image-pull-policy=Always --olm=false
----

Note `--olm=false` is necessary as otherwise the OLM bundle version is preferred.

=== Use

Now you can play with Camel K:

[source]
----
./kamel run examples/Sample.java
----

To add additional dependencies to your routes:

[source]
----
./kamel run -d camel-dns examples/dns.js
----

[[local-development]]
== Local development environment
If you need to develop and test your Camel K operator locally, you can follow the link:local-development.html[local development procedure].

[[debugging]]
== Debugging and Running from IDE

Sometimes it's useful to debug the code from the IDE when troubleshooting.

.**Debugging the `kamel` binary**

It should be straightforward: just execute the https://github.com/apache/camel-k/tree/main/cmd/kamel/main.go[/cmd/kamel/main.go] file from the IDE (e.g. Goland) in debug mode.

.**Debugging the operator**

It is a bit more complex (but not so much).

You are going to run the operator code **outside** OpenShift in your IDE so, first of all, you need to **stop the operator running inside**:

[source]
----
// use kubectl in plain Kubernetes
oc scale deployment/camel-k-operator --replicas 0
----

You can scale it back to 1 when you're done, and you have updated the operator image.

You can set up the IDE (e.g. Goland) to execute the https://github.com/apache/camel-k/blob/main/cmd/manager/main.go[/cmd/manager/main.go] file in debug mode with `operator` as the argument.

When configuring the IDE task, make sure to add all required environment variables in the *IDE task configuration screen*:

* Set the `KUBERNETES_CONFIG` environment variable to point to your Kubernetes configuration file (usually `<homedir>/.kube/config`).
* Set the `WATCH_NAMESPACE` environment variable to a Kubernetes namespace you have access to.
* Set the `OPERATOR_NAME` environment variable to `camel-k`.


After you set up the IDE task, with Java 11+ to be used by default, you can run and debug the operator process.

NOTE: The operator can be fully debugged in CRC, because it uses OpenShift S2I binary builds under the hood.
The build phase cannot be (currently) debugged in Minikube because the Kaniko builder requires that the operator and the publisher pod share a common persistent volume.

[[publishing]]
== Building Metadata for Publishing the Operator in Operator Hub

Publishing to an operator hub requires creation and submission of metadata, required in a specific
https://github.com/operator-framework/operator-registry/#manifest-format[format]. The
https://sdk.operatorframework.io/docs/cli[operator-sdk] provides tools to help with the creation of this metadata.

=== `bundles`
The latest packaging format used for deploying the operator to an OLM registry. This generates a CSV and related metadata
files in a directory named `bundle`. The directory contains a Dockerfile that allows for building the bundle into a
single image. It is this image that is submitted to the OLM registry.

To generate the bundle for camel-k, use the following command:
----
make bundle
----
The bundle directory is created at the root of the camel-k project filesystem.
