# Bitnami package for JRuby

## What is JRuby?

> JRuby is a 100% Java implementation of the Ruby programming language. It is Ruby for the JVM. JRuby provides a complete set of core built-in classes and syntax for the Ruby language.

[Overview of JRuby](http://jruby.org/)
Trademarks: This software listing is packaged by Bitnami. The respective trademarks mentioned in the offering are owned by the respective companies, and use of them does not imply any affiliation or endorsement.

## TL;DR

```console
docker run -it --name jruby bitnami/jruby:latest
```

## Why use Bitnami Images?

* Bitnami closely tracks upstream source changes and promptly publishes new versions of this image using our automated systems.
* With Bitnami images the latest bug fixes and features are available as soon as possible.
* Bitnami containers, virtual machines and cloud images use the same components and configuration approach - making it easy to switch between formats based on your project needs.
* All our images are based on [**minideb**](https://github.com/bitnami/minideb) -a minimalist Debian based container image that gives you a small base container image and the familiarity of a leading Linux distribution- or **scratch** -an explicitly empty image-.
* All Bitnami images available in Docker Hub are signed with [Docker Content Trust (DCT)](https://docs.docker.com/engine/security/trust/content_trust/). You can use `DOCKER_CONTENT_TRUST=1` to verify the integrity of the images.
* Bitnami container images are released on a regular basis with the latest distribution packages available.

Looking to use JRuby in production? Try [VMware Tanzu Application Catalog](https://bitnami.com/enterprise), the enterprise edition of Bitnami Application Catalog.

## Supported tags and respective `Dockerfile` links

Learn more about the Bitnami tagging policy and the difference between rolling tags and immutable tags [in our documentation page](https://docs.bitnami.com/tutorials/understand-rolling-tags-containers/).

You can see the equivalence between the different tags by taking a look at the `tags-info.yaml` file present in the branch folder, i.e `bitnami/ASSET/BRANCH/DISTRO/tags-info.yaml`.

Subscribe to project updates by watching the [bitnami/containers GitHub repo](https://github.com/bitnami/containers).

## Get this image

The recommended way to get the Bitnami JRuby Docker Image is to pull the prebuilt image from the [Docker Hub Registry](https://hub.docker.com/r/bitnami/jruby).

```console
docker pull bitnami/jruby:latest
```

To use a specific version, you can pull a versioned tag. You can view the [list of available versions](https://hub.docker.com/r/bitnami/jruby/tags/) in the Docker Hub Registry.

```console
docker pull bitnami/jruby:[TAG]
```

If you wish, you can also build the image yourself by cloning the repository, changing to the directory containing the Dockerfile and executing the `docker build` command. Remember to replace the `APP`, `VERSION` and `OPERATING-SYSTEM` path placeholders in the example command below with the correct values.

```console
git clone https://github.com/bitnami/containers.git
cd bitnami/APP/VERSION/OPERATING-SYSTEM
docker build -t bitnami/APP:latest .
```

## Entering the JRuby Interactive Console

By default, running this image will drop you into the JRuby Interactive Console (`jirb`), where you can interactively test and try things out in JRuby.

```console
docker run -it --name jruby bitnami/jruby:latest
```

**Further Reading:**

* [JRuby Interactive Console Documentation](https://github.com/jruby/jruby/wiki/GettingStarted#jirb-ruby-interactive-console)

## Configuration

### Running your Ruby script

The default work directory for the JRuby image is `/app`. You can mount a folder from your host here that includes your Ruby script, and run it normally using the `ruby` command.

```console
docker run -it --name jruby -v /path/to/app:/app bitnami/jruby:latest \
  ruby script.rb
```

### Running a Ruby app with gems

If your Ruby app has a `Gemfile` defining your app's dependencies and start script, you can install the dependencies before running your app.

```console
docker run -it --name jruby -v /path/to/app:/app bitnami/jruby:latest \
  sh -c "bundle install && jruby script.rb"
```

or by modifying the [`docker-compose.yml`](https://github.com/bitnami/containers/blob/main/bitnami/ruby/docker-compose.yml) file present in this repository:

```yaml
jruby:
  ...
  command: "sh -c 'bundle install && jruby script.rb'"
  volumes:
    - .:/app
  ...
```

**Further Reading:**

* [rubygems.org](https://rubygems.org/)
* [bundler.io](http://bundler.io/)

### Accessing a Ruby app running a web server

This image exposes port `3000` in the container, so you should ensure that your web server is binding to port `3000`, as well as listening on `0.0.0.0` to accept remote connections from your host.

Below is an example of a [Sinatra](http://www.sinatrarb.com/) app listening to remote connections on port `3000`:

```ruby
require 'sinatra'

set :bind, '0.0.0.0'
set :port, 3000

get '/hi' do
  "Hello World!"
end
```

To access your web server from your host machine you can ask Docker to map a random port on your host to port `3000` inside the container.

```console
docker run -it --name jruby -P bitnami/jruby:latest
```

Run `docker port` to determine the random port Docker assigned.

```console
$ docker port jruby
3000/tcp -> 0.0.0.0:32769
```

You can also manually specify the port you want forwarded from your host to the container.

```console
docker run -it --name jruby -p 8080:3000 bitnami/jruby:latest
```

Access your web server in the browser by navigating to `http://localhost:8080`.

## Connecting to other containers

If you want to connect to your Ruby web server inside another container, you can use Docker networking to create a network and attach all the containers to that network.

### Serving your Ruby app through an nginx frontend

We may want to make our Ruby web server only accessible via an nginx web server. Doing so will allow us to setup more complex configuration, serve static assets using nginx, load balance to different Ruby instances, etc.

#### Step 1: Create a network

```console
docker network create app-tier --driver bridge
```

or using Docker Compose:

```yaml
version: '2'

networks:
  app-tier:
    driver: bridge
```

#### Step 2: Create a virtual host

Let's create an nginx virtual host to reverse proxy to our JRuby container.

```nginx
server {
    listen 0.0.0.0:80;
    server_name yourapp.com;

    location / {
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header HOST $http_host;
        proxy_set_header X-NginX-Proxy true;

        # proxy_pass http://[your_jruby_container_link_alias]:3000;
        proxy_pass http://myapp:3000;
        proxy_redirect off;
    }
}
```

Notice we've substituted the link alias name `myapp`, we will use the same name when creating the container.

Copy the virtual host above, saving the file somewhere on your host. We will mount it as a volume in our nginx container.

#### Step 3: Run the JRuby image with a specific name

```console
docker run -it --name myapp \
  --network app-tier \
  -v /path/to/app:/app \
  bitnami/jruby:latest jruby script.rb
```

or using Docker Compose:

```yaml
version: '2'
myapp:
  image: bitnami/jruby:latest
  command: jruby script.rb
  networks:
    - app-tier
  volumes:
    - .:/app
```

#### Step 4: Run the nginx image

```console
docker run -it \
  -v /path/to/vhost.conf:/bitnami/nginx/conf/vhosts/yourapp.conf \
  --network app-tier \
  bitnami/nginx:latest
```

or using Docker Compose:

```yaml
version: '2'
nginx:
  image: bitnami/nginx:latest
  networks:
    - app-tier
  volumes:
    - /path/to/vhost.conf:/bitnami/nginx/conf/vhosts/yourapp.conf
```

## Maintenance

### Upgrade this image

Bitnami provides up-to-date versions of JRuby, including security patches, soon after they are made upstream. We recommend that you follow these steps to upgrade your container.

#### Step 1: Get the updated image

```console
docker pull bitnami/jruby:latest
```

#### Step 2: Stop the running container

Stop the currently running container using the command

```console
docker stop jruby
```

#### Step 3: Remove the currently running container

```console
docker-compose rm -v jruby
```

#### Step 4: Run the new image

Re-create your container from the new image.

```console
docker run --name jruby bitnami/jruby:latest
```

or using Docker Compose:

```console
docker-compose up ruby
```

## Using `docker-compose.yaml`

Please be aware this file has not undergone internal testing. Consequently, we advise its use exclusively for development or testing purposes.

If you detect any issue in the `docker-compose.yaml` file, feel free to report it or contribute with a fix by following our [Contributing Guidelines](https://github.com/bitnami/containers/blob/main/CONTRIBUTING.md).

## Contributing

We'd love for you to contribute to this container. You can request new features by creating an [issue](https://github.com/bitnami/containers/issues) or submitting a [pull request](https://github.com/bitnami/containers/pulls) with your contribution.

## Issues

If you encountered a problem running this container, you can file an [issue](https://github.com/bitnami/containers/issues/new/choose). For us to provide better support, be sure to fill the issue template.

## License

Copyright &copy; 2024 Broadcom. The term "Broadcom" refers to Broadcom Inc. and/or its subsidiaries.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

<http://www.apache.org/licenses/LICENSE-2.0>

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
