If you want to contribute documentation to this project which manages the docs with AsciiBinder, you’ve come to the right place.

Installing AsciiBinder

AsciiBinder is distributed as a Ruby gem, use the gem command to install it:

gem install ascii_binder

But be aware of one additional prerequisite:

Java: AsciiBinder bundles ditaa for ASCII-based diagramming support. However, ditaa depends upon a Java runtime to transform ASCII diagrams into image files. So, make sure you have a JVM installed (OpenJDK works fine) and set the ${JAVA_HOME} environment variable so that ditaa can find the JVM.

Making a Copy of the OpenNMS Docs Repo

If you already know how to use git, then this is going to sound very familiar. If not, here’s the full walk-through:

  1. Install git.

  2. If the docs source is hosted on GitHub, you will probably next need to fork the OpenNMS Helm repo.

  3. Using git, clone the repo (either the original or your fork, as appropriate) to your local system: git clone <repo URL>

If the project that you are working in already has version branches, then you will want to set up local copies of those as well. After you have cloned the repo to your local system, you can track those branches with the command:

$ git checkout -b <local_branch_name> <remote_repo>/<remote_branch_name>

Write the Docs

The documentation for the project lives in the docs directory within the source code repository you have checked out. Each main section is structured in directories and contain the text .adoc files. The text files need to be written in the AsciiDoc format.

Every new created directory or text file needs to be included in the general structure of the documentation. Within the _topic_map.yml the generic layout is defined.

Structure of the _topic_map.yml file
Name: Project Info (1)
Dir: project-info (2)
Topics: (3)
  - Name: Welcome (4)
    File: index (5)
  - Name: How to Build the Docs
    File: how-to-build-docs
Name: Architecture (6)
Dir: architecture
    - Name: Overview
      File: index
1 Friendly section name Project Info which is used in the left navigation
2 Directory name with the files which are shown under Project Info
3 Each topic in Project Info
4 Friendly name in the left navigation
5 Text file with the content, the .adoc extension is automatically appended
6 Second second Architecture with a reference to a directory which contains the topics

In case images needs to be included, use a directory images inside a topic folder. Within the text file images are included as the following:

// At the beginning of the .adoc text file
:imagesdir: ./images(1)

.Overview of the structure of Helm(2)
image::helm-diagram.svg[Helm Diagram, 600](3)
1 Lookup directory for images for this text file
2 Description of the image
3 Include the image with an alternative text and a proportional with of 600 pixels

The _distro_map.yml is used to control the overall behavior how docs are generated for different branches and distributions. It is normally not necessary to touch this file just by creating or changing existing content. Anyways the file is described as the following:

helm: (1)
  name: Helm
  author: OpenNMS Docs Team <opennms-docs@lists.sourceforge.net>
  site: opennms (2)
  site_name: OpenNMS
  site_url: https://docs.opennms.org/helm
    master: (3)
      name: Latest (4)
      dir: latest (5)
1 System name of distro, used when conditionalizing content on a per-distro basis.
2 System name of site, used to pick up the correct index file and organize the included distros.
3 Git branch name that represents a version of this distro
4 User-readable name of this version of this distro
5 Directory on the site where this version of this distro should go

Building the Docs

The documentation is located in the docs directory. Transforming an AsciiBinder repo into a bunch of documentation is pretty easy:

asciibinder build <docs_dir>
Running just the asciibinder binary command in the docs directory is equivalent to asciibinder build.

Build Output

AsciiBinder starts by reading the distro config file and then it processes docs multiple times - once for every distribution defined in the distro config file, multiplied by every branch. You can see the HTML produced by this process under the _preview directory in the docs directory.

Previews are organized by distro and then by branch; the generic path to a given version of the docs is:


The branch_dir_name, which comes from the distro config file, is not necessarily identical to the branch name. Following on this build behavior, the simplest way to inspect the output of your build is to open a web browser and navigate to the file that you want, in the distro / branch path that you are working with. However, have a look at the section on Instant Preview for information on how to get instant feedback on your modifications.

Instant Preview with LiveReload

If you are interested in seeing instant feedback on your changes to an AsciiDoc file, you can take advantage of AsciiBinder’s live preview capability by running:

asciibinder watch

When you do this, you are starting a Guard process that runs in the foreground on that terminal. To gain the full effects of the guard, first you will need to prepare your web browser with a LiveReload plugin - check here for the most up-to-date plugins and instructions.

Working with Instant Preview

With asciibinder watch running in a terminal, and an HTML file from your _preview area open in a webbrowser, you can enable LiveReload in the browser. Once you have done that, any time you save the source .adoc file for the HTML page that you are watching, AsciiBinder will automatically rebuild the page and your browser will update with the changes. If you are new to AsciiDoc, or if you are trying out a new layout, this is a helpful way of getting instant feedback on your work.

Exiting Instant Preview

To stop the asciibinder watch process, you can either:

  • Type exit and hit <ENTER>` or

  • Press <CTRL>+C to break out of the Guard shell

Packaging Sites for Publication

The site packaging action performs three distinct operations:

  1. Clean out previously generated content from the _preview and _package directories

  2. Build the docs as per asciibinder build

  3. Based on rules in the _distro_map.yml file, selectively copy content from the _preview area into the _package area on a site-by-site basis.

The result of this is that the _package are will contain a subdirectory for each site that is being built, and all of the files in those site directories will be ready for direct copying onto the site’s web server.

Invoking the package action is very simple:

asciibinder package

Presently, AsciiBinder does not include logic to actually push the files out to the hosting server. This is better done with a CI system (like Jenkins) that can rebuild the docs in response to changes in the source code and then automatically redeploy the websites using something like rsync.

For information on how to configure a site, refer to the Maintainer’s Guide.

Cleaning Out Build & Package Artifacts

To clean up the the contents of the _preview and _package directories and start fresh, you can run:

asciibinder clean