README.md - brooklyn-docs - Git at Google

 Brooklyn Website and Docs Source
 ================================

 Contributor Workflow
 --------------------

 The contributor workflow is identical to that used by the main project, with
 pull requests and contributor licenses required. Therefore you should
 familiarise yourself with the standard workflow for Apache Brooklyn:

 * [Guide for contributors][CONTRIB]
 * [Guide for committers][COMMIT]

 [CONTRIB]: https://brooklyn.apache.org/community/how-to-contribute-docs.html
 [COMMIT]: https://brooklyn.apache.org/developers/committers/index.html

 The documents are written in [kramdown](http://kramdown.gettalong.org/syntax.html) a superset of Markdown
 which is processed into HTML using [Jekyll](https://jekyllrb.com/). In addition to the standard set of options
 and notation available with these platforms, a number of custom plug-ins have been implemented specifically
 for the Brooklyn docs. These are detailed in the [contributing to docs](https://brooklyn.apache.org/contributing) doc.

 Workstation Setup
 -----------------

 First, if you have not already done so, clone the `brooklyn` repository and subprojects
 and set up the remotes as described in [Guide for committers][COMMIT].

 The Brooklyn documentation uses [Jekyll](https://jekyllrb.com/) to process the site content into HTML.
 This in turn requires Ruby and gems as described in the `Gemfile`:
 install [RVM](http://rvm.io/) to manage Ruby installations and sets of Ruby gems.

     curl -sSL https://get.rvm.io | bash -s stable --auto-dotfiles

 Close your shell session and start a new one, to get the new
 environment that RVM has configured. Change directory to the location where
 this project is (where this file is located).

 RVM should detect its configuration inside `Gemfile` and try to configure itself.
 Most likely it will report that the required version of Ruby is not installed,
 and it will show the command that you need to run to install the correct version.
 Follow the instructions it shows, typically something like `rvm get master && rvm install 3.1.2`
 (confirm version on [Gemfile](./Gemfile)).

 Once the correct version of Ruby is installed, change to your home directory
 and then change back (`cd ~ ; cd -`).
 This will cause RVM to re-load configuration from `Gemfile` with the correct version of Ruby.

 Finally, run this command to install all the required Gems
 at the correct versions:

     bundle install

 Any time you need to reset your Ruby environment for `jekyll` to run correctly,
 go to this directory (or the `_build` subdir) and re-run the above command.

 On some platforms there may be some fiddling required before `jekyll` runs without errors,
 but the ecosystem is fairly mature and most problems can be resolved with a bit of googling.
 Some issues we've encountered are:

  * on Mac, install xcode and its command-line tools
  * if ruby gets confused about versions,
    [clean out your gems](http://judykat.com/ken-judy/force-bundler-rebuild-ruby-rails-gemset/)
  * if `libxml2` fails, set `bundle config build.nokogiri --use-system-libraries` before the install
    (more details [here](http://www.nokogiri.org/tutorials/installing_nokogiri.html))
  * on Ubuntu, `sudo apt-get install libxslt-dev libxml2-dev libcurl4-openssl-dev python-minimal`
  * if openssl library headers are not found, set the dir explicitly, eg for `eventmachine` try `gem install eventmachine -- --with-openssl-dir=/usr/local/opt/openssl@1.1`
  * if `libv8` complains: `gem install libv8 -- --with-system-v8` or eg `gem install libv8 -v '3.16.14.19' -- --with-system-v8`
  * for rubyracer to find v8: `gem install therubyracer -- --with-v8-dir=/usr/local/opt/v8@3.15`
     * needs v8 installed by brew as: brew install v8-315


 If you are building the PDF documentation, this requires [wkhtmltopdf](http://wkhtmltopdf.org/).
 You can download it from [here](http://wkhtmltopdf.org/downloads.html) or use the usual apt-get / yum / brew.

 Seeing the Website and Docs
 ---------------------------

 To build and see most of the documentation, run this command in this folder:

     jekyll serve

 This will start up a local web server. The URL is printed by Jekyll when the server starts,
 e.g. http://localhost:4000/ . The server will continue to run until you press Ctrl+C.
 Modified files will be detected and regenerated (but that might take up to 1m).
 Add `--no-watch` argument to turn off regeneration, or use `jekyll build` instead
 to generate a site in `_site` without a server.

 This does <i>not</i> generate API docs and certain other material;
 see the notes on `_build/build.sh` below for that.


 Project Structure
 -----------------

 Note that there are two interlinked micro-sites in this project:

 * `/website`: this contains the main Brooklyn website, including committer instructions,
   download instructions, and "learn more" pages;
   this content has **only one instance** on the live website,
   and as changes are published they replace old content

 * `/guide`: this contains the user guide and information pertaining to a
   specific Brooklyn version, including code structure and API documentation;
   the live website contains a **copy of the guide for each Brooklyn version**,
   with the code coming from the corresponding branch in `git`

 In addition note the following folders:

 * `/style`: contains JS, CSS, and image resources;
   on the live website, this folder is installed at the root *and*
   into archived versions of the guide.

 * `/_build`: contains build scripts and configuration files,
   and tests for some of the plugins

 * `/_plugins`: contains Jekyll plugins which supply tags and generation
   logic for the sites, including links and tables of contents

 * `/_layouts`: contains HTML templates used by pages

 * `/_includes`: contains miscellaneous content used by templates and pages

 Jekyll automatically excludes any file or folder beginning with `_`
 from direct processing, so these do *not* show up in the `_site` folder
 (except where they are embedded in other files).

 **A word on branches:**  The `/website` folder can be built against any branch;
 typically changes are made and published from `master`, to ensure that all versions
 are listed correctly.
 In contrast the `/guide` folder should be updated and built against the branch for which
 instructions are being made, e.g. `master` for latest snapshot updates,
 or `0.7.0-M2` for that milestone release.
 It *is* permitted to make changes to docs (and docs only!) after a release has
 been made. In most cases, these changes should also be made to master.


 Website Structure
 -----------------

 The two micro-sites above are installed on the live website as follows:

 * `/`: contains the website
 * `/v/<version>`: contains specific versions of the guide,
   with the special folder `/v/latest` containing the recent preferred stable/milestone version

 The site itself is hosted at `brooklyn.apache.org` with a `CNAME`
 record from `brooklyn.io`.

 Content is published to the site by updating an
 Apache subversion repository, `brooklyn-site-public` at
 `https://svn.apache.org/repos/asf/brooklyn/site`.
 See below for more information.


 Building the Website and Guide
 ------------------------------

 For most users, the `jekyll serve` command described above is sufficient to test changes locally.
 The main reason to use the build scripts (and to read this section) is to push changes to the server
 (requires Apache Brooklyn commit rights), or to test generated content such as API docs.

 The build is controlled by config files in `_build/` and accessed through `_build/build.sh`.
 There are a number of different builds possible; to list these, run:

     _build/build.sh help

 The normal build outputs to `_site/`.  The three builds which are most relevant to updating the live site are:

 * **website-root**: to build the website only, in the root
 * **guide-latest**: to build the guide only, in `/v/latest/`
 * **guide-version**: to build the guide only, in the versioned namespace e.g. `/v/<version>/`

 There are some others, including `test-both`, which apply slightly different configurations
 useful for testing.
 Supported options beyond that include `--serve`, to start a web browser serving the content of `_site/`,
 and `--skip-javadoc`, to speed up the build significantly by skipping javadoc generation.
 A handy command for testing the live files, analogous to `jekyll serve`
 but with the correct file structure, and then checking links, is:

     _build/build.sh test-both --skip-javadoc --serve

 And to run link-checks quickly (without validating external links), use:

     htmlproof --href_ignore "https?://127.*" --alt_ignore ".*" --disable_external _site


 Preparing for a Release
 -----------------------

 When doing a release and changing versions:

 * Before branching:
   * Change the `brooklyn-stable-version` variable in `_config.yml`
   * Update `website/meta/versions.md` with a bit of info on this release
 *  In the branch, with `change-version.sh` run (e.g. from `N.SNAPSHOT` to `N`)
   * Ensure the `guide/start/release-notes.md` file is current
   * Build and publish `website-root`, `guide-latest`, and `guide-version`
 * In master, with `change-version.sh` run (e.g. to `N+1-SNAPSHOT`)
   * Clear old stuff in the `guide/start/release-notes.md` file
   * Optionally build and public `guide-version`


 Publishing the Website and Guide
 --------------------------------

 The Apache website publication process is based around the Subversion repository;
 the generated HTML files must be checked in to Subversion, whereupon an automated process
 will publish the files to the live website.
 So, to push changes the live site, you will need to have the website directory checked out
 from the Apache subversion repository. We recommend setting this up as a sibling to your
 `brooklyn` git project directory:

     # verify we're in the right location and the site does not already exist
     ls _build/build.sh || { echo "ERROR: you should be in the docs/ directory to run this command" ; exit 1 ; }
     ls ../../brooklyn-site-public > /dev/null && { echo "ERROR: brooklyn-site-public dir already exists" ; exit 1 ; }
     pushd `pwd -P`/../..

     svn --non-interactive --trust-server-cert co https://svn.apache.org/repos/asf/brooklyn/site brooklyn-site-public

     # verify it
     cd brooklyn-site-public
     ls style/img/apache-brooklyn-logo-244px-wide.png || { echo "ERROR: checkout is wrong" ; exit 1 ; }
     export BROOKLYN_SITE_DIR=`pwd`
     popd
     echo "SUCCESS: checked out site in $BROOKLYN_SITE_DIR"

 With this checked out, the `build.sh` script can automatically copy generated files into the right subversion sub-directories
 with the `--install` option.  (This assumes the relative structure described above; if you have a different
 structure, set BROOKLYN_SITE_DIR to point to the directory as above.  Alternatively you can copy files manually,
 using the instructions in `build.sh` as a guide.)

 A typical update consists of the following commands (or a subset),
 copied to `${BROOKLYN_SITE_DIR-../../brooklyn-site-public}`:

     # ensure svn repo is up-to-date (very painful otherwise)
     cd ${BROOKLYN_SITE_DIR-../../brooklyn-site-public}
     svn up
     cd -

     # versioned guide, safe for snapshots, relative to /v/<version>/
     _build/build.sh guide-version --install

     # main website, if desired, relative to /
     _build/build.sh website-root --install

     # this version as the latest guide, if desired, relative to /v/latest/
     _build/build.sh guide-latest --install

 (If HTML-Proofer find failures, then fix the links etc. Unfortunately, the javadoc build
 gives a lot of warnings. Fixing those is not part of this activity).

 You can then preview the public site of [localhost:4000](http://localhost:4000) with:

     _build/serve-public-site.sh

 Next it is recommended to go to the SVN dir and
 review the changes using the usual `svn` commands -- `status`, `diff`, `add`, `rm`, etc.
 Note in particular that deleted files need special attention (there is no analogue of
 `git add -A`!). Look at deletions carefully, to try to avoid breaking links, but once
 you've done that these commands might be useful:

     cd ${BROOKLYN_SITE_DIR-../../brooklyn-site-public}
     svn add * --force
     export DELETIONS=$( svn status | sed -e '/^!/!d' -e 's/^!//' )
     if [ ! -z "${DELETIONS}" ] ; then svn rm ${DELETIONS} ; fi

 Then check in the changes (probably picking a better message than shown here):

     svn ci -m 'Update Brooklyn website'

 The changes should become live within a few minutes.

 SVN commits can be **slow**, particularly if you've regenerated javadoc.
 (The date is included in all javadoc files so the commands above will cause *all* javadoc to be updated.)
 Use `_build/build.sh guide-version --install --skip-javadoc` to update master while re-using the previously installed javadoc.
 That command will fail if javadoc has not been generated for that version.


 More Notes on the Code
 ----------------------

 # Plugins

 We use some custom Jekyll plugins, in the `_plugins` dir:

 * include markdown files inside other files (see, for example, the `*.include.md` files
   which contain text which is used in multiple other files)
   * `read_jekyll` will read a file and jekyll-process it (eg for nested `{% ... readj ` calls;
     it's just like `include_relative` but with two differences: when `readj` is used
     nested `read_jekyll` calls are relative to the included file where it is contained,
     rather than relative to the root md file which made the first `read_jekyll` call
     (so in general it's more intuitive than `include_relative`),
     and `include_relative` processes front matter whereas `read_jekyll` mangles it
   * `read_literal` is like `read_jekyll` but without the jekyll/tag processing
   * `read` will autodetect based on filename -- jekyll for `*.md` and literal for all others
 * generate the site structure / menu objects
 * parse JSON which we can loop over in our markdown docs (to build up models; previously used
   for the TOC in the guide, but now replaced with site_structure)
 * trim whitespace of ends of variables


 # Versions

 Archived versions are kept under `/v/` in the website.  New versions should be added with
 the appropriate directory (`_build/build.sh guide-version` above will do this).
 These versions take their own copy of the `style` files so that changes there will not affect future versions.

 A list of available versions is in `website/meta/versions.md`.
	Brooklyn Website and Docs Source
	================================

	Contributor Workflow
	--------------------

	The contributor workflow is identical to that used by the main project, with
	pull requests and contributor licenses required. Therefore you should
	familiarise yourself with the standard workflow for Apache Brooklyn:

	* [Guide for contributors][CONTRIB]
	* [Guide for committers][COMMIT]

	[CONTRIB]: https://brooklyn.apache.org/community/how-to-contribute-docs.html
	[COMMIT]: https://brooklyn.apache.org/developers/committers/index.html

	The documents are written in [kramdown](http://kramdown.gettalong.org/syntax.html) a superset of Markdown
	which is processed into HTML using [Jekyll](https://jekyllrb.com/). In addition to the standard set of options
	and notation available with these platforms, a number of custom plug-ins have been implemented specifically
	for the Brooklyn docs. These are detailed in the [contributing to docs](https://brooklyn.apache.org/contributing) doc.

	Workstation Setup
	-----------------

	First, if you have not already done so, clone the `brooklyn` repository and subprojects
	and set up the remotes as described in [Guide for committers][COMMIT].

	The Brooklyn documentation uses [Jekyll](https://jekyllrb.com/) to process the site content into HTML.
	This in turn requires Ruby and gems as described in the `Gemfile`:
	install [RVM](http://rvm.io/) to manage Ruby installations and sets of Ruby gems.

	curl -sSL https://get.rvm.io \| bash -s stable --auto-dotfiles

	Close your shell session and start a new one, to get the new
	environment that RVM has configured. Change directory to the location where
	this project is (where this file is located).

	RVM should detect its configuration inside `Gemfile` and try to configure itself.
	Most likely it will report that the required version of Ruby is not installed,
	and it will show the command that you need to run to install the correct version.
	Follow the instructions it shows, typically something like `rvm get master && rvm install 3.1.2`
	(confirm version on [Gemfile](./Gemfile)).

	Once the correct version of Ruby is installed, change to your home directory
	and then change back (`cd ~ ; cd -`).
	This will cause RVM to re-load configuration from `Gemfile` with the correct version of Ruby.

	Finally, run this command to install all the required Gems
	at the correct versions:

	bundle install

	Any time you need to reset your Ruby environment for `jekyll` to run correctly,
	go to this directory (or the `_build` subdir) and re-run the above command.

	On some platforms there may be some fiddling required before `jekyll` runs without errors,
	but the ecosystem is fairly mature and most problems can be resolved with a bit of googling.
	Some issues we've encountered are:

	* on Mac, install xcode and its command-line tools
	* if ruby gets confused about versions,
	[clean out your gems](http://judykat.com/ken-judy/force-bundler-rebuild-ruby-rails-gemset/)
	* if `libxml2` fails, set `bundle config build.nokogiri --use-system-libraries` before the install
	(more details [here](http://www.nokogiri.org/tutorials/installing_nokogiri.html))
	* on Ubuntu, `sudo apt-get install libxslt-dev libxml2-dev libcurl4-openssl-dev python-minimal`
	* if openssl library headers are not found, set the dir explicitly, eg for `eventmachine` try `gem install eventmachine -- --with-openssl-dir=/usr/local/opt/openssl@1.1`
	* if `libv8` complains: `gem install libv8 -- --with-system-v8` or eg `gem install libv8 -v '3.16.14.19' -- --with-system-v8`
	* for rubyracer to find v8: `gem install therubyracer -- --with-v8-dir=/usr/local/opt/v8@3.15`
	* needs v8 installed by brew as: brew install v8-315


	If you are building the PDF documentation, this requires [wkhtmltopdf](http://wkhtmltopdf.org/).
	You can download it from [here](http://wkhtmltopdf.org/downloads.html) or use the usual apt-get / yum / brew.

	Seeing the Website and Docs
	---------------------------

	To build and see most of the documentation, run this command in this folder:

	jekyll serve

	This will start up a local web server. The URL is printed by Jekyll when the server starts,
	e.g. http://localhost:4000/ . The server will continue to run until you press Ctrl+C.
	Modified files will be detected and regenerated (but that might take up to 1m).
	Add `--no-watch` argument to turn off regeneration, or use `jekyll build` instead
	to generate a site in `_site` without a server.

	This does <i>not</i> generate API docs and certain other material;
	see the notes on `_build/build.sh` below for that.


	Project Structure
	-----------------

	Note that there are two interlinked micro-sites in this project:

	* `/website`: this contains the main Brooklyn website, including committer instructions,
	download instructions, and "learn more" pages;
	this content has only one instance on the live website,
	and as changes are published they replace old content

	* `/guide`: this contains the user guide and information pertaining to a
	specific Brooklyn version, including code structure and API documentation;
	the live website contains a copy of the guide for each Brooklyn version,
	with the code coming from the corresponding branch in `git`

	In addition note the following folders:

	* `/style`: contains JS, CSS, and image resources;
	on the live website, this folder is installed at the root and
	into archived versions of the guide.

	* `/_build`: contains build scripts and configuration files,
	and tests for some of the plugins

	* `/_plugins`: contains Jekyll plugins which supply tags and generation
	logic for the sites, including links and tables of contents

	* `/_layouts`: contains HTML templates used by pages

	* `/_includes`: contains miscellaneous content used by templates and pages

	Jekyll automatically excludes any file or folder beginning with `_`
	from direct processing, so these do not show up in the `_site` folder
	(except where they are embedded in other files).

	A word on branches: The `/website` folder can be built against any branch;
	typically changes are made and published from `master`, to ensure that all versions
	are listed correctly.
	In contrast the `/guide` folder should be updated and built against the branch for which
	instructions are being made, e.g. `master` for latest snapshot updates,
	or `0.7.0-M2` for that milestone release.
	It is permitted to make changes to docs (and docs only!) after a release has
	been made. In most cases, these changes should also be made to master.


	Website Structure
	-----------------

	The two micro-sites above are installed on the live website as follows:

	* `/`: contains the website
	* `/v/<version>`: contains specific versions of the guide,
	with the special folder `/v/latest` containing the recent preferred stable/milestone version

	The site itself is hosted at `brooklyn.apache.org` with a `CNAME`
	record from `brooklyn.io`.

	Content is published to the site by updating an
	Apache subversion repository, `brooklyn-site-public` at
	`https://svn.apache.org/repos/asf/brooklyn/site`.
	See below for more information.


	Building the Website and Guide
	------------------------------

	For most users, the `jekyll serve` command described above is sufficient to test changes locally.
	The main reason to use the build scripts (and to read this section) is to push changes to the server
	(requires Apache Brooklyn commit rights), or to test generated content such as API docs.

	The build is controlled by config files in `_build/` and accessed through `_build/build.sh`.
	There are a number of different builds possible; to list these, run:

	_build/build.sh help

	The normal build outputs to `_site/`. The three builds which are most relevant to updating the live site are:

	* website-root: to build the website only, in the root
	* guide-latest: to build the guide only, in `/v/latest/`
	* guide-version: to build the guide only, in the versioned namespace e.g. `/v/<version>/`

	There are some others, including `test-both`, which apply slightly different configurations
	useful for testing.
	Supported options beyond that include `--serve`, to start a web browser serving the content of `_site/`,
	and `--skip-javadoc`, to speed up the build significantly by skipping javadoc generation.
	A handy command for testing the live files, analogous to `jekyll serve`
	but with the correct file structure, and then checking links, is:

	_build/build.sh test-both --skip-javadoc --serve

	And to run link-checks quickly (without validating external links), use:

	htmlproof --href_ignore "https?://127." --alt_ignore "." --disable_external _site



	Preparing for a Release
	-----------------------

	When doing a release and changing versions:

	* Before branching:
	* Change the `brooklyn-stable-version` variable in `_config.yml`
	* Update `website/meta/versions.md` with a bit of info on this release
	* In the branch, with `change-version.sh` run (e.g. from `N.SNAPSHOT` to `N`)
	* Ensure the `guide/start/release-notes.md` file is current
	* Build and publish `website-root`, `guide-latest`, and `guide-version`
	* In master, with `change-version.sh` run (e.g. to `N+1-SNAPSHOT`)
	* Clear old stuff in the `guide/start/release-notes.md` file
	* Optionally build and public `guide-version`


	Publishing the Website and Guide
	--------------------------------

	The Apache website publication process is based around the Subversion repository;
	the generated HTML files must be checked in to Subversion, whereupon an automated process
	will publish the files to the live website.
	So, to push changes the live site, you will need to have the website directory checked out
	from the Apache subversion repository. We recommend setting this up as a sibling to your
	`brooklyn` git project directory:

	# verify we're in the right location and the site does not already exist
	ls _build/build.sh \|\| { echo "ERROR: you should be in the docs/ directory to run this command" ; exit 1 ; }
	ls ../../brooklyn-site-public > /dev/null && { echo "ERROR: brooklyn-site-public dir already exists" ; exit 1 ; }
	pushd `pwd -P`/../..

	svn --non-interactive --trust-server-cert co https://svn.apache.org/repos/asf/brooklyn/site brooklyn-site-public

	# verify it
	cd brooklyn-site-public
	ls style/img/apache-brooklyn-logo-244px-wide.png \|\| { echo "ERROR: checkout is wrong" ; exit 1 ; }
	export BROOKLYN_SITE_DIR=`pwd`
	popd
	echo "SUCCESS: checked out site in $BROOKLYN_SITE_DIR"

	With this checked out, the `build.sh` script can automatically copy generated files into the right subversion sub-directories
	with the `--install` option. (This assumes the relative structure described above; if you have a different
	structure, set BROOKLYN_SITE_DIR to point to the directory as above. Alternatively you can copy files manually,
	using the instructions in `build.sh` as a guide.)

	A typical update consists of the following commands (or a subset),
	copied to `${BROOKLYN_SITE_DIR-../../brooklyn-site-public}`:

	# ensure svn repo is up-to-date (very painful otherwise)
	cd ${BROOKLYN_SITE_DIR-../../brooklyn-site-public}
	svn up
	cd -

	# versioned guide, safe for snapshots, relative to /v/<version>/
	_build/build.sh guide-version --install

	# main website, if desired, relative to /
	_build/build.sh website-root --install

	# this version as the latest guide, if desired, relative to /v/latest/
	_build/build.sh guide-latest --install

	(If HTML-Proofer find failures, then fix the links etc. Unfortunately, the javadoc build
	gives a lot of warnings. Fixing those is not part of this activity).

	You can then preview the public site of [localhost:4000](http://localhost:4000) with:

	_build/serve-public-site.sh

	Next it is recommended to go to the SVN dir and
	review the changes using the usual `svn` commands -- `status`, `diff`, `add`, `rm`, etc.
	Note in particular that deleted files need special attention (there is no analogue of
	`git add -A`!). Look at deletions carefully, to try to avoid breaking links, but once
	you've done that these commands might be useful:

	cd ${BROOKLYN_SITE_DIR-../../brooklyn-site-public}
	svn add * --force
	export DELETIONS=$( svn status \| sed -e '/^!/!d' -e 's/^!//' )
	if [ ! -z "${DELETIONS}" ] ; then svn rm ${DELETIONS} ; fi

	Then check in the changes (probably picking a better message than shown here):

	svn ci -m 'Update Brooklyn website'

	The changes should become live within a few minutes.

	SVN commits can be slow, particularly if you've regenerated javadoc.
	(The date is included in all javadoc files so the commands above will cause all javadoc to be updated.)
	Use `_build/build.sh guide-version --install --skip-javadoc` to update master while re-using the previously installed javadoc.
	That command will fail if javadoc has not been generated for that version.


	More Notes on the Code
	----------------------

	# Plugins

	We use some custom Jekyll plugins, in the `_plugins` dir:

	* include markdown files inside other files (see, for example, the `*.include.md` files
	which contain text which is used in multiple other files)
	* `read_jekyll` will read a file and jekyll-process it (eg for nested `{% ... readj ` calls;
	it's just like `include_relative` but with two differences: when `readj` is used
	nested `read_jekyll` calls are relative to the included file where it is contained,
	rather than relative to the root md file which made the first `read_jekyll` call
	(so in general it's more intuitive than `include_relative`),
	and `include_relative` processes front matter whereas `read_jekyll` mangles it
	* `read_literal` is like `read_jekyll` but without the jekyll/tag processing
	* `read` will autodetect based on filename -- jekyll for `*.md` and literal for all others
	* generate the site structure / menu objects
	* parse JSON which we can loop over in our markdown docs (to build up models; previously used
	for the TOC in the guide, but now replaced with site_structure)
	* trim whitespace of ends of variables


	# Versions

	Archived versions are kept under `/v/` in the website. New versions should be added with
	the appropriate directory (`_build/build.sh guide-version` above will do this).
	These versions take their own copy of the `style` files so that changes there will not affect future versions.

	A list of available versions is in `website/meta/versions.md`.