fix docsite build issue

[jboyd01]

Disclaimer: I don't have much knowledge around ruby/jekyll/docsite, this fixed the issue locally.

@carolynvs is out for 2 weeks, but please review on your return.

Travis builds are erroring out with

./build/docs.sh generate
+++dirname ./build/docs.sh
++cd ./build/..
++pwd
+REPO_ROOT=/home/travis/build/kubernetes-incubator/service-catalog
+DOCSITE=/home/travis/build/kubernetes-incubator/service-catalog/docsite
+DEST=/home/travis/build/kubernetes-incubator/service-catalog/docsite/_site
+generate
+clean
+[[ -d /home/travis/build/kubernetes-incubator/service-catalog/docsite/_site ]]
+mkdir -p /home/travis/build/kubernetes-incubator/service-catalog/docsite/_site
+echo 'Generating site...'
Generating site...
+docker run -it --rm -v /home/travis/build/kubernetes-incubator/service-catalog/docsite:/srv/jekyll -v /home/travis/build/kubernetes-incubator/service-catalog/docs:/srv/docs -v /home/travis/build/kubernetes-incubator/service-catalog/docsite/.bundler:/usr/local/bundle jekyll/jekyll jekyll build
Unable to find image 'jekyll/jekyll:latest' locally
latest: Pulling from jekyll/jekyll
Status: Downloaded newer image for jekyll/jekyll:latest
ruby 2.5.1p57 (2018-03-29 revision 63029) [x86_64-linux-musl]
Traceback (most recent call last):
    12: from /usr/gem/bin/jekyll:23:in `<main>'
    11: from /usr/gem/bin/jekyll:23:in `load'
    10: from /usr/gem/gems/jekyll-3.8.1/exe/jekyll:11:in `<top (required)>'
     9: from /usr/gem/gems/jekyll-3.8.1/lib/jekyll/plugin_manager.rb:50:in `require_from_bundler'
     8: from /usr/local/lib/ruby/site_ruby/2.5.0/bundler.rb:107:in `setup'
     7: from /usr/local/lib/ruby/site_ruby/2.5.0/bundler/runtime.rb:20:in `setup'
     6: from /usr/local/lib/ruby/site_ruby/2.5.0/bundler/runtime.rb:108:in `block in definition_method'
     5: from /usr/local/lib/ruby/site_ruby/2.5.0/bundler/definition.rb:227:in `requested_specs'
     4: from /usr/local/lib/ruby/site_ruby/2.5.0/bundler/definition.rb:238:in `specs_for'
     3: from /usr/local/lib/ruby/site_ruby/2.5.0/bundler/definition.rb:171:in `specs'
     2: from /usr/local/lib/ruby/site_ruby/2.5.0/bundler/spec_set.rb:85:in `materialize'
     1: from /usr/local/lib/ruby/site_ruby/2.5.0/bundler/spec_set.rb:85:in `map!'
/usr/local/lib/ruby/site_ruby/2.5.0/bundler/spec_set.rb:91:in `block in materialize': Could not find public_suffix-3.0.2 in any of the sources (Bundler::GemNotFound)
make: *** [docs] Error 1

Googling the error, I updated the docs.sh to do a bundle update. I got an error about "Invalid date ': Document 'vendor/cache/ruby/2.5.0/gems/jekyll-3.6.0/lib/site_template/_posts/0000-00-00-welcome-to-jekyll.markdown.erb' does not have a valid date in the YAML front matter." and found I needed to update docsite/_config.yml with an exclude of [vendor]

[jpeeler]

The last error looks like to me that a bundle add public_suffix should fix this. I'm assuming that'll update the gemfile and lock file appropriately.

[jboyd01]

Jeff pointed out wrong/bad to do bundle update. I did a bundle add public_suffix that updated the Gemfile, with the missing gem, changed docs.sh do a bundle install (not an update), then it builds the docsite. Feels more correct.

[MHBauer]

ran it locally, also works.

my guess is there was an update to the jekyll image on dockerhub.

LGTM

[MHBauer]

this is the only thing I don't have any feeling for what it does.

[nilebox]

LGTM. I have no idea about ruby/jekyll, but since this change makes the build green, seems critical to merge.

[carolynvs]

Shoot, I should have pinned the jekyll image to a version. Yes since I created our site, the upstream k8s.io site moved to Hugo. I'd like to follow their lead (since I totally ripped off their site) and switch over as well at some point.

I'll add an issue for that, since I don't want to use ruby anyway. 😇

• Migrate site to hugo #2085 - Migrate to Hugo
• Split doc site build into separate travis job #2086 - Split doc site build into separate travis job

[carolynvs]

Thanks for fixing the build, @jboyd01! 💖