Remove bootstrap dependency.

[cjcenizal]

Relates to #7364.

Changes

• Remove Bootstrap NPM dependency.
• Move Bootstrap files into src/ui/public/styles/bootstrap and update import statements.
• Remove glyphicons and carousel styles (doesn't look like we're using either).

Next steps

• I'll make PRs to remove some of the other unused top-level Bootstrap components, e.g. breadcrumbs.

File size

It's worth noting that the original filesize of our compiled CSS was 949kb. Already, by removing the glyphicons and carousel LESS, this filesize has dropped to 890kb.

[tylersmalley]

I spoke with @cjcenizal about bringing bootstrap.less in, while still referencing the less files from node_modules (@import "~bootstrap/less/grid.less";) until we want to modify them. While this would help in the case we want to upgrade, it creates more of a burden for refactoring, which is the ultimate goal. We're not looking to maintain or upgrade alongside bootstrap.

[Bargs]

@cjcenizal maybe it makes sense to merge this PR and then start removing the other bootstrap components? I'm thinking it's going to take a while to review all of those sub-PRs, and then this one meta-PR is going to have to be re-reviewed with all of them merged. I think it's best to merge things into master incrementally if possible.

[cjcenizal]

@Bargs I'm game. @tylersmalley What do you think?

[tylersmalley]

It's probably a good idea. It would be much easier to review the refactoring which was done as individual PRs. This PR as is should not have any impact on the UI as it's just moving the dependency into the repo.

[cjcenizal]

@Bargs @tylersmalley OK I updated the description. Can you give me some LGTMs? Then I'll merge.

[tylersmalley]

Where did these go?

[cjcenizal]

After removing the carousel classes, there are no more references to these variables so I felt it was safe to remove them.

[Bargs]

I see some references to glyphicons in ui-bootstrap-tpls.js in the spalger.angular-bootstrap module. Is it really safe to remove these without also removing angular-bootstrap?

Same question applies to carousel now that I search for it.

[Bargs]

Not really a big deal, but maybe these comments should be updated: https://github.com/elastic/kibana/blob/master/src/ui/public/styles/dark-theme.less#L8

[cjcenizal]

@Bargs Great catch re glyphicons. Looks like we may be using two components (daypicker and timepicker) which rely on a few specific glyphicons, so I'll update the PR to retain those. We're not using the other two components (carousel and rating) which use glyphicons.

[cjcenizal]

@Bargs I'll put the carousel classes back and remove them along with the Angular stuff in a later PR.

[Bargs]

Sounds like a plan. I think it'll be nice for historical reasons to have a PR that only moves the files around, without changing anything anyways. That way we have a good base to look at in the commit history.

[cjcenizal]

@Bargs @tylersmalley Could you please re-review? I put back carousel and glyphicons.

[Bargs]

LGTM

[tylersmalley]

LGTM