Update Bootstrap to v5

[beorn7]

While the know security problems of the used Bootstrap library (4.3.1) do not affect the Pushgateway, it would be good to update to Bootstrap v5 eventually.

As far as I can see, v5 has dropped the Glyphicons support, so an update is definitely more involved than just downloading Bootstrap 5 and put it into the resources directory.

[SRasaikar]

Hi @beorn7 would also like to know if this is still up for grabs ? is migration to bootstrap icons a possibility given that Bootstrap dropped the support for Glyphicons ?

[beorn7]

Any help welcome. And yeah, whatever icons appear suitable -- and are freely available in agreement with our Apache 2 license.

[SRasaikar]

On it, Thank you very much @beorn7

[beorn7]

To avoid misunderstandings: While I maintain the Pushgateway, I am not very knowledgeable with Bootstrap. @SRasaikar if you tackle this, be aware that you have to be the Bootstrap expert here and teach me how it goes. And I don't think we should rely on AI tools to provide the expertise here. At least one human who knows what we are doing should be in the chain.

[SRasaikar]

Acknowledged , will research , learn and will come up with reasonings for changes i come up with.

[dswarbrick]

Debian is also encouraging package maintainers to migrate to Bootstrap 5 as and where possible. The libjs-bootstrap5 package in Debian depends on the bootstrap-icons package, which is https://github.com/twbs/icons upstream - described as a "free, high quality, open source icon library with over 2,000 icons", (MIT license). However, I don't know if the icon CSS style names are the same as what Bootstrap 4 used.

The only glyphicon styles that I can see referenced in the pushgateway UI assets are glyphicon-collapse-down and glyphicon-collapse-up, which look pretty similar to caret-down-square and caret-up-square respectively.