feature request: Exclude `/` also from job names

[Kamilcuk]

Proposal

The proposal is to disallow slash / from job names.

Use-cases

The use case is to use job/group/task format when referencing a task in a group within a job. Currently, job names are allowed to contain slashes, but group and task names are not. I think it would be great to also disallow task names to contain slashes, for easier referencing without any escaping. It would also make easier to make HTTP requests, where / is the URL parts separator.

Attempted Solutions

The solution, like in the case of nomad web UI, is to visually distinguish job name from the separator. Another is to escape \/ slash like in sed.

[tgross]

Hi @Kamilcuk! If we were starting from scratch I think we all agree we'd be a lot more aggressive about the allowed characters for jobs. Did you know you can include emoji in job IDs!? The trouble with this is that many users have lots of existing jobs that might contain /, as we haven't disallowed them before.

This could use some discussion because it might be possible to validate only on submit time in a safe way, but I suspect it's going to be a non-starter because of the number of jobs users might need to migrate.

[lgfa29]

Also noting that, due to a bug in net/http.ServeMux, jobs starting, ending, or with repeated slashes cannot be managed at all because Go will remove/collapse them: #11749

The bug has been fixed in golang/go@3563792 but not released yet.

[Kamilcuk]

Did you know you can include emoji in job IDs!?

Actually, we knew and tested that, and emoji nicely render in the UI. Now me! Did you know that docker driver fails with tasks with emoji, because docker containers can't be named with emoji? Docker containers can only be named with normal characters.