Send + Sync Issues with list_containers

[Thrane20]

I have been using numerous dockworker methods inside my tokio / warp server, however one particular method never compiles under a tokio context, and that is ::list_containers

Spent quite a many, many hours trying to figure this out, but the error is:

"dyn for<'a> Fn(&'a str) -> Cow<'_, [u8]> cannot be shared between threads safely
the trait Sync is not implemented for dyn for<'a> Fn(&'a str) -> Cow<'_, [u8]>, which is required by impl Future<Output = Result<impl Reply, Infallible>>: Send" - for whenever this function is in the mix.

I've checked the dockworker code, and there's nothing specifically different here that's obviously problematic, however, the only different struct at play is ContainerFilters - but I can't see anything in there that would make Reply + Send incompatible.

Anyone else used dockworker inside a tokio context with no problems? I've exhausted all my investigations thus far...

[DrWalrus1]

Did some digging around using a project I'm working on that uses Rocket. Seems like Serializer in this instance is not thread safe, need to wrap the param prep in a closure and return a thread safe string. Will figure out how to make a test for this and add it to my fork before opening a PR

[eldesh]

Thank you for reporting the issue. To help us better understand and resolve the problem, could you please provide a minimal, complete, and verifiable example of the code that reproduces the bug?

[DrWalrus1]

@eldesh you'll find a fix for this in this pr

This is an example that I altered in a commit: 46eedbe

Though to keep the code example not messy I removed it

[eldesh]

@DrWalrus1 If we cannot actually see the problem here, we cannot confirm the fix and therefore cannot incorporate the fix.
Can you show us the code that reproduces the problem?

[DrWalrus1]

@eldesh have coded up a small (broken) example here https://github.com/DrWalrus1/dockworker-fix-example.

This is how I ran into the problem.
Rocket seems to be spawning a tokio thread under the hood and when you call this method the call to serializer seems to be trying to be shared references across threads