Implement MaxRequestBodySize feature for IIS inprocess

[jkotalik]

Fixes #8293.

I'm okay if this slips to preview6. I'll leave comments in the diff.

[analogrelay]

Moving this out of preview 5. We are starting to limit preview 5 work to essential stuff only.

[jkotalik]

I'm going to block myself on merging this until I figure out why a set of IIS tests aren't running on PRs.

[jkotalik]

Re-enabled some IIS tests, this should now report success/failures correctly now.

[Tratcher]

I also wonder if we can integrate closer with maxAllowedContentLength, or even override it? Let's talk offline.

[jkotalik]

This now adds support for reading the IIS content length limit and logs a warning per request/in the constructor for the Server.

[jkotalik]

@aspnet-hello triage https://dev.azure.com/dnceng/public/_build/results?buildId=180325

[aspnet-hello]

This comment was made automatically. If there is a problem contact [email protected].

I've triaged the above build. I've created/commented on the following issue(s)
https://github.com/aspnet/AspNetCore-Internal/issues/2479

[discostu105]

We just upgraded to preview-6 and suddenly our web.config setting (maxAllowedContentLength) seems to not be working anymore. We run on IIS in-process. Here is the config: https://github.com/Dynatrace/superdump/blob/master/src/SuperDumpService/web.config

Anything wrong with the config at first glance? Should we file an issue for this? @jkotalik

[Tratcher]

seems to not be working anymore

What is the error?

[discostu105]

the setting from web.config is not respected anymore, so it uses a much lower default.

[analogrelay]

If you're seeing the setting be ignored, definitely file a new bug and provide a runnable sample that reproduces the problem. We can always close it if it turns out there isn't a problem (though if the behavior is confusing to you, that's a problem ;)). We don't track merged PRs like this so it's likely this will get lost if we stop checking our GitHub notifications ;). Also, include any logs from the app since it looks like we should be logging a warning if there's a conflict between these options.

@jkotalik From a very cursory look at the code, I wonder if the fact that we set a default size limit in the managed code is conflicting here. Perhaps the default (if the setting isn't set) should be to just use whatever the web.config value is (if one is present)?