Codecov Report

Merging #1794 into master will decrease coverage by 0.02%.
The diff coverage is 11.11%.

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- Coverage   49.95%   49.92%   -0.03%     
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  Lines       13843    13852       +9     
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+ Hits         6915     6916       +1     
- Misses       6928     6936       +8

I think the idea of having better UA strings is not bad, but I'm not a fan of this particular solution, as it only provides a set of statically generated UAs, which doesn't solve the issue of using Streamlink "anonymously" / "transparently". The current CHROME UA is pretty much outdated and all of Streamlink's HTTP requests using this UA can be identified pretty easily. Same would be true for this suggested approach, but for a set of static UA strings instead of one.

Having something like CHROME_LATEST that gets included during build time by some external library like fake-useragent and which changes in each Streamlink release would be much better, since those UAs are not unique to Streamlink and are based on up2date real world usage statistics. A random UA string could also be generated by using this lib, if needed.

@bastimeyer Why add yet another dependency for build or core one when you can add a simple function like this and update manually from time to time.

using random old versions makes you more unique than the latest stable version

which is exactly the opposite of what you probably wanted

https://github.com/streamlink/streamlink/blob/master/src/streamlink/plugin/api/useragents.py

the streamlink useragents should be changed once a month or so,
they are very old which means they are very unique right now.

using a dependency is maybe a bit to much for this.

python-requests/2.18.4 is currently the most used User-Agent of Streamlink,
which is fine as it's used very often but it could be also changed to Firefox or Chrome

It might be nice to have a few more choices - but you'd want it to be consistent across requests in the same session. We could randomly assign a default, then plugins can change it as needed.

I don't think we'd want to add fake-useragent as a dependency, but you could probably use the output file from that to update the useragents list semi-automatically. Taking the most popular version of Chrome, Firefox, Opera, etc.