Is there one website that contains all relevant DevOps news and gets updated on a daily basis?
There is a protocol for this: RSS, Rich Site Summary. Technically, there are 3 protocols RSS, RSS2 and Atom, but most readers support all of them, and many servers mix RSS and RSS2 features.

First, choose your RSS reader, from:


browser add-ons like Feedbro,
centralized aggregators like Feedly and FeedReader,
stand-alone applications like RSSOwl
mail clients like Thunderbird.


Second, choose the sources you care about and subscribe to them - you're the curator and most news websites publish RSS feeds. Many don't even know about it, as CMSs like Wordpress sometimes publish an RSS feed by default. I wouldn't be surprised if it had something to do with SEO... Soon, you'll have an OPML list of your favourites.

From your question:


https://kubernetes.io/feed.xml
https://www.docker.com/blog/feed/
https://ubuntu.com/blog/feed
https://aws.amazon.com/blogs/devops/feed/
https://devblogs.microsoft.com/devops/feed/
https://cloudblog.withgoogle.com/products/devops-sre/rss
https://blog.centos.org/feed/
https://github.blog/feed/


And a few personal recommendations:


https://www.theregister.co.uk/devops/headlines.atom
http://feeds.arstechnica.com/arstechnica/security
https://stackoverflow.blog//feed
https://xkcd.com/rss.xml
https://www.theregister.co.uk/data_centre/bofh/headlines.atom


Many readers will have an option to search for a feeds on a website, which simplifies the search.