Failed first instance creation results in duplicate auto-created VCNs/Gateways/Subnets
Summary
If the initial host creation fails, duplicate network resources to have been associated with it may be generated and not removedContent
I was trying to create a free micro E2 instance in my São Paulo home region with my newly-registered account, and ran into the issue that host resources had been exhausted in the region - I tried manually selecting all three fault domains, and tweaking another few options, clicking the option to create it every time; but no luck. I hope that'll be fixed soon, but it's only tangentially related to the main issue.
Eventually I created a VM.Standard2.1 instance (again, through the web interface), which worked; however, on reviewing all my resources using the search interface, I found 11 separate virtual cloud networks with corresponding route tables and gateways. I was able to remove these one by one from the list (annoyingly, not all at once), but it wasn't clear why I had so many, until I saw the creation times corresponded to my attempts to create my free instance. Of course, at that point I had no network, so it needed to create one too...