The generated vector config is a snapshot of the app list and their sink properties, but it was only ever written by `logs:set` and `logs:vector-start`. Renaming an app left a source filtering on a label no container carries and gave the new name no source at all, so the app kept a sink with nothing feeding it. Cloning produced the same result for the clone, and destroying an app left its source and sink behind, the latter still pointing at an endpoint decommissioned along with the app. The global relabel transform embeds app names directly in generated VRL, so a rename also left behind a branch naming an app that no longer existed. Every case was silent, and the only repair was an operator running `logs:vector-start`. The `post-app-clone-setup`, `post-app-rename-setup` and `post-delete` triggers now rewrite the config, warning rather than failing so that a config write cannot abort the app operation whose state it is derived from.
Closes#8918.
This is almost certainly the correct default for Dokku. While it's a BC break and might cause an increase in memory usage, the api is mostly internal and therefore this is safe to use.
The io/ioutil package has been deprecated as of Go 1.16 [1]. This commit
replaces the existing io/ioutil functions with their new definitions in
io and os packages.
[1]: https://golang.org/doc/go1.16#ioutil
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>