Script to decide if new version is good

[fiunchinho]

Wimpy could execute a shell script right after deploying the new version, and before deleting the old one.
This script could check error ratio in /metrics endpoint (or whatever logic is needed) to determine if the new version is good, and the old one can be removed.
The default script could just exit 0

[ismaelfernandezscmspain]

Sounds good but isn't it trivial.
Do you want to reference only HTTP metrics or instance metrics too?
I think about instance metrics and is a bit difficult because is not the same measure it in the morning that in afternoon.

I like saying that you can have false positives.

[fiunchinho]

Playing around with Spring and some metrics library, we can an Spring application to show in the /metrics endpoint the HTTP error ratio for an application. The ratio should be similar through the day (since it's a ratio, not just a number).

Anyway, that's not something that wimpy should care about. The user would provide the script: wimpy just executes whatever the user has in her repository, and if the exit code is 0, the old CloudFormation is removed. If the exit code is 1, the old one is kept, and the new one is removed. The script could do anything.