We have encountered an issue with the envoy-proxy not being live before the main application needs to fetch an external url. In some cases this results in the applications dying. In some cases we have changed our own application to retry for up to a second to give the proxy time to startup, but in other cases we are using 3d party applications. In these cases we can workaround the issue by extending the image with an own image that has a built in wait.
Both solutions are quite ugly and I wonder if there is a more beautiful way to approach this issue.