Fixes in operator, fixes in examples, additional examples. and cleanup

[antru6]

Fixes in operator:

• fixed multiple runs of experiment
• added halt loop in federation to wait for init of its update status (integration with istio)

Clean-up of examples:

• moved all example containers, example engine templates, example benchmark specifications, and experiment specifications in examples/ directory
• removed deprecated .yaml files

Fixes in example containers:

• added more delay in virtuoso for sidecar (integration with istio)
• added halt loop and delay in strabon for sidecar (integration with istio)

Additional examples:

• added strabon-related templates
• added "uno" federator template - an mock-up federation engine which acts as a proxy for a single dataset, in order to evaluate benchmarks for standalone datasets.
• added the synthetic workload for geographica benchmark and experiment

[stasinos]

Please explain how the delay of "10" was calculated, and how to derive this number for future Docker images.

[kostbabis]

Please explain how the delay of "10" was calculated, and how to derive this number for future Docker images.

There is an issue in istio where the sidecar proxy takes too long time to go up since its launched as a main container alongside the others in the pod. Every connection that happens after the istio init container and before the proxy main container is up will fail, thus we need to wait before downloading dumps for example.

There is already a loop at the very beggining that checks connection by repeating curl localhost:15000 every 3 sec

But in our tests seemed to not always be enough. In minikube it was but in the cluster it wasnt. The extra 10 seconds are probably more than enough to make sure that istio is up if there is also that loop present in the beggining of the main container.