TSD Entropy

In order for the cryptography algorithms to function properly - specifically, for the DOA microservice (Data Out API) - there should be enough entropy in the system. Otherwise, one would experience problems like this: https://github.com/actions/virtual-environments/issues/672

Since DOA is running in the Docker container, it might be not enough entropy inside by default and it needs to be injected from the outside (the host machine). For this purpose, one would need to mount the host's /dev/urandom/ to the inside. This is done in the Docker Swarm deployment file:

...
    volumes:
        ...
        - /dev/urandom:/dev/random
        ...
...

Usually, it should be enough. However, if there's not enough entropy on the host machine itself, then additional entropy generators can be installed (for example, rng-tools or haveged).