It runs out of entropy? Not sure if this applies to containers, but had something like this happen in a virtual machine we used for builds (Jenkins). I made the mistake of instantiating a cryptographically secure PRNG during build time; the initialization needed entropy to seed the CSPRNG with, and this would lock up the whole virtual machine in the middle of the build. It seems that headless VMs have no possible source of entropy, unless explicitly configured to use host's source. Maybe something similar happens with containers?
