docker.io 20.10.21-0ubuntu2 (armhf binary) in ubuntu lunar

 Docker complements kernel namespacing with a high-level API which operates at
 the process level. It runs unix processes with strong guarantees of isolation
 and repeatability across servers.
 .
 Docker is a great building block for automating distributed systems:
 large-scale web deployments, database clusters, continuous deployment systems,
 private PaaS, service-oriented architectures, etc.
 .
 This package contains the daemon and client. Using docker.io on non-amd64 hosts
 is not supported at this time. Please be careful when using it on anything
 besides amd64.
 .
 Also, note that kernel version 3.8 or above is required for proper operation of
 the daemon process, and that any lower versions may have subtle and/or glaring
 issues.