Reference:
https://github.com/containers/skopeo https://github.com/whirlwin/skopeo-service https://www.linuxhelp.com/questions/shasum-command-not-found https://stackoverflow.com/questions/6801704/checksum-remote-file#:~:text=In%20order%20to%20make%20a,file%2C%20if%20it%20was%20changed. https://stackoverflow.com/questions/4880486/curl-to-download-and-upload-same-file-simultaneously