Regarding HTTP secret, it will be randomly generated by the private registry instance upon startup by default. However, it is a problem if you run multiple pods, because each pod may have a different HTTP secret that occur an error when Docker client push or pull the image. So we explicitly state that all pods will use the same HTTP secret, via the following steps:

1. Use the openssl command to create a http.secret file under the secrets directory:

//create 8 byte random HEX string by OpenSSL 
$ openssl rand -hex -out secrets/http.secret 8

2. Check the secrets directory, which has three files now:

$ ls secrets/
domain.crt domain.key http.secret