The only way changing the admin password and enable encryption is by injecting configuration files into the container. Commands are executed in the Docker project directory for the Minion.

Create the configuration file to enable encryption
vi org.apache.karaf.jaas.cfg
Enable encryption for the admin password
encryption.enabled = true
encryption.prefix = {CRYPT}
encryption.suffix = {CRYPT}
encryption.algorithm = SHA-512
encryption.encoding = hexadecimal
Create a property file for the SSH user for the Karaf Shell
vi users.properties
Set a secure admin password for Karaf
admin = my-new-password,_g_:admingroup(1)
_g_\:admingroup = group,admin,manager,viewer,systembundles,ssh(2)
1 Replace the string my-karaf-password with your new password in plainttext
2 Assign permissions to allow administrative tasks and access via SSH
Set Minion process as owner and restrictive file permissions
chown 10001:10001 users.properties
chmod 600 users.properties
Inject the configuration files with the
volumes:
  - ./minion-config.yaml:/opt/minion/minion-config.yaml
  - ./scv.jce:/opt/minion/scv.jce
  - ./users.properties:/opt/minion/etc/users.properties
  - ./org.apache.karaf.jaas.cfg:/opt/minion/etc/org.apache.karaf.jaas.cfg
Restart the Minion container
docker-compose restart minion