instruction: Create a Dockerfile for security
output: ```dockerfile
  from the user name or ID. If
  you provide both the user and group name or ID, separate them by a colon
  (:) character. The following formats all work for the value, assuming
  the UID and GID of testuser are 1001:testusertestuser:testuser10011001:1001testuser:10011001:testuser
  
  {
   "userns-remap": "testuser"
  }
  NoteTo use the dockremap user and have Docker create it for you,
  set the value to default rather than testuser.Save the file and restart Docker.If you are using the dockremap user, verify that Docker created it using
  the id command.
  
  $ id dockremap
  
  uid=112(dockremap) gid=116(dockremap) groups=116(dockremap)
  Verify that the entry has been added to /etc/subuid and /etc/subgid:
  
  $ grep dockremap /etc/subuid
  
  dockremap:231072:65536
  
  $ grep dockremap /etc/subgid
  
  dockremap:231072:65536
  If these entries are not present, edit the files as the root user and
  assign a starting UID and GID that is the highest-assigned one plus the
  offset (in this case, 65536). Be careful not to allow any overlap in the
  ranges.Verify that previous images are not available using the docker image ls
  command. The output should be empty.Start a container
  ```