github.com/pwn-term/docker@v0.0.0-20210616085119-6e977cce2565/cli/man/src/image/tag.md (about)

     1  Assigns a new alias to an image in a registry. An alias refers to the
     2  entire image name including the optional `TAG` after the ':'. 
     3  
     4  # OPTIONS
     5  **NAME**
     6     The image name which is made up of slash-separated name components, 
     7     optionally prefixed by a registry hostname. The hostname must comply with 
     8     standard DNS rules, but may not contain underscores. If a hostname is 
     9     present, it may optionally be followed by a port number in the format 
    10     `:8080`. If not present, the command uses Docker's public registry located at
    11     `registry-1.docker.io` by default. Name components may contain lowercase 
    12     letters, digits and separators. A separator is defined as a period, one or
    13     two underscores, or one or more dashes. A name component may not start or end 
    14     with a separator.
    15  
    16  **TAG**
    17     The tag assigned to the image to version and distinguish images with the same
    18     name. The tag name must be valid ASCII and may contain lowercase and
    19     uppercase letters, digits, underscores, periods and hyphens. A tag name
    20     may not start with a period or a hyphen and may contain a maximum of 128
    21     characters.
    22  
    23  # EXAMPLES
    24  
    25  ## Tagging an image referenced by ID
    26  
    27  To tag a local image with ID "0e5574283393" into the "fedora" repository with 
    28  "version1.0":
    29  
    30      docker image tag 0e5574283393 fedora/httpd:version1.0
    31  
    32  ## Tagging an image referenced by Name
    33  
    34  To tag a local image with name "httpd" into the "fedora" repository with 
    35  "version1.0":
    36  
    37      docker image tag httpd fedora/httpd:version1.0
    38  
    39  Note that since the tag name is not specified, the alias is created for an
    40  existing local version `httpd:latest`.
    41  
    42  ## Tagging an image referenced by Name and Tag
    43  
    44  To tag a local image with name "httpd" and tag "test" into the "fedora"
    45  repository with "version1.0.test":
    46  
    47      docker image tag httpd:test fedora/httpd:version1.0.test
    48  
    49  ## Tagging an image for a private repository
    50  
    51  Before pushing an image to a private registry and not the central Docker
    52  registry you must tag it with the registry hostname and port (if needed).
    53  
    54      docker image tag 0e5574283393 myregistryhost:5000/fedora/httpd:version1.0