| <p> |
| <b>ARG</b> defines a variable that users can pass at build-time to the builder with the docker build command using the --build-arg <varname>=<value> flag. If a user specifies a build argument that was not defined in the Dockerfile, the build outputs an error. |
| </p> |
| <br/> |
| <p> |
| <pre> |
| ARG user1 # Defines an build argument called 'user1' without any default values |
| ARG buildno # Defines an build argument called 'buildno' without any default values |
| |
| ARG user1=someuser # Defines and declares a default value for the build argument 'user1' |
| ARG buildno=123 # Defines and declares a default value for the build argument 'buildno' |
| </pre> |
| </p> |
