Specifying Environmental Variables
You can use a configuration file to specify the value of an environmental variable in the configuration file, follow these instructions:
• Use the ENV or RUN entry to specify the value of an environment variable or to run an external application.
• Use the equal sign (=) following ENV to change the existing value of the variable.
• Use the plus and equal to signs (+=) to add a value after an existing value of the variable.
• Use the minus and equal to signs (-=) to insert a value before an existing value of the variable.
• Use the RUN entry to run an external command on startup.