Hello,
This is a feature request for liquibase command line to support receiving DB passwords from environment variables, like e.g. the postgres and other rdbms management tools do.

At present (v. 4.3.4) it seems that the only way to pass a password to the command line app is:

1. to pass it via the --password command line option (which would be visible to other processes)
2. to write it to liquibase.properties (which is not desirable when working with multiple databases at once in different environments via e.g. tunnels)

For example, if liquibase could accept the environment variable liquibase_password or similar, then I could retrieve the password from a vault and run the command without obviously exposing the secret anywhere.