Values in a Compose file can be set by variables and interpolated at runtime. Compose files use a Bash-like
syntax `${VARIABLE}`. Both `$VARIABLE` and `${VARIABLE}` syntax is supported.
Title: Variable Substitution in Compose Files
Summary
Compose files allow for dynamic configuration through variable substitution. Variables are referenced using Bash-like syntax, either `${VARIABLE}` or `$VARIABLE`.