Uses shell-style variable interpolation inside the Compose file.
Section: Environment Variables and Env Files
Interpolate variables into compose file
yaml
yaml
services:
api:
image: "myapi:${APP_TAG:-latest}"
ports:
- "${APP_PORT:-3000}:3000"Explanation
Great for portable dev and CI environments.
Learn the surrounding workflow
Compare similar commands or jump into common fixes when this command is part of a bigger troubleshooting path.
Related commands
Same sheet · prioritizing Environment Variables and Env Files
Environment as key/value map
Provide container environment values inline in YAML.
Environment as list
Alternative environment syntax using `KEY=value` entries.
Load variables from env file
Loads container environment variables from one or more files.
Pass env file at runtime
Uses a specific env file when rendering the Compose project.
Minimal web + db stack
Simple two-service stack with port publishing and environment variables.
Define optional profiles
Marks a service as optional unless its profile is enabled.