Below are tips & tricks for deploying an application that uses App Config.

Serialize APP_CONFIG_SCHEMA variable using CLI

To make deployment easier, "resolve" your schema at build time using the create-schema CLI subcommand. This will inline all schema references into one file, which is easy to set as the APP_CONFIG_SCHEMA variable.

APP_CONFIG_SCHEMA=$(npx @app-config/cli create-schema --format json)

One option is to pass this into a Dockerfile as a build argument and use ENV. Or in non-docker environments, export it before deploying/running the application.

Serialize APP_CONFIG variable using CLI

When deploying, you'll want to use the APP_CONFIG environment variable. Generate a "frozen" value using the CLI, for the environment you're deploying to. This simplifies all of the values in config, and enables spec compliant apps to work.

APP_CONFIG=$(NODE_ENV=production npx @app-config/cli create --format json --secrets)

Configuration should be dynamic, so you should set this variable when deploying.

Use app-config-inject for frontends

Create a re-useable deployment container by using app-config-inject. This makes it easy to share the same code between environments, even for statically built web apps.