Fix docker compose, edit documentation

packages/api/README.md

@@ -35,14 +35,19 @@ pnpm run dev
 
 ## Docker
 
-The API is also dockerized. In order to run the API from a docker, run:
+The API is also dockerized. Docker needs to publish the port of the server (running inside the docker) to the port on
+the host machine. By default, it expects the server is running on port `8090` and publishes it to the `8090` on the
+host. To change this, you need to modify both `signed-api.json` configuration and use `PORT` environment variable with
+the same value.
+
+In order to run the API from a docker, run:
 
 ```bash
-# starts the API on port 4000
+# Starts the API on port 8090
 pnpm run docker:start
-# or in a detached mode
+# Or in a detached mode
 pnpm run docker:detach:start
-# optionally specify port
+# Optionally specify port (also make sure the same port is specified inside `signed-api.json`)
 PORT=5123 pnpm run docker:start
 ```
 

packages/api/docker/docker-compose.yml

@@ -6,7 +6,18 @@ services:
       context: ../../../
       dockerfile: ./packages/api/docker/Dockerfile
     ports:
-      - '${PORT:-4000}:${PORT:-4000}'
+      - '${PORT-8090}:${PORT:-8090}'
     environment:
       - NODE_ENV=production
-      - PORT=${PORT:-4000}
+    volumes:
+      # Mount the config file path to the container /dist/config folder where the API expects it to be.
+      #
+      # Environment variables specified in the docker-compose.yml file are applied to all operations that affect the
+      # service defined in the compose file, including the build process ("docker compose build"). Docker Compose will
+      # expect that variable to be defined in the environment where it's being run, and it will throw an error if it is
+      # not. For this reason we provide a default value.
+      #
+      # Docker Compose doesn't allow setting default values based on the current shell's environment, so we can't access
+      # current working directory and default to "$(pwd)/config". For this reason we default to the config folder
+      # relative to the docker-compose.yml file.
+      - ${CONFIG_PATH:-../config}:/usr/src/app/packages/api/dist/config

packages/api/src/utils.ts

@@ -20,6 +20,5 @@ export const generateErrorResponse = (
   return { statusCode, headers: COMMON_HEADERS, body: JSON.stringify({ message, detail, extra }) };
 };
 
-// TODO: Ensure this works in a docker (need to mount the config folder).
 export const getConfig = () =>
   configSchema.parse(JSON.parse(readFileSync(join(__dirname, '../config/signed-api.json'), 'utf8')));