Update README to include Docker info

README.md

@@ -12,6 +12,57 @@ In order to use this sample, you should have:
 - Oracle Java (JDK) installed: Minimum JDK8 or newer.
 - Apache Maven build tool (newest version)
 
+## Running via [Docker Hub](https://hub.docker.com/repository/docker/hapiproject/hapi)
+
+Each tagged/released version of `hapi-fhir-jpaserver` is built as a Docker image and published to Docker hub. To run the published Docker image from DockerHub:
+
+```
+docker pull hapiproject/hapi:latest
+docker run -p 8080:8080 hapiproject/hapi:tagname
+```
+
+This will run the docker image with the default configuration, mapping port 8080 from the container to port 8080 in the host. Once running, you can access `http://localhost:8080/hapi-fhir-jpaserver/fhir` in the browser to access the HAPI FHIR server's UI.
+
+If you change the mapped port, you need to change the configuration used by HAPI to have the correct `server_address` property/value.
+
+### Configuration via environment variables
+
+You can customize HAPI directly from the `run` command using environment variables. For example:
+
+`docker run -p 8090:8080 -e server_address=http://localhost:8090/hapi-fhir-jpaserver/fhir hapiproject/hapi:tagname`
+
+HAPI looks in the environment variables for properties in the [hapi.properties](https://github.com/hapifhir/hapi-fhir-jpaserver-starter/blob/master/src/main/resources/hapi.properties) file.
+
+### Configuration via overridden hapi.properties file
+
+You can customize HAPI by telling HAPI to look for the `hapi.properties` file in a different location:
+
+`docker run -p 8090:8080 -e hapi.properties=/some/directory/with/hapi.properties hapiproject/hapi:tagname`
+
+### Example docker-compose.yml
+
+```
+version: '3.7'
+services:
+  web:
+    image: "hapiproject/hapi:tagname"
+    ports:
+      - "8090:8080"
+    configs:
+      - source: hapi
+        target: /data/hapi/hapi.properties
+    volumes:
+      - hapi-data:/data/hapi
+    environment:
+      JAVA_OPTS: '-Dhapi.properties=/data/hapi/hapi.properties'
+configs:
+  hapi:
+     external: true
+volumes:
+    hapi-data:
+        external: true
+```
+
 ## Running locally
 
 The easiest way to run this server is to run it directly in Maven using a built-in Jetty server. To do this, change `src/main/resources/hapi.properties` `server_address` and `server.base` with the values commented out as _For Jetty, use this_ and then execute the following command: