Correct docker repository for the ingestion server, update docs

ingestion_server/README.md

@@ -125,7 +125,7 @@ database_table_to_elasticsearch_model = {
 
 This codebase is deployed as a Docker image to the GitHub Container Registry [ghcr.io](https://ghcr.io). The deployed image is then pulled in the production environment. See the [`ci_cd.yml`](../.github/workflows/ci_cd.yml) workflow for deploying to GHCR.
 
-The published image can be deployed using the minimal [`docker-compose.yml`](docker-compose.yml) file defined in this folder (do not forget to update the `.env` file for production). The repository `justfile` can be used, but the environment variable `IS_PROD` must be set to `true` in order for it to reference the production `docker-compose.yml` file here.
+The published image can be deployed using the minimal [`docker-compose.yml`](docker-compose.yml) file defined in this folder (do not forget to update the `.env` file for production). The repository `justfile` can be used, but the environment variable `IS_PROD` must be set to `true` in order for it to reference the production `docker-compose.yml` file here. The version of the image to use can also be explicitly defined using the `IMAGE_TAG` environment variable (e.g. `IMAGE_TAG=v2.1.1`).
 
 ### Old Docker Hub images
 

ingestion_server/docker-compose.yml

@@ -1,13 +1,15 @@
 version: "2.4"
 services:
   ingestion_server:
-    image: ghcr.io/wordpress/openverse-ingestion-server:latest
+    # Allow the image tag to be set to a specific version, default to latest
+    image: ghcr.io/wordpress/openverse-ingestion_server:${IMAGE_TAG:-latest}
     ports:
       - "8001:8001"
     env_file:
       - .env
     dns:
       # Related to DNS management on the production box.
-      # Not sure if this is strictly necessary, but it exists
-      # in the current, running system so we are retaining it here.
+      # 172.16.0.0–172.31.255.255 is a reserved IP range by the (IANA) for
+      # private/internal networking. This specific IP is the dns resolution address
+      # for a default AWS Virtual Private Cloud.
       - 172.31.0.2