Fix: DATADIR defaults to /updater/data

Dockerfile

@@ -85,6 +85,7 @@ ENV \
     PUBLICIPV6_HTTP_PROVIDERS=all \
     PUBLICIP_DNS_PROVIDERS=all \
     HTTP_TIMEOUT=10s \
+    DATADIR=/updater/data \
 
     # Web UI
     LISTENING_PORT=8000 \

README.md

@@ -41,7 +41,7 @@
     - OpenDNS
     - OVH
     - Selfhost.de
-    - [Spdyn](spdyn.de)
+    - Spdyn
     - Strato.de
     - Variomedia.de
     - **Want more?** [Create an issue for it](https://github.com/qdm12/ddns-updater/issues/new/choose)!
@@ -180,6 +180,7 @@ Note that:
 | `LISTENING_PORT` | `8000` | Internal TCP listening port for the web UI |
 | `ROOT_URL` | `/` | URL path to append to all paths to the webUI (i.e. `/ddns` for accessing `https://example.com/ddns` through a proxy) |
 | `HEALTH_SERVER_ADDRESS` | `127.0.0.1:9999` | Health server listening address |
+| `DATADIR` | `/updater/data` | Directory to read and write data files from internally |
 | `BACKUP_PERIOD` | `0` | Set to a period (i.e. `72h15m`) to enable zip backups of data/config.json and data/updates.json in a zip file |
 | `BACKUP_DIRECTORY` | `/updater/data` | Directory to write backup zip files to if `BACKUP_PERIOD` is not `0`. |
 | `LOG_LEVEL` | `info` | Level of logging, `debug`, `info`, `warning` or `error` |