Add Dockerfile

This commit adds a first working Dockerfile for this program, as well as
instructions on how to use it. This will need more detailing in the
future, but this will do for now.

Dockerfile

@@ -0,0 +1,14 @@
+FROM golang:1.19 AS builder
+WORKDIR /go/src/git.faercol.me/public-ip-tracker/
+COPY tracker ./
+RUN CGO_ENABLED=0 make build
+
+# Replace with from scratch later on
+FROM alpine:latest
+WORKDIR /root
+COPY --from=builder go/src/git.faercol.me/public-ip-tracker/build/tracker ./
+
+VOLUME [ "/config" ]
+
+ENTRYPOINT [ "./tracker" ]
+CMD [ "-config", "/config/config.json" ]

README.md

@@ -27,3 +27,38 @@ The relevant channel is monitored during the program execution. This allows the
 command to the bot in order to get the current public IP on-demand.
 
 > Insert example here
+
+
+## Deploy
+
+### Configuration file
+
+For now, the program is configured through a JSON configuration file. Here is a sample :
+
+```json
+{
+    "telegram": {
+        "token": "<your_bot_token>",
+        "channel_id": 9999999
+    },
+    "polling_frequency": 5
+}
+```
+
+
+### Docker
+
+You can use the provided Dockerfile to build your own image.
+
+```bash
+docker build -t public-ip-tracker .
+```
+
+You can then use the provided configuration file sample, and provide it to the program using the
+`/config` volume
+
+> I might add support for environment variables in the future.
+
+```bash
+docker run -it -v /path/to/your/dir/with/json/file:/config public-ip-tracker
+```