Add Dockerfile and requirements.txt

[robrankin]

Added a Dockerfile as it's handy to have for environments that containerise everything.

[harryhaaren]

Hi All (Harry here - not the author of the project - but was using the script for grabbing stats (thanks to original author!) so figured I'd try contribute a bit.

PR here looks good, build the image and tested - works perfectly. docker build . results in a valid image, and docker run <image_id> gives the normal "usage" output as expected, same as the script gives "on baremetal". Adding valid switch IP and password, both work find.

One potential improvement is to use a minimalized base for the script? Today's image is ~1GB (!) which seems very large for a simple dockerized python3+script? Usually Alpine is a better/smaller image base, it seems the official Python image folks make an alpine version available too (link), which reduces the total image to ~60MB :)

python:3
<none>          <none>            578cb428b665   7 minutes ago   1.03GB

python:alpine3.20
<none>          <none>            4a5788ce332c   2 seconds ago   59.8MB

The following diff will change the Dockerfile to the new image:

diff --git a/Dockerfile b/Dockerfile
index 55f6ccf..0bd850e 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3
+FROM python:alpine3.20
 
 WORKDIR /essstat