Is there a straight forward way to generate a
.txt file containing each URL (or corresponding IP) visited during a docker build process?
An example list might look like this:
# urls.txt https://hub.docker.com/ https://www.npmjs.com/
(but a real case using an extensive Dockerfile may be more complex and contain many more URLs/IPs).
Things I tried so far
1. Installing and using an intrusion detection engine
IDSs I attempted to install and use were feature rich and probably more complex than required for what I'm attempting. Configuring IDS engines is not trivial (especially for someone with little network knowledge), so I'd like to explore simpler solutions, if possible.
2. Collecting and parsing docker build logs
I captured build logs with this:
docker build --no-cache --progress=plain . &> build.log
and extracted lines containing a URL with this regular expression:
A lot of URLs are found, but... i) it doesn't find URLs which aren't explicitly stated in the build logs, and ii) it finds URLs which aren't actually accessed but which are simply stated in logs (i.e. logs along the lines of "For more info, visit https://www.example.com".
How can I generate a nice clean list of each external URL visited during a
docker build process?