[WIP] Nodesource cert verification issue

[jurre]

As per nodesource/distributions#1266 the
LetsEncrypt DST Root CA X3 has expired last week, and this prevents us
from building the docker image.

Installing libgnutls30 as suggested in that thread seems to fix it,
but to be entirely honest I am not sure why.

Until the nodesource maintainers suggest a solution, this at least
unblocks container builds, but I'd recommend that we only use this in
local development and not publish it.

[baseballlover723]

it may be worth clearing the docker cache. I had some issues with it in #4250. And I found that a clean docker build or building without the caching enabled worked, so clearing the docker cache might be able to fix the image without having to add anything to the image. Adding libgnutls30 might be working because it forces the docker to download a fresh copy of nodesource. Not 100% sure if this will work, but its worth a shot

[jurre]

it may be worth clearing the docker cache. I had some issues with it in #4250. And I found that a clean docker build or building without the caching enabled worked, so clearing the docker cache might be able to fix the image without having to add anything to the image. Adding libgnutls30 might be working because it forces the docker to download a fresh copy of nodesource. Not 100% sure if this will work, but its worth a shot

Yep, this is exactly right, clearing the cache installs the latest version of ca-certificates which resolves the issue. I'd meant to open a PR that fixes this on Friday but I didn't get around to it, so will try to do so today