How do I add a CA root certificate inside a docker image?

Question

I am running an ASP.NET Core 1.1 Web API in a Docker 1.13.1 container on Ubuntu 14.04.

When the code attempts to retrieve some data from an HTTPS server, I get this

Answer 1

The task itself is not specific to docker as you would need to add that CA on a normal system too. There is an answer on the askubuntu community on how to do this.

So in a Dockerfile you would do the following (don't forget chmod in case you're running the container with a user other than root):

ADD your_ca_root.crt /usr/local/share/ca-certificates/foo.crt
RUN chmod 644 /usr/local/share/ca-certificates/foo.crt && update-ca-certificates