Using ENV var instructions in Readme Leads to invalid key

[byoung]

Spinning up a key server while following the ENV var setup instructions will lead to an invalid key.

Running this to startup the key server

docker run -e DOCKER-SSH-KEY="$(cat ~/.ssh/id_rsa)" --name=keyserver -d mdsol/docker-ssh-exec -server

Then running any build command with a Dockerfile that contains a git clone of a private repo:

RUN docker-ssh-exec git clone -q 'ssh://git@github.com/mdsol/belker-python.git'

Will lead to this error

Step 9/21 : RUN docker-ssh-exec git clone -q 'ssh://git@github.com/mdsol/belker-python.git'
 ---> Running in d35e5372139e
Broadcasting UDP key request...
Got key from server.
Broadcasting UDP env request...
Recieved env from server
Setting 0 ENV vars from server: 
Writing key to /root/.ssh/id_rsa
Running command: git clone -q ssh://git@github.com/mdsol/belker-python.git
Warning: Permanently added the RSA host key for IP address '140.82.114.4' to the list of known hosts.
Load key "/root/.ssh/id_rsa": invalid format
git@github.com: Permission denied (publickey).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

Using the first (non ENV var) method to spin up the container does work.

[byoung]

Only difference in the key between the two methods was that the env var approach stripped the trailing newline.