Docker context problem

Your problem is right there:how can docker context know about your key?

Docker uses the ssh agent and thus the mechanisms for ssh. Add the host’s config and identify file to the ssh config file and you should be good:

cat >> ~/.ssh/config <<-EOF
Host 54.152.94.40
     HostName 54.152.94.40
     User ubuntu
     IdentityFile ~/Downloads/Docker1KeyPair.pem 
EOF

Then try docker --context remote ps again