Keep getting Could not read CA certificate when trying to start docker

Please follow this guide: Docker for Mac vs Docker Toolbox

Worked for me, you need to unset the variables instead of creating them for mac.

# grep for DOCKER ENV vars
env | grep DOCKER
unset <DOCKER_VARS>

Usually most people have install boot2docker and old version of virtualbox. As said in installation guide, before installing Docker for Mac, we have to uninstall boot2docker and reinstall virtualbox to high version. https://docs.docker.com/engine/installation/mac/#/docker-for-mac

Even though we have installed Docker for Mac, we still encountered error "Could not read CA certificate".

My solution is to remove the docker related environment variables (DOCKER*) from .bash_profile. It seems a long term solution.

1. vim ~/.bash_profile

2. Comment something like DOCKER_*

3. source ~/.bash_profile

4. relaunch the terminal, you should have no problem on running : docker info or docker ps

Hope it helps.

I found my solution here

I needed to update my .bash_profile to look like:

export DOCKER_HOST=tcp://192.168.99.100:2376
export DOCKER_MACHINE_NAME=default
export DOCKER_TLS_VERIFY=1
export DOCKER_CERT_PATH=~/.docker/machine/machines/default

and then run the following to generate the missing ca.pem:

docker-machine regenerate-certs default

I posted this in case this could help anyone else. Thanks/props go to everyone in that thread on github which was found after an hour of pain.

I encountered the same error due to the reason that I had setup the environment to a particular docker machine which I later deleted but my environment was still set to the deleted machine. So docker calls were being redirected the a non-existant machine causing the error.

I unset the environment variables and the issue was fixed:

eval $(docker-machine env -u)

To see which environment variable would be unset run:

docker-machine env -u