Handle 'cannot connect to Docker daemon' correctly

[purestaketdb]

Minor issue when running './sandbox up' on OS X when the Docker daemon has been turned off. Sandbox util incorrectly reports progress, while also showing errors from Docker.

`Building a new Docker Image...
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?
ERRO[0000] failed to dial gRPC: cannot connect to the Docker daemon. Is 'docker daemon' running on this host?: dial unix /var/run/docker.sock: connect: connection refused

Starting a new Docker Container...
docker: Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?.
See 'docker run --help'.

Sandbox started! Printing status...
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?`

Fix: Correct flow to exit out if daemon is not running or update bolded status messages to indicate issue.

[winder]

Strange, set -e is supposed to terminate the program when an error like this happens.

Does this script execute for you?

#!/bin/bash

set -e

invalid-command

echo "Should not get here"

[purestaketdb]

It did not reach the echo statement. This is really minor in the grand scheme of thing, as the errors are outputted along the way.

[winder]

@purestaketdb could you see if the improvement @fabrice102 made fixes this?

[winder]

Let me know if this is still an issue, closing due to inactivity.

[modernlearner]

I just ran into this issue with "connection refused". It looks like the docker.pid or docker.sock permissions have to be changed to allow a connection. The Docker installation guide is a misleading because it considers docker installed successfully when the command sudo docker run hello-world works.

However, without running as root:

$ docker run hello-world
docker: Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Post http://%2Fvar%2Frun%2Fdocker.sock/v1.24/containers/create: dial unix /var/run/docker.sock: connect: permission denied.
See 'docker run --help'.

Based on a stackoverflow answer you can do this to fix the issue:

$ sudo chmod o=rwx /var/run/docker.sock
$ docker run hello-world # make sure it worked

After doing this I was able to run the ./sandbox up and start to see some progress in setting up the docker containers.

As per #23 it would be great to see this mentioned in the README or to see a more helpful error message that suggests doing the above.

[fabrice102]

Thanks @modernlearner for your answer to detect Docker running.

However, doing

sudo chmod o=rwx /var/run/docker.sock

should only be done on experimental machines without any important data.

On Linux, it indeed gives full root access to any user of the machine.
See https://docs.docker.com/engine/security/#docker-daemon-attack-surface

Adding your username to the group docker is slightly better:

sudo groupadd docker
sudo usermod -aG docker $USER

(followed by logging out and logging back in)
However, it is still quite dangerous as it gives root access to yourself without the protection that sudo offers (i.e., asking for the user password and logging any sudo command).
See https://docs.docker.com/engine/install/linux-postinstall/#manage-docker-as-a-non-root-user