Why won't docker work?

I recently installed docker on RHEL 7.2 and had a lot of trouble getting the daemon to start. I eventually rebooted the server and it did SEEM to start but I can't get any response from docker, which says the daemon is not running.

[Scott@Spock FIORd0_XFS]$ systemctl status docker.service
● docker.service - Docker Application Container Engine
Loaded: loaded (/usr/lib/systemd/system/docker.service; enabled; vendor preset: disabled)
Active: active (running) since Fri 2017-08-18 11:40:12 EDT; 1h 16min ago
Docs: http://docs.docker.com
Main PID: 3179 (dockerd-current)
CGroup: /system.slice/docker.service
├─3179 /usr/bin/dockerd-current --add-runtime docker-runc=/usr/libexec/docker/docker-runc-current --default-runtime=docker-runc --authorization-plugin=rhel-...
└─3517 /usr/bin/docker-containerd-current -l unix:///var/run/docker/libcontainerd/docker-containerd.sock --shim docker-containerd-shim --metrics-interval=0 ...

Aug 18 11:40:10 Spock.RHEL dockerd-current[3179]: time="2017-08-18T11:40:10.530300967-04:00" level=info msg="Graph migration to content-addressability took 0.00 seconds"
Aug 18 11:40:10 Spock.RHEL dockerd-current[3179]: time="2017-08-18T11:40:10.530762011-04:00" level=warning msg="mountpoint for pids not found"
Aug 18 11:40:10 Spock.RHEL dockerd-current[3179]: time="2017-08-18T11:40:10.531290461-04:00" level=info msg="Loading containers: start."
Aug 18 11:40:10 Spock.RHEL dockerd-current[3179]: ..time="2017-08-18T11:40:10.569282865-04:00" level=info msg="Firewalld running: true"
Aug 18 11:40:11 Spock.RHEL dockerd-current[3179]: time="2017-08-18T11:40:11.634355282-04:00" level=info msg="Default bridge (docker0) is assigned with an IP a... address"
Aug 18 11:40:12 Spock.RHEL dockerd-current[3179]: time="2017-08-18T11:40:12.005316065-04:00" level=info msg="Loading containers: done."
Aug 18 11:40:12 Spock.RHEL dockerd-current[3179]: time="2017-08-18T11:40:12.005460122-04:00" level=info msg="Daemon has completed initialization"
Aug 18 11:40:12 Spock.RHEL dockerd-current[3179]: time="2017-08-18T11:40:12.005493465-04:00" level=info msg="Docker daemon" commit="0fdc778/1.12.6" graphdrive...on=1.12.6
Aug 18 11:40:12 Spock.RHEL systemd[1]: Started Docker Application Container Engine.
Aug 18 11:40:12 Spock.RHEL dockerd-current[3179]: time="2017-08-18T11:40:12.033481075-04:00" level=info msg="API listen on /var/run/docker.sock"
Hint: Some lines were ellipsized, use -l to show in full.
[Scott@Spock FIORd0_XFS]$ docker pull servethehome/monero_cpu_minergate
Using default tag: latest
Cannot connect to the Docker daemon. Is the docker daemon running on this host?
[Scott@Spock FIORd0_XFS]$ docker info
Cannot connect to the Docker daemon. Is the docker daemon running on this host?
[Scott@Spock FIORd0_XFS]$ systemctl enable docker.service
[Scott@Spock FIORd0_XFS]$ systemctl status docker.service
● docker.service - Docker Application Container Engine
Loaded: loaded (/usr/lib/systemd/system/docker.service; enabled; vendor preset: disabled)
Active: active (running) since Fri 2017-08-18 11:40:12 EDT; 1h 18min ago
Docs: http://docs.docker.com
Main PID: 3179 (dockerd-current)
CGroup: /system.slice/docker.service
├─3179 /usr/bin/dockerd-current --add-runtime docker-runc=/usr/libexec/docker/docker-runc-current --default-runtime=docker-runc --authorization-plugin=rhel-...
└─3517 /usr/bin/docker-containerd-current -l unix:///var/run/docker/libcontainerd/docker-containerd.sock --shim docker-containerd-shim --metrics-interval=0 ...

Aug 18 11:40:10 Spock.RHEL dockerd-current[3179]: time="2017-08-18T11:40:10.530300967-04:00" level=info msg="Graph migration to content-addressability took 0.00 seconds"
Aug 18 11:40:10 Spock.RHEL dockerd-current[3179]: time="2017-08-18T11:40:10.530762011-04:00" level=warning msg="mountpoint for pids not found"
Aug 18 11:40:10 Spock.RHEL dockerd-current[3179]: time="2017-08-18T11:40:10.531290461-04:00" level=info msg="Loading containers: start."
Aug 18 11:40:10 Spock.RHEL dockerd-current[3179]: ..time="2017-08-18T11:40:10.569282865-04:00" level=info msg="Firewalld running: true"
Aug 18 11:40:11 Spock.RHEL dockerd-current[3179]: time="2017-08-18T11:40:11.634355282-04:00" level=info msg="Default bridge (docker0) is assigned with an IP a... address"
Aug 18 11:40:12 Spock.RHEL dockerd-current[3179]: time="2017-08-18T11:40:12.005316065-04:00" level=info msg="Loading containers: done."
Aug 18 11:40:12 Spock.RHEL dockerd-current[3179]: time="2017-08-18T11:40:12.005460122-04:00" level=info msg="Daemon has completed initialization"
Aug 18 11:40:12 Spock.RHEL dockerd-current[3179]: time="2017-08-18T11:40:12.005493465-04:00" level=info msg="Docker daemon" commit="0fdc778/1.12.6" graphdrive...on=1.12.6
Aug 18 11:40:12 Spock.RHEL systemd[1]: Started Docker Application Container Engine.
Aug 18 11:40:12 Spock.RHEL dockerd-current[3179]: time="2017-08-18T11:40:12.033481075-04:00" level=info msg="API listen on /var/run/docker.sock"
Hint: Some lines were ellipsized, use -l to show in full.
[Scott@Spock FIORd0_XFS]$ docker info
Cannot connect to the Docker daemon. Is the docker daemon running on this host?
[Scott@Spock FIORd0_XFS]$