Docker can't connect to docker daemon

Question

After I update my Docker version to 0.8.0, I get an error message while entering sudo docker version:

Client version: 0.8.0 Go version (client): go1.2 Git commit (client): cc3a8c8 2014/02/19 12:54:16 Can't connect to docker daemon. Is 'docker -d' running on this host? 

And I've followed the instructions and entered command sudo docker -d, and I got this:

[/var/lib/docker|2462000b] +job initserver() [/var/lib/docker|2462000b.initserver()] Creating server open /var/lib/docker/aufs/layers/cf2414da53f9bcfaa48bc3d58360d7f1cfd3784e4fe51fbef95197709dfc285d: no such file or directory[/var/lib/docker|2462000b] -job initserver() = ERR (1) 2014/02/19 12:55:57 initserver: open /var/lib/docker/aufs/layers/cf2414da53f9bcfaa48bc3d58360d7f1cfd3784e4fe51fbef95197709dfc285d: no such file or directory 

How do I solve the problem?

Answer 1

Linux

The Post-installation steps for Linux documentation reveals the following steps:

1. Create the docker group.

    sudo groupadd docker

2. Add the user to the docker group.

    sudo usermod -aG docker $(whoami)

3. Log out and log back in to ensure docker runs with correct permissions.
4. Start docker.

    sudo service docker start

Mac OS X

As Dayel Ostraco says is necessary to add environments variables:

docker-machine start # Start virtual machine for docker docker-machine env  # It's helps to get environment variables eval "$(docker-machine env default)" # Set environment variables 

The docker-machine start command outputs the comments to guide the process.

Answer 2

Linux

To run docker daemon on Linux (from CLI), run:

$ sudo service docker start # Ubuntu/Debian 

^{Note: Skip the $ character when copy and pasting.}

On RedHat/CentOS, run: sudo systemctl start docker.

To initialize the "base" filesystem, run:

$ sudo service docker stop $ sudo rm -rf /var/lib/docker $ sudo service docker start 

or manually like:

$ sudo docker -d --storage-opt dm.basesize=20G 

Install docker-machine on Linux

To install machine binaries on Linux:

• locally:

  install -vm755 <(curl -L https://github.com/docker/machine/releases/download/v0.5.3/docker-machine_linux-amd64) $HOME/bin/docker-machine 

• global:

  sudo bash -c 'install -vm755 <(curl -L https://github.com/docker/machine/releases/download/v0.5.3/docker-machine_linux-amd64) /usr/local/bin/docker-machine' 

macOS

On macOS the docker binary is only a client and you cannot use it to run the docker daemon, because Docker daemon uses Linux-specific kernel features, therefore you can’t run Docker natively in OS X. So you have to install docker-machine in order to create VM and attach to it.

Install docker-machine on macOS

If you don't have docker-machine command yet, install it by using one of the following methods:

• Using Brew command: brew install docker-machine docker.

• manually from GitHub:

  install -v <(curl https://github.com/docker/machine/releases/download/v0.5.3/docker-machine_linux-amd64) /usr/local/bin/docker-machine 

See: Get started with Docker for Mac.

Configure docker-machine on macOS

To start Docker Machine via Homebrew, run:

brew services start docker-machine 

To create a default machine (if you don't have one, see: docker-machine ls):

docker-machine create --driver virtualbox default 

Then set-up the environment for the Docker client:

eval "$(docker-machine env default)" 

Then double-check by listing containers:

docker ps 

See: Get started with Docker Machine and a local VM.

---

Install Docker.app on macOS

Alternatively to above solution, you can install a Docker app by:

brew cask install docker 

Check this post for more details. See also: Cannot connect to the Docker daemon on macOS