<p>when Every time I try to minikube start on Linux (ubuntu 18.04), I always get this Docker validation errors.<a href="https://i.stack.imgur.com/pMZy4.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/pMZy4.png" alt="enter image description here" /></a></p>

Miraz
<p>This works fine for me:</p>
<pre class="lang-sh prettyprint-override"><code>myuser@mymachine:~$ minikube start --driver=docker
😄  minikube v1.11.0 on Ubuntu 16.04
✨  Using the docker driver based on user configuration
👍  Starting control plane node minikube in cluster minikube
🚜  Pulling base image ...
🔥  Creating docker container (CPUs=2, Memory=2200MB) ...
🌐  Found network options:
    ▪ NO_PROXY=169.254.169.254
🐳  Preparing Kubernetes v1.18.3 on Docker 19.03.2 ...
    ▪ env NO_PROXY=169.254.169.254
    ▪ kubeadm.pod-network-cidr=10.244.0.0/16
🔎  Verifying Kubernetes components...
🌟  Enabled addons: default-storageclass, storage-provisioner
🏄  Done! kubectl is now configured to use &quot;minikube&quot;

</code></pre>
<p>Make sure that <code>/var/run/docker.sock</code> has the right permission to be accessed by your user</p>
<pre class="lang-sh prettyprint-override"><code>myuser@mymachine:~$ sudo chmod o+rw /var/run/docker.sock
myuser@mymachine:~$ ls -la /var/run/docker.sock
srw-rw-rw- 1 root docker 0 Jul  6 17:42 /var/run/docker.sock
</code></pre>
<p>Make sure the docker daemon is running:</p>
<pre class="lang-sh prettyprint-override"><code>myuser@mymachine:~$ ps -Af | grep dockerd
root     12723     1  0 Jul06 ?        00:01:11 /usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock
root     18598 17596  0 19:19 ?        00:00:05 /usr/bin/dockerd -H tcp://0.0.0.0:2376 -H unix:///var/run/docker.sock --default-ulimit=nofile=1048576:1048576 --tlsverify --tlscacert /etc/docker/ca.pem --tlscert /etc/docker/server.pem --tlskey /etc/docker/server-key.pem --label provider=docker --insecure-registry 10.96.0.0/12
adminra+ 31177 26444  0 19:36 pts/0    00:00:00 grep --color=auto dockerd
</code></pre>
