[Solved] Docker: An error occurred trying to connect

Solution #1:

If you are using windows command prompt instead of Docker QuickStart Terminal see official docs you should make following steps (assuming your docker machine has the name default):

1. docker-machine start default or create new one
2. docker-machine lswill show you your machine running

3. docker-machine env --shell cmd default and you’ll see something like

   SET DOCKER_TLS_VERIFY=1
   SET DOCKER_HOST=tcp://192.168.99.100:2376
   SET DOCKER_CERT_PATH=C:UsersArseny.dockermachinemachinesdefault
   SET DOCKER_MACHINE_NAME=default
   REM Run this command to configure your shell:
   REM     FOR /f "tokens=*" %i IN ('docker-machine env --shell cmd default') DO %i
   

4. Run FOR /f "tokens=*" %i IN ('docker-machine env --shell cmd default') DO %i
5. Enjoy

Solution #2:

If you want to use PowerShell (in Windows 7) instead of Docker Quickstart Terminal then enter following commands step by step in your powershell terminal:

NOTE: You must have to start Docker Quickstart Terminal first before
performing below operations

docker-machine.exe env --shell powershell it will display below commands on terminal:

$Env:DOCKER_TLS_VERIFY = "1"
$Env:DOCKER_HOST = "tcp://192.168.99.100:2376"
$Env:DOCKER_CERT_PATH = "C:Userspratikpat.dockermachinemachinesdefault"
$Env:DOCKER_MACHINE_NAME = "default"
# Run this command to configure your shell:
# & "C:Program FilesDocker Toolboxdocker-machine.exe" env --shell powershell | Invoke-Expression

Execute last displayed command to configure your shell:

& "C:Program FilesDocker Toolboxdocker-machine.exe" env --shell powershell | Invoke-Expression

Solution #3:

I got same error on Windows 7 inside Docker Terminal. So I had to do the following. In case somebody like me is searching for this.

$ docker-machine rm default
$ docker-machine create --driver virtualbox default

Solution #4:

When it happened to me I was a secondary user, in other words Docker installed under a different account. So I tried [re]creating the machine as Admin:

C:WINDOWSsystem32>docker-machine create --driver "hyperv" default
Creating CA: C:Users
onAdmin.dockermachinecertsca.pem
Creating client certificate: C:Users
onAdmin.dockermachinecertscert.pem
Running pre-create checks...
(default) Image cache directory does not exist, creating it at C:Users
onAdmin.dockermachinecache...
(default) No default Boot2Docker ISO found locally, downloading the latest release...
(default) Latest release for github.com/boot2docker/boot2docker is v1.12.3
(default) Downloading C:Users
onAdmin.dockermachinecacheoot2docker.iso from https://github.com/boot2docker/boot2docker/releases/download/v1.12.3/boot2docker.iso...
(default) 0%....10%....20%....30%....40%....50%....60%....70%....80%....90%....100%
Creating machine...
(default) Copying C:Users
onAdmin.dockermachinecacheoot2docker.iso to C:Users
onAdmin.dockermachinemachinesdefaultoot2docker.iso...
(default) Creating SSH key...
(default) Creating VM...
(default) Using switch "DockerNAT"
(default) Creating VHD
(default) Starting VM...
(default) Waiting for host to start...
Waiting for machine to be running, this may take a few minutes...
Detecting operating system of created instance...
Waiting for SSH to be available...


Sadly, it did not work. Even running docker in an Admin shell fails.

Solution #5:

you can solve problem on docker dekstop to;

Under Settings->General do you have Expose daemon on tcp://localhost:2375 without TLS enabled? You need to if you want to access the daemon as described.

Solution #6:

All I got to do was to run

docker-machine env --shell cmd default

and then

eval "$(boot2docker shellinit)"