Couldn't connect to Docker daemon at http+docker://localhost

Tutor
#1

I have a DigitalOcean VPS on an IP like 82.196..
I installed Docker, then Tutor based on documentations.
But I get the error in the title when I run quickstart:

    $ tutor local quickstart
    ==================================================
    Interactive platform configuration
    ==================================================
    Your website domain name for students (LMS) 82.196.***.***
    Your website domain name for teachers (CMS) 82.196.***.***/cms 
    Your platform name/title [My Ins.] 
    Your public contact email address [myemail@gmail.com] 
    The default language code for the platform [en] 
    Activate SSL/TLS certificates for HTTPS access? Important note: this will NOT work in a         development environment. [y/N] n
    Configuration saved to /home/hitaro/.local/share/tutor/config.yml
    ================================================
    Updating the current environment
    ================================================
    Environment generated in /home/hitaro/.local/share/tutor/env
    ==============================================
    Stopping any existing platform
    ==============================================
    docker-compose -f /home/hitaro/.local/share/tutor/env/local/docker-compose.yml --project-name tutor_local rm --stop --force
    ERROR: Couldn't connect to Docker daemon at http+docker://localhost - is it running?
    
    If it's at a non-standard location, specify the URL with the DOCKER_HOST environment variable.
    Error: Command failed with status 1: docker-compose -f /home/hitaro/.local/share/tutor/env/local/docker-compose.yml --project-name tutor_local rm --stop --force

What’s wrong here?

#2

There seems to be an issue with your docker installation. What is the output of the following commands?

docker --version
docker run --rm hello-world
groups
#3

Hi @regis I have the same issue with my installation
docker --version
Docker version 19.03.5, build 633a0ea838

#4

This is my actual docker run --rm hellow-world
docker run --rm 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/v1.40/containers/create: dial unix /var/run/docker.sock: connect: permi ssion denied.

groups
ubuntu adm dialout cdrom floppy sudo audio dip video plugdev netdev lxd

#5

Hi @regis
sudo docker run hello-world

Hello from Docker!
This message shows that your installation appears to be working correctly.

To generate this message, Docker took the following steps:

  1. The Docker client contacted the Docker daemon.
  2. The Docker daemon pulled the “hello-world” image from the Docker Hub.
    (amd64)
  3. The Docker daemon created a new container from that image which runs the
    executable that produces the output you are currently reading.
  4. The Docker daemon streamed that output to the Docker client, which sent it
    to your terminal.

To try something more ambitious, you can run an Ubuntu container with:
$ docker run -it ubuntu bash

Share images, automate workflows, and more with a free Docker ID:
https://hub.docker.com/

For more examples and ideas, visit:
https://docs.docker.com/get-started/

#6

Hi @roberto! Please don’t use sudo: Why we should not use "Sudo tutor local quickstart"?
This issue has been raised so many times I know need to add it to the FAQ.

#7