"Cannot connect to the docker socket. Cannot proceed."

[Saiv46]

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Steps to reproduce

1. Install Docker Desktop
2. Run the command from README

# For x64 CPUs:
sudo docker run \
--sig-proxy=false \
--name nextcloud-aio-mastercontainer \
--restart always \
--publish 80:80 \
--publish 8080:8080 \
--publish 8443:8443 \
--volume nextcloud_aio_mastercontainer:/mnt/docker-aio-config \
--volume /var/run/docker.sock:/var/run/docker.sock:ro \
nextcloud/all-in-one:latest

Expected behavior

Containers should start properly (like Portainer)

Actual behavior

Containers fails with messages:

Cannot connect to the docker socket. Cannot proceed.

Host OS

NAME="Linux Mint"
VERSION="21 (Vanessa)"
ID=linuxmint
ID_LIKE="ubuntu debian"
PRETTY_NAME="Linux Mint 21"
VERSION_ID="21"
HOME_URL="https://www.linuxmint.com/"
SUPPORT_URL="https://forums.linuxmint.com/"
BUG_REPORT_URL="http://linuxmint-troubleshooting-guide.readthedocs.io/en/latest/"
PRIVACY_POLICY_URL="https://www.linuxmint.com/"
VERSION_CODENAME=vanessa
UBUNTU_CODENAME=jammy

Nextcloud AIO version

latest

Current channel

Other valuable info

[szaimen]

Can you run sudo ss -x -a | grep docker.sock? What does it return?

[szaimen]

Hi, did you follow https://nextcloud.com/blog/your-guide-to-the-nextcloud-all-in-one-on-windows-10-11/?

[szaimen]

I have the assuption that the Docker Desktop update v4.19 broke things. See #2450

[havkacik]

@szaimen, yes I followed the manual you referred to. I suspect new Docker Desktop version 4.19 broke NextCloud functionality, too.

Desktop Docker 4.16 running on another Windows 11 machine has been working well with default WSL2 (docker-desktop, docker-desktop-data).

I also installed older version Docker Desktop to v4.18 in Windows 10 machine and it's working smoothly with default WSL2 (docker-desktop, docker-desktop-data).

If you can fix this for the new Docker Desktop v4.19, that would be great.

[szaimen]

If you can fix this for the new Docker Desktop v4.19, that would be great.

This needs to be fixed in Docker Desktop unfortunately.

See docker/for-win#13447 and docker/for-mac#6823

[szaimen]

All right!

Please try this one then:

# For x64 CPUs:
sudo docker run \
--sig-proxy=false \
--name nextcloud-aio-mastercontainer \
--restart always \
--publish 80:80 \
--publish 8080:8080 \
--publish 8443:8443 \
--volume nextcloud_aio_mastercontainer:/mnt/docker-aio-config \
--volume /home/saiv46/.docker/desktop/docker.sock:/var/run/docker.sock:ro \
-e DOCKER_SOCKET_PATH=/home/saiv46/.docker/desktop/docker.sock \
nextcloud/all-in-one:latest

(I've adjusted --volume /var/run/docker.sock:/var/run/docker.sock:ro and added DOCKER_SOCKET_PATH)

[Saiv46]

Same error

[szaimen]

all right, then I don*t have many ideas what could be the problem. It works over here without any problem.

I can only suggest to switch to "normal" docker and to not use docker Desktop for this as it is much easier with "normal" docker.

Apart from that I've found this for you: https://docs.docker.com/desktop/faqs/linuxfaqs/#how-do-i-enable-file-sharing

[Saiv46]

If it was file sharing problem, then it would output:

docker: Error response from daemon: Mounts denied: 
The path /home/saiv46/.docker/desktop/docker.sock is not shared from the host and is not known to Docker.
You can configure shared paths from Docker -> Preferences... -> Resources -> File Sharing.
See https://docs.docker.com/ for more info.

Instead, something inside Nextcloud container errors on non-root docker

[szaimen]

Instead, something inside Nextcloud container errors on non-root docker

sorry, no idea. As I said, it works over here and I even have tested it successfully with docker rootles.

[Saiv46]

Well, thanks for help then.

[szaimen]

But I have one idea left.

Could you try this one?

# For x64 CPUs:
sudo docker run \
--sig-proxy=false \
--name nextcloud-aio-mastercontainer \
--restart always \
--publish 80:80 \
--publish 8080:8080 \
--publish 8443:8443 \
--volume nextcloud_aio_mastercontainer:/mnt/docker-aio-config \
--volume /home/saiv46/.docker/desktop/docker.sock.raw:/var/run/docker.sock:ro \
-e DOCKER_SOCKET_PATH=/home/saiv46/.docker/desktop/docker.sock.raw \
nextcloud/all-in-one:latest

[Saiv46]

No luck

[szaimen]

Just wanted to leave a code pointer here but no idea why it fails on you:

all-in-one/Containers/mastercontainer/start.sh

Lines 17 to 50 in 3091135

	# Check if socket is available and readable
	if ! [ -a "/var/run/docker.sock" ]; then
	echo "Docker socket is not available. Cannot continue."
	exit 1
	elif ! mountpoint -q "/mnt/docker-aio-config"; then
	echo "/mnt/docker-aio-config is not a mountpoint. Cannot proceed!"
	exit 1
	elif ! sudo -u www-data test -r /var/run/docker.sock; then
	echo "Trying to fix docker.sock permissions internally..."
	DOCKER_GROUP=$(stat -c '%G' /var/run/docker.sock)
	DOCKER_GROUP_ID=$(stat -c '%g' /var/run/docker.sock)
	# Check if a group with the same group id of /var/run/docker.socket already exists in the container
	if grep -q "^$DOCKER_GROUP:" /etc/group; then
	# If yes, add www-data to that group
	echo "Adding internal www-data to group $DOCKER_GROUP"
	usermod -aG "$DOCKER_GROUP" www-data
	else
	# Delete the docker group for cases when the docker socket permissions changed between restarts
	groupdel docker &>/dev/null
	# If the group doesn't exist, create it
	echo "Creating docker group internally with id $DOCKER_GROUP_ID"
	groupadd -g "$DOCKER_GROUP_ID" docker
	usermod -aG docker www-data
	fi
	if ! sudo -u www-data test -r /var/run/docker.sock; then
	echo "Docker socket is not readable by the www-data user. Cannot continue."
	exit 1
	fi
	fi
	# Check if api version is supported
	if ! sudo -u www-data docker info &>/dev/null; then
	echo "Cannot connect to the docker socket. Cannot proceed."

[Weax]

--volume /var/run/docker.sock:/var/run/docker.sock:ro \
try to change /var to //var - this helped me

[RandyR34]

This "double slash" advice helped me also. Couple tests below.

(Success) Two slashes on left side. One slash on right side:
//var/run/docker.sock:/var/run/docker.sock

(Success) Two slashes on (both) left and right side:
//var/run/docker.sock://var/run/docker.sock

[Zoey2936]

the right side should never be changed

[chuckt62]

Thanks Weax,
The left side //var fixed it!

[Seraff]

Had the same problem. The answer #485 helped.

Installed docker using the recommended method and everything works fine.

curl -fsSL get.docker.com | sudo sh

[shalak]

I have the same issue:

nextcloud-aio-mastercontainer  | Docker socket is not available. Cannot continue.
nextcloud-aio-mastercontainer exited with code 0
nextcloud-aio-mastercontainer exited with code 1
nextcloud-aio-mastercontainer exited with code 1
nextcloud-aio-mastercontainer exited with code 1
nextcloud-aio-mastercontainer exited with code 1
nextcloud-aio-mastercontainer exited with code 1

Docker was installed using get.docker.com script.

The /var/run/docker.sock exists:

root# ls -al /var/run/docker.sock
srw-rw---- 0 root 29 sty 15:34 /var/run/docker.sock
root# ss -x -a | grep docker.sock
u_str LISTEN 0      4096                           /var/run/docker.sock 133333            * 0
u_str LISTEN 0      4096                               /run/docker.sock 82606             * 0

Here is more diagnostics:

root# systemctl status docker
● docker.service - Docker Application Container Engine
     Loaded: loaded (/lib/systemd/system/docker.service; enabled; vendor preset: enabled)
    Drop-In: /etc/systemd/system/docker.service.d
             └─docker.conf, wait-for-cifs.conf, wait-for-nfs.conf
     Active: active (running) since Sun 2023-01-29 15:34:59 CET; 1h 5min ago
TriggeredBy: ● docker.socket
       Docs: https://docs.docker.com
   Main PID: 24743 (dockerd)
      Tasks: 16
     Memory: 848.8M
        CPU: 2min 34.621s
     CGroup: /system.slice/docker.service
             └─24743 /usr/bin/dockerd

root# systemctl status docker.socket
● docker.socket - Docker Socket for the API
     Loaded: loaded (/lib/systemd/system/docker.socket; enabled; vendor preset: enabled)
     Active: active (running) since Fri 2023-01-27 20:45:17 CET; 1 day 19h ago
   Triggers: ● docker.service
     Listen: /run/docker.sock (Stream)
      Tasks: 0 (limit: 19067)
     Memory: 0B
        CPU: 3ms
     CGroup: /system.slice/docker.socket



root# cat /lib/systemd/system/docker.socket
[Unit]
Description=Docker Socket for the API

[Socket]
ListenStream=/var/run/docker.sock
SocketMode=0660
SocketUser=root
SocketGroup=docker

[Install]
WantedBy=sockets.target

I'm starting AIO with following docker-compose:

services:
  caddy:
    image: caddy:alpine
    restart: unless-stopped
    container_name: caddy
    volumes:
      - /srv/fast/caddy/Caddyfile:/etc/caddy/Caddyfile
      - /srv/fast/caddy/certs:/certs
      - /srv/fast/caddy/config:/config
      - /srv/fast/caddy/data:/data
      - /srv/fast/caddy/sites:/srv
      - /mnt/ssl:/mnt/ssl
    network_mode: "host"

  nextcloud:
    image: nextcloud/all-in-one:latest
    restart: unless-stopped
    container_name: nextcloud-aio-mastercontainer
    ports:
      - "8080:8080"
    environment:
      - APACHE_PORT=11000
      - NEXTCLOUD_DATADIR="/srv/fast/ncdata"
      - NEXTCLOUD_MEMORY_LIMIT=2048M
      - nextcloud_aio_mastercontainer:/mnt/docker-aio-config
      - /var/run/docker.sock:/var/run/docker.sock:ro
    depends_on:
      - caddy

volumes:
  nextcloud_aio_mastercontainer:

I wonder why do we mount the /var/run/docker.sock with ro? Doesn't it force the socket to be read-only?

[shalak]

Ok, now I see what I did wrong :) I must've removed the volumes: key and volumes ended up in environment: 🤦 anyhow - my question still stands - why is it supposed to be mounted as ro?

[szaimen]

ro or rw doesnt make a difference honestly. It will work with both.

[shalak]

How is it possible? Docker daemon should not allow AIO to write anything to the socket, thus making it not work at all! What am I missing here?

[szaimen]

AIO speaks via http to the docker socket and does not make any changes to it itself. That is why ro works as well.

[ArmenMadoyan]

in my MacBook I changed --volume /var/run/docker.sock:/var/run/docker.sock:ro to
--volume /var/run/docker.sock.raw:/var/run/docker.sock:ro and it worked fine

[szaimen]

Indeed: https://github.com/nextcloud/all-in-one#how-to-run-aio-on-macos

[z3r0r4]

I might have found a solution to this!
I was able to get nextcloud aio up and running and controllable from windows and docker desktop by running the command in the wsl2 terminal instead of the powershell or windows cmd.
The command i used was sudo docker run --sig-proxy=false --name nextcloud-aio-mastercontainer --restart always --publish 80:80 --publish 8080:8080 --publish 8443:8443 --volume nextcloud_aio_mastercontainer:/mnt/docker-aio-config --volume /var/run/docker.sock:/var/run/docker.sock:ro nextcloud/all-in-one:latest
with the output:
Trying to fix docker.sock permissions internally... Creating docker group internally with id 1001 WARNING: No blkio throttle.read_bps_device support WARNING: No blkio throttle.write_bps_device support WARNING: No blkio throttle.read_iops_device support WARNING: No blkio throttle.write_iops_device support Initial startup of Nextcloud All-in-One complete! You should be able to open the Nextcloud AIO Interface now on port 8080 of this server! E.g. https://internal.ip.of.this.server:8080 If your server has port 80 and 8443 open and you point a domain to your server, you can get a valid certificate automatically by opening the Nextcloud AIO Interface via: https://your-domain-that-points-to-this-server.tld:8443 [02-May-2023 13:15:59] NOTICE: fpm is running, pid 134 [02-May-2023 13:15:59] NOTICE: ready to handle connections {"level":"info","ts":1683033359.0319157,"msg":"using provided configuration","config_file":"/Caddyfile","config_adapter":""}

[szaimen]

Thanks for the workaround! However this is still a bug of Docker Desktop 4.19 and needs to be fixed! See #2450

[z3r0r4]

Youre welcome! Maybe the answer marker should be switched to this then

[szaimen]

Possibly this would have helped:
#485 (reply in thread)

[jastranlove2020]

2025-05-19
Windows Docker 4.41.2

• Container could not run with command prompt due to the error "Cannot connect to the docker socket. Cannot proceed." persisted. Run with WSL it works fine. The GUI can start and stop normal afterward

brian@ServerUPro:~$ sudo docker run --sig-proxy=false --name nextcloud-aio-mastercontainer --restart always --pu
blish 8002:80 --publish 8081:8080 --publish 8443:8443 --volume nextcloud_aio_mastercontainer:/mnt/docker-aio-config --vo
lume /mnt/wsl/docker-desktop-bind-mounts/Ubuntu-22.04/docker.sock:/var/run/docker.sock:ro nextcloud/all-in-one:latest
Trying to fix docker.sock permissions internally...
Creating docker group internally with id 1001
WARNING: No blkio throttle.read_bps_device support

[wijnen]

Since the update to the nextcloud-aio container from a few days ago, I now have the same error on my Synology NAS and I have found the problem in my case. To figure it out, I read /start.sh and saw that it runs "docker info" to see if the socket works. If it doesn't, it gives that error.

To check what happened, I tried the docker run command with the extra options --tty --interactive --entrypoint /bin/bash. From there, I attempted to run docker info. That resulted in this output:

0ba7e1490e9a:~/docker-aio# docker info
Client:
 Version:    29.0.2
 Context:    default
 Debug Mode: false

Server:
ERROR: Error response from daemon: client version 1.52 is too new. Maximum supported API version is 1.43
errors pretty printing info
0ba7e1490e9a:~/docker-aio#

So obviously, docker on my NAS is too old. But it doesn't look like I can upgrade it. So my question is now: how can I get a version of nextcloud aio that uses the older docker?

[szaimen]

Hi, see #7223

[wijnen]

Thanks!

For anyone finding this post, who does not want to read through that thread: the solution (really workaround) is to add --env DOCKER_API_VERSION=1.43 to the command line of docker run.

It works fine for me.