How to fix error during connect: Get http://docker:2375/v1.40/info: dial tcp: connect: connection refused in Docker

What this error means

The "dial tcp: connect: connection refused" error indicates that your Docker client is trying to connect to a Docker daemon via TCP (typically on port 2375 or 2376), but the connection is being actively refused. This is different from a timeout - a "connection refused" means something is listening on the network stack but explicitly rejecting the connection, or nothing is bound to that port at all. This error commonly appears in several scenarios: - **CI/CD pipelines**: When using Docker-in-Docker (dind) services in GitLab CI, GitHub Actions, or Jenkins, where the Docker daemon runs as a separate service container - **Remote Docker hosts**: When the DOCKER_HOST environment variable points to a remote machine or container - **WSL environments**: When Windows Subsystem for Linux is configured to connect to Docker Desktop via TCP - **Development tools**: IDEs and build tools that need to communicate with Docker over TCP The URL in the error message (e.g., `http://docker:2375`) reveals important information: the hostname being contacted and the port being used. Port 2375 is the default unencrypted Docker API port, while port 2376 is used for TLS-encrypted connections.

Typical symptoms

• Docker commands fail with 'dial tcp: connect: connection refused'
• CI/CD pipeline jobs fail during Docker build or push steps
• Error message shows connection to 'docker:2375' or 'localhost:2375'
• 'docker version' or 'docker info' commands fail with connection errors
• Docker-in-Docker (dind) service appears to start but Docker commands fail
• DOCKER_HOST is set but Docker daemon is unreachable

Common causes

1. Docker daemon is not running on the target host
2. Docker daemon is not configured to listen on TCP port 2375/2376
3. In CI/CD: Docker-in-Docker (dind) service has not fully started yet
4. Wrong hostname in DOCKER_HOST - using 'localhost' instead of 'docker' in container environments
5. Firewall blocking TCP port 2375 or 2376
6. Docker Desktop 'Expose daemon on tcp://localhost:2375' setting is disabled
7. Network isolation preventing container-to-container communication
8. TLS mismatch: client expecting non-TLS on 2375 but daemon configured for TLS on 2376
9. VPN or proxy interfering with local network connections

How to fix "error during connect: Get http://docker:2375/v1.40/info: dial tcp: connect: connection refused"

sudo systemctl status docker

Get-Service *docker*

# Linux
sudo systemctl start docker

# Windows/macOS
# Open Docker Desktop application

echo $DOCKER_HOST

unset DOCKER_HOST
docker version

# .gitlab-ci.yml
image: docker:latest

services:
  - docker:dind

variables:
  # CORRECT: Use 'docker' hostname for the dind service
  DOCKER_HOST: tcp://docker:2375

  # For TLS-enabled Docker 19.03+:
  # DOCKER_HOST: tcp://docker:2376
  # DOCKER_TLS_CERTDIR: "/certs"
  # DOCKER_CERT_PATH: "/certs/client"
  # DOCKER_TLS_VERIFY: 1

build:
  script:
    - docker version
    - docker build -t myimage .

jobs:
  build:
    runs-on: ubuntu-latest
    services:
      dind:
        image: docker:dind
        options: --privileged
        ports:
          - 2375:2375
        env:
          DOCKER_TLS_CERTDIR: ""

    steps:
      - uses: actions/checkout@v4

      - name: Wait for Docker daemon
        run: |
          timeout 30 sh -c 'until docker info; do sleep 1; done'
        env:
          DOCKER_HOST: tcp://localhost:2375

      - name: Build image
        run: docker build -t myimage .
        env:
          DOCKER_HOST: tcp://localhost:2375

#!/bin/bash
# wait-for-docker.sh

echo "Waiting for Docker daemon..."
TIMEOUT=30
ELAPSED=0

while ! docker info >/dev/null 2>&1; do
  if [ $ELAPSED -ge $TIMEOUT ]; then
    echo "Timeout waiting for Docker daemon"
    exit 1
  fi
  echo "Docker not ready, waiting..."
  sleep 2
  ELAPSED=$((ELAPSED + 2))
done

echo "Docker daemon is ready!"
docker version

timeout 30 sh -c 'until docker info >/dev/null 2>&1; do sleep 1; done'

curl http://localhost:2375/version
# or
docker -H tcp://localhost:2375 version

sudo mkdir -p /etc/systemd/system/docker.service.d
sudo tee /etc/systemd/system/docker.service.d/override.conf << EOF
[Service]
ExecStart=
ExecStart=/usr/bin/dockerd -H fd:// -H tcp://127.0.0.1:2375
EOF

sudo systemctl daemon-reload
sudo systemctl restart docker

{
  "hosts": ["unix:///var/run/docker.sock", "tcp://127.0.0.1:2375"]
}

sudo systemctl restart docker

ss -tlnp | grep 2375
curl http://127.0.0.1:2375/version

# Check current rules
sudo ufw status

# Allow port 2375 (only if needed for remote access)
sudo ufw allow 2375/tcp

# Check if port is allowed
sudo firewall-cmd --list-ports

# Allow port 2375
sudo firewall-cmd --permanent --add-port=2375/tcp
sudo firewall-cmd --reload

# Check if port is blocked
netsh advfirewall firewall show rule name=all | findstr "2375"

# Allow port (PowerShell as Administrator)
New-NetFirewallRule -DisplayName "Docker TCP" -Direction Inbound -LocalPort 2375 -Protocol TCP -Action Allow

# Using netcat
nc -zv docker 2375
nc -zv localhost 2375

# Using curl
curl -v http://docker:2375/version
curl -v http://localhost:2375/version

# Using telnet
telnet docker 2375

# Linux
ss -tlnp | grep 2375
netstat -tlnp | grep 2375

# Windows
netstat -ano | findstr 2375

# Check if 'docker' hostname resolves
getent hosts docker
nslookup docker

# In Kubernetes, check service discovery
kubectl get svc
kubectl get endpoints

Advanced notes

# Generate TLS certificates
docker run --rm -v ~/.docker:/certs paulczar/omgwtfssl

# Configure daemon for TLS
# /etc/docker/daemon.json
{
  "hosts": ["unix:///var/run/docker.sock", "tcp://0.0.0.0:2376"],
  "tls": true,
  "tlscacert": "/etc/docker/ca.pem",
  "tlscert": "/etc/docker/server-cert.pem",
  "tlskey": "/etc/docker/server-key.pem",
  "tlsverify": true
}

# Client configuration
export DOCKER_HOST=tcp://hostname:2376
export DOCKER_TLS_VERIFY=1
export DOCKER_CERT_PATH=~/.docker

# Use SSH directly
export DOCKER_HOST=ssh://user@remotehost
docker ps

# Or create a Docker context
docker context create remote --docker "host=ssh://user@remotehost"
docker context use remote

# GitLab CI - add debug output
script:
  - docker logs $(docker ps -q --filter ancestor=docker:dind) || echo "No dind container found"
  - cat /var/log/docker.log || true
  - dmesg | tail -20 || true

Frequently asked questions

What does "error during connect: Get http://docker:2375/v1.40/info: dial tcp: con" mean?

The "dial tcp: connect: connection refused" error indicates that your Docker client is trying to connect to a Docker daemon via TCP (typically on port 2375 or 2376), but the connection is being actively refused. This is different from a timeout - a "connection refused" means something is listening on the network stack but explicitly rejecting the connection, or nothing is bound to that port at all. , http://docker:2375) reveals important information: the hostname being contacted and the port being used.

How do I fix "error during connect: Get http://docker:2375/v1.40/info: dial tcp: con"?

This error occurs when the Docker CLI cannot establish a TCP connection to the Docker daemon. The daemon may not be running, not listening on the expected port, or network/firewall issues are blocking the connection.

What causes "error during connect: Get http://docker:2375/v1.40/info: dial tcp: con"?

Docker daemon is not running on the target host Docker daemon is not configured to listen on TCP port 2375/2376 In CI/CD: Docker-in-Docker (dind) service has not fully started yet

Is the "error during connect: Get http://docker:2375/v1.40/info: dial tcp: con" error serious?

It is a medium-severity error — more of a blocker than a risk. The steps above resolve it.

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Official resources & further reading

• 📚Docker Official Documentation
• 📖
  Troubleshooting the Docker daemon - Docker Docs(Official Docs)
• 📖
  Common troubleshooting topics - Docker Desktop Docs(Official Docs)
• 💬
  Error response from daemon: connection refused - Docker Forums(Stack Overflow)
• 💬
  WSL and Docker for Windows connection issues - Docker Forums(Stack Overflow)
• 💬
  Docker can't connect to docker daemon - Stack Overflow(Stack Overflow)
• 💬
  Docker remote daemon (TCP): Cannot connect - Stack Overflow(Stack Overflow)
• 📖
  How to fix cannot connect to Docker daemon - GeeksforGeeks(Official Docs)
• 📖
  How to Resolve Cannot connect to Docker daemon Error - PhoenixNAP(Official Docs)
• 📖
  100 Common Docker Errors and Solutions - DEV Community(Official Docs)
• 🐙
  Enable TCP port 2375 for external connection to Docker - GitHub Gist(GitHub)