Docker EngineCài xong rồi, nhưng bạn vừa đặt cái gì lên máy mình?

$ docker run hello-world
permission denied while trying to connect to the Docker daemon socket

$ ps -eo pid,ppid,comm --sort=pid | grep -E 'dockerd|containerd'
   4023       1 dockerd
  41499       1 containerd
  63273       1 containerd-shim
  69893       1 containerd-shim

$ ps -ef | grep containerd-shim | head -1
root 63273 1 0 Aug22 ? 00:00:13 /usr/bin/containerd-shim-runc-v2 -namespace moby -id 2c78bad120ed864a1129a281b661077433c6cdeda0a136b2fc7c355f9ccf0c72 -address /run/containerd/containerd.sock

$ docker --version
Docker version 29.1.3, build 29.1.3-0ubuntu3~24.04.2

$ docker buildx version
docker: unknown command: docker buildx

$ docker info | sed -n '/Plugins:/,/Server:/p'
 Plugins:
  compose: Docker Compose (Docker Inc.)
    Version:  2.40.3+ds1-0ubuntu1~24.04.1
    Path:     /usr/libexec/docker/cli-plugins/docker-compose
  trust: Manage trust on Docker images (Docker Inc.)
    Version:  29.1.3

$ for p in docker.io docker-doc docker-compose docker-compose-v2 podman-docker containerd runc; do
>   sudo apt-get remove -y $p
> done

$ sudo apt-get update
$ sudo apt-get install -y ca-certificates curl
$ sudo install -m 0755 -d /etc/apt/keyrings
$ sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg -o /etc/apt/keyrings/docker.asc
$ sudo chmod a+r /etc/apt/keyrings/docker.asc

$ echo "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.asc] \
  https://download.docker.com/linux/ubuntu $(. /etc/os-release && echo "$VERSION_CODENAME") stable" \
  | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
$ sudo apt-get update
$ sudo apt-get install -y docker-ce docker-ce-cli containerd.io \
      docker-buildx-plugin docker-compose-plugin

$ sudo usermod -aG docker $USER
$ newgrp docker
$ id
uid=1000(doanhcd) gid=1000(doanhcd) groups=1000(doanhcd),27(sudo),100(users),112(docker)

$ sudo tee /etc/docker/daemon.json >/dev/null <<'JSON'
{
  "log-driver": "json-file",
  "log-opts": { "max-size": "10m", "max-file": "3" },
  "live-restore": true
}
JSON
$ sudo systemctl restart docker
$ docker info --format '{{.LoggingDriver}} · live-restore={{.LiveRestoreEnabled}}'
json-file · live-restore=true

$ ls -l /var/run/docker.sock
srw-rw---- 1 root docker 0 Aug 21 14:53 /var/run/docker.sock

$ getent group docker
docker:x:112:doanhcd

$ docker version
Client:
 Version:           29.1.3
 API version:       1.52
 Go version:        go1.24.4
 OS/Arch:           linux/amd64
 Context:           default

Server:
 Engine:
  Version:          29.1.3
  API version:      1.52 (minimum version 1.44)
  OS/Arch:          linux/amd64
 containerd:
  Version:          2.2.1
 runc:
  Version:          1.3.4-0ubuntu1~24.04.1
 docker-init:
  Version:          0.19.0

$ docker info | sed -n '/^Server:/,/Kernel/p' | head -18
Server:
 Containers: 6
  Running: 6
 Images: 153
 Server Version: 29.1.3
 Storage Driver: overlayfs
  driver-type: io.containerd.snapshotter.v1
 Logging Driver: json-file
 Cgroup Driver: systemd
 Cgroup Version: 2

$ docker run hello-world
Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
4f55086f7dd0: Pull complete
Digest: sha256:5dd0d3e6e255913fc30f90b9f2b1d359cc2cbdb48090cc4b65f1676e203243cc
Status: Downloaded newer image for hello-world:latest

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

 1. The Docker client contacted the Docker daemon.
 2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
 3. The Docker daemon created a new container from that image…
 4. The Docker daemon streamed that output to the Docker client…

$ docker compose version
Docker Compose version 2.40.3+ds1-0ubuntu1~24.04.1