Deploy Docker Using an Ansible Playbook and Systemd Service

This article describes a step‑by‑step process for deploying Docker on multiple Linux hosts using Ansible and systemd.

1. Preparation – Create a working directory on the control node:

[root@k8s-master2 ~]# mkdir docker-deploy
[root@k8s-master2 ~]# cd docker-deploy/
[root@k8s-master2 docker-deploy]# ls
[root@k8s-master2 docker-deploy]# mkdir files
[root@k8s-master2 docker-deploy]# cd files/

Place the Docker binary archive ( docker-18.09.6.tgz) and the docker.service file inside the files directory.

2. Ansible Playbook – Create deploy.yaml with the following content:

---
- hosts: webservers
  vars:
    remoter_user: root
  gather_facts: false
  tasks:
    - name: 分发解压包
      unarchive: src=/files/docker-18.09.6.tgz dest=/tmp
    - name: 移动二进制文件
      shell: mv /tmp/docker/* /usr/bin
    - name: 分发 service 文件
      copy: src=files/docker.service dest=/usr/lib/systemd/system
    - name: 启动设置开机启动
      systemd: name=docker state=restarted enabled=yes
    - name: docker 启动状态
      shell: docker info
      register: docker
    - debug: var=docker.stdout_lines

This playbook unpacks the Docker archive, moves binaries to /usr/bin, copies the systemd service file, enables and restarts the Docker service, and finally checks the Docker status.

3. Systemd Service File – The docker.service file should contain:

[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
After=network-online.target firewalld.service containerd.service
Wants=network-online.target

[Service]
Type=notify
ExecStart=/usr/bin/dockerd
ExecReload=/bin/kill -s HUP $MAINPID
TimeoutSec=0
RestartSec=2
Restart=always
StartLimitBurst=3
StartLimitInterval=60s
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity
TasksMax=infinity
Delegate=yes
KillMode=process

[Install]
WantedBy=multi-user.target

4. Execution and Verification – Run the playbook from the control node:

[root@k8s-master2 docker-deploy]# ansible-playbook deploy.yaml

After the playbook completes, verify Docker installation on each node:

[root@k8s-node2 ~]# docker --version
Docker version 18.09.6, build 481bc77

The article also provides links to related Ansible tutorials for conditional statements, loops, and batch configuration distribution.