Build a Gitlab server using Docker

Docker official website and docs

https://docs.docker.com

Install docker

There’re several ways to install docker. You can install it via apt, or a deb file, or the script.

Install using the convenience script

curl -fsSL https://get.docker.com -o get-docker.sh
sudo sh get-docker.sh

To use Aliyun mirror, execute sudo sh get-docker.sh --mirror Aliyun

Wait until the installation finishes. On debian or ubuntu, the docker service is automatically started after the installation. To make it start at system boot, use the following;

sudo systemctl enable docker.service
sudo systemctl enable containerd.service

(Optional) Manage docker as a non-root user

The docker daemon requires to be run as root because it binds a Unix socket instead of a TCP port, which is only owned by user root. That’s why the installation script and docker itself needs to be executed by sudo. If you don’t want to preface the docker command with sudo, you can create a usergroup called docker and add users to it.

sudo groupadd docker
sudo usermod -aG docker $USER

Log out and log in to make sure the group membership is re-evaluated. You can also try newgrp docker to activate the changes to groups.

换国内源

首先执行以下命令，查看是否在 docker.service 文件中配置过镜像地址

sudo systemctl cat docker | grep '\-\-registry\-mirror'

如果有输出，执行 sudo systemctl cat docker 查看 ExecStart= 出现的位置，修改对应的文件内容去掉 --registry-mirror 参数及其值。

如果没有输出，在 /etc/docker/daemon.json 中写入以下内容

{
  "registry-mirrors": [
    "https://hub-mirror.c.163.com",
    "https://mirror.baidubce.com"
  ]
}

然后重新启动docker服务

sudo systemctl daemon-reload
sudo systemctl restart docker

Verify that docker is installed and functioning

docker --version

The output should look similar to

Then,

docker run hello-world

If you see the output of hello-world, the docker is functioning well. This command does the following steps:

• First, check if you have an image called hello-world locally. No local image was found.
• Then it looks the docker hub (the default source is ‘hub.docker.com’) to see if there’s an online image called hello-world. It found that image, and pull (download) it, equivalent to docker pull hello-world.
• Finally it starts a container with the image, and the executable files inside the container produces the output what you see on the terminal screen.

Install gitlab using docker

Step1: pull gitlab’s docker image

docker pull gitlab/gitlab-ce

Step2: run gitlab

docker run --detach \
  --hostname gitlab.example.com \
  --publish 443:443 --publish 80:80 --publish 22:22 \
  --name gitlab \
  --restart always \
  --volume /srv/gitlab/config:/etc/gitlab \
  --volume /srv/gitlab/logs:/var/log/gitlab \
  --volume /srv/gitlab/data:/var/opt/gitlab \
  gitlab/gitlab-ce:latest

The meaning of the command is as follows:

• --name gitlab: the container name
• --restart always: always let the container running, to let the container start at system boot
• --publish 443:443 --publish 80:80 --publish 22:22: Map network ports
  You may want to use another port than 80, 443, as it might be occupied by another service like nginx or apache. Change to --publish HOST_PORT:CONTAINER_PORT to map port HOST_PORT of the host to CONTAINER_PORT in the container (e.g. --publish 20080:80).
• --volume /srv/gitlab/config:/etc/gitlab: map gitlab config, log, and data directories
• gitlab/gitlab-ce:latest: the image you need to run

Step3: Check the container status

Use

docker container ls

to list all containers, which should have the gitlab container you have just created. The status starting means it is initializing. Wait it until the status become healthy.

After the initialization is complete, visit http://your_ip:HOST_PORT and you should see the gitlab login page.

Step 4: Modify user root’s password

The default (and the admin) user is ‘root’ in gitlab, and the default password is a randomly generated long string. We have to go into the gitlab container and modify the password.

Use docker ps to see the gitlab container ID, and use (replace ce539268a90c with the container ID)

docker exec -it ce539268a90c bash

to enter the terminal of the container.

Then, inside the container, execute

cd /opt/gitlab/bin
gitlab-rails console  # this may take some time

and you should see the following

After that, find the root user by entering

u=User.where(id:1).first

and change its password by entering

u.password='12345678'
u.password_confirmation='12345678'
u.save

and the password is changed.