Install docker on Centos 7

Step 1 — Install Docker

$ sudo yum install -y yum-utils device-mapper-persistent-data lvm2

Configure the docker-ce repo:

$ sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo

Install docker-ce:

$ sudo yum install docker-ce

Set Docker to start automatically at boot time:

$ sudo systemctl enable docker.service

Finally, start the Docker service:

$ sudo systemctl start docker.service

Step 2 — Install Docker Compose

Install Extra Packages for Enterprise Linux

$ sudo yum install epel-release

Install python-pip

$ sudo yum install -y python-pip

Then install Docker Compose:

$ sudo pip install docker-compose

You will also need to upgrade your Python packages on CentOS 7 to get docker-compose to run successfully:

$ sudo yum upgrade python*

To verify a successful Docker Compose installation, run:

$ docker-compose version

Install Gitlab with docker

sudo docker run -d \
    -e GITLAB_OMNIBUS_CONFIG="external_url 'http://192.168.10.51/'; gitlab_rails['lfs_enabled'] = true;gitlab_rails['gitlab_shell_ssh_port'] = 822" \
    -p 8443:8443 -p 880:880 -p 822:822 \
    --name gitlab \
    --restart always \
    -v /srv/gitlab/config:/etc/gitlab \
    -v /srv/gitlab/logs:/var/log/gitlab \
    -v /srv/gitlab/data:/var/opt/gitlab \
    gitlab/gitlab-ce:latest

Gitlab docker container – backup and restore

Two examples:

• backup and restore GitLab docker container with volumes
• backup and restore only useful data

Gitlab is running in Docker container on server a.example.com. Container was create by command:

docker run --detach --hostname gitlab.example.com \
--publish 192.168.0.101:443:443 \
--publish 192.168.0.101:80:80 \
--publish 192.168.0.101:2222:22 \
--name gitlab-example --restart always \
--volume /storage/gitlab/config:/etc/gitlab \
--volume /storage/gitlab/logs:/var/log/gitlab \
--volume /storage/gitlab/data:/var/opt/gitlab \
gitlab/gitlab-ce:latest

Full backup (including docker images)

You need to complete 4 steps:

• backup container gitlab-example
• backup volume /etc/gitlab
• backup volume /var/log/gitlab
• backup volume /var/opt/gitlab Commands:

docker stop gitlab-example
docker commit gitlab-example local/gitlab-example-container-20170417
docker save local/gitlab-example-container-20170417 > /root/gitlab-example-container-20170417.tar
docker run --rm --volumes-from gitlab-example -v $(pwd):/backup ubuntu tar cvf /backup/gitlab-example-volume-etc-20170417.tar /etc/gitlab
docker run --rm --volumes-from gitlab-example -v $(pwd):/backup ubuntu tar cvf /backup/gitlab-example-volume-log-20170417.tar /var/log/gitlab
docker run --rm --volumes-from gitlab-example -v $(pwd):/backup ubuntu tar cvf /backup/gitlab-example-volume-opt-20170417.tar /var/opt/gitlab

Full restore (including docker images)

Restore on second server b.example.com. Example CentOS 7.3:

yum -y install epel-release
yum -y install docker-io
systemctl enable docker
systemctl start docker

Upload 4 files from server a.example.com to b.example.com:

gitlab-example-container-20170417.tar
gitlab-example-volume-etc-20170417.tar
gitlab-example-volume-log-20170417.tar
gitlab-example-volume-opt-20170417.tar

Load image:

docker load -i gitlab-example-container-20170417.tar 

Create container:

docker create --hostname gitlab.example.com \
--publish 192.168.0.102:443:443 \
--publish 192.168.0.102:80:80 \
--publish 192.168.0.102:2222:22 \
--name gitlab-example --restart always \
--volume /storage/gitlab/config:/etc/gitlab \
--volume /storage/gitlab/logs:/var/log/gitlab \
--volume /storage/gitlab/data:/var/opt/gitlab \
local/gitlab-example-container-20170417

Restore volumes:

mkdir -p /storage/gitlab/config
mkdir -p /storage/gitlab/logs
mkdir -p /storage/gitlab/data
docker run --rm --volumes-from gitlab-example -v $(pwd):/backup ubuntu bash -c "cd /etc && tar xvf /backup/gitlab-example-volume-etc-20170417.tar --strip 1"
docker run --rm --volumes-from gitlab-example -v $(pwd):/backup ubuntu bash -c "cd /var/log && tar xvf /backup/gitlab-example-volume-log-20170417.tar --strip 2"
docker run --rm --volumes-from gitlab-example -v $(pwd):/backup ubuntu bash -c "cd /var/opt && tar xvf /backup/gitlab-example-volume-opt-20170417.tar --strip 2"

Start container:

docker start gitlab-example

Backup and restore only useful data

Backup cron job daily:

# crontab -e
0 7 * * * /bin/docker exec -i gitlab-example /opt/gitlab/bin/gitlab-rake gitlab:backup:create CRON=1

By default backup files will be saved inside container to: /var/opt/gitlab/backups/

On host system (in my example) backup is located on host system: /storage/gitlab/data/backups/

Restore Find available backup files:

# docker exec -it gitlab-example ls /var/opt/gitlab/backups/
1492443013_2017_04_17_gitlab_backup.tar

Restore backup with time stamp 1492443013_2017_04_17

docker exec -it gitlab-example /opt/gitlab/bin/gitlab-rake gitlab:backup:restore BACKUP=1492443013_2017_04_17