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Docker auf RHEL / CentOS 7
In this 3-article series, we will discuss about Docker, is an open-source lightweight virtualization tool which runs at top of Operating System level, allowing users to create, run and deploy applications, encapsulated into small containers.
Installation von Docker und Docker-Compose
Step 1 - Install deps, add docker Repo and setup Docker:
# yum install -y yum-utils device-mapper-persistent-data lvm2 # yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo # yum update # yum install docker-ce docker-ce-cli containerd.io # systemctl start docker && systemctl enable docker
Step 2 - Install docker-compose binary:
# newest_version="$(curl -s https://api.github.com/repos/docker/compose/releases/latest | grep -Po '"tag_name": "\K.*?(?=")')"
# curl -L "https://github.com/docker/compose/releases/download/${newest_version}/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose
# chmod +x /usr/local/bin/docker-compose
# curl -L https://raw.githubusercontent.com/docker/compose/$(docker-compose version --short)/contrib/completion/bash/docker-compose -o /etc/bash_completion.d/docker-compose
# docker-compose version
Installation Docker Environment
Step 1 - Create Project Folder:
# mkdir /opt/docker-PROJECT
Step 2 - Create Project Docker Compose-File:
# vim /opt/docker-PROJECT/docker_compose.yml
DEMO - Docker Compose File:
version: "3.2"
services:
# ----------------------------------------------------------------------------
pihole:
image: IMAGE/IMAGE:latest
container_name: "PROJECT-main"
volumes:
- /opt/docker-PROJECT/DOCKERHOST/:/etc/CONTAINER/
- /etc/localtime:/etc/localtime:ro
environment:
- VARIABLE1=value_xy
- VARIABLE2=value_xy
#ports:
# - 53:53/tcp
# - 53:53/udp
# - 67:67/udp
# - 81:80
#networks:
# - local
restart: always
network_mode: "host"
# ------------------------------------------------------------------------------
#networks:
# local:
# driver: bridge
Step 3 - Start / Stop Docker Compose Projects:
# docker-compose -f /opt/docker-PROJECT/docker_compose.yml up -d # docker-compose -f /opt/docker-PROJECT/docker_compose.yml down
Enabling access to files protected by SELinux
In order to give a container access to files protected by SELinux, you need to use one of the following volume options: z or Z.
z(lower): relabels the content you’re mounting into the container, and makes it shareable between containers.
Z(upper): relabels the content you’re mounting into the container, and makes it private. So, mounting this file in another container won’t work.
Docker Grundlagen
This type of Linux containers are proven to be fast, portable and secure. The processes that run in a Docker container are always isolated from the main host, preventing outside tampering.
Part 2: How to Deploy and Run Applications into Docker Containers on CentOS/RHEL 7/6
https://www.linuxtechi.com/install-use-docker-compose-to-deploy-containers-in-centos7/
This tutorial provides a starting point on how to install Docker, create and run Docker containers on CentOS/RHEL 7/6, but barley scratches the surface of Docker.
https://www.tecmint.com/install-docker-and-learn-containers-in-centos-rhel-7-6/