DOCKER FOR ALX COURSEWORK

Using docker as driver for ALX Courswork

NOTE:

using Arch linux distro

"$" represents bash prompt

Prerequisites

1. Internet Connection

Building these images and containers requires internet access as builds are relatively large. approx. > 1.0GB

2. Docker Engine

Intall Docker as Non-Root (Rootless Mode)

1. Install newuidmap and newgidmap

   $ sudo pacman -S shadow

2. /etc/subuid and /etc/subgid should contain at least 65,536 subordinate UIDs/GIDs for the user. Ex:

   $ id -u
   1001
   $ whoami
   testuser
   $ grep ^$(whoami): /etc/subuid
   testuser:231072:65536
   $ grep ^$(whoami): /etc/subgid$
   testuser:231072:65536
   

   Edit /etc/subuid and /etc/subgid if necessary

3. If the system-wide Docker daemon is already running, consider disabling it:

   $ sudo systemctl disable --now docker.service docker.socket

4. Install rootless docker

   $ curl -fsSL https://get.docker.com/rootless | sh

5. Set export variables to bashrc

   $ echo 'export PATH="$HOME/bin:$PATH"' >> ~/.bashrc`
   $ echo 'export DOCKER_HOST=unix://$XDG_RUNTIME_DIR/docker.sock' >> ~/.bashrc
   

Run docker daemon as non-root user (Rootless mode)

3. Docker-Compose

• Install docker-compose

  $ sudo pacman -S docker-compose

Usage

Start Docker Service

NOTE: Do not use sudo

$ systemctl --user start docker

• Optional: Enable docker service; run at startup

  $ systemctl --user enable docker`
  $ sudo loginctl enable-linger $(whoami)
  

Create images

$ bash ./generate_arch_linux_dockerfile.sh

Enter Username to use in docker container:

• It will prompt for username which will be used to create a sudoer user in arch linux sandbox docker container. If username is empty it will exit

Enter base directory to persist container data:

• It will prompt for base directory. This will be the directory in the host machine where container directories and files will be persisted. Your projects and configuration will be stored there. If base directory is empty it will exit

** VOLUME PERMISSIONS PART 1 **

Note: I've had problems with volume permissions and not being able to modify mouted volumes in container.
Workaround (hacky) is to change the .ALX/arch/ALX permissions to allow rwx permissions to all

$ sudo chmod a+rwx "your_base_directory"/.ALX/arch/ALX

** This will be the first part. Read on after we lauch our containers at the end

Enter user password (archlinux sandbox):

• It will prompt for user password. This will used as sudoer password for arch linux user. If user password is empty it will exit. Prompt doesn't show input.

• Docker files will be generated, ALX-Archlinux.Dockerfile, docker-compose.yml ,etc.

  Optional: Open and review to make sure they are generated correctly

• Build docker images and containers,

  $ docker-compose up --build

  should be run in same directory as generated docker-compose.yml

  Wait for it to finish building images and containers, requires internet connection

  On successful build you should see something like

  alx_mysql_test_auto      | 2023-02-18  1:24:08 0 [Note] mariadbd: ready for connections.
  alx_mysql_test_auto      | Version: '10.10.3-MariaDB-1:10.10.3+maria~ubu2204'  socket: '/run/mysqld/mysqld.sock'  port: 3306  mariadb.org binary distribution
  ...
  

• To run in background after initial build

  $ docker-compose up -d

connect to containers

- Archlinux
$ docker exec -it alx_archlinux_test_auto /bin/bash

- You'll have prompt in container (archlinux sandbox)
  [username@host ~]$ ls -a
  .  ..  .bash_history  .bash_logout  .bash_profile  .bashrc  .cache  .config  .local  .ssh  ALX

- To access mysql from archlinux container
[username@host ~]$ mysql -hdb -uroot -p
[*] password is "password"

- Execute sql script to hbtnbd database
[username@host ~]$ cat example.sql | mysql -hdb -uroot -p hbtndb

** VOLUME PERMISSIONS PART 2 **

- Change to ALX directory we changed permissions 
- make sure you are in the container and not host system
 $ cd ALX/

- create file
 $ touch dummy

- Get owner name/owner group of user who created file
 $ ls -al dummy
-rw-r--r-- 1 232071 232071 0 Feb 19 09:05 dummy 

- In this case it owner is 232071 and group is 232071
- note OWNER_NAME and OWNER_GROUP as we'll use it to change folder owners on host

- stop docker running containers
- make sure you are in same directory as docker-compose.yml (IN THE HOST SYSTEM)
$ docker-compose stop

- make sure containers are not running)
$ docker container ps ; should not show arch linux container running

- change owner/group of files in host system
$ sudo chown "$OWNER_NAME:$OWNER_GROUP" -R "path_to_base_directory/.ALX"
- OWNER_NAME and OWNER_GROUP are values got above (in this case 232071 and 232071)

- Relaunch containers (in background)
$ docker-compose up -d

 - MySQL
 $ docker exec -it alx_mysql_test_auto mysql -uroot -hdb -p
 [*] password is "password"

 - MySQL using mycli (A Terminal Client for MySQL with AutoCompletion and Syntax Highlighting)
 - It will connect via socket
 $ docker exec -it alx_mysql_test_auto mycli
 [*] password is "password"

 $ docker exec -it alx_mysql_test_auto /bin/bash
 - Log in as root user to mysql container. (BE CAREFUL)

 - To access mysql from archlinux container
 [username@host ~]$ mysql -hdb -uroot -p
 [*] password is "password"

 - Execute sql script to hbtnbd database
 [username@host ~]$ cat example.sql | mysql -hdb -uroot -p hbtndb