What is Docker?
=============================
Container mgmt tool.
1 APP	2 APP	5 APP
tool		PS ---> 2VS --> 5Container
- save cost - 	1GB	1GB  --  1GB
- save time     1 day   5 mn     1 sec
- imp quality 
mgmt
- create - start - stop - restart - pause - up - kill - rm
Written in Go
by Docker
By Soloman Hykes
Release 
Community
Enterprise	
Version
24.x
-----------------------------------------------------
What is Container?
--------------------------------
Container a light weight APP env runtime powered kernal managed by Dockers
Container has
a user ns
1 net ns
1 pidtree ns
1 mnt ns
request byd docker to kernal....
=====================================================
VMS ---> VM Image(BOOTFS + ROOTFS + USERFS + APPFS)
Container --> Docker Image (ROOTFS + USERFS + APPFS)
======================================================
IN ORDER TO RUN APP
HARDWARE
KERNEL
NAMESPACE
USER
PID
NET
MNT (ROOTFS)
CGROUPS
Capabilites
Install Docker - \
https://www.devopsschool.com/blog/how-to-install-docker-in-linux/
<blockquote class="wp-embedded-content" data-secret="Nf6zRv8lIE"><a href="https://www.devopsschool.com/blog/how-to-install-docker-in-linux/">Docker Tutorials: How to Install Docker in Ubuntu?</a></blockquote><iframe class="wp-embedded-content" sandbox="allow-scripts" security="restricted" style="position: absolute; visibility: hidden;" title="“Docker Tutorials: How to Install Docker in Ubuntu?” — DevOpsSchool.com" src="https://www.devopsschool.com/blog/how-to-install-docker-in-linux/embed/#?secret=29Q5oFUTFl#?secret=Nf6zRv8lIE" data-secret="Nf6zRv8lIE" width="600" height="338" frameborder="0" marginwidth="0" marginheight="0" scrolling="no"></iframe>
Docker architecture
-----------------------------------------------
YOU --> Docker Client --> Docker Server --> ContainerD --> Kernel
-----------------
Check image in local REPO
download it from hub.docker.com
===================================
Docker engine
Component of Docker
----------------------------
Docker Engine
Docker images
From Docker Rergistry
hub.docker.com
Docker Container
YOU --> Docker Client --> Docker Server --> ContainerD --> Kernel
1 user
1 net
1 pid tree
1 mount(roofs) from image
=== container
250  sudo apt-get update
251  sudo apt-get install ca-certificates curl gnupg lsb-release
252  sudo mkdir -p /etc/apt/keyrings
253  curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpg
254  clear
255  echo   "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/ubuntu \
$(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
256  sudo apt-get update
257  sudo apt-get install docker-ce docker-ce-cli containerd.io docker-compose-plugin
258  clear
259  docker
260  clear
261  docker info
262  clear
263  docker version
264  which docker
265  which dockerd
266  which containerd
267  ps -eaf | grep docker
268  ps -eaf | grep containers
269  ps -eaf | grep containerd
270  history
============================================
==========================================================
209  ls
210  docker ps
211  docker ps -a
212  docker images
213  docker pull httpd
214  clear
215  docker images
216  docker ps
217  docker ps -a
218  docker create httpd\
219  docker create httpd
220  docker ps -a
221  docker create httpd
222  clear
223  docker ps -a
224  docker start bfe559b0cfb4
225  docker ps -a
226  docker start crazy_gould
227  docker ps -a
228  docker stop bfe559b0cfb4
229  clear
230  docker ps -a
231  docker restart 3f6c93e0de8a
232  docker ps -a
233  clea
234  clear
235  docker ps -a
236  docker pause 3f6c93e0de8a
237  docker ps -a
238  docker stats
239  docker ps -a
240  docker unpause 3f6c93e0de8a
241  docker ps -a
242  clear
243  docker ps -a
244  docker kill 3f6c93e0de8a
245  docker ps -a
246  docker rm bfe559b0cfb4 3f6c93e0de8a
247  clear
248  docker ps -a
=========================================
How to consume Container?
=====================================
--- Using SHELL
258  docker exec -it 1c15c991569f /bin/bash
259  docker exec 1c15c991569f ls
--- Using Network
263  docker inspect 1c15c991569f
264  curl http://172.17.0.2
==============================================
RUN
================================
pull + create + start + attach to a pid1 of the cont.
==============================================
RUN -d 
================================
pull + create + start + DO NOT attach to a pid1 of the cont.
==================================
268  docker ps
269  docker attach 1c15c991569f
270  docker ps
271  docker ps -a
272  clear
273  docker run httpd
274  docker run -d httpd
275  docker ps
docker run -d -p 80:80 httpd
docker run -d -p 82:80 httpd
208  clear
209  docker run -d -p 80:80 httpd
210  docker run -d -p 81:80 httpd
211  netstat tulpn
212  netstat -tulpn
213  netstat
214  clear
215  docker run -d -p 82:80 httpd
216  docker ps
217  clear
218  docker ps
=================================================
How to create an Docker Images
========================================
==================================================================
What is Docker Image
--------------------------
collection of filesystem
----------------------------------
UBUNTU + JAVA + GIT + Apache2
-----------------------------
M 1- Using Existing Container
1  clear
2  apt-get install git
3  apt-get update
4  clear
5  ls
6  apt-get install git -y
7  git
8  clear
9  java
10  apt-get install openjdk-11-jdk -y
11  clear
12  java
13  cler
14  clea
15  clear
16  apt-get install apache2
17  git
18  java
19  which apache2
20  history
=======================
278  docker run -itd ubuntu
279  docker ps
280  clear
281  docker exec -it b96bcff46a70 /bin/bash
282  clear
283  docker history httpd
284  clear
285  ls
286  docker images
287  docker ps
288  docker exec b96bcff46a70 git
289  docker exec b96bcff46a70 java
290  docker exec b96bcff46a70 which apache2
291  clear
292  docker ps
293  docker history ubuntu
294  docker commit -m"ub-up-ap-java-git" -a"Rajesh Kumar" b96bcff46a70 ub-up-ap-java-git
295  docker images
296  clear
297  docker images
298  docker history ubuntu
299  docker history ub-up-ap-java-git
300  docker run -itd 04aeb5947f09
301  docker ps
302  docker images
303  docker run -itd ub-up-ap-java-git
304  docker images
305  docker ps
306  docker exec d95a3ad3b8da java
307  history
308  docker history ub-up-ap-java-git
309  history
==============================================
https://hub.docker.com/r/devopsschools/sataug2023
310  clear
311  docker images
312  docker into
313  docker info
314  clear
315  cd /var/lib/docker
316  ls
317  cd overlay2
318  ls
319  clear
320  ls
321  clear
322  cd
323  clear
324  ls
325  docker images
326  docker save -o ub-up-ap-java-git.tar ub-up-ap-java-git
327  ls
328  docker images
329  docker run -itd ubuntu
330  docker exec -it 1ad086930a58b318351ec3234791452f35ce66debf2e0bf1bf105d78678015e0
331  docker exec -it 1ad086930a58b318351ec3234791452f35ce66debf2e0bf1bf105d78678015e0 /bin/bash
332  clear
333  ls
334  docker ps
335  docker commit -m"hello world" -a"Rajesh Kumar" ubhello 1ad086930a58
336  docker commit -m"hello world" -a"Rajesh Kumar"  1ad086930a58 ubhello
337  clear
338  docker images
339  docker tag ubhello devopsschools/sataug2023
340  docker images
341  docker login
342  clear
343  docker images
344  docker push devopsschools/sataug2023
345  history
===================================================
Dockerfile
-------------------------------------------
FROM ubuntu
MAINTAINER Rajesh Kumar DevOps@rajeshkumar.xyz
RUN apt-get update
RUN apt-get install apache2 -y
RUN apt-get install git -y
COPY snap.tar /tmp
ENV JAVA_HOME /opt/java
Refr
- https://github.com/jenkinsci/docker/blob/587b2856cd225bb152c4abeeaaa24934c75aa460/Dockerfile
https://github.com/CentOS/sig-cloud-instance-images/blob/b2d195220e1c5b181427c3172829c23ab9cd27eb/docker/Dockerfile
Code language: JavaScript (javascript)