Docker Part1

Docker Part1

Class 79th DOCKER INTRO Part1 1st August

Monolithic :Means single application ,server database deployed in single server is called monolithic application

Microservice: We have split the server and service muliple instance for single application 

APPLICATION: Collection of services 

MONOLITHIC: multiple services are deployed on single server with single database.

MICRO SERVICES: multiple services are deployed on multiple servers with multiple database.

BASED ON USERS AND APP COMPLEXITY WE NEED TO SELECT THE ARCHITECTURE.

FACTORS AFFECTING FOR USING MICROSERVICES:

F-1: COST 

F-2: MAINTAINANCE

Micro service we are using containers 

CONTAINERS: its free of cost and can create multiple containers.

its same as a server/vm.

it will not have any operating system.

os will be on images.

(SERVER=AMI, CONTAINER=IMAGE)

CONTAINER TOOLS: DOCKER, CONTAINERD, ROCKET, CRI-O, PODMAN, 

KATA CONTAINER 

DOCKER: 

• Its an free & opensource tool.
• it is platform independent.
• used to create, run & deploy applications on containers.
• it is introduced on 2013 by solomenhykes & sebastian phal.
• We used GO language to develop the docker.
• here we write files on YAML.
• before docker user faced lot of problems, but after docker there is no issues with the application.
• Docker will use host resources (cpu, mem, n/w, os).
• Docker can run on any OS but it natively supports Linux distributions.

CONTAINERIZATION/DOCKERIZATION:

Process of packing an application with its dependencies(maps).

ex: PUBG

APP= PUBG & DEPENDECY = MAPS

APP= CAKE & DEPENDECY = KNIFE

Step1: ubuntu apt , if amazon linux yum 

ubuntu@ip-10-0-2-61:~$ sudo -i

root@ip-10-0-2-61:~# apt update

root@ip-10-0-2-61:~# apt install docker.io -y

root@ip-10-0-2-61:~# docker --version

Docker version 27.5.1, build 27.5.1-0ubuntu3~24.04.2

Step2: Docker is service you need start ,Active  by package default it will start only

root@ip-10-0-2-61:~# systemctl start docker.service

root@ip-10-0-2-61:~# systemctl status docker.service

● docker.service - Docker Application Container Engine

     Loaded: loaded (/usr/lib/systemd/system/docker.service; enabled; preset: enabled)

     Active: active (running) since Fri 2025-08-08 18:30:59 UTC; 6min ago

TriggeredBy: ● docker.socket

       Docs: https://docs.docker.com

   Main PID: 844 (dockerd)

      Tasks: 8

     Memory: 101.0M (peak: 102.0M)

        CPU: 492ms

     CGroup: /system.slice/docker.service

             └─844 /usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock

Step3: If you want to create container , you need image for that image you need get image from docker hub 

No images ,if container run need os , os exist in image , image exists 

root@ip-10-0-2-61:~# docker images

REPOSITORY   TAG       IMAGE ID   CREATED   SIZE

Step4: docker hub, using pull it wil get it from the the docker hub 

https://hub.docker.com/search?q=ubuntu

root@ip-10-0-2-61:~# docker pull ubuntu

Using default tag: latest

latest: Pulling from library/ubuntu

32f112e3802c: Already exists

Digest: sha256:a08e551cb33850e4740772b38217fc1796a66da2506d312abe51acda354ff061

Status: Downloaded newer image for ubuntu:latest

docker.io/library/ubuntu:latest

root@ip-10-0-2-61:~#

root@ip-10-0-2-61:~# docker images

REPOSITORY   TAG       IMAGE ID       CREATED       SIZE

ubuntu       latest    65ae7a6f3544   3 weeks ago   78.1MB

Step5: using image creating container ,command docker run ubuntu os , give one name to container give name 

Below command create container container1 name

root@ip-10-0-2-61:~# docker run --name container1 ubuntu

Below command for -it mean interactive terminal , it will go to internal container after created 

Ip-10-0-2-61 ip address is docker host 

92dc1437896a for this inside container 

root@ip-10-0-2-61:~# docker run -it --name container1  ubuntu

root@92dc1437896a:/#

Step6: Container also we will do 

root@92dc1437896a:/# apt update

root@92dc1437896a:/# apt install nginx

root@92dc1437896a:/# ls

bin  bin.usr-is-merged  boot 

if you want exit from the container give command control + D 

root@92dc1437896a:/#

exit

Step7: list of containers 

root@ip-10-0-2-61:~# docker container ls -a

CONTAINER ID   IMAGE          COMMAND                  CREATED         STATUS                          PORTS     NAMES

92dc1437896a   ubuntu         "/bin/bash"              7 minutes ago   Exited (0) About a minute ago             container1

Step8: Control +D exit from the container, Control +pq running container 

COMMANDS:

docker pull ubuntu : pull ubuntu image

docker images : to see list of images

docker run -it --name cont1 ubuntu : to create a container

-it (interactive) - to go inside a container

cat /etc/os-release : to see os flavour

Step9:

root@91c51df69572:/# cat /etc/os-release

PRETTY_NAME="Ubuntu 24.04.2 LTS"

NAME="Ubuntu"

VERSION_ID="24.04"

VERSION="24.04.2 LTS (Noble Numbat)"

VERSION_CODENAME=noble

ID=ubuntu

ID_LIKE=debian

HOME_URL="https://www.ubuntu.com/"

SUPPORT_URL="https://help.ubuntu.com/"

BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"

PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"

UBUNTU_CODENAME=noble

LOGO=ubuntu-logo

step10:

root@ip-10-0-2-61:~# docker images

REPOSITORY   TAG       IMAGE ID       CREATED      SIZE

movies       v1        c6fcfdddf5a7   3 days ago   245MB

root@ip-10-0-2-61:~# docker rmi c6fcfdddf5a7

Error response from daemon: conflict: unable to delete c6fcfdddf5a7 (must be forced) - image is being used by stopped container deff3a8b49f6

root@ip-10-0-2-61:~# docker rmi -f c6fcfdddf5a7

Untagged: movies:v1

Deleted: sha256:c6fcfdddf5a73dad77f764c06db339423e85dd4f86b0a6e70a0f308ecea67200

Deleted: sha256:40ae56197fccc7a31d299cd3e9ddc0f66fdd574b5773dc1df7c886934696312c

Deleted: sha256:4d61e0aa2aa1b2c034371f2b68b212fb7996120cbc8c816c9a712e953fcc7a03

Deleted: sha256:10cacaa9c6716e0559888cc54af4a44beb606a48d0f87cfd81c14c638d8a2d7c

Deleted: sha256:65ae7a6f3544bd2d2b6d19b13bfc64752d776bc92c510f874188bfd404d205a3

root@ip-10-0-2-61:~# docker images

REPOSITORY   TAG       IMAGE ID   CREATED   SIZE

root@ip-10-0-2-61:~#

root@ip-10-0-2-61:~# docker pull ubuntu

Using default tag: latest

latest: Pulling from library/ubuntu

32f112e3802c: Already exists

Digest: sha256:a08e551cb33850e4740772b38217fc1796a66da2506d312abe51acda354ff061

Status: Downloaded newer image for ubuntu:latest

docker.io/library/ubuntu:latest

root@ip-10-0-2-61:~#

root@ip-10-0-2-61:~# docker images

REPOSITORY   TAG       IMAGE ID       CREATED       SIZE

ubuntu       latest    65ae7a6f3544   3 weeks ago   78.1MB

root@ip-10-0-2-61:~#

root@ip-10-0-2-61:~# docker pull redhat/granite-3-2b-instruct

Using default tag: latest

latest: Pulling from redhat/granite-3-2b-instruct

40049f9dc504: Pull complete

968eabd7fc8a: Downloading [================>                                  ]  769.4MB/2.28GB

1e37173e4f88: Download complete

context canceled

root@ip-10-0-2-61:~# docker images

REPOSITORY   TAG       IMAGE ID       CREATED       SIZE

ubuntu       latest    65ae7a6f3544   3 weeks ago   78.1MB

root@ip-10-0-2-61:~# docker run --name container1 ubuntu

root@ip-10-0-2-61:~# docker run -it --name container1  ubuntu

root@92dc1437896a:/# ^C

root@92dc1437896a:/# apt update

root@92dc1437896a:/# apt install nginx

Reading package lists... Done

Building dependency tree... Done

Reading state information... Done

The following additional packages will be installed:

  iproute2 libatm1t64 libbpf1 libcap2-bin libelf1t64 libmnl0 libpam-cap libxtables12 nginx-common

Suggested packages:

  iproute2-doc python3:any fcgiwrap nginx-doc ssl-cert

The following NEW packages will be installed:

  iproute2 libatm1t64 libbpf1 libcap2-bin libelf1t64 libmnl0 libpam-cap libxtables12 nginx nginx-common

0 upgraded, 10 newly installed, 0 to remove and 4 not upgraded.

Need to get 2025 kB of archives.

After this operation, 5799 kB of additional disk space will be used.

Do you want to continue? [Y/n]

Abort.

root@92dc1437896a:/#

root@92dc1437896a:/#

root@92dc1437896a:/# apt install nginx

Reading package lists... Done

Building dependency tree... Done

Reading state information... Done

The following additional packages will be installed:

  iproute2 libatm1t64 libbpf1 libcap2-bin libelf1t64 libmnl0 libpam-cap libxtables12 nginx-common

Suggested packages:

  iproute2-doc python3:any fcgiwrap nginx-doc ssl-cert

The following NEW packages will be installed:

  iproute2 libatm1t64 libbpf1 libcap2-bin libelf1t64 libmnl0 libpam-cap libxtables12 nginx nginx-common

0 upgraded, 10 newly installed, 0 to remove and 4 not upgraded.

Need to get 2025 kB of archives.

After this operation, 5799 kB of additional disk space will be used.

Do you want to continue? [Y/n] y

root@92dc1437896a:/# ls

bin  bin.usr-is-merged  boot  dev  etc  home  lib  lib64  media  mnt  opt  proc  root  run  sbin  sbin.usr-is-merged  srv  sys  tmp  usr  var

root@92dc1437896a:/#

exit

root@ip-10-0-2-61:~# docker container ls -a

CONTAINER ID   IMAGE          COMMAND                  CREATED         STATUS                          PORTS     NAMES

92dc1437896a   ubuntu         "/bin/bash"              7 minutes ago   Exited (0) About a minute ago             container1

deff3a8b49f6   c6fcfdddf5a7   "/usr/sbin/apachectl…"   3 days ago      Exited (0) 3 days ago                     cont1

root@ip-10-0-2-61:~# docker container ls -pq

unknown shorthand flag: 'p' in -pq

See 'docker container ls --help'.

root@ip-10-0-2-61:~# docker container ls -p

unknown shorthand flag: 'p' in -p

See 'docker container ls --help'.

root@ip-10-0-2-61:~# docker run -it --name container1  ubuntu

docker: Error response from daemon: Conflict. The container name "/container1" is already in use by container "92dc1437896aa0ebba784e987052c682ada5c66229501195529b4422bce505fd". You have to remove (or rename) that container to be able to reuse that name.

See 'docker run --help'.

root@ip-10-0-2-61:~# docker run --name container1 ubuntu

docker: Error response from daemon: Conflict. The container name "/container1" is already in use by container "92dc1437896aa0ebba784e987052c682ada5c66229501195529b4422bce505fd". You have to remove (or rename) that container to be able to reuse that name.

See 'docker run --help'.

root@ip-10-0-2-61:~# docker run  ubuntu

root@ip-10-0-2-61:~# docker run -it --name container1  ubuntu

docker: Error response from daemon: Conflict. The container name "/container1" is already in use by container "92dc1437896aa0ebba784e987052c682ada5c66229501195529b4422bce505fd". You have to remove (or rename) that container to be able to reuse that name.

See 'docker run --help'.

root@ip-10-0-2-61:~# docker run -it --name container1

"docker run" requires at least 1 argument.

See 'docker run --help'.

Usage:  docker run [OPTIONS] IMAGE [COMMAND] [ARG...]

Step 11: after inside container control p+q, container is up and running not exist 

Control+d exit from the contrainer 

Create and run a new container from an image

root@ip-10-0-2-61:~# docker run -it --name container2  ubuntu

root@91c51df69572:/# ls

bin  boot  dev  etc  home  lib  lib64  media  mnt  opt  proc  root  run  sbin  srv  sys  tmp  usr  var

root@91c51df69572:/# cat /etc/os-release

PRETTY_NAME="Ubuntu 24.04.2 LTS"

NAME="Ubuntu"

VERSION_ID="24.04"

VERSION="24.04.2 LTS (Noble Numbat)"

VERSION_CODENAME=noble

ID=ubuntu

ID_LIKE=debian

HOME_URL="https://www.ubuntu.com/"

SUPPORT_URL="https://help.ubuntu.com/"

BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"

PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"

UBUNTU_CODENAME=noble

LOGO=ubuntu-logo

root@91c51df69572:/# root@ip-10-0-2-61:~#

root@ip-10-0-2-61:~# docker container ls -a

CONTAINER ID   IMAGE          COMMAND                  CREATED          STATUS                      PORTS     NAMES

91c51df69572   ubuntu         "/bin/bash"              2 minutes ago    Up 2 minutes                          container2

c7863af60d25   ubuntu         "/bin/bash"              3 minutes ago    Exited (0) 2 minutes ago              blissful_bose

92dc1437896a   ubuntu         "/bin/bash"              15 minutes ago   Exited (0) 10 minutes ago             container1

deff3a8b49f6   c6fcfdddf5a7   "/usr/sbin/apachectl…"   3 days ago       Exited (0) 3 days ago                 cont1

root@ip-10-0-2-61:~#

Step 12 :Start the container manually using below command 

root@ip-10-0-2-61:~# docker start container1

container1

root@ip-10-0-2-61:~# docker container ls -a

CONTAINER ID   IMAGE          COMMAND                  CREATED          STATUS                     PORTS     NAMES

91c51df69572   ubuntu         "/bin/bash"              8 minutes ago    Up 8 minutes                         container2

c7863af60d25   ubuntu         "/bin/bash"              9 minutes ago    Exited (0) 9 minutes ago             blissful_bose

92dc1437896a   ubuntu         "/bin/bash"              22 minutes ago   Up 30 seconds                        container1

Stop 

root@ip-10-0-2-61:~# docker stop container1

container1

root@ip-10-0-2-61:~# docker kill container1

container1

ps also same docker container -a 

root@ip-10-0-2-61:~# docker ps -a

CONTAINER ID   IMAGE          COMMAND                  CREATED          STATUS                      PORTS     NAMES

91c51df69572   ubuntu         "/bin/bash"              12 minutes ago   Up 12 minutes                         container2

c7863af60d25   ubuntu         "/bin/bash"              13 minutes ago   Exited (0) 13 minutes ago             blissful_bose

92dc1437896a   ubuntu         "/bin/bash"              26 minutes ago   Up 23 seconds                         container1

root@ip-10-0-2-61:~# docker pause container1

container1

root@ip-10-0-2-61:~# docker unpause container1

container1

Step12: inspect gives you complete  information of the container

root@ip-10-0-2-61:~# docker inspect container1

[

    {

        "Id": "92dc1437896aa0ebba784e987052c682ada5c66229501195529b4422bce505fd",

        "Created": "2025-08-08T19:13:18.076228102Z",

        "Path": "/bin/bash",

        "Args": [],

        "State": {

            "Status": "running",

            "Running": true,

            "Paused": false,

Step13: you want remove the container, you need to kill or stop the container 

root@ip-10-0-2-61:~# docker stop container1

container1

root@ip-10-0-2-61:~# docker rm container1

container1

root@ip-10-0-2-61:~# docker ps -a

CONTAINER ID   IMAGE     COMMAND       CREATED          STATUS          PORTS     NAMES

91c51df69572   ubuntu    "/bin/bash"   17 minutes ago   Up 17 minutes             container2

--Thanks