Jose Castillo Lema

Software Engineer @ RedHat

32 minute read

Serie de artigos sobre containers (Docker, Docker Compose, Docker Swarm e Kubernetes).

Lab 1 - Docker

Usaremos a imagem oficial Ubuntu Linux 18.04 ou Amazon Linux para aprender alguns conceitos importantes do Docker:

  • instalação
  • customização de imagens via Dockerfile
  • upload de imagens no DockerHub

Vamos trabalhar com dois terminais abertos (T1 e T2).

Pre-reqs

Uma máquina virtual Ubuntu Linux 18.04 na Microsoft Azure ou Amazon Linux na AWS:

  • Uma maquina virtual na Microsoft Azure com Ubuntu Linux 18.04. Seguir os passos do lab lab 01 - Virtual Machines.

  • Uma maquina virtual no AWS EC2 com Amazon Linux. Seguir os passos do lab lab 01 - EC2.

Instalação

  1. [T1] Instalação do Docker

    a. [Só no Ubuntu] Atualização dos repositórios

     $ sudo apt update
 Hit:1 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic InRelease
 Get:2 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic-updates InRelease [88.7 kB]
 Get:3 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic-backports InRelease [74.6 kB]
 Get:4 http://security.ubuntu.com/ubuntu bionic-security InRelease [88.7 kB]              
 Get:5 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic/universe amd64 Packages [8570 kB]
 Get:6 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic/universe Translation-en [4941 kB]     
 Get:7 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic/multiverse amd64 Packages [151 kB]
 Get:8 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic/multiverse Translation-en [108 kB]
 Get:9 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic-updates/main amd64 Packages [1011 kB]
 Get:10 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic-updates/main Translation-en [341 kB]
 Get:11 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic-updates/restricted amd64 Packages [76.7 kB]
 Get:12 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic-updates/restricted Translation-en [17.1 kB]
 Get:13 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic-updates/universe amd64 Packages [1092 kB]
 Get:14 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic-updates/universe Translation-en [340 kB]
 Get:15 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic-updates/multiverse amd64 Packages [11.5 kB]
 Get:16 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic-updates/multiverse Translation-en [4832 B]
 Get:17 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic-backports/main amd64 Packages [7516 B]
 Get:18 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic-backports/main Translation-en [4764 B]
 Get:19 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic-backports/universe amd64 Packages [7736 B]
 Get:20 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic-backports/universe Translation-en [4588 B]
 Get:21 http://security.ubuntu.com/ubuntu bionic-security/main amd64 Packages [783 kB] 
 Get:22 http://security.ubuntu.com/ubuntu bionic-security/main Translation-en [247 kB]
 Get:23 http://security.ubuntu.com/ubuntu bionic-security/restricted amd64 Packages [67.8 kB]
 Get:24 http://security.ubuntu.com/ubuntu bionic-security/restricted Translation-en [15.0 kB]
 Get:25 http://security.ubuntu.com/ubuntu bionic-security/universe amd64 Packages [679 kB]
 Get:26 http://security.ubuntu.com/ubuntu bionic-security/universe Translation-en [225 kB]
 Get:27 http://security.ubuntu.com/ubuntu bionic-security/multiverse amd64 Packages [7908 B]
 Get:28 http://security.ubuntu.com/ubuntu bionic-security/multiverse Translation-en [2816 B]
 Fetched 19.0 MB in 4s (4815 kB/s)                               
 Reading package lists... Done
 Building dependency tree       
 Reading state information... Done
 29 packages can be upgraded. Run 'apt list --upgradable' to see them.

    b. [Ubuntu] Instalação dos pacotes

     $ sudo apt install docker.io
 Reading package lists... Done
 Building dependency tree       
 Reading state information... Done
 The following additional packages will be installed:
   bridge-utils cgroupfs-mount containerd pigz runc ubuntu-fan
 Suggested packages:
   ifupdown aufs-tools debootstrap docker-doc rinse zfs-fuse | zfsutils
 The following NEW packages will be installed:
   bridge-utils cgroupfs-mount containerd docker.io pigz runc ubuntu-fan
 0 upgraded, 7 newly installed, 0 to remove and 29 not upgraded.
 Need to get 63.8 MB of archives.
 After this operation, 319 MB of additional disk space will be used.
 Do you want to continue? [Y/n] y
 Get:1 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic/universe amd64 pigz amd64 2.4-1 [57.4 kB]
 Get:2 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic/main amd64 bridge-utils amd64 1.5-15ubuntu1 [30.1 kB]
 Get:3 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic/universe amd64 cgroupfs-mount all 1.4 [6320 B]
 Get:4 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic-updates/universe amd64 runc amd64 1.0.0~rc10-0ubuntu1~18.04.2 [2000 kB]
 Get:5 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic-updates/universe amd64 containerd amd64 1.3.3-0ubuntu1~18.04.2 [21.7 MB]
 Get:6 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic-updates/universe amd64 docker.io amd64 19.03.6-0ubuntu1~18.04.1 [39.9 MB]
 Get:7 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic/main amd64 ubuntu-fan all 0.12.10 [34.7 kB]
 Fetched 63.8 MB in 2s (41.7 MB/s)
 Preconfiguring packages ...
 Selecting previously unselected package pigz.
 (Reading database ... 57065 files and directories currently installed.)
 Preparing to unpack .../0-pigz_2.4-1_amd64.deb ...
 Unpacking pigz (2.4-1) ...
 Selecting previously unselected package bridge-utils.
 Preparing to unpack .../1-bridge-utils_1.5-15ubuntu1_amd64.deb ...
 Unpacking bridge-utils (1.5-15ubuntu1) ...
 Selecting previously unselected package cgroupfs-mount.
 Preparing to unpack .../2-cgroupfs-mount_1.4_all.deb ...
 Unpacking cgroupfs-mount (1.4) ...
 Selecting previously unselected package runc.
 Preparing to unpack .../3-runc_1.0.0~rc10-0ubuntu1~18.04.2_amd64.deb ...
 Unpacking runc (1.0.0~rc10-0ubuntu1~18.04.2) ...
 Selecting previously unselected package containerd.
 Preparing to unpack .../4-containerd_1.3.3-0ubuntu1~18.04.2_amd64.deb ...
 Unpacking containerd (1.3.3-0ubuntu1~18.04.2) ...
 Selecting previously unselected package docker.io.
 Preparing to unpack .../5-docker.io_19.03.6-0ubuntu1~18.04.1_amd64.deb ...
 Unpacking docker.io (19.03.6-0ubuntu1~18.04.1) ...
 Selecting previously unselected package ubuntu-fan.
 Preparing to unpack .../6-ubuntu-fan_0.12.10_all.deb ...
 Unpacking ubuntu-fan (0.12.10) ...
 Setting up runc (1.0.0~rc10-0ubuntu1~18.04.2) ...
 Setting up cgroupfs-mount (1.4) ...
 Setting up containerd (1.3.3-0ubuntu1~18.04.2) ...
 Created symlink /etc/systemd/system/multi-user.target.wants/containerd.service → /lib/systemd/system/containerd.service.
 Setting up bridge-utils (1.5-15ubuntu1) ...
 Setting up ubuntu-fan (0.12.10) ...
 Created symlink /etc/systemd/system/multi-user.target.wants/ubuntu-fan.service → /lib/systemd/system/ubuntu-fan.service.
 Setting up pigz (2.4-1) ...
 Setting up docker.io (19.03.6-0ubuntu1~18.04.1) ...
 Adding group `docker' (GID 115) ...
 Done.
 Created symlink /etc/systemd/system/sockets.target.wants/docker.socket → /lib/systemd/system/docker.socket.
 docker.service is a disabled or a static unit, not starting it.
 Processing triggers for systemd (237-3ubuntu10.41) ...
 Processing triggers for man-db (2.8.3-2ubuntu0.1) ...
 Processing triggers for ureadahead (0.100.0-21) ...

    [Amazon Linux] Instalação dos pacotes

     $ sudo yum install -y docker

    [Amazon Linux] Iniciar o serviço:

     $ sudo systemctl start docker
 $ sudo systemctl enable docker

    c. Conferir que o usuário não faz parte do grupo docker, e consecuentemente nao tem permissão para rodar comandos docker:

     $ groups
 ubuntu adm dialout cdrom floppy sudo audio dip video plugdev lxd netdev

    d. Adicionar o usuário (ubuntu) ao grupo docker:

    [Ubuntu]

     $ sudo usermod -aG docker ubuntu

    [Amazon Linux]

     $ sudo usermod -aG docker ec2-user

    e. Reiniciar a VM para que as mudanças de grupo sejam aplicadas:

     $ sudo reboot
 Connection to ec2-18-210-19-170.compute-1.amazonaws.com closed by remote host.
 Connection to ec2-18-210-19-170.compute-1.amazonaws.com closed.

    f. Após o reboot, confirmar que o usuário pertence ao grupo docker:

     $ groups
 ubuntu adm dialout cdrom floppy sudo audio dip video plugdev lxd netdev docker

    g. Rodar um docker version para validar a instalação, e conferir que é mostrada tanto a versão do cliente quanto a do servidor:

      $ docker version
  Client:
   Version:           19.03.6
   API version:       1.40
   Go version:        go1.12.17
   Git commit:        369ce74a3c
   Built:             Fri Feb 28 23:45:43 2020
   OS/Arch:           linux/amd64
   Experimental:      false

  Server:
   Engine:
    Version:          19.03.6
    API version:      1.40 (minimum version 1.12)
    Go version:       go1.12.17
    Git commit:       369ce74a3c
    Built:            Wed Feb 19 01:06:16 2020
    OS/Arch:          linux/amd64
    Experimental:     false
   containerd:
    Version:          1.3.3-0ubuntu1~18.04.2
    GitCommit:        
   runc:
    Version:          spec: 1.0.1-dev
    GitCommit:        
   docker-init:
    Version:          0.18.0
    GitCommit:

Primeiros passos

  1. [T1] Listar as imagens do repositório local (o catálogo deveria estar vazio, pois não baixamos nenhuma imagem ainda): 
     $ docker images
 REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
  2. [T1] Buscar imagens dentro do catálogo do DockerHub: 
     $ docker search mongodb
 NAME                                DESCRIPTION                                     STARS               OFFICIAL            AUTOMATED
 mongo                               MongoDB document databases provide high avai…   7041                [OK]                
 mongo-express                       Web-based MongoDB admin interface, written w…   735                 [OK]                
 tutum/mongodb                       MongoDB Docker image – listens in port 27017…   229                                     [OK]
 bitnami/mongodb                     Bitnami MongoDB Docker Image                    123                                     [OK]
 frodenas/mongodb                    A Docker Image for MongoDB                      18                                      [OK]
 centos/mongodb-32-centos7           MongoDB NoSQL database server                   8                                       
 webhippie/mongodb                   Docker images for MongoDB                       7                                       [OK]
 centos/mongodb-26-centos7           MongoDB NoSQL database server                   5                                       
 centos/mongodb-36-centos7           MongoDB NoSQL database server                   5                                       
 eses/mongodb_exporter               mongodb exporter for prometheus                 4                                       [OK]
 neowaylabs/mongodb-mms-agent        This Docker image with MongoDB Monitoring Ag…   4                                       [OK]
 centos/mongodb-34-centos7           MongoDB NoSQL database server                   3                                       
 quadstingray/mongodb                MongoDB with Memory and User Settings           3                                       [OK]
 tozd/mongodb                        Base image for MongoDB server.                  2                                       [OK]
 mongodbsap/mongodbdocker                                                            2                                       
 zadki3l/mongodb-oplog               Simple mongodb image with single-node replic…   2                                       [OK]
 ssalaues/mongodb-exporter           MongoDB Replicaset Prometheus Compatible Met…   2                                       
 xogroup/mongodb_backup_gdrive       Docker image to create a MongoDB database ba…   1                                       [OK]
 bitnami/mongodb-exporter                                                            1                                       
 openshift/mongodb-24-centos7        DEPRECATED: A Centos7 based MongoDB v2.4 ima…   1                                       
 ansibleplaybookbundle/mongodb-apb   An APB to deploy MongoDB.                       1                                       [OK]
 targetprocess/mongodb_exporter      MongoDB exporter for prometheus                 0                                       [OK]
 gebele/mongodb                      mongodb                                         0                                       [OK]
 phenompeople/mongodb                 MongoDB is an open-source, document databas…   0                                       [OK]
 astronomerio/mongodb-source         Mongodb source.                                 0                                       [OK]
  3. [T1] Fazer o download (pull) da imagem do Ubuntu no repositório local: 
     $ docker pull ubuntu
 Using default tag: latest
 latest: Pulling from library/ubuntu
 692c352adcf2: Pull complete 
 97058a342707: Pull complete 
 2821b8e766f4: Pull complete 
 4e643cc37772: Pull complete 
 Digest: sha256:55cd38b70425947db71112eb5dddfa3aa3e3ce307754a3df2269069d2278ce47
 Status: Downloaded newer image for ubuntu:latest
 docker.io/library/ubuntu:latest
  4. [T1] Listar as imagens novamente, conferir que existe a imagem ubuntu: 
     $ docker images
 REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
 ubuntu              latest              adafef2e596e        11 days ago         73.9MB
  5. [T1] Deletar a imagem (opcional): 
     $ docker image rm ubuntu
  6. [T1] Rodar um comando de exemplo (hostname) dentro do container: 
     $ docker run ubuntu hostname
 c293c1989a56
  7. [T1] Medir o tempo do comando anterior: 
     $ time docker run ubuntu hostname
 7aa02808ccfc

 real	0m0.812s
 user	0m0.023s
 sys	0m0.027s

    Note-se que em menos de um segundo:

    • Docker criou o container
    • Rodou o comando hostname nele
    • Printou a sainda
    • Deletou o container
  8. [T1] Conferir que tanto container quanto o host compartilham o Kernel: 
     $ uname -a
 Linux ip-172-31-60-180 5.3.0-1023-aws #25~18.04.1-Ubuntu SMP Fri Jun 5 15:18:30 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

 $ docker run ubuntu uname -a
 Linux de0407ee790f 5.3.0-1023-aws #25~18.04.1-Ubuntu SMP Fri Jun 5 15:18:30 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
  9. [T1] Executar a imagem ubuntu em modo interativo. Observe-se que o prompt muda quando logamos no container: usuário root com hostname 5b83d8b5b521 (o ID do container em este caso). 
    $ docker run -it ubuntu
root@d8924e5138b3:/#
  10. [T2] Sem sair do container no 1o terminal, listar os containers em execução no 2o terminal: 
    $ docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
d8924e5138b3        ubuntu              "/bin/bash"         14 seconds ago      Up 13 seconds                           xenodochial_allen
  11. [T1] Continuando no 1o terminal, criar um arquivo ainda dentro do container e sair do container: 
    root@d8924e5138b3:/# touch meuArquivo
    
root@d8924e5138b3:/# ls
bin   dev  home  lib32  libx32  meuArquivo  opt   root  sbin  sys  usr
boot  etc  lib   lib64  media   mnt         proc  run   srv   tmp  var

root@d8924e5138b3:/# exit
  12. [T1] Conferir que o container não está mais em execução: 
    $ docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
  13. [T1] Rodar o container novamente, e confirmar que o arquivo criado não existe mais. Containers são efêmeros, não armazenam nenhum tipo de mudança, sejam arquivos, dados, softwares instalados, etc.: 
    $ docker run -it ubuntu
root@5b83d8b5b521:/# ls
bin   dev  home  lib32  libx32  mnt  proc  run   srv  tmp  var
boot  etc  lib   lib64  media   opt  root  sbin  sys  usr

root@5b83d8b5b521:/# ls meuArquivo
ls: meuArquivo: No such file or directory

Customização de imagens

Via docker commit

  1. Customização de imagens via docker commit.

    Vamos criar uma imagem customizada instalando algum software, por exemplo o nmap (um scanner de portas).

    a. [T1] Sem sair do container, atualizar os repositórios:

    root@5b83d8b5b521:/# apt update
Get:1 http://security.ubuntu.com/ubuntu focal-security InRelease [107 kB]
Get:2 http://archive.ubuntu.com/ubuntu focal InRelease [265 kB]
Get:3 http://security.ubuntu.com/ubuntu focal-security/universe amd64 Packages [45.2 kB]
Get:4 http://archive.ubuntu.com/ubuntu focal-updates InRelease [111 kB]
Get:5 http://security.ubuntu.com/ubuntu focal-security/restricted amd64 Packages [33.9 kB]
Get:6 http://archive.ubuntu.com/ubuntu focal-backports InRelease [98.3 kB]
Get:7 http://security.ubuntu.com/ubuntu focal-security/main amd64 Packages [165 kB]
Get:8 http://security.ubuntu.com/ubuntu focal-security/multiverse amd64 Packages [1078 B]
Get:9 http://archive.ubuntu.com/ubuntu focal/multiverse amd64 Packages [177 kB]
Get:10 http://archive.ubuntu.com/ubuntu focal/main amd64 Packages [1275 kB]
Get:11 http://archive.ubuntu.com/ubuntu focal/restricted amd64 Packages [33.4 kB]
Get:12 http://archive.ubuntu.com/ubuntu focal/universe amd64 Packages [11.3 MB]
Get:13 http://archive.ubuntu.com/ubuntu focal-updates/universe amd64 Packages [165 kB]
Get:14 http://archive.ubuntu.com/ubuntu focal-updates/restricted amd64 Packages [33.9 kB]
Get:15 http://archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages [330 kB]
Get:16 http://archive.ubuntu.com/ubuntu focal-updates/multiverse amd64 Packages [4202 B]
Get:17 http://archive.ubuntu.com/ubuntu focal-backports/universe amd64 Packages [3209 B]
Fetched 14.2 MB in 2s (6179 kB/s)                      
Reading package lists... Done
Building dependency tree       
Reading state information... Done
1 package can be upgraded. Run 'apt list --upgradable' to see it.

    b. [T1] Instalar o pacote nmap. O flag -y pula a pregunta de confirmação:

    root@5b83d8b5b521:/# apt install -y nmap
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following additional packages will be installed:
  libblas3 liblinear4 liblua5.3-0 libpcap0.8 libssl1.1 lua-lpeg nmap-common
Suggested packages:
  liblinear-tools liblinear-dev ncat ndiff zenmap
The following NEW packages will be installed:
  libblas3 liblinear4 liblua5.3-0 libpcap0.8 libssl1.1 lua-lpeg nmap nmap-common
0 upgraded, 8 newly installed, 0 to remove and 1 not upgraded.
Need to get 7115 kB of archives.
After this operation, 31.3 MB of additional disk space will be used.
Get:1 http://archive.ubuntu.com/ubuntu focal/main amd64 libssl1.1 amd64 1.1.1f-1ubuntu2 [1318 kB]
Get:2 http://archive.ubuntu.com/ubuntu focal/main amd64 libpcap0.8 amd64 1.9.1-3 [128 kB]
Get:3 http://archive.ubuntu.com/ubuntu focal/main amd64 libblas3 amd64 3.9.0-1build1 [142 kB]
Get:4 http://archive.ubuntu.com/ubuntu focal/universe amd64 liblinear4 amd64 2.3.0+dfsg-3build1 [41.7 kB]
Get:5 http://archive.ubuntu.com/ubuntu focal/main amd64 liblua5.3-0 amd64 5.3.3-1.1ubuntu2 [116 kB]
Get:6 http://archive.ubuntu.com/ubuntu focal/universe amd64 lua-lpeg amd64 1.0.2-1 [31.4 kB]
Get:7 http://archive.ubuntu.com/ubuntu focal/universe amd64 nmap-common all 7.80+dfsg1-2build1 [3676 kB]
Get:8 http://archive.ubuntu.com/ubuntu focal/universe amd64 nmap amd64 7.80+dfsg1-2build1 [1662 kB]
Fetched 7115 kB in 1s (7120 kB/s)
debconf: delaying package configuration, since apt-utils is not installed
Selecting previously unselected package libssl1.1:amd64.
(Reading database ... 4122 files and directories currently installed.)
Preparing to unpack .../0-libssl1.1_1.1.1f-1ubuntu2_amd64.deb ...
Unpacking libssl1.1:amd64 (1.1.1f-1ubuntu2) ...
Selecting previously unselected package libpcap0.8:amd64.
Preparing to unpack .../1-libpcap0.8_1.9.1-3_amd64.deb ...
Unpacking libpcap0.8:amd64 (1.9.1-3) ...
Selecting previously unselected package libblas3:amd64.
Preparing to unpack .../2-libblas3_3.9.0-1build1_amd64.deb ...
Unpacking libblas3:amd64 (3.9.0-1build1) ...
Selecting previously unselected package liblinear4:amd64.
Preparing to unpack .../3-liblinear4_2.3.0+dfsg-3build1_amd64.deb ...
Unpacking liblinear4:amd64 (2.3.0+dfsg-3build1) ...
Selecting previously unselected package liblua5.3-0:amd64.
Preparing to unpack .../4-liblua5.3-0_5.3.3-1.1ubuntu2_amd64.deb ...
Unpacking liblua5.3-0:amd64 (5.3.3-1.1ubuntu2) ...
Selecting previously unselected package lua-lpeg:amd64.
Preparing to unpack .../5-lua-lpeg_1.0.2-1_amd64.deb ...
Unpacking lua-lpeg:amd64 (1.0.2-1) ...
Selecting previously unselected package nmap-common.
Preparing to unpack .../6-nmap-common_7.80+dfsg1-2build1_all.deb ...
Unpacking nmap-common (7.80+dfsg1-2build1) ...
Selecting previously unselected package nmap.
Preparing to unpack .../7-nmap_7.80+dfsg1-2build1_amd64.deb ...
Unpacking nmap (7.80+dfsg1-2build1) ...
Setting up lua-lpeg:amd64 (1.0.2-1) ...
Setting up libssl1.1:amd64 (1.1.1f-1ubuntu2) ...
debconf: unable to initialize frontend: Dialog
debconf: (No usable dialog-like program is installed, so the dialog based frontend cannot be used. at /usr/share/perl5/Debconf/FrontEnd/Dialog.pm line 76.)
debconf: falling back to frontend: Readline
debconf: unable to initialize frontend: Readline
debconf: (Can't locate Term/ReadLine.pm in @INC (you may need to install the Term::ReadLine module) (@INC contains: /etc/perl /usr/local/lib/x86_64-linux-gnu/perl/5.30.0 /usr/local/share/perl/5.30.0 /usr/lib/x86_64-linux-gnu/perl5/5.30 /usr/share/perl5 /usr/lib/x86_64-linux-gnu/perl/5.30 /usr/share/perl/5.30 /usr/local/lib/site_perl /usr/lib/x86_64-linux-gnu/perl-base) at /usr/share/perl5/Debconf/FrontEnd/Readline.pm line 7.)
debconf: falling back to frontend: Teletype
Setting up libblas3:amd64 (3.9.0-1build1) ...
update-alternatives: using /usr/lib/x86_64-linux-gnu/blas/libblas.so.3 to provide /usr/lib/x86_64-linux-gnu/libblas.so.3 (libblas.so.3-x86_64-linux-gnu) in auto mode
Setting up libpcap0.8:amd64 (1.9.1-3) ...
Setting up nmap-common (7.80+dfsg1-2build1) ...
Setting up liblua5.3-0:amd64 (5.3.3-1.1ubuntu2) ...
Setting up liblinear4:amd64 (2.3.0+dfsg-3build1) ...
Setting up nmap (7.80+dfsg1-2build1) ...
Processing triggers for libc-bin (2.31-0ubuntu9) ...

    c. [T1] Conferir a versão instalada:

    root@5b83d8b5b521:/# nmap --version
Nmap version 7.80 ( https://nmap.org )
Platform: x86_64-pc-linux-gnu
Compiled with: liblua-5.3.3 openssl-1.1.1d nmap-libssh2-1.8.2 libz-1.2.11 libpcre-8.39 libpcap-1.9.1 nmap-libdnet-1.12 ipv6
Compiled without:
Available nsock engines: epoll poll select

    d. [T2] No 2o terminal, confirmar o ID do container em execução (no qual acabamos de instalar o nmap):

    $ docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
5b83d8b5b521        ubuntu              "/bin/bash"         18 minutes ago      Up 18 minutes                           compassionate_edison

    e. [T2] Criar uma nova imagem (ubuntu_com_nmap) a partir do container:

    $ docker commit 5b8 ubuntu_com_nmap
sha256:287d2c84024a50ba13c9d8304d57df853feea9b3dd9df785313111480a84eecc

    f. Confirmar a criação da imagem (com um tamanho maior a imagem original):

    $ docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
ubuntu_com_nmap     latest              287d2c84024a        7 seconds ago       127MB
ubuntu              latest              adafef2e596e        11 days ago         73.9MB

    g. Confirmar que na nova imagem, tem de fato o nmap instalado:

    $ docker run ubuntu_com_nmap nmap --version
Nmap version 7.80 ( https://nmap.org )
Platform: x86_64-pc-linux-gnu
Compiled with: liblua-5.3.3 openssl-1.1.1d nmap-libssh2-1.8.2 libz-1.2.11 libpcre-8.39 libpcap-1.9.1 nmap-libdnet-1.12 ipv6
Compiled without:
Available nsock engines: epoll poll select

    h. Confirmar que a imagem original não foi alterada e não tem o nmap instalado:

    $ docker run ubuntu nmap --version
docker: Error response from daemon: OCI runtime create failed: container_linux.go:349: starting container process caused "exec: \"nmap\": executable file not found in $PATH": unknown.

Via Dockerfile

  1. Customização de imagens via Dockerfile. Este é o metodo recomendado para customizar imagens, pois é mais reproduzível que docker commit.

    a. Criar o arquivo Dockerfile com o seguinte conteúdo:

    FROM ubuntu
    
MAINTAINER Jose Castillo <profjose.lema@fiap.com.br>
    
RUN apt-get update
RUN apt-get install -y nmap

    b. “Compilar” o Dockerfile:

    $ docker build -t ubuntu-com-nmap-viadockerfile .
Sending build context to Docker daemon  15.87kB
Step 1/4 : FROM ubuntu
 ---> adafef2e596e
Step 2/4 : MAINTAINER Jose Castillo
 ---> Running in d3894b0f5f25
Removing intermediate container d3894b0f5f25
 ---> 94aab8c83039
Step 3/4 : RUN apt-get update
 ---> Running in 4ea03e5d7f32
Get:1 http://security.ubuntu.com/ubuntu focal-security InRelease [107 kB]
Get:2 http://security.ubuntu.com/ubuntu focal-security/multiverse amd64 Packages [1078 B]
Get:3 http://security.ubuntu.com/ubuntu focal-security/universe amd64 Packages [45.2 kB]
Get:4 http://security.ubuntu.com/ubuntu focal-security/restricted amd64 Packages [33.9 kB]
Get:5 http://security.ubuntu.com/ubuntu focal-security/main amd64 Packages [165 kB]
Get:6 http://archive.ubuntu.com/ubuntu focal InRelease [265 kB]
Get:7 http://archive.ubuntu.com/ubuntu focal-updates InRelease [111 kB]
Get:8 http://archive.ubuntu.com/ubuntu focal-backports InRelease [98.3 kB]
Get:9 http://archive.ubuntu.com/ubuntu focal/multiverse amd64 Packages [177 kB]
Get:10 http://archive.ubuntu.com/ubuntu focal/universe amd64 Packages [11.3 MB]
Get:11 http://archive.ubuntu.com/ubuntu focal/main amd64 Packages [1275 kB]
Get:12 http://archive.ubuntu.com/ubuntu focal/restricted amd64 Packages [33.4 kB]
Get:13 http://archive.ubuntu.com/ubuntu focal-updates/universe amd64 Packages [165 kB]
Get:14 http://archive.ubuntu.com/ubuntu focal-updates/multiverse amd64 Packages [4202 B]
Get:15 http://archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages [329 kB]
Get:16 http://archive.ubuntu.com/ubuntu focal-updates/restricted amd64 Packages [33.9 kB]
Get:17 http://archive.ubuntu.com/ubuntu focal-backports/universe amd64 Packages [3209 B]
Fetched 14.2 MB in 2s (5775 kB/s)
Reading package lists...
Removing intermediate container 4ea03e5d7f32
 ---> 3bf3668ec12d
Step 4/4 : RUN apt-get install -y nmap
 ---> Running in 057b00bbe74b
Reading package lists...
Building dependency tree...
Reading state information...
The following additional packages will be installed:
  libblas3 liblinear4 liblua5.3-0 libpcap0.8 libssl1.1 lua-lpeg nmap-common
Suggested packages:
  liblinear-tools liblinear-dev ncat ndiff zenmap
The following NEW packages will be installed:
  libblas3 liblinear4 liblua5.3-0 libpcap0.8 libssl1.1 lua-lpeg nmap
  nmap-common
0 upgraded, 8 newly installed, 0 to remove and 1 not upgraded.
Need to get 7115 kB of archives.
After this operation, 31.3 MB of additional disk space will be used.
Get:1 http://archive.ubuntu.com/ubuntu focal/main amd64 libssl1.1 amd64 1.1.1f-1ubuntu2 [1318 kB]
Get:2 http://archive.ubuntu.com/ubuntu focal/main amd64 libpcap0.8 amd64 1.9.1-3 [128 kB]
Get:3 http://archive.ubuntu.com/ubuntu focal/main amd64 libblas3 amd64 3.9.0-1build1 [142 kB]
Get:4 http://archive.ubuntu.com/ubuntu focal/universe amd64 liblinear4 amd64 2.3.0+dfsg-3build1 [41.7 kB]
Get:5 http://archive.ubuntu.com/ubuntu focal/main amd64 liblua5.3-0 amd64 5.3.3-1.1ubuntu2 [116 kB]
Get:6 http://archive.ubuntu.com/ubuntu focal/universe amd64 lua-lpeg amd64 1.0.2-1 [31.4 kB]
Get:7 http://archive.ubuntu.com/ubuntu focal/universe amd64 nmap-common all 7.80+dfsg1-2build1 [3676 kB]
Get:8 http://archive.ubuntu.com/ubuntu focal/universe amd64 nmap amd64 7.80+dfsg1-2build1 [1662 kB]
debconf: delaying package configuration, since apt-utils is not installed
Fetched 7115 kB in 1s (7096 kB/s)
Selecting previously unselected package libssl1.1:amd64.
(Reading database ... 4122 files and directories currently installed.)
Preparing to unpack .../0-libssl1.1_1.1.1f-1ubuntu2_amd64.deb ...
Unpacking libssl1.1:amd64 (1.1.1f-1ubuntu2) ...
Selecting previously unselected package libpcap0.8:amd64.
Preparing to unpack .../1-libpcap0.8_1.9.1-3_amd64.deb ...
Unpacking libpcap0.8:amd64 (1.9.1-3) ...
Selecting previously unselected package libblas3:amd64.
Preparing to unpack .../2-libblas3_3.9.0-1build1_amd64.deb ...
Unpacking libblas3:amd64 (3.9.0-1build1) ...
Selecting previously unselected package liblinear4:amd64.
Preparing to unpack .../3-liblinear4_2.3.0+dfsg-3build1_amd64.deb ...
Unpacking liblinear4:amd64 (2.3.0+dfsg-3build1) ...
Selecting previously unselected package liblua5.3-0:amd64.
Preparing to unpack .../4-liblua5.3-0_5.3.3-1.1ubuntu2_amd64.deb ...
Unpacking liblua5.3-0:amd64 (5.3.3-1.1ubuntu2) ...
Selecting previously unselected package lua-lpeg:amd64.
Preparing to unpack .../5-lua-lpeg_1.0.2-1_amd64.deb ...
Unpacking lua-lpeg:amd64 (1.0.2-1) ...
Selecting previously unselected package nmap-common.
Preparing to unpack .../6-nmap-common_7.80+dfsg1-2build1_all.deb ...
Unpacking nmap-common (7.80+dfsg1-2build1) ...
Selecting previously unselected package nmap.
Preparing to unpack .../7-nmap_7.80+dfsg1-2build1_amd64.deb ...
Unpacking nmap (7.80+dfsg1-2build1) ...
Setting up lua-lpeg:amd64 (1.0.2-1) ...
Setting up libssl1.1:amd64 (1.1.1f-1ubuntu2) ...
debconf: unable to initialize frontend: Dialog
debconf: (TERM is not set, so the dialog frontend is not usable.)
debconf: falling back to frontend: Readline
debconf: unable to initialize frontend: Readline
debconf: (Can't locate Term/ReadLine.pm in @INC (you may need to install the Term::ReadLine module) (@INC contains: /etc/perl /usr/local/lib/x86_64-linux-gnu/perl/5.30.0 /usr/local/share/perl/5.30.0 /usr/lib/x86_64-linux-gnu/perl5/5.30 /usr/share/perl5 /usr/lib/x86_64-linux-gnu/perl/5.30 /usr/share/perl/5.30 /usr/local/lib/site_perl /usr/lib/x86_64-linux-gnu/perl-base) at /usr/share/perl5/Debconf/FrontEnd/Readline.pm line 7.)
debconf: falling back to frontend: Teletype
Setting up libblas3:amd64 (3.9.0-1build1) ...
update-alternatives: using /usr/lib/x86_64-linux-gnu/blas/libblas.so.3 to provide /usr/lib/x86_64-linux-gnu/libblas.so.3 (libblas.so.3-x86_64-linux-gnu) in auto mode
Setting up libpcap0.8:amd64 (1.9.1-3) ...
Setting up nmap-common (7.80+dfsg1-2build1) ...
Setting up liblua5.3-0:amd64 (5.3.3-1.1ubuntu2) ...
Setting up liblinear4:amd64 (2.3.0+dfsg-3build1) ...
Setting up nmap (7.80+dfsg1-2build1) ...
Processing triggers for libc-bin (2.31-0ubuntu9) ...
Removing intermediate container 057b00bbe74b
 ---> 4647bd58aa0e
Successfully built 4647bd58aa0e
Successfully tagged ubuntu-com-nmap-viadockerfile:latest

    c. Conferir que a nova imagem foi criada (e tem o mesmo tamanho que a imagem criada via docker commit):

    $ docker images
REPOSITORY                      TAG                 IMAGE ID            CREATED             SIZE
ubuntu-com-nmap-viadockerfile   latest              4647bd58aa0e        13 seconds ago      127MB
ubuntu_com_nmap                 latest              287d2c84024a        18 minutes ago      127MB
ubuntu                          latest              adafef2e596e        11 days ago         73.9MB

    d. Testar a nova imagem:

    $ docker run ubuntu-com-nmap-viadockerfile nmap --version
Nmap version 7.80 ( https://nmap.org )
Platform: x86_64-pc-linux-gnu
Compiled with: liblua-5.3.3 openssl-1.1.1d nmap-libssh2-1.8.2 libz-1.2.11 libpcre-8.39 libpcap-1.9.1 nmap-libdnet-1.12 ipv6
Compiled without:
Available nsock engines: epoll poll select

DockerHub

  1. Upload da nova imagem no DockerHub:

    a. Criar uma conta gratuita

    b. Logar na conta desde o terminal com o usuário recém criado:

    $ docker login
Login with your Docker ID to push and pull images from Docker Hub. If you don't have a Docker ID, head over to https://hub.docker.com to create one.
Username: josecastillolema
Password: 
WARNING! Your password will be stored unencrypted in /home/ubuntu/.docker/config.json.
Configure a credential helper to remove this warning. See
https://docs.docker.com/engine/reference/commandline/login/#credentials-store

Login Succeeded

    c. Taggear a imagem. O nome da imagem deve ser username/nome da imagem:

    $ docker tag ubuntu-com-nmap-viadockerfile josecastillolema/fiap-bdt

    d. Fazer o upload (push) da imagem:

    $ docker push josecastillolema/fiap-bdt

    e. Conferir a imagem no portal do DockerHub:

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