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Laboratório

Será utilitzada a aplicação:

~/devops-simulador-caos/src$ ls
Dockerfile  package.json  server.ts  tsconfig.json  views

Editar o Dockerfile:

$ vim Dockerfile

FROM node:20.9.0
WORKDIR /app
COPY package*.json ./
RUN npm install
RUN apt update && apt install stress --yes
COPY . .
RUN npm run compile
HEALTHCHECK --interval=10s --timeout=5s --retries=1 --start-period=30s CMD ["curl","-f","http://localhost:3000/health"]
EXPOSE 3000
CMD ["npm", "start"]

Construir a imagem:

~/devops-simulador-caos/src$ docker image build \
          -t marcelodpbarbieri/simulador-caos:v2 \
          -f Dockerfile .
[+] Building 12.5s (13/13) FINISHED                              docker:default
 => [internal] load build definition from Dockerfile                       0.0s
 => => transferring dockerfile: 332B                                       0.0s
 => [internal] load metadata for docker.io/library/node:20.9.0             1.8s
 => [auth] library/node:pull token for registry-1.docker.io                0.0s
 => [internal] load .dockerignore                                          0.0s
 => => transferring context: 53B                                           0.0s
 => [1/7] FROM docker.io/library/node:20.9.0@sha256:146bbe4eaee99ae885be2  0.2s
 => => resolve docker.io/library/node:20.9.0@sha256:146bbe4eaee99ae885be2  0.0s
 => => sha256:a6759aea6838201fb9b76b3ffccce537c745cef4b76 2.00kB / 2.00kB  0.0s
 => => sha256:03501b0671a4e8450444678df0aad9c78ecce5fe2f4 7.52kB / 7.52kB  0.0s
 => => sha256:146bbe4eaee99ae885be2a0a767f63a4b96032141d7 1.21kB / 1.21kB  0.0s
 => [internal] load build context                                          0.0s
 => => transferring context: 24.80kB                                       0.0s
 => [2/7] WORKDIR /app                                                     0.0s
 => [3/7] COPY package*.json ./                                            0.0s
 => [4/7] RUN npm install                                                  5.6s
 => [5/7] RUN apt update && apt install stress --yes                       3.1s
 => [6/7] COPY . .                                                         0.0s
 => [7/7] RUN npm run compile                                              1.3s
 => exporting to image                                                     0.2s
 => => exporting layers                                                    0.2s
 => => writing image sha256:fcf7250a5d8e31876ba86365cd12ec249c21dc6318bfe  0.0s
 => => naming to docker.io/marcelodpbarbieri/simulador-caos:v2             0.0s          

O healthcheck não foi exposto na construção, pois o sistema de arquivos não está sendo alterado. O healthcheck altera os metadados da imagem:

$ docker image inspect marcelodpbarbieri/simulador-caos:v2 | grep -Ei -A 6 "health"
            "Healthcheck": {
                "Test": [
                    "CMD",
                    "curl",
                    "-f",
                    "http://localhost:3000/health"
                ],
                "Interval": 10000000000,
                "Timeout": 5000000000,
                "StartPeriod": 30000000000,
                "Retries": 1
            },

Subir a imagem para o Docker Registry:

$ docker push marcelodpbarbieri/simulador-caos:v2
The push refers to repository [docker.io/marcelodpbarbieri/simulador-caos]
e192a053efd8: Pushed
68f77f0eebc6: Pushed
78936593e0c9: Pushed
080495642fe4: Pushed
06f78889df4d: Pushed
142f1e5cc194: Pushed
eba1ea52dc39: Layer already exists
17e3b73cb8fa: Layer already exists
b2c52efb0fe6: Layer already exists
652b81616682: Layer already exists
80bd043d4663: Layer already exists
30f5cd833236: Layer already exists
7c32e0608151: Layer already exists
7cea17427f83: Layer already exists
v2: digest: sha256:bee75b3afc0de959174f75812f4f818af51dca88da8ba9715081dc2e5491466d size: 3257

Atualizar a tag latest:

$ docker image tag marcelodpbarbieri/simulador-caos:v2 \
                   marcelodpbarbieri/simulador-caos:latest
$ docker image ls
REPOSITORY                         TAG       IMAGE ID       CREATED         SIZE
marcelodpbarbieri/simulador-caos   latest    fcf7250a5d8e   4 minutes ago   1.17GB
marcelodpbarbieri/simulador-caos   v2        fcf7250a5d8e   4 minutes ago   1.17GB
$ docker push marcelodpbarbieri/simulador-caos:latest
The push refers to repository [docker.io/marcelodpbarbieri/simulador-caos]
e192a053efd8: Layer already exists
68f77f0eebc6: Layer already exists
78936593e0c9: Layer already exists
080495642fe4: Layer already exists
06f78889df4d: Layer already exists
142f1e5cc194: Layer already exists
eba1ea52dc39: Layer already exists
17e3b73cb8fa: Layer already exists
b2c52efb0fe6: Layer already exists
652b81616682: Layer already exists
80bd043d4663: Layer already exists
30f5cd833236: Layer already exists
7c32e0608151: Layer already exists
7cea17427f83: Layer already exists
latest: digest: sha256:bee75b3afc0de959174f75812f4f818af51dca88da8ba9715081dc2e5491466d size: 3257

Editar o arquivo compose.yaml e alterar a versão para v2:

~$ vim compose.yaml

services:
  web:
    image: marcelodpbarbieri/simulador-caos:v2
    ports:
      - 8080:3000
    restart: always

Subir o Docker Compose:

~$ docker compose up -d
[+] Running 2/2
 ✔ Network marcelo_default  Created                                        0.1s
 ✔ Container marcelo-web-1  Started                                        0.3s

Monitoramento:

$ watch 'docker container ls -a'

Container em execução e saudável:

Caso seja utilizada a versão 1 da imagem, o healthcheck não seria habilitado:

$ vim compose.yaml

services:
  web:
    image: marcelodpbarbieri/simulador-caos:v1
    ports:
      - 8080:3000
    restart: always

~$ docker compose up -d
[+] Running 1/1
 ✔ Container marcelo-web-1  Started                                       10.8s

Retornar para a versão 2 onde o healthcheck está habilitado:

~$ vim compose.yaml

services:
  web:
    image: marcelodpbarbieri/simulador-caos:v1
    ports:
      - 8080:3000
    restart: always

~$ docker compose up -d
[+] Running 1/1
 ✔ Container marcelo-web-1  Started                                       10.9s

Desabilitar o healthcheck no Docker Compose:

~$ vim compose.yaml

services:
  web:
    image: marcelodpbarbieri/simulador-caos:v2
    ports:
      - 8080:3000
    restart: always
    healthcheck:
      disable: true

~$ docker compose up -d
[+] Running 1/1
 ✔ Container marcelo-web-1  Started                                       10.8s