Docker

Docker before docker:

• chroot
• cgroups (limitação pro processo que está rodando)
• namespace (monta um ambiente isolado pro processo)

https://www.baeldung.com/linux/rootfs

Container é um processo ou um grupo de processos que usa o sistema operacional de forma isolada.

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Creating a docker container for mysql

Pull MySQL image sudo docker pull mysql

Start a MySQL container using the image, passing a password and a default database name

sudo docker run --name mysql_docker -p 33060:3306 -e MYSQL_ROOT_PASSWORD=mysql123 -e MYSQL_DATABASE=projectmanager -d mysql

Execute the mysql cli to be able to create tables, users, etc sudo docker exec -it mysql_docker mysql -p

Dockerfile example:

FROM golang:1.22.0 AS build-stage
    WORKDIR /app

    COPY go.mod go.sum ./
    RUN go mod download

    COPY *.go ./

    RUN CGO_ENABLED=0 GOOS=linux go build -o /api

FROM build-stage as run-test-stage
    RUN go test -v ./...

FROM scratch as run-release-stage
    WORKDIR /app

    COPY --from=build-stage /api /api

    EXPOSE 8080

    CMD ["/api"]

Docker Compose

Example

version: '3.8'

services:
  mysql_docker:
    image: mysql
    container_name: mysql_docker
    environment:
      MYSQL_ROOT_PASSWORD: mysql123
      MYSQL_DATABASE: projectmanager
    ports:
      - "33060:3306"
    restart: unless-stopped

  backend:
    build:
      context: .
      dockerfile: Dockerfile.backend
    depends_on:
      - mysql_docker
    network_mode: "host"

To start the docker-compose run this comand in the root of the project sudo docker-compose up -d

To see the logs of the backend container: sudo docker-compose logs backend