Set up a dev environment
Important
Dev Environments is no longer under active development.
While the current functionality remains available, it may take us longer to respond to support requests.
Changes to Dev Environments with Docker Desktop 4.13
Docker has simplified how you configure your dev environment project. All you need to get started is a
compose-dev.yaml
file. If you have an existing project with a.docker/
folder this is automatically migrated the next time you launch.If you are using
.docker/docker-compose.yaml
, we move it to../compose-dev.yaml
. If you are using.docker/config.json
, we create a../compose-dev.yaml
file with a single service named "app”. It is configured to use the image or Dockerfile referenced in the JSON as a starting point.
To set up a dev environment, there are additional configuration steps to tell Docker Desktop how to build, start, and use the right image for your services.
Dev Environments use an compose-dev.yaml
file located at the root of your project. This file allows you to define the image required for a dedicated service, the ports you'd like to expose, along with additional configuration options.
The following is an example compose-dev.yaml
file.
version: "3.7"
services:
backend:
build:
context: backend
target: development
secrets:
- db-password
depends_on:
- db
db:
image: mariadb
restart: always
healthcheck:
test: [ "CMD", "mysqladmin", "ping", "-h", "127.0.0.1", "--silent" ]
interval: 3s
retries: 5
start_period: 30s
secrets:
- db-password
volumes:
- db-data:/var/lib/mysql
environment:
- MYSQL_DATABASE=example
- MYSQL_ROOT_PASSWORD_FILE=/run/secrets/db-password
expose:
- 3306
proxy:
build: proxy
ports:
- 8080:80
depends_on:
- backend
volumes:
db-data:
secrets:
db-password:
file: db/password.txt
In the yaml file, the build context backend
specifies that that the container should be built using the development
stage (target
attribute) of the Dockerfile located in the backend
directory (context
attribute)
The development
stage of the Dockerfile is defined as follows:
# syntax=docker/dockerfile:1
FROM golang:1.16-alpine AS build
WORKDIR /go/src/github.com/org/repo
COPY . .
RUN go build -o server .
FROM build AS development
RUN apk update \
&& apk add git
CMD ["go", "run", "main.go"]
FROM alpine:3.12
EXPOSE 8000
COPY --from=build /go/src/github.com/org/repo/server /server
CMD ["/server"]
The development
target uses a golang:1.16-alpine
image with all dependencies you need for development. You can start your project directly from VS Code and interact with the others applications or services such as the database or the frontend.
In the example, the Docker Compose files are the same. However, they could be different and the services defined in the main Compose file may use other targets to build or directly reference other images.
What's next?
Learn how to distribute your dev environment