flask: dev envs support & misc improvements (#263)

* Docker Desktop Development Environments config
* Use cache volumes for pip
* Upgrade from Python 3.7 -> Python 3.10
* Use port `8000` to avoid conflicts with Airplay on
  macOS for default Flask port `5000`
* Use `SIGINT` to gracefully stop Flask

Signed-off-by: Milas Bowman <milas.bowman@docker.com>
This commit is contained in:
Milas Bowman 2022-07-08 09:22:59 -04:00 committed by GitHub
parent 457fe0e668
commit ec552567c7
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5 changed files with 71 additions and 24 deletions

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@ -0,0 +1,10 @@
services:
web:
build:
context: app
target: dev-envs
stop_signal: SIGINT
ports:
- '8000:8000'
volumes:
- /var/run/docker.sock:/var/run/docker.sock

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@ -16,37 +16,38 @@ Project structure:
```
services:
web:
build: app
build:
context: app
target: builder
ports:
- '5000:5000'
- '8000:8000'
```
## Deploy with docker compose
```
$ docker compose up -d
Creating network "flask_default" with the default driver
Building web
Step 1/6 : FROM python:3.7-alpine
...
...
Status: Downloaded newer image for python:3.7-alpine
Creating flask_web_1 ... done
[+] Building 1.1s (16/16) FINISHED
=> [internal] load build definition from Dockerfile 0.0s
... 0.0s
=> => naming to docker.io/library/flask_web 0.0s
[+] Running 2/2
⠿ Network flask_default Created 0.0s
⠿ Container flask-web-1 Started
```
## Expected result
Listing containers must show one container running and the port mapping as below:
```
$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
c126411df522 flask_web "python3 app.py" About a minute ago Up About a minute 0.0.0.0:5000->5000/tcp flask_web_1
$ docker compose ps
NAME COMMAND SERVICE STATUS PORTS
flask-web-1 "python3 app.py" web running 0.0.0.0:8000->8000/tcp
```
After the application starts, navigate to `http://localhost:5000` in your web browser or run:
After the application starts, navigate to `http://localhost:8000` in your web browser or run:
```
$ curl localhost:5000
$ curl localhost:8000
Hello World!
```
@ -54,3 +55,14 @@ Stop and remove the containers
```
$ docker compose down
```
## Use with Docker Development Environments
You can use this sample with the Dev Environments feature of Docker Desktop.
![Screenshot of creating a Dev Environment in Docker Desktop](../dev-envs.png)
To develop directly on the services inside containers, use the HTTPS Git url of the sample:
```
https://github.com/docker/awesome-compose/tree/master/flask
```

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@ -1,7 +1,27 @@
FROM python:3.7-alpine
# syntax=docker/dockerfile:1.4
FROM --platform=$BUILDPLATFORM python:3.10-alpine AS builder
WORKDIR /app
COPY requirements.txt /app
RUN pip3 install -r requirements.txt --no-cache-dir
RUN --mount=type=cache,target=/root/.cache/pip \
pip3 install -r requirements.txt
COPY . /app
ENTRYPOINT ["python3"]
CMD ["app.py"]
FROM builder as dev-envs
RUN <<EOF
apk update
apk add git
EOF
RUN <<EOF
addgroup -S docker
adduser -S --shell /bin/bash --ingroup docker vscode
EOF
# install Docker tools (cli, buildx, compose)
COPY --from=gloursdocker/docker / /

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@ -6,4 +6,4 @@ def hello():
return "Hello World!"
if __name__ == '__main__':
app.run(host='0.0.0.0')
app.run(host='0.0.0.0', port=8000)

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@ -1,5 +1,10 @@
services:
web:
build: app
build:
context: app
target: builder
# flask requires SIGINT to stop gracefully
# (default stop signal from Compose is SIGTERM)
stop_signal: SIGINT
ports:
- '5000:5000'
- '8000:8000'