demo-flask-app

Basic Python 3.8 Flask application to run in a Kubernetes cluster.

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Build

$: docker build -t tty0/flask_app:1.0

How to run

You need to have all requirements installed.

Local execution

$ cd src/
$ pip install -r requirements.txt
$ export FLASK_APP=server.py
$ export FLASK_RUN_PORT=8000
$ export FLASK_DEBUG=True
$ flask run --host=0.0.0.0

Run in Docker (meinheld)

$ docker run -p 8080 -it tty0/flask_app

Run in Kubernetes (Helm)

Be sure to have Helm 3 installed: (https://helm.sh/docs/intro/install/

1. Edit values.yaml file in order to setup your environment.

2. First test installation with --dry-run parameter. You can specify the namespace by using -n modificator or alter any input parameter with --set=<PARAMETER:VALUE>.

$ cd ./helm/demo-flask-app
$ helm install demo-flask-app . -n default
Release "demo-flask-app" has been upgraded. Happy Helming!
NAME: demo-flask-app
LAST DEPLOYED: Thu Sep  3 23:01:39 2020
NAMESPACE: wildwest
STATUS: deployed
REVISION: 4
TEST SUITE: None
NOTES:
1. Get the application URL by running these commands:
  export POD_NAME=$(kubectl get pods --namespace wildwest -l "00app.kubernetes.io/name=demo-flask-app,app.kubernetes.io/instance=demo-flask-app" -o jsonpath="{.items[0].metadata.name}")
  echo "Visit http://127.0.0.1:8080 to use your application"
  kubectl --namespace wildwest port-forward $POD_NAME 8080:8000

Values.yaml

# Default values for demo-flask-app.
# This is a YAML-formatted file.
# Declare variables to be passed into your templates.

replicaCount: 5

image:
  repository: tty0/flask_app
  pullPolicy: Always
  tag: "1.0"

service:
  type: ClusterIP
  port: 8000

limits:
  cpu: 0.2
  memory: 128Mi
requests:
  cpu: 0.4
  memory: 256Mi

autoscaling:
  enabled: true
  minReplicas: 1
  maxReplicas: 10
  targetCPUUtilizationPercentage: 80
  targetMemoryUtilizationPercentage: 80

conf:
  salute: "better ask for forgiveness than permission"
  header: "https://demo.org/web/image/1309/badges.jpg"

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Authors

Module managed by Facu de la Cruz

License

Apache 2.0