Implement flask-ops task

.circleci/config.yml

@@ -0,0 +1,69 @@
+version: 2.1
+jobs:
+  tests:
+    docker:
+      - image: circleci/python:3.7.4
+    steps:
+      - checkout
+      - run:
+          name: Create venv
+          command: |
+            virtualenv flaskops
+      - run:
+          name: Install python dependencies
+          command: |
+            . flaskops/bin/activate
+            pip install --no-cache-dir -r requirements.txt
+      - run:
+          name: Run Linter
+          command: |
+            . flaskops/bin/activate
+            pylint --load-plugins pylint_flask --fail-under=7 app.py tests.py
+      - run:
+          name: Run Unit tests
+          command: |
+            . flaskops/bin/activate
+            python tests.py
+      - store_artifacts:
+          path: test-reports/
+          destination: tr:${CIRCLE_SHA1}
+      - store_test_results:
+          path: test-reports/
+  build:
+    machine: true
+    steps:
+      - checkout
+      - run:
+          name: Build Docker Image
+          command: |
+            docker build --build-arg secret_salt=${SECRET_SALT} -t registry.heroku.com/${HEROKU_APP_NAME}/web .
+      - run:
+          name: Integration Tests
+          command: |
+            docker run --rm -it registry.heroku.com/${HEROKU_APP_NAME}/web python -m pytest -vv
+      - run:
+         name: Push Docker Image to Heroku Registry
+         command: |
+            echo $HEROKU_API_KEY | docker login --username=_ --password-stdin registry.heroku.com
+            docker push registry.heroku.com/${HEROKU_APP_NAME}/web
+  deploy:
+    machine: true
+    steps:
+      - checkout
+      - run:
+          name: Deploy to Heroku
+          command: |
+            bash .circleci/setup-heroku.sh
+            echo $HEROKU_API_KEY | docker login --username=_ --password-stdin registry.heroku.com
+            heroku container:release web --app ${HEROKU_APP_NAME}
+workflows:
+  version: 2
+  flask-ops-cicd:
+    jobs:
+      - tests
+      - build:
+          requires:
+            - tests
+      - deploy:
+          requires:
+            - build

.circleci/setup-heroku.sh

@@ -0,0 +1,15 @@
+#!/bin/bash
+git remote add heroku https://git.heroku.com/circleci-demo-python-flask.git
+wget https://cli-assets.heroku.com/branches/stable/heroku-linux-amd64.tar.gz
+sudo mkdir -p /usr/local/lib /usr/local/bin
+sudo tar -xvzf heroku-linux-amd64.tar.gz -C /usr/local/lib
+sudo ln -s /usr/local/lib/heroku/bin/heroku /usr/local/bin/heroku
+
+cat > ~/.netrc << EOF
+machine api.heroku.com
+  login $HEROKU_LOGIN
+  password $HEROKU_API_KEY
+machine git.heroku.com
+  login $HEROKU_LOGIN
+  password $HEROKU_API_KEY
+EOF

.gitignore

@@ -6,6 +6,9 @@ __pycache__/
 # C extensions
 *.so
 
+# Pycharm
+.idea/
+
 # Distribution / packaging
 .Python
 build/

Dockerfile

@@ -0,0 +1,13 @@
+FROM python:3.7
+ARG secret_salt
+ENV SALT=$secret_salt
+ENV PYTHONUNBUFFERED=1
+ENV PYTHONDONTWRITEBYTECODE=1
+RUN mkdir /flask-app
+WORKDIR /flask-app
+COPY requirements.txt /flask-app/
+EXPOSE 5000
+RUN pip install --upgrade pip
+RUN pip install -r requirements.txt
+COPY . /flask-app/
+CMD ["bash", "start.sh"]

app.py

@@ -1,29 +1,31 @@
+"""
 ### ACME CORP
 ### Customer session key generator. Protects PII.
 ### / 2020
+"""
+import hashlib
+import os
+import secrets
+import string
 
 from flask import Flask
 
-import string
-import secrets
-import hashlib
-
 app = Flask(__name__)
 
+SUPER_SECRET_SALT = os.environ.get('SALT')
 
-# !! DON'T EXPOSE THIS KEY !!
-super_secret_salt = "68874260280172957479"
 
 def encrypt_string(hash_string):
     sha_signature = \
         hashlib.sha256(hash_string.encode()).hexdigest()
     return sha_signature
 
-# Generate a simple key
-def generate():
+
+def generate(salt):
     rand_device = string.ascii_letters + string.digits
-    return encrypt_string((''.join(secrets.choice(rand_device) for i in range(8))).join(super_secret_salt))
+    return encrypt_string((''.join(secrets.choice(rand_device) for i in range(8))).join(salt))
+
 
 @app.route('/')
 def signature():
-    return generate()
+    return generate(SUPER_SECRET_SALT)

requirements.txt

@@ -0,0 +1,3 @@
+flask
+pylint-flask
+pytest

start.sh

@@ -1,4 +1,9 @@
 #!/bin/bash
 
 export FLASK_APP=app.py
-flask run
+if [ -z "$PORT" ]
+then
+  flask run --host=0.0.0.0 --port=5000
+else
+  flask run --host=0.0.0.0 --port="$PORT"
+fi

tests.py

@@ -0,0 +1,27 @@
+"""
+Unit tests for flask-ops application
+"""
+import unittest
+
+from app import encrypt_string
+
+
+class TestApp(unittest.TestCase):
+    """
+    Test app.py
+    """
+    def test_encrypt_string_empty(self):
+        self.assertEqual(encrypt_string(''),
+                         'e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855')
+
+    def test_encrypt_string_lower_block_size(self):
+        self.assertEqual(encrypt_string('qwerty'),
+                         '65e84be33532fb784c48129675f9eff3a682b27168c0ea744b2cf58ee02337c5')
+
+    def test_encrypt_string_equal_block_size(self):
+        self.assertEqual(encrypt_string('a' * 64),
+                         'ffe054fe7ae0cb6dc65c3af9b61d5209f439851db43d0ba5997337df154668eb')
+
+
+if __name__ == '__main__':
+    unittest.main()

tests/conftest.py

@@ -0,0 +1,25 @@
+import pytest
+from flask import Flask
+
+from app import generate
+
+
+@pytest.fixture()
+def app():
+    app = Flask(__name__)
+
+    test_salt = "124325246546379565"
+
+    @app.route('/')
+    def signature():
+        return generate(test_salt)
+    return app
+
+
+@pytest.fixture()
+def request_qty():
+    return 1
+
+@pytest.fixture
+def client(app):
+    return app.test_client()

tests/test_app.py

@@ -0,0 +1,15 @@
+import pytest
+
+
+def test_health(app, client):
+    res = client.get('/')
+    assert res.status_code == 200
+
+
+@pytest.mark.parametrize('request_qty', [1, 10, 20, 50])
+def test_uniq_responses(app, client, request_qty):
+    responses = set()
+    for request in range(request_qty):
+        res = client.get('/')
+        responses.add(res.data)
+    assert len(responses) == request_qty