Feature: improve experience with dockerized tests and runtime execution

.gitignore

@@ -1,2 +1,4 @@
 *.pyc
-.cache/
+.cache/
+.idea/
+db/

Dockerfile

@@ -0,0 +1,49 @@
+FROM python:3.8.16-alpine3.17 AS builder
+
+# https://stackoverflow.com/questions/59554493/unable-to-fire-a-docker-build-for-django-and-mysql/59554601#59554601
+RUN apk add musl-dev python3-dev mariadb-dev gcc build-base bash
+
+WORKDIR /viasat/minitwit
+
+COPY requirements.txt .
+
+RUN pip install -r requirements.txt
+
+ENV FLASK_APP=minitwit.py
+ENV LC_ALL=en_US.utf-8
+ENV LANG=en_US.utf-8
+
+COPY ./static /viasat/minitwit/static
+COPY ./templates /viasat/minitwit/templates
+
+COPY *.py /viasat/minitwit
+COPY *.sql /viasat/minitwit
+
+####
+#### tester image that installs the dev dependencies and executes the test cases during build
+#### and during a container execution! The build will fail if any test case fails.
+#### The test image is good for inspection of test environments and ca be used in CI/CD envs.
+####
+FROM builder AS tester
+
+# Only copy the development tools from the requirements for tests
+COPY requirements-dev.txt .
+RUN pip install -r requirements-dev.txt
+
+# All the requirements are installed and so the test cases can be executed 
+CMD ["pytest", "test_minitwit.py"]
+
+###
+### Runtime environment containing only the runtime dependencies.
+### Note that this image does NOT have anything for testing!
+###
+FROM builder AS runtime
+
+# All the other resources are there, so let's add the run-app as it's part of the runtime
+# Note that the builder runtime defines the WORKDIR already so we can COPY to .
+COPY run-app .
+COPY init-db .
+
+RUN rm -rf requirements* test_minitwit.py
+
+ENTRYPOINT ["bash", "/viasat/minitwit/run-app"]

docker-compose.yaml

@@ -0,0 +1,31 @@
+version: "3.8"
+
+services:
+
+  ####
+  #### Executes the test cases locally within a test image and prepares the container for execution.
+  ####
+  #### docker compose build minitwit-test
+  ####
+  minitwit-test:
+    image: viasat/minitwit-test
+    platform: linux/amd64
+    build:
+      context: .
+      target: tester
+
+  ####
+  #### Runs the runtime server locally with the port mapping local:container
+  ####
+  #### docker compose up --build minitwit-runtime
+  ####
+  minitwit-runtime:
+    image: viasat/minitwit
+    platform: linux/amd64
+    build:
+      context: .
+      target: runtime
+    ports:
+      - 4000:5000
+    volumes:
+      - ./db:/var/minitwit

init-db

@@ -4,4 +4,11 @@ export FLASK_APP=minitwit.py
 export LC_ALL=en_US.utf-8
 export LANG=en_US.utf-8
 
+DB_DIR=${DB_DIR:-/var/minitwit}
+
+# Initialize the path where the db is
+if [ ! -d ${DB_DIR} ]; then
+  mkdir -p ${DB_DIR}
+fi
+
 flask initdb

requirements-dev.txt

@@ -0,0 +1 @@
+pytest==5.3.2

requirements.txt

@@ -1,5 +1,4 @@
 Flask>=2.2
-pytest==5.3.2
 SQLAlchemy >= 1.3.0, < 2.0
 boto3>=1.26
 mysqlclient>=2.1

run-app

@@ -4,4 +4,11 @@ export FLASK_APP=minitwit.py
 export LC_ALL=en_US.utf-8
 export LANG=en_US.utf-8
 
+export DB_DIR=${DB_DIR:-/var/minitwit}
+
+if [ ! -f ${DB_DIR}/minitwit.db ] || [ -n "${INIT_DB}" ]; then
+  echo "Initializing database at ${DB_DIR}/minitwit.db"
+  ./init-db
+fi
+
 flask run --host=0.0.0.0 --with-threads --no-debugger --no-reload

test_minitwit.py

@@ -20,7 +20,14 @@ def client(request):
     minitwit.app.config['DATABASE'] = 'sqlite:///' + minitwit.app.config['DATABASE'] 
     client = minitwit.app.test_client()
     with minitwit.app.app_context():
-        minitwit.init_db()
+       # Required to not fail the tests at /var/minitwit/minitwit.db
+       # sqlalchemy.exc.OperationalError: (sqlite3.OperationalError) unable to open database file
+       db_dir = "/var/minitwit"
+       if not os.path.exists(db_dir):
+          os.makedirs(db_dir)
+
+       # Note that this is the same as the production db /var/minitwit/minitwit.db
+       minitwit.init_db()
 
     def teardown():
         """Get rid of the database again after each test."""