drift-backend

System drift analysis service

This is a flask app that provides an API for drift-frontend. It listens on port 8080 by default with gunicorn. Prometheus stats will be stored in a temp directory.

Coding guidelines

1. All python code must be python 3.8 compatible
2. The code should follow linting from pylint
3. The code should follow formatter from black
4. The code should follow imports order from isort

Required dependencies:

• pipenv
• pre-commit

Work with pre-commit hooks

# installs pre-commit hooks into the repo
pre-commit install --install-hooks

# run pre-commit hooks for staged files
pre-commit run

# run pre-commit hooks for all files in repo
pre-commit run --all-files

# bump versions of the pre-commit hooks automatically
pre-commit autoupdate

# bypass pre-commit check
git commit --no-verify

To set up pipenv:

yum install -y pipenv
pipenv install # will pull in deps and create virtualenv, and will print next steps to run

To run unit tests

With your pipenv shell activated.

Run: ./run_unit_tests.sh to run all unit test. Since we use pytest we can pass all pytest args to this script, for example:

• Run with verbose

./run_unit_tests.sh -vv

• Run only one test

./run_unit_tests.sh -k TEST_NAME

you can aggregate pytest args in same command, eg: ./run_unit_tests.sh -k TEST_NAME -vv

to set up temp directory (command will return a temp dir that you'll use later)

mktemp -d

To run (inventory service URL can be obtained from drift or platform team):

prometheus_multiproc_dir=mktemp -d INVENTORY_SVC_URL=<inventory service url> ./run_app.sh

To set the debug level (info by default):

LOG_LEVEL=debug prometheus_multiproc_dir=/tmp/tempdir INVENTORY_SVC_URL=<inventory service url> ./run_app.sh

The prometheus_multiproc_dir should be a path to a directory for sharing info between app processes. If the dir does not already exist, the app will create one.

The same info as above, but in handy table form:

env var name	required?	expected values	description
INVENTORY_SVC_URL	yes	URL	URL for inventory service (do not include path)
LOG_LEVEL	no	string	lowercase log level (info by default)
prometheus_multiproc_dir	yes	string	path to dir for sharing stats between processes
PATH_PREFIX	no	string	API path prefix (default: /api)
APP_NAME	no	string	API app name (default: drift)

If you would like to use this service with insights-proxy, you can use the included local-drift-backend.js like so:

SPANDX_CONFIG=drift-backend/local-drift-backend.js bash insights-proxy/scripts/run.sh

If you use run_app.sh, drift app will be invoked via gunicorn. This should be OK in most cases; even pdb runs fine inside of gunicorn.

However, if you want to use flask's server, use python3 standalone_flask_server.py with the aforementioned environment vars.

To run SonarQube:

1. Make sure that you have SonarQube scanner installed.
2. Duplicate the sonar-scanner.properties.sample config file.

  cp sonar-scanner.properties.sample sonar-scanner.properties

3. Update sonar.host.url, sonar.login in sonar-scanner.properties.
4. Run the following command

java -jar /path/to/sonar-scanner-cli-4.6.0.2311.jar -D project.settings=sonar-scanner.properties

5. Review the results in your SonarQube web instance.