catastrophe-brandon / insights-host-inventory

Insights Inventory

This project is the home of the host-based inventory for the Insights Platform.

Getting Started

This project uses pipenv to manage the development and deployment environments. To set the project up for development do the following:

pipenv install --dev

Afterwards you can activate the virtual environment by running:

pipenv shell

Included is a docker-compose file dev.yml that will start a postgres database that is useful for development.

docker-compose -f dev.yml up

Initialize/update the database tables

Run the following commands to run the db migration scripts which will maintain the db tables.

The database migration scripts determine the DB location, username, password and db name from the INVENTORY_DB_HOST, INVENTORY_DB_USER, INVENTORY_DB_PASS and INVENTORY_DB_NAME environment variables.

python manage.py db migrate
python manage.py db upgrade

By default the database container will use a bit of local storage so that data you enter will be persisted across multiple starts of the container. If you want to destroy that data do the following:

docker-compose down

Running the Tests

It is possible to run the tests using pytest:

prometheus_multiproc_dir=/path/to/prometheus_multiprocess/ pytest --cov=.

Or you can run the tests individually:

prometheus_multiproc_dir=/path/to/prometheus_multiprocess/ ./test_api.py
prometheus_multiproc_dir=/path/to/prometheus_multiprocess/ pytest test_db_model.py
./test_unit.py
pytest test_json_validators.py

Depending on the environment, it might be necessary to set the DB related environment variables (INVENTORY_DB_NAME, INVENTORY_DB_HOST, etc). See information on prometheus_multiproc_dir environment variable below.

Running the server

Prometheus was designed to run in a multi-threaded environment whereas gunicorn uses a multi-process architecture. As a result, there is some work to be done to make prometheus integrate with gunicorn.

A temp directory for prometheus needs to be created before the server starts. The prometheus_multiproc_dir environment needs to point to this directory. The contents of this directory need to be removed between runs.

A command to run the server in a cluster.

gunicorn -c gunicorn.conf.py --log-config=$INVENTORY_LOGGING_CONFIG_FILE run

Running the server locally for development. In this case it’s not necessary to care about the Prometheus temp directory or to set the prometheus_multiproc_dir environment variable. This is done automatically.

python run_gunicorn.py 

Configuration environment variables

 prometheus_multiproc_dir=/path/to/prometheus_dir
 APP_NAME="inventory"
 PATH_PREFIX="/r/insights/platform"
 INVENTORY_DB_USER="insights"
 INVENTORY_DB_PASS="insights"
 INVENTORY_DB_HOST="localhost"
 INVENTORY_DB_NAME="insights"
 INVENTORY_DB_POOL_TIMEOUT="5"
 INVENTORY_DB_POOL_SIZE="5"
 INVENTORY_LOGGING_CONFIG_FILE=logconf.ini

Deployment

The application provides some management information about itself. These endpoints are exposed at the root path / and thus are accessible only from inside of the deployment cluster.

• /health responds with 200 to any GET requests, point your liveness or readiness probe here.
• /metrics offers metrics and monitoring intended to be pulled by Prometheus.
• /version responds with a json doc that contains the build version info (the value of the OPENSHIFT_BUILD_COMMIT environment variable)

API Documentation

The API is described by an OpenAPI specification file swagger/api/api.spec.yaml. The application exposes a browsable Swagger UI Console at /r/insights/platform/inventory/api/v1/ui/.

Operation

The Insights Inventory service is responsible for storing information about hosts and deduplicating hosts as they are reported. The Inventory service uses the canonical facts to perform the deduplication. The canonical facts are:

• insights_id
• rhel_machine_id
• subscription_manager_id
• satellite_id
• bios_uuid
• ip_addresses
• fqdn
• mac_addresses
• external_id

Hosts are added and updated by sending a POST to the /hosts endpoint. (See the API Documentation for more details on the POST method). This method returns an id which should be used to reference the host by other services in the Insights platform.

Overview of the deduplication process

If the update request includes an insights_id, then the inventory service will lookup the host using the insights_id. If the inventory service finds a host with a matching insights_id, then the host will be updated and the canonical facts from the update request will replace the existing canonical facts.

If the update request does not include an insights_id, then the canonical facts will be used to lookup the host. If the canonical facts from the update request are a subset or a superset of the previously stored canonical facts, then the host will be updated and any new canonical facts from the request will be added to the existing host entry.

If the canonical facts based lookup does not locate an existing host, then a new host entry is created.

Testing API Calls

It is necessary to pass an authentication header along on each call to the service. For testing purposes, it is possible to set the required identity header to the following:

x-rh-identity: eyJpZGVudGl0eSI6eyJhY2NvdW50X251bWJlciI6IjAwMDAwMDEifX0=

This is the base64 encoding of the following json doc:

'{"identity":{"account_number":"0000001"}}'