FybrikModule chaining sample

This sample shows how to implement a use case where, based on the data source and governance policies, the Fybrik manager determines that it must deploy two FybrikModules to allow a workload access to a dataset. One FybrikModule handles reading the data and the second does the data transformation. Data is passed between the FybrikModules without writing to intermediate storage.

The data read in this example is the userdata dataset, a Parquet file found in https://github.com/Teradata/kylo/blob/master/samples/sample-data/parquet/userdata2.parquet. Two FybrikModules are available for use by the Fybrik control plane: the arrow-flight-module and the airbyte-module. Only the airbyte-module can give read access to the dataset. However, it does not have any data transformation capabilities. Therefore, to satisfy constraints, the Fybrik manager must deploy both modules: the airbyte module for reading the dataset, and the arrow-flight-module for transforming the dataset based on the governance policies.

To recreate this scenario, you will need a copy of the Fybrik repository (git clone https://github.com/fybrik/fybrik.git), and a copy of the airbyte-module repository (git clone https://github.com/fybrik/airbyte-module.git). Set the following environment variables: FYBRIK_DIR for the path of the fybrik directory, and AIRBYTE_MODULE_DIR for the path of the airbyte-module directory.

Install Fybrik Prerequisites. Follow the instruction in the Fybrik Quick Start Guide. Stop before the "Install control plane" section.

Before installing the control plane, we need to customize the Fybrik taxonomy to define the new connection and interface types. Run:

cd $FYBRIK_DIR
go run main.go taxonomy compile --out custom-taxonomy.json --base charts/fybrik/files/taxonomy/taxonomy.json $AIRBYTE_MODULE_DIR/fybrik/fybrik-taxonomy-customize.yaml
helm install fybrik-crd charts/fybrik-crd -n fybrik-system --wait
helm install fybrik charts/fybrik --set global.tag=master --set global.imagePullPolicy=Always -n fybrik-system --wait --set-file taxonomyOverride=custom-taxonomy.json

Install the Airbyte module:

kubectl apply -f $AIRBYTE_MODULE_DIR/module.yaml -n fybrik-system

Install the arrow-flight module for transformations:

kubectl apply -f https://raw.githubusercontent.com/fybrik/arrow-flight-module/master/module.yaml -n fybrik-system

Create a new namespace for the application, and set it as default:

kubectl create namespace fybrik-airbyte-sample
kubectl config set-context --current --namespace=fybrik-airbyte-sample

Create an asset (the userdata asset) in fybrik's mini data catalog, the policy to access it (we use a policy that requires redactions to PII columns), and a FybrikApplication indicating the workload, context, and data requested:

kubectl apply -f $AIRBYTE_MODULE_DIR/fybrik/asset.yaml
kubectl -n fybrik-system create configmap sample-policy --from-file=$AIRBYTE_MODULE_DIR/fybrik/sample-policy-restrictive.rego
kubectl -n fybrik-system label configmap sample-policy openpolicyagent.org/policy=rego
while [[ $(kubectl get cm sample-policy -n fybrik-system -o 'jsonpath={.metadata.annotations.openpolicyagent\.org/policy-status}') != '{"status":"ok"}' ]]; do echo "waiting for policy to be applied" && sleep 5; done
kubectl apply -f $AIRBYTE_MODULE_DIR/fybrik/application.yaml

After the FybrikApplication is applied, the Fybrik control plane attempts to create the data path for the application. Fybrik realizes that the Airbyte module can give the application access to the userdata dataset, and that the arrow-flight module could provide the redaction transformation. Fybrik deploys both modules in the fybrik-blueprints namespace. To verify that the Airbyte module and the arrow-flight module were indeed deployed, run:
```
kubectl get pods -n fybrik-blueprints
```
You should see pods with names similar to:
```
NAME                                                              READY   STATUS    RESTARTS   AGE
my-app-fybrik-airbyte-sample-airbyte-module-airbyte-module4kvrq   2/2     Running   0          43s
my-app-fybrik-airbyte-sample-arrow-flight-module-arrow-flibxsq2   1/1     Running   0          43s
```

To verify that the Airbyte module gives access to the userdata dataset, run:

cd $AIRBYTE_MODULE_DIR/helm/client
./deploy_airbyte_module_client_pod.sh
kubectl exec -it my-shell -n default -- python3 /root/client.py --host my-app-fybrik-airbyte-sample-arrow-flight-module.fybrik-blueprints --port 80 --asset fybrik-airbyte-sample/userdata

You should see the following output:

       registration_dttm      id first_name last_name  email  ...     country birthdate     salary                     title comments
0    2016-02-03T13:36:39     1.0      XXXXX     XXXXX  XXXXX  ...   Indonesia     XXXXX  140249.37  Senior Financial Analyst         
1    2016-02-03T00:22:28     2.0      XXXXX     XXXXX  XXXXX  ...       China     XXXXX        NaN                                   
2    2016-02-03T18:29:04     3.0      XXXXX     XXXXX  XXXXX  ...      France     XXXXX  236219.26                   Teacher         
3    2016-02-03T13:42:19     4.0      XXXXX     XXXXX  XXXXX  ...      Russia     XXXXX        NaN    Nuclear Power Engineer         
4    2016-02-03T00:15:29     5.0      XXXXX     XXXXX  XXXXX  ...      France     XXXXX   50210.02             Senior Editor         
..                   ...     ...        ...       ...    ...  ...         ...       ...        ...                       ...      ...
995  2016-02-03T13:36:49   996.0      XXXXX     XXXXX  XXXXX  ...       China     XXXXX  185421.82                                  "
996  2016-02-03T04:39:01   997.0      XXXXX     XXXXX  XXXXX  ...    Malaysia     XXXXX  279671.68                                   
997  2016-02-03T00:33:54   998.0      XXXXX     XXXXX  XXXXX  ...      Poland     XXXXX  112275.78                                   
998  2016-02-03T00:15:08   999.0      XXXXX     XXXXX  XXXXX  ...  Kazakhstan     XXXXX   53564.76        Speech Pathologist         
999  2016-02-03T00:53:53  1000.0      XXXXX     XXXXX  XXXXX  ...     Nigeria     XXXXX  239858.70                                   

[1000 rows x 13 columns]

Alternatively, one can access the userdata dataset from a Jupyter notebook, as described in the notebook sample. To determine the virtual endpoint from which to access the data set, run:

ENDPOINT_SCHEME=$(kubectl get fybrikapplication my-app -o jsonpath={.status.assetStates.fybrik-notebook-sample/userdata.endpoint.fybrik-arrow-flight.scheme})
ENDPOINT_HOSTNAME=$(kubectl get fybrikapplication my-app -o jsonpath={.status.assetStates.fybrik-notebook-sample/userdata.endpoint.fybrik-arrow-flight.hostname})
ENDPOINT_PORT=$(kubectl get fybrikapplication my-app -o jsonpath={.status.assetStates.fybrik-notebook-sample/userdata.endpoint.fybrik-arrow-flight.port})
printf "${ENDPOINT_SCHEME}://${ENDPOINT_HOSTNAME}:${ENDPOINT_PORT}"

Note that the virtual endpoint determined from the FybrikApplication status points to the arrow-flight transform module, although this transparent to the user.

Insert a new notebook cell to install pandas and pyarrow packages:

%pip install pandas pyarrow

Finally, given the endpoint value determined above, insert the following to a new notebook cell:

import json
import pyarrow.flight as fl

# Create a Flight client
client = fl.connect('<ENDPOINT>')

# Prepare the request
request = {
    "asset": "fybrik-airbyte-sample/userdata",
}

# Send request and fetch result as a pandas DataFrame
info = client.get_flight_info(fl.FlightDescriptor.for_command(json.dumps(request)))
reader: fl.FlightStreamReader = client.do_get(info.endpoints[0].ticket)
print(reader.read_pandas())