Creating a custom plugin with Oracle

1. In your command prompt, navigate to the directory where your DAG code is stored. For example:

   cd dags

2. Copy the contents of the following code sample and save locally as oracle.py.

   from airflow import DAG
   from airflow.operators.python_operator import PythonOperator
   from airflow.utils.dates import days_ago
   import os
   import cx_Oracle
   
   DAG_ID = os.path.basename(__file__).replace(".py", "")
   
   def testHook(**kwargs):
       cx_Oracle.init_oracle_client()
       version = cx_Oracle.clientversion()
       print("cx_Oracle.clientversion",version)
       return version
   
   with DAG(dag_id=DAG_ID, schedule_interval=None, catchup=False, start_date=days_ago(1)) as dag:
       hook_test = PythonOperator(
           task_id="hook_test",
           python_callable=testHook,
           provide_context=True 
       )

Pull the Amazon Linux container image

1. In your command prompt, pull the Amazon Linux container image, and run the container locally. For example:

   docker pull amazonlinux
   docker run -it amazonlinux:latest /bin/bash

   Your command prompt should invoke a bash command line. For example:

   bash-4.2#

2. Install the Linux-native asynchronous I/O facility (libaio).

   yum -y install libaio

3. Keep this window open for subsequent steps. We'll be copying the following files locally: lib64/libaio.so.1, lib64/libaio.so.1.0.0, lib64/libaio.so.1.0.1.

Download client folder

1. Install the unzip package locally. For example:

   sudo yum install unzip

2. Create an oracle_plugin directory. For example:

   mkdir oracle_plugin
   cd oracle_plugin

3. Use the following curl command to download the instantclient-basic-linux.x64-18.5.0.0.0dbru.zip from Oracle Instant Client Downloads for Linux x86-64 (64-bit).

   curl https://download.oracle.com/otn_software/linux/instantclient/185000/instantclient-basic-linux.x64-18.5.0.0.0dbru.zip > client.zip

4. Unzip the client.zip file. For example:

   unzip *.zip

Extract files from Docker

1. In a new command prompt, display and write down your Docker container ID. For example:

   docker container ls

   Your command prompt should return all containers and their IDs. For example:

   debc16fd6970

2. In your oracle_plugin directory, extract the lib64/libaio.so.1, lib64/libaio.so.1.0.0, lib64/libaio.so.1.0.1 files to the local instantclient_18_5 folder. For example:

   docker cp debc16fd6970:/lib64/libaio.so.1 instantclient_18_5/
   docker cp debc16fd6970:/lib64/libaio.so.1.0.0 instantclient_18_5/
   docker cp debc16fd6970:/lib64/libaio.so.1.0.1 instantclient_18_5/

• Copy the contents of the following code sample and save locally as env_var_plugin_oracle.py.

  from airflow.plugins_manager import AirflowPlugin
  import os
  
  os.environ["LD_LIBRARY_PATH"]='/usr/local/airflow/plugins/instantclient_18_5'
  os.environ["DPI_DEBUG_LEVEL"]="64"
  
  class EnvVarPlugin(AirflowPlugin):                
      name = 'env_var_plugin' 

Zip the contents of the plugin directory

1. In your command prompt, navigate to the oracle_plugin directory. For example:

   cd oracle_plugin

2. Zip the instantclient_18_5 directory in plugins.zip. For example:

   zip -r ../plugins.zip ./

3. You should see the following in your command prompt:

   oracle_plugin$ ls
   client.zip		instantclient_18_5

4. Remove the client.zip file. For example:

   rm client.zip

Zip the env_var_plugin_oracle.py file

1. Add the env_var_plugin_oracle.py file to the root of the plugins.zip. For example:

   zip plugins.zip env_var_plugin_oracle.py

2. Your plugins.zip should now include the following:

   env_var_plugin_oracle.py
   instantclient_18_5/