msrahman07 / infrastructure-as-code-oci

Oracle Cloud Infrastructure Compute Instance Provisioning

This guide explains how to provision a compute instance in Oracle Cloud Infrastructure (OCI) using Python scripts and the OCI Python SDK. The provided Python script (create_instance.py) automates the process of launching a compute instance.

Prerequisites

Before you begin, ensure you have the following prerequisites:

1. Install OCI Python SDK:

   Install the Oracle Cloud Infrastructure Python SDK on your local machine. Follow the instructions in the official installation guide.

2. Generate API Key and Configuration File:

   Generate an API key and create a configuration file (~/.oci/config) to authenticate with OCI. Refer to the following resources for guidance:

   • Generate API Key
   • Configure ~/.oci/config

3. Define Configuration Variables:

   In the oci_config.py file (located in the same folder as create_instance.py), define the following variables:

   • compartment_id: Your designated compartment ID in your tenancy.
   • ssh_public_key_path: Path to your RSA public key for SSH communication with the instance.
   • shape_name: Name of the desired shape for the compute instance.
   • operating_system_version: The OS version you want to use.
   • public_subnet_id: Public subnet ID from your Virtual Cloud Network (VCN).
   • instance_name: Set a name for your compute instance.

create_instance.py Code Description

Below is a description of the functions and code in create_instance.py:

1. config = oci.config.from_file("~/.oci/config", "DEFAULT"): Creates an account configuration from ~/.oci/config.

2. identity_client = oci.identity.IdentityClient(config): Generates an identity client for working with OCI's identity and access management.

3. compute_client = oci.core.ComputeClient(config): Creates a compute client for interacting with compute instances in OCI.

4. compute_client_composite_operations = oci.core.ComputeClientCompositeOperations(compute_client): Creates a compute client composite to perform composite operations.

5. compartment_id = oci_config.compartment_id: Retrieves the compartment ID specified in oci_config.py.

6. get_availability_domain(identity_client, compartment_id): Retrieves a list of all available domains in your tenancy and selects the first one.

7. get_shape(compute_client, compartment_id, availability_domain): Retrieves a list of available shapes and selects one based on the shape name defined in oci_config.py.

8. get_image(compute, compartment_id, shape): Retrieves a list of available images, selects an image based on the specified OS and version.

9. get_launch_instance_details(compartment_id, availability_domain, shape, image, subnet_id, ssh_public_key): Generates instance launch details and metadata based on provided arguments.

10. launch_instance(compute_client_composite_operations, launch_instance_details): Creates an OCI compute instance based on launch details and waits for the instance to reach the 'RUNNING' state.

Running the Script

To provision a compute instance, follow these steps:

1. Install Dependencies:

   Install the required dependencies using pip:

   pip install oci

2. Run the Script: python create_instance.py

Customization

You can customize the script further based on your requirements, such as adding additional metadata, customizing the shape configuration, or specifying a different OS image.