The OCI service that can be used as a target deployment environment for adopting a DevOps framework and a consumption-based pricing model, while providing features like automated rollouts and rollbacks, self-healing of failed containers, and configuration management, without the overhead of managing security patches and scaling, is OCI Container Engine for Kubernetes (OKE) with virtual nodes. OKE is a fully managed service that allows you to run and manage your containerized applications on OCI using Kubernetes, an open-source system for automating deployment, scaling, and management of containerized applications. OKE provides features such as automated rollouts and rollbacks, self-healing of failed containers, configuration management, service discovery, load balancing, etc. OKE also supports virtual nodes, which are serverless compute resources that are automatically provisioned and scaled by OCI based on your application workload demands. Virtual nodes eliminate the need for managing worker node infrastructure, such as security patches, updates, scaling, etc. Virtual nodes also offer a consumption-based pricing model, where you only pay for the resources you consume when your containers are running. Verified Reference: [Container Engine for Kubernetes - Oracle Cloud Infrastructure Developer Tools], [Virtual Nodes - Oracle Cloud Infrastructure Container Engine for Kubernetes]

The statement that is true about managing cluster add-ons in OCI OKE Cluster is that when creating a new cluster, essential cluster add-ons cannot be disabled. A cluster add-on is a software component that provides additional functionality or integration for your OKE cluster. OCI OKE Cluster supports two types of cluster add-ons: essential and optional. Essential cluster add-ons are required for your cluster to function properly and cannot be disabled or customized. These include CoreDNS, Kubernetes Dashboard, Metrics Server, and WebLogic Operator. Optional cluster add-ons are not required for your cluster to function but provide additional features or benefits. These include Kiali Operator, Istio Operator, Vault Agent Injector, and Vault KMS Plugin. You can enable or disable optional cluster add-ons as per your needs. Verified Reference: [Cluster Add-Ons - Oracle Cloud Infrastructure Container Engine for Kubernetes], [Managing Cluster Add-Ons - Oracle Cloud Infrastructure Container Engine for Kubernetes]

To create an OCI IAM policy that will be used in a DevOps CI/CD pipeline for deployment to an OKE environment, you need to use a dynamic group and grant it the permission to manage all-resources in the target compartment. A dynamic group is a group of OCI resources that match a set of rules defined by the administrator. You can use a dynamic group to assign IAM policies to resources such as build pipelines and deployment pipelines. By granting the dynamic group the permission to manage all-resources, you allow it to perform any action on any resource type in the compartment, including OKE clusters, node pools, and Kubernetes resources. Verified Reference: [Dynamic Groups - Oracle Cloud Infrastructure Identity and Access Management], [Creating Dynamic Groups - Oracle Cloud Infrastructure Identity and Access Management]

The approach that should be used to trigger emails when a new file is created in an OCI Object Storage bucket is to create a rule in the OCI Events service that sends the bucket event to an OCI Notifications service topic configured with an email subscriber. The OCI Events service is a service that allows you to react to changes in your OCI resources by creating rules that match events of interest and trigger actions based on those events. The OCI Notifications service is a service that allows you to broadcast messages to distributed components through topics and subscriptions. By using these services together, you can achieve the following workflow:

Create an OCI Notifications service topic and add an email subscriber with the customer's email address.

Create an OCI Events service rule that matches the Object Storage bucket event type ''com.oraclecloud.objectstorage.createobject'' and specifies the Notifications topic as the action.

Whenever a new file is created in the Object Storage bucket, an event will be generated and matched by the rule, which will send a message to the Notifications topic.

The Notifications topic will deliver the message to the email subscriber, which will trigger an email to the customer. Verified Reference: [Events - Oracle Cloud Infrastructure Developer Tools], [Notifications - Oracle Cloud Infrastructure Developer Tools]

The recommended approach in OCI for creating identical blue-green environments for deploying a critical application is to use two separate OKE clusters to ensure complete separation between environments. A blue-green environment is a deployment technique that involves creating two identical environments (blue and green) and switching traffic between them after testing. This technique allows you to reduce downtime, minimize risk, and improve user experience. To create blue-green environments in OCI, you can use two separate OKE clusters, one for the blue environment and one for the green environment. Each cluster will have its own set of resources, such as node pools, pods, services, deployments, etc., that are isolated from each other. You can also use OCI Load Balancing service to route traffic between the clusters based on your criteria. Verified Reference: [Deployment Strategies - Oracle Cloud Infrastructure DevOps], [Creating Clusters - Oracle Cloud Infrastructure Container Engine for Kubernetes]