The best options for ensuring that the pipelines that run in the Pods have the appropriate IAM permissions to perform the Terraform deployments are to create a new Kubernetes service account and assign the service account to the Pods, and to use Workload Identity to authenticate as the Google service account. A Kubernetes service account is an identity that represents an application or a process running in a Pod. A Google service account is an identity that represents a Google Cloud resource or service. Workload Identity is a feature that allows you to bind Kubernetes service accounts to Google service accounts. By using Workload Identity, you can avoid creating and managing JSON service account keys, which are less secure and require more maintenance. You can also assign the appropriate IAM permissions to the Google service account that corresponds to the Kubernetes service account.

Comprehensive and Detailed Explanation:

When using Managed Service for Prometheus, metrics may not appear in Cloud Monitoring if PodMonitoring is misconfigured. The most likely issue is that the PodMonitoring configuration does not reference a valid port.

PodMonitoring is required to collect metrics from workloads in GKE.

If the port is incorrect or missing, metrics won’t be scraped.

???? Why not other options?

A (Check quota limits)❌→ If quotas were exceeded, you’d see explicit errors, but the question states no errors were encountered.

B (Grafana installation check)❌→ Grafana is not required for Prometheus metric collection.

C (monitoring.servicesViewer IAM role issue)❌→ This role allows viewing metrics, but does not affect metric collection.

???? Official Reference:

Managed Service for Prometheus - PodMonitoring

GKE Monitoring Troubleshooting

The best option for ensuring that the warehouse system accurately reflects product inventory at the time orders are placed and minimizing the impact on customers is to increase the number of Pod replicas. Increasing the number of Pod replicas will increase the scalability and availability of your microservice, which will allow it to handle more Pub/Sub messages and update stock information faster. This way, you can reduce the backlog of undelivered messages and oldest unacknowledged message age, which are causing delays in updating product inventory. You can use Horizontal Pod Autoscaler or Cloud Monitoring metrics-based autoscaling to automatically adjust the number of Pod replicas based on load or custom metrics.

Reason : Incident has not occurred yet, even when development team is already pushing new features multiple times a week. The option A says, to define an error budget " policy " , not to define error budget(It is already present). Just simple means to bring in all stakeholders, and decide how to consume the error budget effectively that could bring balance between feature deployment and reliability.

The goals of this policy are to: -- Protect customers from repeated SLO misses -- Provide an incentive to balance reliability with other featureshttps://sre.google/workbook/error-budget-policy/

https://cloud.google.com/architecture/continuous-delivery-toolchain-spinnaker-cloud

https://spinnaker.io/guides/user/pipeline/triggers/pubsub/

 The most efficient way to build an automated pipeline that deploys the application when the image is updated is to use Cloud Pub/Sub to trigger a Spinnaker pipeline. This way, you can leverage the built-in integration between GCR and Cloud Pub/Sub, and use Spinnaker as a continuous delivery platform for deploying your application .

Cloud Build is a service that executes your builds on Google Cloud Platform infrastructure1. Cloud Build can be used as a pipeline runner for your CI pipeline, which is a process that automates the integration and testing of your code2. Cloud Build private pools are private, dedicated pools of workers that offer greater customization over the build environment, including the ability to access resources in a private VPC network3. A VPC network is a virtual network that provides connectivity for your Google Cloud resources and services. By using Cloud Build private pools, you can implement a solution that minimizesmanagement overhead, as Cloud Build private pools are hosted and fully-managed by Cloud Build and scale up and down to zero, with no infrastructure to set up, upgrade, or scale3. You can also implement a solution that meets your security requirement, as Cloud Build private pools use network peering to connect into your private VPC network and do not expose API traffic publicly.

https://sre.google/workbook/implementing-slos/

https://cloud.google.com/architecture/adopting-slos/

Latency is commonly measured as a distribution. Given a distribution, you can measure various percentiles. For example, you might measure the number of requests that are slower than the historical 99th percentile.

When disaster strikes, the person who declares the incident typically steps into the IC role and directs the high-level state of the incident. The IC concentrates on the 3Cs and does the following: Commands and coordinates the incident response, delegating roles as needed. By default, the IC assumes all roles that have not been delegated yet. Communicates effectively. Stays in control of the incident response. Works with other responders to resolve the incident.https://sre.google/workbook/incident-response/