CCNA Deploying and Implementing a Cloud Solution Questions

kubectl autoscale creates a HorizontalPodAutoscaler targeting the deployment, with --cpu-percent=50 setting the target utilisation and --min=3 --max=10 bounding replica count. This satisfies the requirement to scale web-frontend automatically on CPU, starting from its current 3 replicas.

This is the correct approach because `kubectl expose deployment` with `--type=LoadBalancer` automatically creates a Kubernetes Service that instructs GKE to provision a cloud load balancer and allocate an external IP address. The `--port=80` specifies the Service port, while `--target-port=8080` directs traffic to the container's actual listening port on the Pod, matching the Deployment's container specification. If a reserved static IP is needed, you would reserve it in advance and add the `--load-balancer-ip` flag or annotate the Service; GKE then assigns that address to the load balancer.

The correct approach is to create a new instance template that includes the desired startup script in its metadata, then update the MIG to reference this new template using a rolling update. Since instance templates are immutable, creating a new template is mandatory. A rolling update (e.g., gcloud compute instance-groups managed rolling-action start-update) recreates the managed instances incrementally with the new template, ensuring the startup script executes during their boot. This method preserves availability and aligns with the MIG's declarative management model.

Setting --ingress=internal restricts traffic to sources within the same project or VPC network, blocking public internet access. --no-allow-unauthenticated requires authentication for all requests, ensuring that only authorized callers can invoke the service. This combination enforces both network-level and identity-level restrictions, which is necessary to prevent public access while allowing the frontend to authenticate.

Database Migration Service (DMS) is a fully managed service that automates the entire migration process, including a one-time full load followed by continuous change data capture (CDC) from the source database. This approach keeps the on-premises database online and synchronized during the migration, so you can cut over with minimal downtime. For a large database, DMS handles the heavy lifting of snapshotting and applying changes without needing to manually create or transfer dump files.

The Pub/Sub Subscriber role (roles/pubsub.subscriber) is the correct, least-privileged role for a Cloud Functions trigger. It includes the permissions needed to pull messages (pubsub.subscriptions.consume) and acknowledge them after processing (pubsub.subscriptions.acknowledge), which is exactly what the function's runtime service account must do to read and complete each message from its subscription.

This is the correct custom tier string because it conforms to the required db-custom-<vCPUs>-<memory_in_MB> format for Cloud SQL custom machine types. It specifies 16 vCPUs and 61,440 MB of memory, which is exactly 60 GB when applying the binary conversion factor of 1024 MB per GB. This string accurately represents the administrator's desired 16 vCPU / 60 GB configuration in the unit that Cloud SQL actually uses.

Cloud Run is a fully managed serverless platform that runs stateless HTTP-triggered containers directly from a container image. It automatically scales down to zero when there are no incoming requests, so you incur no charges while idle, and bills only for request duration (CPU, memory, and concurrency metered during request handling). You can deploy any container that listens on HTTP, making it the ideal low-overhead choice for a containerized web application. Unlike GKE or Compute Engine, there is no infrastructure to manage or minimum charge for a running VM.

This is the correct command to import a SQL dump file into a Cloud SQL MySQL instance. The `gcloud sql import sql` command takes the instance name, the Cloud Storage URI of the dump, and the `--database` flag to specify the target database. The Cloud SQL instance's service account must have `storage.objectViewer` permission on the bucket, and the database must already exist. This is the supported, asynchronous import method for managed Cloud SQL.

A StatefulSet provides stable pod names, stable network identities via a headless Service, and ordered deployment and scaling. The headless Service (clusterIP: None) creates DNS records for each pod, enabling peer discovery. The volumeClaimTemplates automatically provisions a PersistentVolumeClaim for each pod, ensuring dedicated storage. This is the standard GKE-native approach for stateful clustered applications.

This is the correct way to configure remote state storage for Google Cloud using Terraform. The `terraform` block wraps the backend declaration, the type is `gcs` for Google Cloud Storage, and the `bucket` and `prefix` arguments accurately define the bucket name and the object key within that bucket. Using a distinct prefix like `"prod"` allows multiple environments or components to share the same bucket while keeping their state files isolated and easily retrievable.

This is the correct command because it uses --region us-central1 to designate a regional cluster, which GKE deploys across multiple zones within that region for redundancy and high availability. The --num-nodes 3 flag sets the number of nodes per zone in the default node pool, ensuring each zone gets three nodes. Together, these flags meet the requirement for a regional GKE cluster named my-cluster.

Archive is the correct choice because it is the lowest-cost Cloud Storage class for data that is accessed less than once a year, offering the cheapest per-gigabyte monthly price for long-term retention. It does incur retrieval fees and a 365-day minimum storage duration, but for true archival data with infrequent access these trade-offs are acceptable. This class also has no availability SLA, which is fine for this access pattern but means it should only be used for durable, rarely accessed data.

'kubectl get pods' is the canonical command to list pods in the current namespace. It queries the Kubernetes API and returns a table with columns such as NAME, READY, STATUS, RESTARTS, and AGE, one row per pod. This is the expected answer because the question asks for a command that lists pods, and 'get' is the standard verb for retrieving resource lists.

Correct. If the Cloud Storage bucket already has CMEK enabled by default, no further Terraform configuration is required for encryption; the bucket's default key handles encryption at rest.

Enabling OS Login by setting the project metadata key enable-oslogin to TRUE is the foundational step. This tells Compute Engine to use IAM-based authentication for SSH, allowing the engineer to log in with Google credentials rather than managing SSH keys. Once enabled at the project level, instances inherit the setting, and a user with the compute.osLogin role can SSH without manual key distribution. This is the required first action to meet the engineer's need.

Configuring the gcs backend with a bucket name is the correct way to store Terraform state for GCP resources. The gcs backend uses a Cloud Storage bucket, which natively supports state file versioning, server-side encryption (including customer-managed keys via Cloud KMS), and access control through GCP IAM, providing both security and consistency for team use. It also enables state locking via bucket objects to prevent concurrent modifications. This is the recommended solution for centralized, durable remote state in GCP.

Persistent Disk is durable, network-attached block storage that you can attach to a Compute Engine instance like a physical disk. It survives instance stops and can be detached from one instance and reattached to another, enabling stateful failover. Persistent Disk also supports snapshots, resizing, and zonal or regional replication, making it the appropriate choice for a stateful application. For these reasons, Persistent Disk is the correct answer.

A 503 from Cloud Run specifically signals that a request arrived but no container instance was available to accept it within the timeout window. Each instance can process only a fixed number of concurrent requests—the default concurrency is 80—so when all existing instances are saturated and the autoscaler cannot add new instances quickly enough (or the 'max instances' setting has been reached), the server returns Service Unavailable. The fix is to raise the max instances limit, lower the concurrency setting, or enable additional CPU to reduce per-instance bottleneck.

The `--runtime` flag is mandatory because it tells the Cloud Functions deployment service which language runtime to use, such as `python312` or `nodejs20`. This value must match the code you are uploading, including the expected base image and dependencies, so the platform can build the function in the correct environment. Without specifying it, the gcloud command will fail, as there is no sensible default language choice.

This is the correct command because it explicitly selects the 'cos-stable' image family from the 'cos-cloud' project, which yields the latest stable release of Container-Optimized OS. COS is a Google-supported OS with Docker, containerd, and Kubernetes tools preinstalled, optimized for running containerized workloads. Including both --image-family and --image-project ensures that gcloud resolves the family from the proper project, avoiding ambiguity with the default compute project.

Compute Engine sends a SIGTERM signal before stopping an instance, and the shutdown period can be extended beyond the default 90 seconds by setting a graceful shutdown duration on the instance template or MIG. By handling SIGTERM, the application can finish processing the current Pub/Sub message and acknowledge it, ensuring no task is lost during scale-in or maintenance events. This directly addresses the requirement with minimal architectural change.

Cloud Run is a fully managed serverless platform that executes containers in a stateless, request-driven model: when there are no incoming requests, it can scale the service down to zero instances, so you are not charged for idle resources. It automatically scales up to handle traffic spikes, and billing is based on request duration and CPU/memory usage during active processing, measured in 100ms increments. This makes it the most operationally efficient choice for a containerized web application that expects variable traffic.

Cloud SQL for MySQL is a fully managed relational database service that provides the exact MySQL engine required by the application. It supports regional high availability through synchronous replication across two zones, automated backups, and point-in-time recovery, meeting both performance and durability needs without operational overhead. Its compatibility with standard MySQL drivers and protocols makes it the ideal choice for a regional MySQL workload.

This command is correct because it explicitly provides the required function name (`my-function`), specifies the Node.js 16 runtime, sets `--trigger-http` to create an HTTP-triggered Cloud Function, names the entry point (`helloHttp`) that matches the exported function in your source code, and pins the region (`us-central1`) to avoid ambiguity. In Cloud Functions, `--trigger-http` creates a public HTTPS endpoint and deploys the function to the specified location, making this the complete and valid invocation.

Adding the script to the instance template using the metadata key 'startup-script' is the recommended, automated approach because Compute Engine stores the metadata in the instance template and executes the script on every VM boot. The MIG automatically applies this metadata to all instances it creates, including during autoscaling, rolling updates, and instance recreation after a failure. This guarantees the configuration is consistently applied without manual intervention, and the script can be updated by editing the template and rolling out a new version of the MIG.

The --ingress=internal flag restricts traffic to sources within the same project or VPC network, preventing public internet access. The --no-allow-unauthenticated flag requires authentication for all requests, ensuring the service is not publicly accessible. Deploying with the Artifact Registry image path is correct. This combination meets the requirement of internal-only access with authentication.

The --set-env-vars flag injects key-value pairs as environment variables during gcloud functions deploy, making them readable by the function's runtime code. This passes configuration at deployment time without hardcoding values, satisfying the stem's requirement for supplying parameters when the HTTP-triggered function is created.

A Service of type LoadBalancer in GKE creates an external passthrough Network Load Balancer in Google Cloud, provisioning an external forwarding rule with a stable public IP address from a regional pool. This IP remains fixed for the lifetime of the Service unless the Service is deleted or a reserved static IP is explicitly configured, making it the correct choice for a microservice that needs a durable public endpoint without additional configuration.

Archive is the lowest-cost Cloud Storage class, designed for data accessed less than once a year, and it supports the 10-year retention requirement. Nearline and Coldline assume more frequent access, so they cost more for this pattern.

CPU utilization metrics drive the Horizontal Pod Autoscaler's scaling decisions. By default, HPA reads the average CPU utilization across all pods in a target Deployment, comparing it against the target percentage you set relative to each pod's CPU request. This is the most common and default metric type, requiring pods to have explicit `resources.requests.cpu` values. Custom and external metrics can be used, but CPU utilization is the built-in, standard input for autoscaling.

Custom domain mapping on Cloud Run registers the domain and provisions a Google-managed TLS certificate so the domain points to the service's default URL. This is a mandatory step to expose the application at the customer's chosen domain. While it handles the domain mapping, it does not by itself provide multi-region low latency; that requires a global load balancer with multiple regional backends.

With OS Login enabled and roles/compute.osLogin granted, gcloud compute ssh authenticates using the Google account and manages SSH keys through OS Login, so no manual key setup is needed. This satisfies the scenario by connecting the developer to the instance in the specified zone.

The gcs backend block points Terraform at the Cloud Storage bucket holding remote state, and the prefix namespaces the state object within that bucket. Versioning is configured on the bucket itself, so the backend only needs bucket and prefix.

Cloud Run is a fully managed serverless container platform that automatically scales in response to incoming requests, including scaling to zero when idle, so you only pay for the exact compute time consumed. It doesn't require any cluster or infrastructure management, and it can be used with Knative Serving APIs, making it the most direct fit for a stateless containerized application that needs to scale to zero.

This command correctly deploys an HTTP-triggered Cloud Function: `gcloud functions deploy` creates or updates a function resource, `--runtime python39` selects the Python 3.9 execution environment, and `--trigger-http` configures an HTTPS endpoint that invokes the function on web requests. No other trigger type is needed. The command will return a URL for the deployed function.

The `--tier=db-custom-4-15360` flag defines a custom machine type with exactly 4 vCPUs and 15360 MB (15 GB) of RAM, satisfying the stem's sizing constraint. Combined with `--database-version=MYSQL_8_0`, `--region=us-east1` and `--root-password`, it fulfils every stated requirement in one command.

This is the correct command because n1-standard-4 is the general-purpose machine type that provides exactly 4 vCPUs and 15 GB of memory, satisfying the stated requirement. It also explicitly sets --image-family=debian-10 and --image-project=debian-cloud, which tells gcloud to use the latest active Debian 10 image from the official debian-cloud project. The command is complete and creates a reproducible Debian 10 VM with the desired vCPU count.

Correct. The 'gcs' backend requires a 'bucket' argument. This configuration will store the state file in the root of the bucket.

The `kubectl logs my-pod` command retrieves the logs of the primary container running inside the specified pod by reading the container's stdout/stderr streams. This is the direct, native Kubernetes approach for accessing application log output, and if the pod has multiple containers, you must append `-c <container>` to select a specific one. It does not require shell access or any extra tooling, making it the correct command for viewing logs.

Automated backups in Cloud SQL are mandatory for point-in-time recovery (PITR) and for creating read replicas. Without them, you cannot perform a restore to a specific timestamp, and you lose the baseline backup needed for replica creation. They also provide a daily recovery point that protects against data loss or corruption.

This is the correct configuration because it uses the required `terraform` block with a `backend "gcs"` block, and includes both the `bucket` name (where the state file is stored) and a `prefix` (the object path within the bucket). The backend type is exactly `"gcs"`, and this syntax registers Google Cloud Storage as the remote state backend, enabling shared state and locking across the team.

A LoadBalancer Service is the appropriate choice for a containerized web application that needs a stable external IP. When you create this Service on Google Kubernetes Engine, the cloud-controller-manager automatically provisions a Google Cloud (TCP/UDP) load balancer and assigns a regional static external IP address. This gives clients a stable, publicly reachable endpoint, which precisely matches the requirement for an internet-facing web application.

This correct command creates a zonal GKE cluster because --zone targets a single zone, us-central1-a, and the cluster's control plane and nodes are both provisioned there. The --num-nodes=3 flag defines the initial size of the default node pool, and --machine-type=e2-standard-4 sets each node's VM shape. This exactly meets the requirement for a 3-node zonal cluster.

The Database Migration Service requires a pre-provisioned Cloud SQL instance as the destination, so creating one first defines the target tier, storage, and network configuration before any migration job is started. Without an existing instance, DMS has nowhere to replicate the initial snapshot or stream incoming changes. This is the necessary first step in a low-downtime migration, even though the actual data movement happens later via a DMS job.

A Deployment is the core workload resource that declaratively manages a set of identical pods through a ReplicaSet. It defines the desired state—container image, replicas, and labels—and performs rolling updates and rollbacks, ensuring pods converge to that state. For a stateless microservice, a Deployment is mandatory to run the application reliably; scaling (manually or via HPA) and service selection all operate on the Deployment's pod labels. Without it, you would have no managed pod lifecycle, no self-healing, and no update strategy.

Running `kubectl expose deployment my-service --type=LoadBalancer` creates a Service of type LoadBalancer, which on GKE signals the cloud controller manager to provision a Google Cloud TCP/UDP load balancer. This load balancer receives a stable external IP address that persists for the lifetime of the Service, independent of node lifecycle. It is the standard way to expose a single deployment to the internet, as it also automatically forwards traffic to the backing pods.

This flag directly associates the Cloud Function with a Pub/Sub topic. When a message is published to that topic, Pub/Sub delivers it as an event to the function, which is how you configure a message-triggered function. Unlike other triggers, this is the standard and only appropriate flag for Pub/Sub message events in the gcloud beta functions deploy command. It ensures the function is invoked asynchronously with the message payload as the event data.

The metrics-server aggregates CPU and memory usage from kubelets via the Summary API and exposes them through the metrics.k8s.io API. The HorizontalPodAutoscaler (HPA) controller repeatedly queries that API to obtain current resource utilization; if no metrics-server is installed, the metrics API is unavailable and the HPA reports 'unable to retrieve metrics' and does not scale. It is the lightweight, cluster-local component that provides the raw numbers the HPA needs, whereas GCP's monitoring service is not directly consulted by the HPA.

The bucket must be named exactly www.example.com to serve content from that custom domain. When you create a bucket with this name, verify the domain in Cloud Console, and add a CNAME record from www.example.com to c.storage.googleapis.com, Cloud Storage automatically maps the bucket to the hostname. This exact match is required for HTTPS and proper static site hosting.

Setting the bucket's default encryption to point at the KMS key is the step that activates customer-managed encryption for Cloud Storage. All objects uploaded after this change are automatically encrypted with the selected Cloud KMS key instead of Google-owned keys. Without this configuration, the key ring and key remain unused and the bucket continues using default encryption.

The -m flag enables gsutil's multithreaded, parallel execution mode, so many objects upload concurrently instead of sequentially. This directly addresses the stem's slow bulk upload by saturating available bandwidth across multiple threads rather than processing one file at a time.

gcloud functions deploy with --trigger-topic creates an event-driven Cloud Function subscribed to a Pub/Sub topic. The --runtime python39 specifies the Python 3.9 execution environment, --entry-point my_entry identifies the function name inside main.py to invoke, and --region sets the deployment location. This is the only valid command that directly deploys the function and wires it to the specified Pub/Sub topic.

The REGIONAL availability type provisions a standby instance in a second zone within the same region, satisfying the high-availability constraint. The db-n1-standard-4 tier supplies exactly 4 vCPUs and 15 GB memory, matching the required sizing.

The --allow-unauthenticated flag is the correct option because it explicitly grants the role roles/run.invoker to allUsers, enabling public access to the Cloud Run service. This flag is a required parameter when deploying a service that must respond to HTTP requests without any authentication, such as a public API or webhook. It overrides the default behavior, which denies access to unauthenticated users.

This command correctly uses gcloud sql instances create with the supported database version MYSQL_8_0, the properly prefixed tier db-n1-standard-2, the target region us-central1, and the --root-password flag to set the initial root password. These are all valid and required parameters for provisioning a Cloud SQL for MySQL 8.0 instance from the command line.

The --allow-unauthenticated flag grants the allUsers IAM binding, satisfying the public internet access requirement, while --platform managed and --region target the fully managed Cloud Run service. The --image flag correctly references the Container Registry path.

Setting min-instances to a value greater than 0, such as 1, instructs Cloud Run to keep at least one instance always running and fully initialized, so baseline traffic never experiences the latency penalty of a cold start. This pre-warmed instance is ready to serve immediately, eliminating the delay caused by pulling a container image and booting the runtime. Note that this approach incurs billing even when there is no traffic, and it only removes cold starts for the first instance; a sudden burst beyond that instance's concurrency can still trigger new cold starts.

Horizontal Pod Autoscaler (HPA) continuously observes the average CPU utilization of the pods in a Deployment (via metrics-server) and automatically adjusts the `replicas` field to keep utilization near the configured target, e.g., 70%. This directly fulfills the stated need to scale the application based on load — when CPU usage rises, HPA adds pods; when it drops, HPA removes excess pods. Note that HPA is about pod-level elasticity and does not by itself provide zone resilience; to meet the production requirement fully, you would combine HPA with a regional multi-zone cluster so that scaled-out pods can be scheduled across failure domains.

The gcloud sql import sql command streams the SQL dump from the Cloud Storage bucket directly into the specified database on the instance, handling the 10GB file without local download. It satisfies the stem's requirement to import a SQL dump from Cloud Storage into Cloud SQL for PostgreSQL.

A BigQuery federated query with an external table definition lets you query data that remains in Cloud Storage without loading it into BigQuery's managed storage. You define an external table pointing at files in GCS (CSV, JSON, Avro, Parquet, etc.) with optional schema auto-detection, and the query engine reads the source natively at query time. This matches a one-time analysis by eliminating the load job, copying no data, and charging only for the bytes scanned during execution.

This command creates a regional GKE cluster in the us-central1 region, using --region rather than --zone. The --num-nodes=3 flag sets three e2-medium nodes in the cluster, and the regional scope means the control plane is replicated across the zones in us-central1, providing higher availability. This is the only option that correctly combines the required node specification with a regional location.

The HTTP(S) Load Balancer is a correct component because it provides a single anycast IP address that distributes incoming traffic across the backend Compute Engine instances in the managed instance group. It also performs health checks on those instances and automatically routes traffic only to healthy VMs, which is essential for a highly available application and is the standard external entry point for a MIG-based deployment.

Enabling OS Login at the project or instance level, then assigning IAM roles such as roles/compute.osLogin or roles/compute.osAdminLogin to users, is the recommended pattern for SSH access. OS Login links the Linux account on the instance to the user's Google identity, automatically provisions a temporary SSH key when the user runs gcloud compute ssh, and allows instant revocation simply by removing the IAM policy binding.

The --source flag makes Cloud Run build the image from the local directory using Buildpacks or the supplied Dockerfile, removing manual image construction. --platform managed and --region satisfy the fully managed regional deployment the stem requires.

The health check drives autohealing, replacing unhealthy instances automatically. maxSurge=1 with maxUnavailable=0 keeps capacity at or above target throughout the rolling update, so no instance is removed before a replacement is ready, satisfying the no-downtime constraint.

The --source flag tells gcloud to treat the current directory as source code, automatically invoking Cloud Build to containerize it using buildpacks before deploying to Cloud Run in the specified region. This single command combines the build and deploy steps, which is exactly what the requirement of a one-command deployment asks for. The service name 'my-service' is provided, and the region ensures the service is created in us-central1.

Cloud Logging is the correct choice because it is the native, centralized log storage and retrieval service for Google Cloud, and Cloud Run automatically sends both request logs and platform logs to it. Application output written to stdout/stderr is also captured as structured logs. You can view these logs immediately in the Logs Explorer and filter them by resource type, severity, or labels.

This is the standard way to create a regional GKE cluster. The --region flag designates a regional cluster where the control plane is replicated across three zones in that region, and nodes are spread across those zones (3 nodes per zone by default with --num-nodes 3). This provides higher availability and is exactly what the engineer needs.

This is the correct command. 'gcloud sql import sql' explicitly tells the Cloud SQL API that the source file is a SQL dump (typically generated by mysqldump or pg_dump). The arguments specify the instance name, the Cloud Storage URI of the dump file, and the target database using the --database flag. This syntax works for both MySQL and PostgreSQL instances and is the standard way to import SQL dump files.

Using the `--service-account` flag with `gcloud run deploy` explicitly assigns the specified IAM service account as the runtime identity for the Cloud Run service. This is the correct syntax because the flag is designed to set the service account that the container will run as, and `--platform managed` ensures the command targets Cloud Run (fully managed) rather than other platforms. The deployed service will inherit the IAM permissions of `my-sa@my-project.iam.gserviceaccount.com`, which is exactly what the DevOps engineer needs.

When you bind a Cloud Run service to a Cloud SQL instance by its connection name, the platform automatically injects and runs the Cloud SQL Auth Proxy as a sidecar container. The proxy connects to the database over an encrypted channel using either a private IP or a Unix socket, and it leverages IAM permissions to authorize the connection. This pattern avoids static IP management, network whitelisting, and manual secret handling, making it the officially recommended integration.

The `--allow-unauthenticated` flag is the correct way to enable public HTTPS access to a Cloud Run service. When set at deploy time, Cloud Run binds the IAM role `roles/run.invoker` to the special `allUsers` principal, allowing any client to invoke the service without providing credentials. This directly satisfies the requirement of making the containerized app reachable from the internet.

This is the correct command because --trigger-topic my-topic binds the function to Pub/Sub, causing it to be invoked every time a message is published to that topic. The --entry-point main identifies the Python callable in the code, while --runtime python39 specifies the runtime. It correctly deploys a background Cloud Function without exposing an HTTP endpoint.

The gcloud sql import sql command imports a SQL dump from a Cloud Storage URI into an existing instance, and --database=mydb directs the dump into the named database. This matches the stem's requirement to load a dump into Cloud SQL for PostgreSQL.