Unit 3: Deploying Microservices - Practice Quiz

1 What is the main purpose of containerization?

2 What is Docker primarily used for?

3 What is a running instance of a Docker image called?

4 Which Docker command builds an image from a Dockerfile in the current directory?

5 Which Dockerfile instruction specifies the base image?

6 Which Dockerfile instruction copies files from the build context into an image?

7 What is a Docker image?

8 What is container orchestration?

9 Which task is commonly handled by a container orchestration platform?

10 Why is container orchestration useful for microservices?

11 What is Kubernetes?

12 What is the smallest deployable unit in Kubernetes?

13 Which part of Kubernetes manages the overall state of a cluster?

14 What is the role of a Kubernetes worker node?

15 Which Kubernetes component communicates with the control plane and manages pods on a worker node?

16 Which Kubernetes resource is commonly used to manage replicated instances of a microservice?

17 Which Kubernetes resource provides a stable network endpoint for a set of pods?

18 What does increasing the replica count of a microservice do?

19 What is Continuous Integration?

20 What commonly happens after code is committed in a CI process?

21 A microservice writes uploaded files inside its container. The files disappear whenever the container is replaced. Which Docker feature should be used to preserve the files?

22 A web service works inside a Docker container but cannot be reached through its published host port. The service is listening only on 127.0.0.1 inside the container. What is the most appropriate correction?

23 A Dockerfile copies the entire source tree before running npm install. Small source-code changes therefore cause dependencies to be reinstalled. Which change best improves build caching?

24 A compiled microservice image contains compilers, source code, and temporary build files, making it unnecessarily large. Which Dockerfile technique best addresses this issue?

25 A security review finds that a microservice runs as root inside its container even though it requires no privileged operations. Which Dockerfile instruction should be used to change its runtime identity?

26 An orchestrator is configured to maintain five instances of a payment service. One host fails and two instances stop. What should the orchestrator do under a desired-state model?

27 During a rolling update, new containers start quickly but need 20 seconds before they can serve requests. Which mechanism should prevent traffic from reaching them too early?

28 Several replicas of a microservice are created and removed dynamically. Client services should not track the IP address of each replica. Which orchestration capability solves this problem?

29 A newly created Pod remains pending because Kubernetes has not yet selected a worker node for it. Which control-plane component is primarily responsible for this selection?

30 The Kubernetes control plane needs a consistent key-value store for cluster configuration and desired-state data. Which component provides this storage?

31 A container in a Pod terminates unexpectedly. Which node-level Kubernetes component observes the Pod specification and works with the container runtime to restart it?

32 A team directly creates a single Kubernetes Pod for a microservice. After the Pod is deleted, no replacement appears. Which resource should the team normally create instead?

33 A Kubernetes Deployment runs three replicas whose Pod IP addresses change over time. Which resource should expose them through a stable internal address?

34 A microservice requires database credentials at runtime. The team wants to avoid embedding them in the container image. Which Kubernetes resource is most appropriate?

35 A Kubernetes cluster has sufficient total CPU, but a Pod remains pending because its declared CPU requirement cannot fit on any single node. Which setting is the scheduler primarily evaluating?

36 A team wants to release a new microservice version to a small percentage of users before wider deployment. Which deployment strategy best supports this goal?

37 Developers merge code only once every few weeks, producing large and difficult integration conflicts. Which CI practice most directly reduces this problem?

38 A CI pipeline takes 45 minutes, but simple formatting errors are discovered only in its final stage. How should the pipeline be improved to fail faster?

39 The same Git commit sometimes produces different container images because dependency versions are resolved differently on each build. Which action best improves reproducibility?

40 A microservice image passes all CI tests in staging. For production, the team rebuilds the source and produces a slightly different image. Which practice better preserves release consistency?

41 A Docker container runs an HTTP server using CMD /app/server. During docker stop, the server often fails to perform its SIGTERM shutdown logic and is eventually killed. Which change most directly addresses the signal-delivery problem?

42 A container writes uploaded files to /data without mounting a volume. After the container is deleted and recreated from the same image, the files disappear. Which explanation is correct?

43 A Node.js Dockerfile copies the entire source tree before running npm ci. Every source-code change therefore causes dependencies to be reinstalled. Which instruction order best improves cache reuse while preserving dependency correctness?

44 A private package registry requires a token during image construction. The final image and its layer history must not contain the token. Which approach is most appropriate?

45 A Go service is compiled in one stage and its binary is copied into a scratch final stage. The container starts but fails when making HTTPS requests because certificate authorities are unavailable. What is the smallest targeted correction?

46 A team must publish one image tag that runs natively on both linux/amd64 and linux/arm64 clusters. What should the registry tag reference?

47 A service has six replicas. Replicas must be distributed as evenly as possible across zones, and no two replicas may run on the same node. Which scheduling policy combination best expresses both requirements?

48 During rolling updates, some requests fail because terminating instances exit while still receiving in-flight traffic. Which design best supports graceful termination?

49 Which sequence most accurately describes how a newly submitted Pod normally becomes a running workload in Kubernetes?

50 In a cluster where all etcd members become unavailable but worker nodes and their networking remain healthy, which immediate behavior is most likely?

51 A Pod is Running, but its readiness probe is failing. Assuming default Service behavior and no special endpoint publication settings, how is the Pod treated?

52 A Deployment has 10 desired replicas, maxSurge: 25%, and maxUnavailable: 25%. Ignoring terminating Pods and probe delays, which limits apply during a rolling update?

53 A legacy service legitimately needs four minutes to initialize, but after startup it should be restarted if it deadlocks. Which Kubernetes probe arrangement best prevents premature restarts without hiding later failures?

54 An HPA targets 50% average CPU utilization. Four ready Pods each have valid CPU requests, and the measured average utilization is 80%. Ignoring stabilization, tolerance, and scaling limits, what replica count does the basic HPA formula select?

55 A Deployment consumes application configuration through environment variables sourced from a ConfigMap. The ConfigMap is updated, but existing Pods retain the old values. Which deployment technique reliably applies the change?

56 A team runs stable and canary Deployments simultaneously and wants exactly 5% of requests sent to the canary. Why is adding both versions behind a standard Kubernetes Service insufficient for precise weighting?

57 Service A is deployed before Service B, and both versions temporarily coexist during rolling updates. A database column must be renamed without downtime. Which migration strategy is safest?

58 Two pull requests independently pass CI against the current main branch, but their combination fails after both are merged. Which CI practice most directly prevents this integration race?

59 A CI pipeline produces different container contents from the same Git commit on different days because base images and packages move. Which policy most improves reproducibility?

60 A provider microservice changes a response field from an integer to a string. The provider's unit tests pass, but several independently deployed consumers depend on the integer type. Which CI technique most directly detects this breaking interaction without running every consumer end-to-end?