시니어 GCP 클라우드 엔지니어 면접 질문과 답변

# 자동 확장을 사용하는 관리형 인스턴스 그룹 생성
gcloud compute instance-groups managed create my-mig \
  --base-instance-name=my-app \
  --template=my-template \
  --size=3 \
  --zone=us-central1-a

# 자동 확장 구성
gcloud compute instance-groups managed set-autoscaling my-mig \
  --max-num-replicas=10 \
  --min-num-replicas=3 \
  --target-cpu-utilization=0.7 \
  --cool-down-period=90

# 로드 밸런서 생성
gcloud compute backend-services create my-backend \
  --protocol=HTTP \
  --health-checks=my-health-check \
  --global

# 백엔드에 인스턴스 그룹 추가
gcloud compute backend-services add-backend my-backend \
  --instance-group=my-mig \
  --instance-group-zone=us-central1-a \
  --global

# GKE 클러스터 생성
gcloud container clusters create my-cluster \
  --num-nodes=3 \
  --machine-type=e2-medium \
  --zone=us-central1-a \
  --enable-autoscaling \
  --min-nodes=3 \
  --max-nodes=10

# 자격 증명 가져오기
gcloud container clusters get-credentials my-cluster \
  --zone=us-central1-a

# 애플리케이션 배포
kubectl apply -f - <<EOF
apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp
spec:
  replicas: 3
  selector:
    matchLabels:
      app: myapp
  template:
    metadata:
      labels:
        app: myapp
    spec:
      containers:
      - name: myapp
        image: gcr.io/my-project/myapp:v1
        ports:
        - containerPort: 8080
        resources:
          requests:
            cpu: 100m
            memory: 128Mi
          limits:
            cpu: 500m
            memory: 512Mi
---
apiVersion: v1
kind: Service
metadata:
  name: myapp-service
spec:
  type: LoadBalancer
  selector:
    app: myapp
  ports:
  - port: 80
    targetPort: 8080
EOF

# Cloud Function 예제
def hello_pubsub(event, context):
    """Pub/Sub 메시지에 의해 트리거됨"""
    import base64
    
    if 'data' in event:
        message = base64.b64decode(event['data']).decode('utf-8')
        print(f'Received message: {message}')
        
        # 메시지 처리
        process_data(message)

# Cloud Function 배포
gcloud functions deploy hello_pubsub \
  --runtime=python312 \
  --trigger-topic=my-topic \
  --entry-point=hello_pubsub

# Cloud Run 배포
gcloud run deploy myapp \
  --image=gcr.io/my-project/myapp:v1 \
  --region=us-central1 \
  --allow-unauthenticated

# 호스트 프로젝트에서 Shared VPC 활성화
gcloud compute shared-vpc enable my-host-project

# 서비스 프로젝트 연결
gcloud compute shared-vpc associated-projects add my-service-project \
  --host-project=my-host-project

# 권한 부여
gcloud projects add-iam-policy-binding my-host-project \
  --member=serviceAccount:[email protected] \
  --role=roles/compute.networkUser

# Recommender API 사용
gcloud recommender recommendations list \
  --project=my-project \
  --location=us-central1 \
  --recommender=google.compute.instance.MachineTypeRecommender

# 중단 가능한 작업용 Spot VM 생성
gcloud compute instances create my-spot-vm \
  --provisioning-model=SPOT \
  --machine-type=e2-medium

# 수명 주기 정책 설정
gsutil lifecycle set lifecycle.json gs://my-bucket

# lifecycle.json
{
  "lifecycle": {
    "rule": [
      {
        "action": {"type": "SetStorageClass", "storageClass": "NEARLINE"},
        "condition": {"age": 30}
      },
      {
        "action": {"type": "Delete"},
        "condition": {"age": 365}
      }
    ]
  }
}

# 최소 권한으로 서비스 계정 사용
gcloud iam service-accounts create my-app-sa \
  --display-name="My App Service Account"

# 특정 역할 부여
gcloud projects add-iam-policy-binding my-project \
  --member=serviceAccount:[email protected] \
  --role=roles/storage.objectViewer \
  --condition='expression=resource.name.startsWith("projects/_/buckets/my-bucket"),title=bucket-access'

# 고객 관리 암호화 키
gcloud kms keyrings create my-keyring \
  --location=global

gcloud kms keys create my-key \
  --location=global \
  --keyring=my-keyring \
  --purpose=encryption

# Cloud Storage와 함께 사용
gsutil -o 'GSUtil:encryption_key=...' cp file.txt gs://my-bucket/

-- 파티션된 테이블 생성
CREATE TABLE mydataset.events
(
  event_id STRING,
  user_id STRING,
  event_type STRING,
  event_data JSON,
  event_timestamp TIMESTAMP
)
PARTITION BY DATE(event_timestamp)
CLUSTER BY user_id, event_type
OPTIONS(
  partition_expiration_days=90,
  require_partition_filter=true
);

-- 구체화된 뷰 생성
CREATE MATERIALIZED VIEW mydataset.daily_summary
AS
SELECT
  DATE(event_timestamp) as event_date,
  event_type,
  COUNT(*) as event_count,
  COUNT(DISTINCT user_id) as unique_users
FROM mydataset.events
GROUP BY event_date, event_type;

-- 시간 기반 파티셔닝
CREATE TABLE mydataset.sales
PARTITION BY DATE(sale_date)
AS SELECT * FROM source_table;

-- 정수 범위 파티셔닝
CREATE TABLE mydataset.user_data
PARTITION BY RANGE_BUCKET(user_id, GENERATE_ARRAY(0, 1000000, 10000))
AS SELECT * FROM source_table;

-- 파티션 필터로 쿼리 (비용 효율적)
SELECT *
FROM mydataset.events
WHERE DATE(event_timestamp) BETWEEN '2024-01-01' AND '2024-01-31'
  AND event_type = 'purchase';

-- 자주 필터링되는 열을 기준으로 클러스터링
CREATE TABLE mydataset.logs
PARTITION BY DATE(log_timestamp)
CLUSTER BY user_id, region, status
AS SELECT * FROM source_logs;

-- 클러스터링의 이점을 얻는 쿼리
SELECT *
FROM mydataset.logs
WHERE DATE(log_timestamp) = '2024-11-26'
  AND user_id = '12345'
  AND region = 'us-east1';

-- 나쁨: SELECT * (모든 열 스캔)
SELECT * FROM mydataset.large_table;

-- 좋음: 특정 열 선택
SELECT user_id, event_type, event_timestamp
FROM mydataset.large_table;

-- 대규모 데이터 세트에 대한 대략적인 집계 사용
SELECT APPROX_COUNT_DISTINCT(user_id) as unique_users
FROM mydataset.events;

-- 자체 조인 방지, 윈도우 함수 사용
SELECT
  user_id,
  event_timestamp,
  LAG(event_timestamp) OVER (PARTITION BY user_id ORDER BY event_timestamp) as prev_event
FROM mydataset.events;

# 최대 바이트 청구 설정
bq query \
  --maximum_bytes_billed=1000000000 \
  --use_legacy_sql=false \
  'SELECT COUNT(*) FROM mydataset.large_table'

# 비용 추정을 위한 드라이 런
bq query \
  --dry_run \
  --use_legacy_sql=false \
  'SELECT * FROM mydataset.large_table'

# Cloud Storage에서 로드
bq load \
  --source_format=NEWLINE_DELIMITED_JSON \
  --autodetect \
  mydataset.mytable \
  gs://mybucket/data/*.json

# 스키마와 함께 로드
bq load \
  --source_format=CSV \
  --skip_leading_rows=1 \
  mydataset.mytable \
  gs://mybucket/data.csv \
  schema.json

# 스트리밍 삽입 (실시간)
from google.cloud import bigquery

client = bigquery.Client()
table_id = "my-project.mydataset.mytable"

rows_to_insert = [
    {"user_id": "123", "event_type": "click", "timestamp": "2024-11-26T10:00:00"},
    {"user_id": "456", "event_type": "purchase", "timestamp": "2024-11-26T10:05:00"},
]

errors = client.insert_rows_json(table_id, rows_to_insert)
if errors:
    print(f"Errors: {errors}")

-- Spanner 인스턴스 생성
gcloud spanner instances create my-instance \
  --config=regional-us-central1 \
  --nodes=3 \
  --description="Production instance"

-- 데이터베이스 생성
gcloud spanner databases create my-database \
  --instance=my-instance \
  --ddl='CREATE TABLE Users (
    UserId INT64 NOT NULL,
    Username STRING(100),
    Email STRING(255),
    CreatedAt TIMESTAMP
  ) PRIMARY KEY (UserId)'

-- 데이터 삽입
gcloud spanner databases execute-sql my-database \
  --instance=my-instance \
  --sql="INSERT INTO Users (UserId, Username, Email, CreatedAt)
        VALUES (1, 'alice', '[email protected]', CURRENT_TIMESTAMP())"

-- 강력한 일관성으로 쿼리
gcloud spanner databases execute-sql my-database \
  --instance=my-instance \
  --sql="SELECT * FROM Users WHERE UserId = 1"

from google.cloud import spanner

# 클라이언트 생성
spanner_client = spanner.Client()
instance = spanner_client.instance('my-instance')
database = instance.database('my-database')

# 강력한 일관성으로 읽기
def read_user(user_id):
    with database.snapshot() as snapshot:
        results = snapshot.execute_sql(
            "SELECT UserId, Username, Email FROM Users WHERE UserId = @user_id",
            params={"user_id": user_id},
            param_types={"user_id": spanner.param_types.INT64}
        )
        for row in results:
            print(f"User: {row[0]}, {row[1]}, {row[2]}")

# 트랜잭션으로 쓰기
def create_user(user_id, username, email):
    def insert_user(transaction):
        transaction.execute_update(
            "INSERT INTO Users (UserId, Username, Email, CreatedAt) "
            "VALUES (@user_id, @username, @email, CURRENT_TIMESTAMP())",
            params={
                "user_id": user_id,
                "username": username,
                "email": email
            },
            param_types={
                "user_id": spanner.param_types.INT64,
                "username": spanner.param_types.STRING,
                "email": spanner.param_types.STRING
            }
        )
    
    database.run_in_transaction(insert_user)

# Cloud SQL 인스턴스 생성
gcloud sql instances create my-instance \
  --database-version=POSTGRES_14 \
  --tier=db-n1-standard-2 \
  --region=us-central1 \
  --root-password=mypassword

# 데이터베이스 생성
gcloud sql databases create mydatabase \
  --instance=my-instance

# 연결
gcloud sql connect my-instance --user=postgres

# 읽기 복제본 생성
gcloud sql instances create my-replica \
  --master-instance-name=my-instance \
  --tier=db-n1-standard-1 \
  --region=us-east1

# 액세스 정책 생성
gcloud access-context-manager policies create \
  --organization=123456789 \
  --title="Production Policy"

# 액세스 수준 생성
gcloud access-context-manager levels create CorpNetwork \
  --policy=accessPolicies/123456789 \
  --title="Corporate Network" \
  --basic-level-spec=access_level.yaml

# access_level.yaml
conditions:
  - ipSubnetworks:
    - 203.0.113.0/24  # 회사 IP 범위
  - members:
    - user:[email protected]

# 경계 생성
gcloud access-context-manager perimeters create production_perimeter \
  --policy=accessPolicies/123456789 \
  --title="Production Perimeter" \
  --resources=projects/123456789012 \
  --restricted-services=storage.googleapis.com,bigquery.googleapis.com \
  --access-levels=accessPolicies/123456789/accessLevels/CorpNetwork

# 경계에 프로젝트 추가
gcloud access-context-manager perimeters update production_perimeter \
  --policy=accessPolicies/123456789 \
  --add-resources=projects/987654321098

# ingress_rule.yaml
ingressPolicies:
  - ingressFrom:
      sources:
        - accessLevel: accessPolicies/123456789/accessLevels/CorpNetwork
      identities:
        - serviceAccount:[email protected]
    ingressTo:
      resources:
        - '*'
      operations:
        - serviceName: storage.googleapis.com
          methodSelectors:
            - method: '*'

# 수신 규칙 적용
gcloud access-context-manager perimeters update production_perimeter \
  --policy=accessPolicies/123456789 \
  --set-ingress-policies=ingress_rule.yaml

# egress_rule.yaml
egressPolicies:
  - egressFrom:
      identities:
        - serviceAccount:[email protected]
    egressTo:
      resources:
        - projects/external-project-id
      operations:
        - serviceName: storage.googleapis.com
          methodSelectors:
            - method: 'google.storage.objects.create'

# 송신 규칙 적용
gcloud access-context-manager perimeters update production_perimeter \
  --policy=accessPolicies/123456789 \
  --set-egress-policies=egress_rule.yaml

# 경계 내에서 액세스 테스트
from google.cloud import storage

def test_access():
    try:
        client = storage.Client()
        bucket = client.bucket('my-protected-bucket')
        blobs = list(bucket.list_blobs())
        print(f"Access granted: {len(blobs)} objects")
    except Exception as e:
        print(f"Access denied: {e}")

# 권한이 있는 네트워크에서 성공
# 권한이 없는 네트워크에서 실패
test_access()

# VPC SC 로그 보기
gcloud logging read \
  'protoPayload.metadata.@type="type.googleapis.com/google.cloud.audit.VpcServiceControlAuditMetadata"' \
  --limit=50 \
  --format=json