1주차 - Istio 소개, 첫걸음 (1)

 

 실습환경 구성(kind k8s & istio)

 

• kind설치(WSL2 - Ubuntu 24.04)

###### Docker 설치 ######
curl -fsSL https://get.docker.com -o get-docker.sh
sudo sh ./get-docker.sh
...

# 설치 확인
docker info
docker ps
sudo systemctl status docker
cat /etc/group | grep docker

###### kind 및 관리 툴 설치 ######

# 기본 사용자 디렉터리 이동
cd $PWD
pwd

#
sudo systemctl stop apparmor && sudo systemctl disable apparmor

# 
sudo apt update && sudo apt-get install bridge-utils net-tools jq tree unzip kubectx kubecolor -y

# Install Kind
curl -Lo ./kind https://kind.sigs.k8s.io/dl/v0.27.0/kind-linux-amd64
chmod +x ./kind
sudo mv ./kind /usr/local/bin/kind
kind --version

# Install kubectl
curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"
chmod +x kubectl
sudo mv ./kubectl /usr/bin
sudo kubectl version --client=true

# Install Helm
curl -s https://raw.githubusercontent.com/helm/helm/master/scripts/get-helm-3 | bash
helm version

# Source the completion
source <(kubectl completion bash)
echo 'source <(kubectl completion bash)' >> ~/.bashrc

# Alias kubectl to k
echo 'alias k=kubectl' >> ~/.bashrc
echo 'complete -o default -F __start_kubectl k' >> ~/.bashrc

# Install Kubeps & Setting PS1
git clone https://github.com/jonmosco/kube-ps1.git
echo -e "source $PWD/kube-ps1/kube-ps1.sh" >> ~/.bashrc
cat <<"EOT" >> ~/.bashrc
KUBE_PS1_SYMBOL_ENABLE=true
function get_cluster_short() {
  echo "$1" | cut -d . -f1
}
KUBE_PS1_CLUSTER_FUNCTION=get_cluster_short
KUBE_PS1_SUFFIX=') '
PS1='$(kube_ps1)'$PS1
EOT

# .bashrc 적용을 위해서 logout 후 터미널 다시 접속 하자
exit

• kind로 k8s(1.23.17)배포(WSL2 - Ubuntu 24.04)

#
git clone https://github.com/AcornPublishing/istio-in-action
cd istio-in-action/book-source-code-master
pwd # 각자 자신의 pwd 경로
code .

# 
kind create cluster --name myk8s --image kindest/node:v1.23.17 --config - <<EOF
kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
nodes:
- role: control-plane
  extraPortMappings:
  - containerPort: 30000 # Sample Application (istio-ingrssgateway)
    hostPort: 30000
  - containerPort: 30001 # Prometheus
    hostPort: 30001
  - containerPort: 30002 # Grafana
    hostPort: 30002
  - containerPort: 30003 # Kiali
    hostPort: 30003
  - containerPort: 30004 # Tracing
    hostPort: 30004
  - containerPort: 30005 # kube-ops-view
    hostPort: 30005
  extraMounts:
  - hostPath: /Users/gasida/Downloads/istio-in-action/book-source-code-master # 각자 자신의 pwd 경로로 설정
    containerPath: /istiobook
networking:
  podSubnet: 10.10.0.0/16
  serviceSubnet: 10.200.1.0/24
EOF

# 설치 확인
docker ps

# 노드에 기본 툴 설치
docker exec -it myk8s-control-plane sh -c 'apt update && apt install tree psmisc lsof wget bridge-utils net-tools dnsutils tcpdump ngrep iputils-ping git vim -y'

# (옵션) kube-ops-view
helm repo add geek-cookbook https://geek-cookbook.github.io/charts/
helm install kube-ops-view geek-cookbook/kube-ops-view --version 1.2.2 --set service.main.type=NodePort,service.main.ports.http.nodePort=30005 --set env.TZ="Asia/Seoul" --namespace kube-system
kubectl get deploy,pod,svc,ep -n kube-system -l app.kubernetes.io/instance=kube-ops-view

## kube-ops-view 접속 URL 확인
open "http://localhost:30005/#scale=1.5"
open "http://localhost:30005/#scale=1.3"

 

• istio 1.17.8 설치

# myk8s-control-plane 진입 후 설치 진행
docker exec -it myk8s-control-plane bash
-----------------------------------
# 코드 파일들 마운트 확인
tree /istiobook/ -L 1

# istioctl 설치
export ISTIOV=1.17.8
echo 'export ISTIOV=1.17.8' >> /root/.bashrc

curl -s -L https://istio.io/downloadIstio | ISTIO_VERSION=$ISTIOV sh -
cp istio-$ISTIOV/bin/istioctl /usr/local/bin/istioctl
istioctl version --remote=false

# default 프로파일 컨트롤 플레인 배포
istioctl x precheck # 설치 전 k8s 조건 충족 검사
istioctl profile list
istioctl install --set profile=default -y

# 보조 도구 설치
kubectl apply -f istio-$ISTIOV/samples/addons

#설치확인
kubectl get istiooperators -n istio-system
kubectl get istiooperators -n istio-system -o yaml
kubectl get all,svc,ep,sa,cm,secret,pdb -n istio-system
kubectl get crd | grep istio.io | sort
kubectl get pod -n istio-system

#빠져나오기
exit
------------------
kubectl get cm -n istio-system istio -o yaml
kubectl get cm -n istio-system istio -o yaml | kubectl neat

 

 서비스 메시에 첫 애플리케이션 배포

https://kimdoky.github.io/devops/2025/04/10/study-istio-week1/

 

• isto injection 설정
  • 애플리케이션 pod에 Envoy 사이드카 프록시 자동 주입 

#
kubectl create ns istioinaction

# 방법1 : yaml에 sidecar 설정을 추가
cat services/catalog/kubernetes/catalog.yaml
docker exec -it myk8s-control-plane istioctl kube-inject -f /istiobook/services/catalog/kubernetes/catalog.yaml


(추천방법)
# 방법2 : namespace에 레이블을 추가하면 istiod (오퍼레이터)가 해당 namepsace의 pod spec에 자동으로 sidecar 설정을 주입
kubectl label namespace istioinaction istio-injection=enabled
kubectl get ns --show-labels

# 
kubectl get mutatingwebhookconfiguration
NAME                         WEBHOOKS   AGE
istio-revision-tag-default   4          9m24s # 특정 revision의 사이드카 주입 설정 관리
istio-sidecar-injector       4          9m45s # Istio는 각 애플리케이션 Pod에 Envoy 사이드카 프록시를 자동으로 주입
                                              ## 네임스페이스나 Pod에 istio-injection=enabled 라벨이 있어야 작동 

kubectl get mutatingwebhookconfiguration istio-sidecar-injector -o yaml

#
kubectl get cm -n istio-system istio-sidecar-injector -o yaml | kubectl neat

 

 

#
cat services/catalog/kubernetes/catalog.yaml
kubectl apply -f services/catalog/kubernetes/catalog.yaml -n istioinaction

cat services/webapp/kubernetes/webapp.yaml 
kubectl apply -f services/webapp/kubernetes/webapp.yaml -n istioinaction

#
kubectl get pod -n istioinaction


# catalog 디플로이먼트에서 파드 관련 spec
kubectl get deploy -n istioinaction catalog -o jsonpath="{.spec.template.spec}" | jq

# catalog 파드 관련 spec : 위 디플로이먼트와 파드 spec 을 비교해보자
kubectl get pod -n istioinaction -l app=catalog -o jsonpath="{.items[0].spec}" | jq


# 접속 테스트용 netshoot 파드 생성
cat <<EOF | kubectl apply -f -
apiVersion: v1
kind: Pod
metadata:
  name: netshoot
spec:
  containers:
  - name: netshoot
    image: nicolaka/netshoot
    command: ["tail"]
    args: ["-f", "/dev/null"]
  terminationGracePeriodSeconds: 0
EOF

# catalog 접속 확인
kubectl exec -it netshoot -- curl -s http://catalog.istioinaction/items/1 | jq


# webapp 접속 확인 : webapp 서비스는 다른 서비스에서 데이터를 집계해 브라우저에 시각적으로 표시한다. 
## 즉 webapp은 다른 백엔드 서비스의 파사드 facade 역할을 한다.
kubectl exec -it netshoot -- curl -s http://webapp.istioinaction/api/catalog/items/1 | jq

# 아래 방법 대신 임시 사용
kubectl port-forward -n istioinaction deploy/webapp 8080:8080
확인 후 CTRL+C 로 종료

#
open http://localhost:8080

 

pod에 side car로 istio-proxy가 설치

 

 

 

• 외부 접근을 위한 ingress 설정
  • gateway, virtualservice

# istioctl proxy-status : 단축어 ps
docker exec -it myk8s-control-plane istioctl proxy-status
docker exec -it myk8s-control-plane istioctl ps

#
cat ch2/ingress-gateway.yaml
cat <<EOF | kubectl -n istioinaction apply -f -
apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
  name: outfitters-gateway
  namespace: istioinaction
spec:
  selector:
    istio: ingressgateway # use istio default controller
  servers:
  - port:
      number: 80
      name: http
      protocol: HTTP
    hosts:
    - "*"
---
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: webapp-virtualservice
  namespace: istioinaction
spec:
  hosts:
  - "*"
  gateways:
  - outfitters-gateway
  http:
  - route:
    - destination:
        host: webapp
        port:
          number: 80
EOF

#
kubectl get gw,vs -n istioinaction

# istioctl proxy-status : 단축어 ps
docker exec -it myk8s-control-plane istioctl proxy-status

ISTIOIGW=istio-ingressgateway-996bc6bb6-647tx.istio-system
WEBAPP=webapp-7685bcb84-nfntj.istioinaction

# istioctl proxy-config : 단축어 pc
docker exec -it myk8s-control-plane istioctl proxy-config all $ISTIOIGW
docker exec -it myk8s-control-plane istioctl proxy-config all $WEBAPP

docker exec -it myk8s-control-plane istioctl proxy-config listener $ISTIOIGW
docker exec -it myk8s-control-plane istioctl proxy-config route $ISTIOIGW
docker exec -it myk8s-control-plane istioctl proxy-config cluster $ISTIOIGW
docker exec -it myk8s-control-plane istioctl proxy-config endpoint $ISTIOIGW
docker exec -it myk8s-control-plane istioctl proxy-config log $ISTIOIGW

docker exec -it myk8s-control-plane istioctl proxy-config listener $WEBAPP
docker exec -it myk8s-control-plane istioctl proxy-config route $WEBAPP
docker exec -it myk8s-control-plane istioctl proxy-config cluster $WEBAPP
docker exec -it myk8s-control-plane istioctl proxy-config endpoint $WEBAPP
docker exec -it myk8s-control-plane istioctl proxy-config log $WEBAPP

# envoy 가 사용하고 있는 인증서 정보 확인
docker exec -it myk8s-control-plane istioctl proxy-config secret $ISTIOIGW
docker exec -it myk8s-control-plane istioctl proxy-config secret $WEBAPP


#
docker exec -it myk8s-control-plane istioctl proxy-config routes deploy/istio-ingressgateway.istio-system
NAME          DOMAINS     MATCH                  VIRTUAL SERVICE
http.8080     *           /*                     webapp-virtualservice.istioinaction
              *           /stats/prometheus*
              *           /healthz/ready*


# istio-ingressgateway 서비스 NodePort 변경 및 nodeport 30000로 지정 변경
kubectl get svc,ep -n istio-system istio-ingressgateway
kubectl patch svc -n istio-system istio-ingressgateway -p '{"spec": {"type": "NodePort", "ports": [{"port": 80, "targetPort": 8080, "nodePort": 30000}]}}'
kubectl get svc -n istio-system istio-ingressgateway

# istio-ingressgateway 서비스 externalTrafficPolicy 설정 : ClientIP 수집 확인
kubectl patch svc -n istio-system istio-ingressgateway -p '{"spec":{"externalTrafficPolicy": "Local"}}'
kubectl describe svc -n istio-system istio-ingressgateway

#
kubectl stern -l app=webapp -n istioinaction
kubectl stern -l app=catalog -n istioinaction

#
curl -s http://127.0.0.1:30000/api/catalog | jq
curl -s http://127.0.0.1:30000/api/catalog/items/1 | jq
curl -s http://127.0.0.1:30000/api/catalog -I | head -n 1

# webapp 반복 호출
while true; do curl -s http://127.0.0.1:30000/api/catalog/items/1 ; sleep 1; echo; done
while true; do curl -s http://127.0.0.1:30000/api/catalog -I | head -n 1 ; date "+%Y-%m-%d %H:%M:%S" ; sleep 1; echo; done
while true; do curl -s http://127.0.0.1:30000/api/catalog -I | head -n 1 ; date "+%Y-%m-%d %H:%M:%S" ; sleep 0.5; echo; done