#はじめに
Kubernetesのクラスタを作ったので、何かしらPodをデプロイしてみる。
単にnginxとかだけをデプロイするのも面白くないので、マイクロサービスのサンプルデモである「sock-shop」を構築する。
sock-shop

デプロイするKubernetesのクラスタはこれで構築した環境
kubeadmでのk8sクラスタの構築

#Gitリポジトリのクローン
手順に沿ってまずはリポジトリをクローンする。

$ sudo git clone https://github.com/microservices-demo/microservices-demo
sudo: git: コマンドが見つかりません

gitコマンドが入ってなかった・・・。

$ sudo yum install git
読み込んだプラグイン:fastestmirror, langpacks
Loading mirror speeds from cached hostfile
・・・
依存性関連をインストールしました:
  perl-Error.noarch 1:0.17020-2.el7                                        perl-Git.noarch 0:1.8.3.1-21.el7_7                                        perl-TermReadKey.x86_64 0:2.30-20.el7

完了しました!

改めてクローン

$ sudo git clone https://github.com/microservices-demo/microservices-demo
Cloning into 'microservices-demo'...
remote: Enumerating objects: 9638, done.
remote: Total 9638 (delta 0), reused 0 (delta 0), pack-reused 9638
Receiving objects: 100% (9638/9638), 52.85 MiB | 2.07 MiB/s, done.
Resolving deltas: 100% (5796/5796), done.

$ ls -l microservices-demo/
合計 36
-rw-r--r--.  1 root root 11357  3月  1 21:24 LICENSE
-rw-r--r--.  1 root root  1674  3月  1 21:24 README.md
drwxr-xr-x. 16 root root  4096  3月  1 21:24 deploy
drwxr-xr-x.  2 root root     6  3月  1 21:24 docs
drwxr-xr-x.  2 root root   185  3月  1 21:24 graphs
drwxr-xr-x.  2 root root    46  3月  1 21:24 healthcheck
drwxr-xr-x.  3 root root    44  3月  1 21:24 install
drwxr-xr-x.  2 root root    41  3月  1 21:24 internal-docs
drwxr-xr-x.  2 root root    82  3月  1 21:24 openapi
-rwxr-xr-x.  1 root root  1526  3月  1 21:24 push.sh
-rw-r--r--.  1 root root  1668  3月  1 21:24 shippable.jobs.yml
-rw-r--r--.  1 root root  2640  3月  1 21:24 shippable.resources.yml
-rw-r--r--.  1 root root   488  3月  1 21:24 shippable.triggers.yml
drwxr-xr-x.  2 root root   196  3月  1 21:24 staging

#sock-shopのデプロイ
##namespaceの作成
sock-shopはnamespaceとして「sock-shop」を使用するので、あらかじめ作成する。

$ kubectl create namespace sock-shop
namespace/sock-shop created
$ kubectl get namespace
NAME              STATUS   AGE
default           Active   4d15h
kube-node-lease   Active   4d15h
kube-public       Active   4d15h
kube-system       Active   4d15h
sock-shop         Active   7s

##デプロイ

$ cd microservices-demo/deploy/kubernetes/
$ kubectl apply -f complete-demo.yaml
service/carts-db created
service/carts created
service/catalogue-db created
service/catalogue created
service/front-end created
service/orders-db created
service/orders created
service/payment created
service/queue-master created
service/rabbitmq created
service/shipping created
service/user-db created
service/user created
unable to recognize "complete-demo.yaml": no matches for kind "Deployment" in version "extensions/v1beta1"
unable to recognize "complete-demo.yaml": no matches for kind "Deployment" in version "extensions/v1beta1"
unable to recognize "complete-demo.yaml": no matches for kind "Deployment" in version "extensions/v1beta1"
unable to recognize "complete-demo.yaml": no matches for kind "Deployment" in version "extensions/v1beta1"
unable to recognize "complete-demo.yaml": no matches for kind "Deployment" in version "extensions/v1beta1"
unable to recognize "complete-demo.yaml": no matches for kind "Deployment" in version "extensions/v1beta1"
unable to recognize "complete-demo.yaml": no matches for kind "Deployment" in version "extensions/v1beta1"
unable to recognize "complete-demo.yaml": no matches for kind "Deployment" in version "extensions/v1beta1"
unable to recognize "complete-demo.yaml": no matches for kind "Deployment" in version "extensions/v1beta1"
unable to recognize "complete-demo.yaml": no matches for kind "Deployment" in version "extensions/v1beta1"
unable to recognize "complete-demo.yaml": no matches for kind "Deployment" in version "extensions/v1beta1"
unable to recognize "complete-demo.yaml": no matches for kind "Deployment" in version "extensions/v1beta1"
unable to recognize "complete-demo.yaml": no matches for kind "Deployment" in version "extensions/v1beta1"

サービスはデプロイできたけど、deploymentは失敗。どうもAPIのバージョンがダメらしい。
とりあえず、削除しておく。

$ kubectl delete -f complete-demo.yaml
service "carts-db" deleted
service "carts" deleted
service "catalogue-db" deleted
service "catalogue" deleted
service "front-end" deleted
service "orders-db" deleted
service "orders" deleted
service "payment" deleted
service "queue-master" deleted
service "rabbitmq" deleted
service "shipping" deleted
service "user-db" deleted
service "user" deleted
unable to recognize "complete-demo.yaml": no matches for kind "Deployment" in version "extensions/v1beta1"
unable to recognize "complete-demo.yaml": no matches for kind "Deployment" in version "extensions/v1beta1"
unable to recognize "complete-demo.yaml": no matches for kind "Deployment" in version "extensions/v1beta1"
unable to recognize "complete-demo.yaml": no matches for kind "Deployment" in version "extensions/v1beta1"
unable to recognize "complete-demo.yaml": no matches for kind "Deployment" in version "extensions/v1beta1"
unable to recognize "complete-demo.yaml": no matches for kind "Deployment" in version "extensions/v1beta1"
unable to recognize "complete-demo.yaml": no matches for kind "Deployment" in version "extensions/v1beta1"
unable to recognize "complete-demo.yaml": no matches for kind "Deployment" in version "extensions/v1beta1"
unable to recognize "complete-demo.yaml": no matches for kind "Deployment" in version "extensions/v1beta1"
unable to recognize "complete-demo.yaml": no matches for kind "Deployment" in version "extensions/v1beta1"
unable to recognize "complete-demo.yaml": no matches for kind "Deployment" in version "extensions/v1beta1"
unable to recognize "complete-demo.yaml": no matches for kind "Deployment" in version "extensions/v1beta1"
unable to recognize "complete-demo.yaml": no matches for kind "Deployment" in version "extensions/v1beta1"

##yamlファイルの修正
kubernetesのバージョンとdeploymentがサポートしているAPIバージョンを確認する。

$ kubectl version --short
Client Version: v1.17.3
Server Version: v1.17.3
$ kubectl explain deployment
KIND:     Deployment
VERSION:  apps/v1
・・・

yamlファイルのAPIバージョンを確認する。

$ head complete-demo.yaml
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: carts-db
  labels:
    name: carts-db
  namespace: sock-shop
spec:
  replicas: 1
  template:

APIのバージョンがkubernetes V1.17ではサポートしていないので、書き換える必要がある。
yamlファイルの変更箇所は以下の2点

変更箇所	before	after
apiVersion	extensions/v1beta1	apps/v1
spec	- (追記)	selecter -> matchLabels

complete-demo.yamlファイルだと一つのファイルにすべて書かれてて、編集がむずかしかったので、manifestsディレクトリのバラバラのyamlファイルを編集することにする。
このシェルスクリプトで一括編集する。

convert.sh

#!/bin/bash

ls *dep* > filelist

echo "Target Files"
echo "---------"
cat filelist

mkdir org

while read FILE
do
        NAME=`grep name: $FILE | head -1 |awk -F':' '{print $2}'`
        mv $FILE org/$FILE.org
        sed -e 's/extensions\/v1beta1/apps\/v1/g' ./org/$FILE.org > ./$FILE-hogehogehoge
        sed -e '/template/i \ \ selector:' ./$FILE-hogehogehoge > ./$FILE-hogehoge
        sed -e '/template/i \ \ \ \ matchLabels:' ./$FILE-hogehoge > ./$FILE-hoge
        sed -e "/template/i \ \ \ \ \ \ name:$NAME" ./$FILE-hoge > ./$FILE
done < filelist

rm filelist
rm *hoge

もっとうまい書き方ありそうな気もするけど・・・
変換後のファイルとオリジナルをdiffで確認しておく。

$ diff carts-db-dep.yaml org/carts-db-dep.yaml.org
2c2
< apiVersion: apps/v1
---
> apiVersion: extensions/v1beta1
11,13d10
<   selector:
<     matchLabels:
<       name: carts-db

構築しているKubernetesのクラスタはPC上にVMを切って作ってるので、ロードバランサはない。
sock-shopのfront-end-svcはロードバランサになっているので、NodePortに変更しておく。

front-end-svc.yaml

---
apiVersion: v1
kind: Service
metadata:
  name: front-end
  labels:
    name: front-end
  namespace: sock-shop
spec:
 # type: LoadBalancer
  type: NodePort
  ports:
  - port: 80
    targetPort: 8079
    nodePort: 30001
  selector:
    name: front-end

##デプロイ（2回目）

$ kubectl apply -f manifests/
deployment.apps/carts-db created
service/carts-db created
deployment.apps/carts created
service/carts created
deployment.apps/catalogue-db created
service/catalogue-db created
deployment.apps/catalogue created
service/catalogue created
deployment.apps/front-end created
service/front-end created
namespace/loadtest created
deployment.apps/orders-db created
service/orders-db created
deployment.apps/orders created
service/orders created
deployment.apps/payment created
service/payment created
deployment.apps/queue-master created
service/queue-master created
deployment.apps/rabbitmq created
service/rabbitmq created
deployment.apps/session-db created
service/session-db created
deployment.apps/shipping created
service/shipping created
Warning: kubectl apply should be used on resource created by either kubectl create --save-config or kubectl apply
namespace/sock-shop configured
deployment.apps/user-db created
service/user-db created
deployment.apps/user created
service/user created

一つWarrningが出ているが、最初のデプロイしたときの何かが残ってたのかな？あとで調べよう。

デプロイされたPodとServiceを確認する。

$ kubectl get pods -n sock-shop
NAME                            READY   STATUS    RESTARTS   AGE
carts-5fc45568c4-r4fqk          1/1     Running   0          9m33s
carts-db-64ff6c747f-vlghp       1/1     Running   0          9m33s
catalogue-69b7ff5bb4-pm988      0/1     Running   0          9m32s
catalogue-db-69cf48ff8-5sztl    1/1     Running   0          9m33s
front-end-6fc8dff6ff-4lxmn      1/1     Running   0          9m32s
orders-74c6b45f4f-42rns         1/1     Running   0          9m32s
orders-db-df75f545f-vvth6       1/1     Running   0          9m32s
payment-7f95f9f77-n5v7p         0/1     Running   0          9m32s
queue-master-85f5644bf5-pgdkt   0/1     Running   0          9m32s
rabbitmq-c7b9db6cc-bb5hn        2/2     Running   0          9m32s
session-db-67fd8d6d7-f2s96      1/1     Running   0          9m32s
shipping-745b9d8755-nvqng       0/1     Running   0          9m31s
user-559d7f794f-65sxs           1/1     Running   0          9m31s
user-db-87f548457-ldqvh         1/1     Running   0          9m31s
$ kubectl get svc -n sock-shop
NAME           TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)             AGE
carts          ClusterIP   10.110.120.109   <none>        80/TCP              10m
carts-db       ClusterIP   10.109.174.164   <none>        27017/TCP           10m
catalogue      ClusterIP   10.108.116.129   <none>        80/TCP              10m
catalogue-db   ClusterIP   10.110.226.123   <none>        3306/TCP            10m
front-end      NodePort    10.107.92.139    <none>        80:30001/TCP        10m
orders         ClusterIP   10.107.232.34    <none>        80/TCP              10m
orders-db      ClusterIP   10.103.162.21    <none>        27017/TCP           10m
payment        ClusterIP   10.108.6.76      <none>        80/TCP              10m
queue-master   ClusterIP   10.97.129.100    <none>        80/TCP              10m
rabbitmq       ClusterIP   10.104.194.103   <none>        5672/TCP,9090/TCP   10m
session-db     ClusterIP   10.108.6.216     <none>        6379/TCP            10m
shipping       ClusterIP   10.105.98.147    <none>        80/TCP              10m
user           ClusterIP   10.100.7.156     <none>        80/TCP              10m
user-db        ClusterIP   10.108.238.79    <none>        27017/TCP           10m

#動作確認
gatewayのブラウザから画面を確認する。
　IPアドレス：workerノードのIPアドレス
　ポート：front-end Serviceのポート

なお、IPアドレスはどちらのworkerノードのIPアドレスでも表示された。Serviceの作りとか後で確認しよう。

#まとめ
手順に沿ってデプロイしただけだけど、マイクロサービスのデモが簡単にできた。
今はとりあえず作っただけなので、マイクロサービスとは何かみたいなことはよくわからないけど、この環境を使って色々と調べていこう。