Jenkins Kubernetes Pluginのyaml中に環境変数を使用する(結局妥協)

#やりたいこと
JenkinsからKubernetesでPodを起動して処理を行うが、その際のvolumeのマウント先をパラメータビルドで動的に変更したい

#結論
yamlの中にenv.XXXなどで指定しておいてもうまくいかない
指定する前に文字列として置換してからしてしないとうまくいかない

#Jenkinsのパラメータ化設定
![image.png](https://qiita-image-store.s3.ap-northeast-1.amazonaws.com/0/46533/e8aa5caf-063d-eb5c-4343-90833a036c1b.png)

#できない例1(${env.DATADIR})
コンテナの起動まで試行するがyamlの解析でエラー
jnlpのConnectまでは成功するが、
実際の処理を行うPod(下記ではscrapy)がCreateContainerErrorを繰り返し進まない

```yaml
def labelname = "scrapy-down"

pipeline {
  agent {
    kubernetes {
      label labelname
      yaml '''
apiVersion: v1
kind: Pod
metadata:
  labels:
    scrapy: scrapy
spec:
  volumes:
  - name: data
    hostPath:
      path: ${env.DATADIR}
  containers:
  - name: scrapy
    image: toru2220/scrapy-chrome
    volumeMounts:
    - name: data
      mountPath: /data
    command:
    - cat
    tty: true
    resources:
      requests:
        memory: "256Mi"
        cpu: "128m"
      limits:
        memory: "512Mi"
        cpu: "512m"    
'''
    }
  } 
  stages {
      stage('scrapy-down') {
          parallel {
              stage('down') {
                  steps {
                      container('scrapy'){ 
                         sh """
                            ls -l /data
                         """
                      }                    
                  }
              }
          }
      }
  }  
}    

```

##Podの起動結果
```bash
# kubectl get pods
NAME                       READY   STATUS                 RESTARTS   AGE
scrapy-down-qh663-7r6zz    1/2     CreateContainerError   0          31s
```

#できない例2(env.DATADIR)
コンテナの起動、処理の完了まで成功するが、volumeのマウントに失敗している

##マウントしたいホスト側ボリューム
```
/mnt/testdir# ls -l
合計 0
-rw-r--r-- 1 root root 0  1月 27 21:57 testfile
```

```yaml
def labelname = "scrapy-down"

pipeline {
  agent {
    kubernetes {
      label labelname
      yaml '''
apiVersion: v1
kind: Pod
metadata:
  labels:
    scrapy: scrapy
spec:
  volumes:
  - name: data
    hostPath:
      path: env.DATADIR
  containers:
  - name: scrapy
    image: toru2220/scrapy-chrome
    volumeMounts:
    - name: data
      mountPath: /data
    command:
    - cat
    tty: true
    resources:
      requests:
        memory: "256Mi"
        cpu: "128m"
      limits:
        memory: "512Mi"
        cpu: "512m"    
'''
    }
  } 
  stages {
      stage('scrapy-down') {
          parallel {
              stage('down') {
                  steps {
                      container('scrapy'){ 
                         sh """
                            ls -l /data
                         """
                      }                    
                  }
              }
          }
      }
  }  
}    
```

##Jenkinsログ
```bash
Started by user unknown or anonymous
Running in Durability level: MAX_SURVIVABILITY
[Pipeline] Start of Pipeline
[Pipeline] podTemplate
[Pipeline] {
[Pipeline] node
Still waiting to schedule task
All nodes of label ‘scrapy-down’ are offline
Agent scrapy-down-tdncp-1tv7j is provisioned from template Kubernetes Pod Template
---
apiVersion: "v1"
kind: "Pod"
metadata:
  labels:
    scrapy: "scrapy"
    jenkins: "slave"
    jenkins/label: "scrapy-down"
  name: "scrapy-down-tdncp-1tv7j"
spec:
  containers:
  - command:
    - "cat"
    image: "toru2220/scrapy-chrome"
    name: "scrapy"
    resources:
      limits:
        memory: "512Mi"
        cpu: "512m"
      requests:
        memory: "256Mi"
        cpu: "128m"
    tty: true
    volumeMounts:
    - mountPath: "/data"
      name: "data"
    - mountPath: "/home/jenkins/agent"
      name: "workspace-volume"
      readOnly: false
    image: "jenkins/jnlp-slave:3.35-5-alpine"
    name: "jnlp"
    volumeMounts:
    - mountPath: "/home/jenkins/agent"
      name: "workspace-volume"
      readOnly: false
  nodeSelector:
    beta.kubernetes.io/os: "linux"
  restartPolicy: "Never"
  securityContext: {}
  volumes:
  - hostPath:
      path: "DATADIR"
    name: "data"
  - emptyDir:
      medium: ""
    name: "workspace-volume"

Running on scrapy-down-tdncp-1tv7j in /home/jenkins/agent/workspace/test
[Pipeline] {
[Pipeline] withEnv
[Pipeline] {
[Pipeline] stage
[Pipeline] { (scrapy-down)
[Pipeline] parallel
[Pipeline] { (Branch: down)
[Pipeline] stage
[Pipeline] { (down)
[Pipeline] container
[Pipeline] {
[Pipeline] sh
+ ls -l /data/
total 0
[Pipeline] }
[Pipeline] // container
[Pipeline] }
[Pipeline] // stage
[Pipeline] }
[Pipeline] // parallel
[Pipeline] }
[Pipeline] // stage
[Pipeline] }
[Pipeline] // withEnv
[Pipeline] }
[Pipeline] // node
[Pipeline] }
[Pipeline] // podTemplate
[Pipeline] End of Pipeline
Finished: SUCCESS
```

#成功例
yamlをgroovyの文字列として定義
kubernetesのyamlへ定義する前にgroovyの文字列置換(replaceAll)で値を変更したのち指定する
(非常に古典的)

```bash
def labelname = "scrapy-down"

def kubeyaml = """
apiVersion: v1
kind: Pod
metadata:
  labels:
    scrapy: scrapy
spec:
  volumes:
  - name: data
    hostPath:
      path: DATADIRVOL
  containers:
  - name: scrapy
    image: toru2220/scrapy-chrome
    volumeMounts:
    - name: data
      mountPath: /data
    command:
    - cat
    tty: true
    resources:
      requests:
        memory: 256Mi
        cpu: 128m
      limits:
        memory: 512Mi
        cpu: 512m  
"""
pipeline {
  agent {
    kubernetes {
      label labelname
      yaml kubeyaml.replaceAll(/DATADIRVOL/,DATADIR)
    }
  }
  stages {
      stage('scrapy-down') {
          parallel {
              stage('down') {
                  steps {
                      container('scrapy'){ 
                         sh """
                            ls -l /data/
                         """
                      }                    
                  }
              }
          }
      }
  }  
}    
```

##Jenkinsログ
```bash
Started by user unknown or anonymous
Running in Durability level: MAX_SURVIVABILITY
[Pipeline] Start of Pipeline
[Pipeline] podTemplate
[Pipeline] {
[Pipeline] node
Still waiting to schedule task
‘Jenkins’ doesn’t have label ‘scrapy-down’
Agent scrapy-down-hd708-533lf is provisioned from template Kubernetes Pod Template
---
apiVersion: "v1"
kind: "Pod"
metadata:
  labels:
    scrapy: "scrapy"
    jenkins: "slave"
    jenkins/label: "scrapy-down"
  name: "scrapy-down-hd708-533lf"
spec:
  containers:
  - command:
    - "cat"
    image: "toru2220/scrapy-chrome"
    name: "scrapy"
    resources:
      limits:
        memory: "512Mi"
        cpu: "512m"
      requests:
        memory: "256Mi"
        cpu: "128m"
    tty: true
    volumeMounts:
    - mountPath: "/data"
      name: "data"
    - mountPath: "/home/jenkins/agent"
      name: "workspace-volume"
      readOnly: false
    image: "jenkins/jnlp-slave:3.35-5-alpine"
    name: "jnlp"
    volumeMounts:
    - mountPath: "/home/jenkins/agent"
      name: "workspace-volume"
      readOnly: false
  nodeSelector:
    beta.kubernetes.io/os: "linux"
  restartPolicy: "Never"
  securityContext: {}
  volumes:
  - hostPath:
      path: "/mnt/albion"
    name: "data"
  - emptyDir:
      medium: ""
    name: "workspace-volume"

Running on scrapy-down-hd708-533lf in /home/jenkins/agent/workspace/test
[Pipeline] {
[Pipeline] withEnv
[Pipeline] {
[Pipeline] stage
[Pipeline] { (scrapy-down)
[Pipeline] parallel
[Pipeline] { (Branch: down)
[Pipeline] stage
[Pipeline] { (down)
[Pipeline] container
[Pipeline] {
[Pipeline] sh
+ ls -l /data/
total 0
-rw-r--r-- 1 root root 0  1月 27 21:57 testfile
[Pipeline] }
[Pipeline] // container
[Pipeline] }
[Pipeline] // stage
[Pipeline] }
[Pipeline] // parallel
[Pipeline] }
[Pipeline] // stage
[Pipeline] }
[Pipeline] // withEnv
[Pipeline] }
[Pipeline] // node
[Pipeline] }
[Pipeline] // podTemplate
[Pipeline] End of Pipeline
Finished: SUCCESS
```