add jenkins node setup

jenkins/jenkins-node.md

@@ -0,0 +1,155 @@
+# Node Setup Guide
+
+* Jenkins Plugins
+
+  * pipeline
+  * node and label
+  * gradle
+  * maven
+
+* Java compiler
+
+  * Java 8
+
+    ```sh
+    # install full jdk8 packge
+    # openjdk-8-jdk-headless exclude some jar file (eg /lib/jconsole.jar)
+    # which is need by alibaba druid dependencies package
+    $ apt install openjdk-8-jdk
+    ```
+
+    
+
+* Slave Agent
+
+  * Create a slave VM. Username as `jenkins`
+
+  * Set to sudo user
+
+    ```sh
+    # add jenkins user
+    $ adduser jenkins
+    
+    # change jenkins to sudo group
+    $ usermod -aG sudo jenkins
+    
+    # check the user group
+    $ groups jenkins
+    
+    # verify sudo access
+    $ su - jenkins
+    
+    
+    ```
+
+  * Optional, add `jenkins` as `sudoer`
+
+  * [reference](https://www.maketecheasier.com/edit-sudoers-file-linux/)
+
+    ```sh
+    # add jenkins as sudoer
+    $ visudo
+    
+    
+    # User privilege specification
+    # username hostlist = (userlist) commandlist
+    # eg. Only allow alex to run apt-get update
+    # alex ALL=(ALL) /usr/bin/apt-get update
+    root    ALL=(ALL:ALL) ALL
+    jenkins ALL=(ALL:ALL) ALL
+    ```
+
+  * Run jenkins node agent
+
+  ```sh
+  # download agent.jar file from jenkins server
+  $ wget https://192.168.0.119/jnlpJars/agent.jar --no-check-certificate
+  
+  # run the agent to connect to server
+  $ sudo java -jar agent.jar -jnlpUrl https://192.168.0.119/computer/jenkins.slave/jenkins-agent.jnlp -noCertificateCheck -secret 39694868bc66890cd5eb6c04b0a51692403ab957ceb1d1b258c353a031334733 -workDir "/home/jenkins"
+  ```
+
+  ## Run agent as service
+
+* [reference](https://www.baeldung.com/linux/run-java-application-as-service)
+
+* create a script file `startagent.sh`
+
+  ```sh
+  #!/bin/bash
+  
+  JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-amd64
+  WORKDIR=/home/jenkins/scripts
+  APP_OPTIONS=" -jnlpUrl https://192.168.0.119/computer/jenkins.slave/jenkins-agent.jnlp -noCertificateCheck -secret @secret-file -workDir \"/home/jenkins\""
+  
+  "${JAVA_HOME}/bin/java" -jar agent.jar $APP_OPTIONS
+  
+  ```
+
+* create the `secret-file`
+
+  ```sh
+  $ echo 39694868bc66890cd5eb6c04b0a51692403ab957ceb1d1b258c353a031334733 > secret-file
+  ```
+
+  
+
+* test the script
+
+  ```sh
+  $ chmod +x startagent.sh
+  
+  # start at background
+  $ ./startagent.sh &
+  
+  # make foreground
+  $ fg
+  ```
+
+* create a service
+
+  * Create the service unit file `jenkinsagent.service`
+
+    ```ini
+    [Unit]
+    Description=Jenkins Agent service
+    
+    [Service]
+    SuccessExitStatus=143
+    User=jenkins
+    Group=sudo
+    
+    WorkingDirectory=/home/jenkins/scripts
+    
+    ExecStart=/home/jenkins/scripts/startagent.sh
+    
+    
+    [Install]
+    WantedBy=multi-user.target
+    ```
+
+  * copy the service unit file to system `/etc/systemd/system`
+
+  ```sh
+  $ sudo cp ./jenkinsagent.service /etc/systemd/system/jenkinsagent.service
+  
+  # reload unit files
+  $ sudo systemctl daemon-reload
+  
+  # enable the service (after tested ok). service will start upon every PC restart
+  $ sudo systemctl enable jenkinsagent.service
+  
+  Created symlink /etc/systemd/system/multi-user.target.wants/jenkinsagent.service -> /etc/systemd/system/jenkinsagent.service.
+  
+  # start the service
+  $ sudo systemctl start jenkinsagent.service
+  
+  # check status o service
+  $ sudo systemctl status jenkinsagent.service
+  
+  # stop the service
+  $ sudo systemctl stop jenkinsagent.service
+  
+  ```
+
+