Installing Jenkins in Cloud Foundry PaaS

1. Get Jenkins
   Go to https://jenkins.io/download/ and download the Generic Java package (.war).
2. Deploy Jenkins
   We are going to deploy jenkins.war to a new instance. jenkins.war is a java app but cannot be deployed with the standard java-buildpack because it must be build for tomcat with another script. Hence, we need to use a custom buildpack and luckly there is one in github.com/Altoros/jenkins-buildpack.
   

   cf push \
       -p jenkins.war \
       -b https://github.com/Altoros/jenkins-buildpack \
       -m 1G \
       nacho-ci
   

   That is all for deploy, when accessing the app for first time a token will be asked so we should check logs or access /home/vcap/.jenkins/secrets/initialAdminPassword via ssh

   bx cf logs nacho-ci --recent
   

   Something like this will be shown:

   ...
   2018-10-13T15:53:28.17+0900 [APP/PROC/WEB/0] ERR INFO: 
   2018-10-13T15:53:28.17+0900 [APP/PROC/WEB/0] ERR *************************************************************
   2018-10-13T15:53:28.17+0900 [APP/PROC/WEB/0] ERR *************************************************************
   2018-10-13T15:53:28.17+0900 [APP/PROC/WEB/0] ERR *************************************************************
   2018-10-13T15:53:28.17+0900 [APP/PROC/WEB/0] ERR Jenkins initial setup is required. An admin user has been created and a password generated.
   2018-10-13T15:53:28.17+0900 [APP/PROC/WEB/0] ERR Please use the following password to proceed to installation:
   2018-10-13T15:53:28.17+0900 [APP/PROC/WEB/0] ERR 9bbc7b5799e14847b4cc8be8c823cc2b
   2018-10-13T15:53:28.17+0900 [APP/PROC/WEB/0] ERR This may also be found at: /home/vcap/.jenkins/secrets/initialAdminPassword
   2018-10-13T15:53:28.17+0900 [APP/PROC/WEB/0] ERR *************************************************************
   2018-10-13T15:53:28.17+0900 [APP/PROC/WEB/0] ERR *************************************************************
   2018-10-13T15:53:28.17+0900 [APP/PROC/WEB/0] ERR *************************************************************
   ...
   

Now copy and paste the token and Jenkins will start :)