README.adoc

General Idea

1. use spring data rest + mysql(cleardb)

2. the db schema/data is not initialized

3. when access the app for the first time, it will crash (due to step 2)

4. cf run-task to the rescue! Encapsulate the task in ApplicationRunner bean under a specific profile (eg. reset). We also want to make use of the services bound to the app (cleardb). 12 factor: "one off admin task"

Prep

mvn clean package
cf push demo -p target/task-demo-0.0.1-SNAPSHOT.jar --random-route --no-start
cf create-service cleardb spark mysql1
cf bind-service demo mysql1
cf start demo

Test

curl demo-XXXX-YYYY.cfapps.io/contacts

Expecting to see the error, because the db is not initialized

$ curl demo-XXXX-YYYY.cfapps.io/contacts
{"timestamp":1486745570429,"status":500,"error":"Internal Server Error","exception":"org.springframework.dao.InvalidDataAccessResourceUsageException","message":"could not extract ResultSet; SQL [n/a]; nested exception is org.hibernate.exception.SQLGrammarException: could not extract ResultSet","path":"/contacts"}

Run task

Open a new terminal to run cf logs demo

Now run the task

cf run-task demo '.java-buildpack/open_jdk_jre/bin/java \
    -Dspring.jpa.hibernate.ddl-auto=update \
    -Dspring.profiles.active=cloud,reset \
    -Dspring.main.web-environment=false \
    -cp . org.springframework.boot.loader.JarLauncher'

Test Again

curl demo-XXXX-YYYY.cfapps.io/contacts

Now it should work, sample output:

{
  "_embedded" : {
    "contacts" : [ {
      "name" : "Alice",
      "_links" : {
        "self" : {
          "href" : "http://demo-spathulate-grainfield.cfapps.io/contacts/2"
        },
        "contact" : {
          "href" : "http://demo-spathulate-grainfield.cfapps.io/contacts/2"
        }
      }
    }, {
      "name" : "Bob",
      "_links" : {
        "self" : {
          "href" : "http://demo-spathulate-grainfield.cfapps.io/contacts/12"
        },
        "contact" : {
          "href" : "http://demo-spathulate-grainfield.cfapps.io/contacts/12"
        }
      }
    }, {
      "name" : "Eve",
      "_links" : {
        "self" : {
          "href" : "http://demo-spathulate-grainfield.cfapps.io/contacts/22"
        },
        "contact" : {
          "href" : "http://demo-spathulate-grainfield.cfapps.io/contacts/22"
        }
      }
    } ]
  },
  "_links" : {
    "self" : {
      "href" : "http://demo-spathulate-grainfield.cfapps.io/contacts"
    },
    "profile" : {
      "href" : "http://demo-spathulate-grainfield.cfapps.io/profile/contacts"
    }
  },
  "page" : {
    "size" : 20,
    "totalElements" : 3,
    "totalPages" : 1,
    "number" : 0
  }
}

Review

Use command cf tasks demo to see the history