SampleHandler

Sample Handler

Description

The sample handler is just that, an example of what a handler looks like code wise and how it operates. A handler can do anything and the input object to the handler is completely open ended.

Result

The sample allows you to specify a result payload (for use in subsequent operations in the Agenda ). This is specified in the resultPayload field. Like the input to your handler the output is completely open ended.

Sample Actions

The sample handler supports a couple of basic actions, each requiring different parameters to be populated.

Sample action parameters

Parameter	Description	Associated action(s)
sleepMilliseconds	(optional) The number of milliseconds to sleep before performing the action	All
logMessage	The message to log	log
externalArgs	The arguments to pass to the externally launch	externalExecute
exceptionMessage	The exception message	exception

Actions

log

This will log the specified message.

exception

This will cause a RuntimeException to be thrown with the exceptionMessage specified.

externalExecute

This will attempt to launch the specified command and arguments externally (currently only Kubernetes pod launching is supported in the Sample).

Sample Payload Explained

⚠️ These have inline comments with ## as a comment prefix... don't copy and paste this invalid json!

Payload files can be found here: /handler/handler-sample-impl/package/local

payload-local.json

{
  "actions": [ ## Array of actions to perform
    {
      "action": "log", ## The action to perform
      "paramsMap": { ## the parameters of the action
        "sleepMilliseconds": 5000, ## causes the action to delay for 5000ms
        "logMessage": "This is a custom log message" ## the log message
      }
    }
  ],
  "resultPayload": { ## result payload to respond with
    "data": "someData"
  }
}

payload.json

{
  "actions": [ ## Array of actions to perform
    {
      "action": "externalExecute",  ## The action to perform
      "paramsMap": { ## the parameters of the action
        "externalArgs": [ ## the array of arguments to run externally
          "ash",
          "-c",
          "ls",
          "-la"
        ]
      }
    }
  ],
  "resultPayload": { ## result payload to respond with
    "data": "someData"
  }
}

Execution

Prerequisites

• IDEA
• Kuberentes (minikube or otherwise) (optional)
  • Should go through Run Local Execution with Minikube

Setup and execute a local run

1. Navigate to /handler/handler-sample-impl/impl/src/main/java/com/comcast/pop/handler/sample/impl/HandlerEntryPoint.java
2. Create a "run" configuration for the main method.
   1. Working directory: (your custom path here)/pop
   2. Program arguments: -launchType local -externalLaunchType local -propFile ./handler/handler-sample-impl/package/local/config/external.properties -payloadFile ./handler/handler-sample-impl/package/local/payload-local.json
3. Attempt to run the new configuration!

Result

You should see the following lines (might be mixed with others)

11:14:22.214 [main] INFO com.comcast.pop.handler.sample.impl.processor.SampleActionProcessor - Performing Action: log
11:14:22.214 [main] INFO com.comcast.pop.handler.sample.impl.action.BaseAction - Performing requested sleep: 5000ms
11:14:27.055 [OperationProgressThread] INFO com.comcast.pop.handler.base.reporter.LogReporter - Progress: {"id":null,"cid":null,"customerId":null,"title":null,"updatedTime":null,"addedTime":null,"agendaProgressId":null,"processingState":"EXECUTING","processingStateMessage":null,"operation":null,"diagnosticEvents":null,"percentComplete":80.0,"attemptCount":null,"attemptTime":null,"startedTime":null,"completedTime":null,"resultPayload":null,"params":{"JobId":"89045f60-3a5c-41c1-ba47-9309940eb1b0"}}
11:14:27.232 [main] INFO com.comcast.pop.handler.sample.impl.action.LogAction - This is a custom log message

Setup and execute a kuberenetes run (requires Minikube setup)

1. Navigate to /handler/handler-sample-impl/impl/src/main/java/com/comcast/pop/handler/sample/impl/HandlerEntryPoint.java
2. Create a "run" configuration for the main method.
   1. Working directory: (your custom path here)/pop
   2. Program arguments: -launchType local -externalLaunchType kubernetes -propFile ./handler/handler-sample-impl/package/local/config/external-minikube.properties -payloadFile ./handler/handler-sample-impl/package/local/payload.json
3. Attempt to run the new configuration!

Result

You should see the following lines (this is a small set of the lines logged)

11:34:51.338 [main] INFO com.comcast.pop.handler.sample.impl.processor.SampleActionProcessor - Performing Action: externalExecute
(...)
11:34:52.078 [main] INFO com.comcast.pop.handler.sample.impl.executor.kubernetes.KubernetesExternalExecutor - Getting progress until the pod pop-sample-ext9f9f525f-67b0-4b77-ad24-c3d6ddfc138b is finished.
(...)
11:34:56.289 [main] INFO com.comcast.pop.handler.sample.impl.executor.kubernetes.KubernetesExternalExecutor - External execution completed with pod status Succeeded
(...)
11:34:56.289 [main] DEBUG com.comcast.pop.handler.sample.impl.executor.kubernetes.KubernetesExternalExecutor - External execution produced: bin
dev
etc
home
lib
media
mnt
opt
proc
root
run
sbin
srv
sys
tmp
usr
var