1. Work with application by opening up the VS Code editor on the TradesAppCloud_withLogTrace.spl SPL source code

Notice the trace and println statements that have been added to the application to show examples of how to define and reference submission time variables, and how to add application trace statements to output these values into the application log.

Search for "LOOK HERE" to see the section of the application that is most relative to this sample.

Notice the names for the two submission time variable names as they will be needed later on.
- _mySubmissionTimeVariable_string_
- _mySubmissionTimeVariable_listOfStrings_

Change the "yourName" string to something of your choosing. This will allow you to see how it gets printed to the log.
Save the application file.

```
{

// LOOK HERE

// define submission time variables; 1 of each supported type (string, list of strings)
rstring mySubmissionTimeVariable_string = getSubmissionTimeValue("mySubmissionTimeVariable_string","defaultValue");
list mySubmissionTimeVariable_listOfStrings = getSubmissionTimeListValue("mySubmissionTimeVariable_listOfStrings","defaultFirstListElement", "defaultSecondListElement"]);

// add trace statements that will display the submission time values that were inputted
appTrc(spl::Trace.info, "mySubmissionTimeVariable_string =" + mySubmissionTimeVariable_string);
appTrc(spl::Trace.info, "mySubmissionTimeVariable_listOfStrings var: ");
for (rstring parm in mySubmissionTimeVariable_listOfStrings) {
appTrc(spl::Trace.info, " String element: "+parm);
}

// notice the following trace statement is 'debug' level,
// & will only show in log when trace level is 'debug' or 'trace'
appTrc(spl::Trace.debug, "*** DEBUG-LEVEL of trace message ***");

// add some print lines - modify "yourName" below if you would like to customize the output.
printStringLn("Average asking price for " + ticker + " is " + (rstring) average);
printStringLn("This sample is being is being tried out by: USER-NAME= " + "yourName");

// submit the tuple
submit(AvgPrice, PrintAvPrice);
}
```

1. Build the application image for the Edge
1. Right click in the TradesAppCloud_withLogTrace application editing window, and select "Build Edge Application Image"
1. Monitor the console output until the "Successfully built the application" message is displayed
1. When prompted, select the base image that contains "streams-base-edge-application", and enter "trades-withtrace" for image name, and "1.0" for image tag
1. Click "Build image"
1. Monitor the console output until "Successfully built the edge application image", and take note of the imagePrefix from the Image Details. It will be needed later during the Develop / Publish application package step when deploying using EAM.

#### 2. Develop / Publish application package

- From CP4D Console, perform these steps. For more information, see [Packaging using Cloud Pak for Data](https://www.ibm.com/support/knowledgecenter/SSQNUZ_3.0.1/svc-edge/usage-register-by-cpd.html) topic.
1. Select CPD Console > Navigation Menu > Analyze > Edge Analytics > Analytics apps
1. Click 'Add Application packages' and fill in these values
| Field | Value |
| ----- | ----- |
| Name | App Control Sample |
| Version | 1.0 |
| Image reference | trades-withtrace:1.0 |
1. Scroll down to Additional attributes > Environment variables and add the following variables. Clicking 'Add more" as needed. See more information on [determining what variables are supported.](#stv)

| Variable Name | Value |
| ------------- | ----- |
| mySubmissionTimeVariable_string | MyFavoriteFootballTeams |
| mySubmissionTimeVariable_listOfStrings | Vikings,Packers,Lions,Bears |
| STREAMS_OPT_TRACE_LEVEL | 3 |
1. Save

#### 3. Deploy application package to an Edge node
From CP4D Console perform these steps. For more information, see [Deploying using Cloud Pak for Data](https://www.ibm.com/support/knowledgecenter/SSQNUZ_3.0.1/svc-edge/usage-deploy-cpd.html) topic. The values for the submission time variables can not be changed at this time.
1. Continuing from the 'Analytics apps' panel
- CPD Console > Navigation Menu > Analyze > Edge Analytics > Analytics apps
1. Go to end of the row with "App Control Sample" and click on three dots to open list of options, and select 'Deploy to edge'
1. When the list of remote systems is displayed, check the box next to the remote system you want to deploy to.
1. Select 'Deploy' option.
1. To verify that the app was deployed successfully, select the "App Control Sample"
1. Verify that there is an application instance for the deployment to your chosen system.

#### 4. View the runtime logs
From CP4D Console, perform these steps. See [Monitoring edge systems and applications with Edge Analytics](https://www.ibm.com/support/knowledgecenter/SSQNUZ_3.0.1/svc-edge/usage-monitor.html) for detailed instructions on how to view status, logs, metrics, etc. for edge applications.
1. Continuing from the 'App Control Sample' panel
- CPD console > Navigation Menu > Analyze > Edge Analytics > Analytics apps > app control sample
1. Go to row for the application instance for the edge node that you would like to see log for, and select three dots at clear right part of row to see the list of options.
1. Select 'Download logs'.
1. Unzip downloaded log package.
1. Open up app-control-sample-xxxx.log file
- This file contains a variety of statements. The standard println output will be in this log, as well as the output from the trace statements. Search for "USER-NAME" for example of println output. You should see the value for 'yourName' that you previously entered in to the application. The statements added due to the application trace statements will contain "#splapptrc".

- Here is a snippet of the log. Notice that the values for the input variables that were supplied made it to the application and were output to this log file. (e.g. MyFavoriteFootballTeams).
Also, notice that the DEBUG-LEVEL message was not in the log. This means the STREAMS_OPT_TRACE_LEVEL runtime-option that set the level to INFO was received and acted upon by the application, so as only trace statements of info level were accepted in the file.

```
2020-08-19T10:07:10.064038778-07:00 stdout F 19 Aug 2020 17:07:10.063+0000 [56] INFO #splapptrc,J[0],P[0],PrintAvPrice M[TradesAppCloud_withLogTrace.spl:appTrc:82] - mySubmissionTimeVariable_string =MyFavoriteFootballTeams
2020-08-19T10:07:10.066033579-07:00 stdout F 19 Aug 2020 17:07:10.063+0000 [56] INFO #splapptrc,J[0],P[0],PrintAvPrice M[TradesAppCloud_withLogTrace.spl:appTrc:83] - mySubmissionTimeVariable_listOfStrings var:
2020-08-19T10:07:10.066033579-07:00 stdout F 19 Aug 2020 17:07:10.064+0000 [56] INFO #splapptrc,J[0],P[0],PrintAvPrice M[TradesAppCloud_withLogTrace.spl:appTrc:85] - String element: Vikings
2020-08-19T10:07:10.066033579-07:00 stdout F 19 Aug 2020 17:07:10.064+0000 [56] INFO #splapptrc,J[0],P[0],PrintAvPrice M[TradesAppCloud_withLogTrace.spl:appTrc:85] - String element: Packers
2020-08-19T10:07:10.066033579-07:00 stdout F 19 Aug 2020 17:07:10.065+0000 [56] INFO #splapptrc,J[0],P[0],PrintAvPrice M[TradesAppCloud_withLogTrace.spl:appTrc:85] - String element: Lions
2020-08-19T10:07:10.066033579-07:00 stdout F 19 Aug 2020 17:07:10.065+0000 [56] INFO #splapptrc,J[0],P[0],PrintAvPrice M[TradesAppCloud_withLogTrace.spl:appTrc:85] - String element: Bears

2020-08-19T10:07:10.066033579-07:00 stdout F This sample is being is being tried out by: USER-NAME= yourName

```

#### 5. Un-deploy application
From CP4D Console, perform these steps. For more information, see [Deleting an application deployment](https://www.ibm.com/support/knowledgecenter/SSQNUZ_3.0.1/svc-edge/usage-unregister.html) topic.
1. Continuing from the 'App Control Sample' panel
- CPD console > Navigation Menu > Analyze > Edge Analytics > Analytics apps > App Control Sample
1. Go to row for the application instance for the edge node that you would like to un-deploy the app from, and select three dots at clear right part of row to see the list of options.
1. Select 'Delete'
1. Confirm the Delete

## Scenario#2 - Develop and deploy application with IBM Edge Application Manager


#### 1. Develop and Build application for the Edge (via VS Code)
These steps are identical to those listed in [scenario#1 Develop and Build section.](#vsc)

#### 2. Select Edge Node(s) for development and deployment (via CP4D Console)
To see list of Edge nodes that have been tethered to this CPD instance, do these steps:
1. login in to CPD Console
1. Select Navigation Menu > Analyze > Edge Analytics > Remote systems
This will display a list of the available nodes. Select one of the _ieam-analytics-micro-edge-system_ type nodes for the development system. Also, select one of these for the deployment system. It can be the same system.

#### 3. Develop / Publish application package
Use the Secure Shell protocol (ssh) to log in to CP4D Edge node chosen for development and perform the following steps. The submission time variables from the application will be included in the resulting application package. The values for the variables are not specifed as part of the application package. For more information, see [Packaging using Edge Application Manager](https://www.ibm.com/support/knowledgecenter/SSQNUZ_3.0.1/svc-edge/usage-register-by-eam.html) topic.

- Install the OpenShift® command-line interface.
For more information, see [Get Started with the CLI 3.11](https://docs.openshift.com/container-platform/3.11/cli_reference/get_started_cli.html) or [Getting started with the CLI 4.3](https://docs.openshift.com/container-platform/4.3/cli_reference/openshift_cli/getting-started-cli.html).

- Setup the environment variables

```
eval export $(cat agent-install.cfg)
export HZN_EXCHANGE_USER_AUTH= _my_eam_api_key_
export OCP_USER="cpd-admin-sa"
export OCP_DOCKER_HOST=_default-route-to-openshift-image-registry_
export OCP_TOKEN=_cpd-admin-sa_openshift-token_
export IMAGE_PREFIX=_imagePrefix_ // from build step
```

- Login to OpenShift and Docker
```
oc login _openshift_cluster_url:port_ --token $OCP_TOKEN --insecure-skip-tls-verify=true
docker login $OCP_DOCKER_HOST --username $OCP_USER --password $(oc whoami -t)
```
- Pull the edge application image to the development node
```
docker pull $OCP_DOCKER_HOST/$IMAGE_PREFIX/trades-withtrace:1.0
```
- Create a cryptographic signing key pair.
```
hzn key create "my_company_name" "my_email_address"
```
- Create EAM service project
```
mkdir app_control_sample; cd app_control_sample
hzn dev service new -s app-control-service -V 1.0 --noImageGen -i $OCP_DOCKER_HOST/$IMAGE_PREFIX/trades-withtrace:1.0
```
- Add submission time variables and runtime-option:trace
1. edit horizon/service.definition.json with editor of your choosing.
1. insert the submission time variables into the "userInput" array such that it looks like the following. See more information on [determining what variables are supported.](#stv)

```
{
"org": "$HZN_ORG_ID",
"label": "$SERVICE_NAME for $ARCH",
"description": "",
"public": true,
"documentation": "",
"url": "$SERVICE_NAME",
"version": "$SERVICE_VERSION",
"arch": "$ARCH",
"sharable": "multiple",
"requiredServices": [],
"userInput": [
{
"name": "mySubmissionTimeVariable_string",
"type": "string",
"defaultValue": "defaultValue"
},
{
"name": "mySubmissionTimeVariable_listOfStrings",
"type": "list of strings",
"defaultValue": "defaultFirstListElement,defaultSecondListElement"
},
{
"name": "STREAMS_OPT_TRACE_LEVEL",
"label" : "Tracing level: 0=OFF, 1=ERROR, 2=WARNING, 3=INFO, 4=DEBUG, 5=TRACE",
"type": "string",
"defaultValue": "1"
}
],
"deployment": {
"services": {
"tradesappcloud-withlogtrace": {
"image": "$OCP_DOCKER_HOST/$IMAGE_PREFIX/trades-withtrace:1.0",
"privileged": false,
"network": ""
}
}
}
}
```
- Test the service by starting the service, reviewing the container logs, and stopping the service.

```
hzn dev service start -S
sudo cat /var/log/syslog | grep trades-withtrace[[]
hzn dev service stop
```

- Publish service

```
hzn exchange service publish -r "$OCP_DOCKER_HOST:$OCP_USER:$OCP_TOKEN" -f horizon/service.definition.json
```

1. verify app-control-service was published and exists in the service list.

hzn exchange service list

- Publish pattern

```
hzn exchange pattern publish -f horizon/pattern.json
```

1. verify pattern-app-control-service pattern was published and exists in this pattern list.


```
hzn exchange pattern list
```

#### 4. Deploy application package to an Edge node
Use the Secure Shell protocol (ssh) to log in to CP4D Edge node chosen for deployment and perform the following steps. For more information, see [Deploying using Edge Application Manager](https://www.ibm.com/support/knowledgecenter/SSQNUZ_3.0.1/svc-edge/usage-deploy-eam.html) topic. The values for the submission time variables from the application will be specified during deployment.
- Edit horizon/userinput.json with editor of your choosing and add the following json to it.

```
{
"services": [
{
"org": "$HZN_ORG_ID",
"url": "app-control-service",
"variables": {
"mySubmissionTimeVariable_string": "MyFavoriteFootballTeams",
"mySubmissionTimeVariable_listOfStrings": ["Vikings,Packers,Lions,Bears"],
"STREAMS_OPT_TRACE_LEVEL" : "3"
}
}
]
}
```

- Deploy pattern/service with user inputs.

```
hzn register -p pattern-app-control-service-amd64 -f horizon/userinput.json

```
- Verify that application is deployed, by checking for an agreement being created. This make take a few minutes to show up.

```
hzn agreement list
```

#### 5. View the runtime logs (ssh to CP4D Edge node chosen for deployment)

hzn service log -f app-control-service

- View log statements
- This log contains a variety of statements. The standard println output will be in this log, as well as the output from the trace statements. Search for "USER-NAME" for example of println output. The trace statements will contain "#splapptrc".
- Here is a snippet of the log. Notice that the input variables that were supplied made it to the application and were output to this log file. (e.g. MyFavoriteFootballTeams). Also, notice that the DEBUG-LEVEL message was not in the log. This means the STREAMS_OPT_TRACE_LEVEL runtime-option that set the level to INFO made it to the application as well.

```
2020-08-19T10:07:10.064038778-07:00 stdout F 19 Aug 2020 17:07:10.063+0000 [56] INFO #splapptrc,J[0],P[0],PrintAvPrice M[TradesAppCloud_withLogTrace.spl:appTrc:82] - mySubmissionTimeVariable_string =MyFavoriteFootballTeams
2020-08-19T10:07:10.066033579-07:00 stdout F 19 Aug 2020 17:07:10.063+0000 [56] INFO #splapptrc,J[0],P[0],PrintAvPrice M[TradesAppCloud_withLogTrace.spl:appTrc:83] - mySubmissionTimeVariable_listOfStrings var:
2020-08-19T10:07:10.066033579-07:00 stdout F 19 Aug 2020 17:07:10.064+0000 [56] INFO #splapptrc,J[0],P[0],PrintAvPrice M[TradesAppCloud_withLogTrace.spl:appTrc:85] - String element: Vikings
2020-08-19T10:07:10.066033579-07:00 stdout F 19 Aug 2020 17:07:10.064+0000 [56] INFO #splapptrc,J[0],P[0],PrintAvPrice M[TradesAppCloud_withLogTrace.spl:appTrc:85] - String element: Packers
2020-08-19T10:07:10.066033579-07:00 stdout F 19 Aug 2020 17:07:10.065+0000 [56] INFO #splapptrc,J[0],P[0],PrintAvPrice M[TradesAppCloud_withLogTrace.spl:appTrc:85] - String element: Lions
2020-08-19T10:07:10.066033579-07:00 stdout F 19 Aug 2020 17:07:10.065+0000 [56] INFO #splapptrc,J[0],P[0],PrintAvPrice M[TradesAppCloud_withLogTrace.spl:appTrc:85] - String element: Bears

2020-08-19T10:07:10.066033579-07:00 stdout F This sample is being is being tried out by: USER-NAME= yourName

```

#### 6. Un-deploy application
For more information, see [Deleting an application deployment](https://www.ibm.com/support/knowledgecenter/SSQNUZ_3.0.1/svc-edge/usage-unregister.html) topic.
```
hzn unregister -f
```

## Additional Resources

For simple applications, the submission time variable names are just how they appear in the application. However, when the same name is used for a submission time variable in different namespaces or composites of the application, the variable names must be prepended by the application namespace and composite operator name. To determine what this fully qualified name looks like, you may retrieve the names of the supported variables by following the "Retrieving service variables for edge applications" topic.

This is also useful to discover the supported variables for an image whose source code is not readily available for. Also, a complete list of the supported runtime options can be discovered this way.