#Azure API Management Event Processor

This sample application demonstrates using the logtoeventhub policy in the Azure API Management service to send events containing HTTP messages to EventHub, consume those events and forward to Moesif, a third party HTTP logging and analytics tool.

In order to run this sample you will need a number Environment variables configured with accounts and keys.

Key Name	Purpose
APIMEVENTS-EVENTHUB-NAME	Azure Event hub name configured to receive events from API Management service
APIMEVENTS-EVENTHUB-CONNECTIONSTRING	Azure Event hub configuration string eg: Endpoint=sb://<sb-url>/;SharedAccessKeyName=<name>;SharedAccessKey=<key>
APIMEVENTS-STORAGEACCOUNT-NAME	Azure Storage Account used for keeping track of what events have been read
APIMEVENTS-STORAGEACCOUNT-KEY	Key for Azure Storage Account
APIMEVENTS-MOESIF-APPLICATION-ID	Your Moesif Application Id(aka Collector Application Id) can be found in the Moesif Portal. After signing up for a Moesif account, your Moesif Application Id will be displayed during the onboarding steps Or any time by logging into the Moesif Portal, click on the top right menu, and then clicking ApiKeys or Installation.
APIMEVENTS-MOESIF-BASE_URI	optional (string) : A local proxy hostname when sending traffic via secure proxy. Please set this field when using secure proxy. For more details, refer secure proxy documentation.
APIMEVENTS-MOESIF-SESSION-TOKEN	Request Header Key containing user's API Token such as "Authorization" or "X-Api-Token"
APIMEVENTS-MOESIF-API-VERSION	API Version to tag the request with such as "v1" or "1.2.1"
APIMEVENTS-LOG-LEVEL	Optional: default log level is warn. Set this env varilable to info or debug to see more logs. Set either in run.bat or Azure app service setting configuration
APIMEVENTS-EVENTHUB-MAX-BATCH-SIZE	Optional: The Eventhub MaxBatchSize value setting.. indicating number of events to fetch from eventhub. Larger batches increase throughput. Default: 100. Try values of 100 - 500

The sample, as is, writes the HTTP messages to the Moesif API Analytics, however, by creating a new implementation of IHttpMessageProcessor it is trivial to change where the HTTP messages are relayed.

How to use this app in Azure App Services

This project can be launched in Azure App Services as a Azure WebJob app. First, download and modify the azure-app-service-webjobs/run.bat file in this repo.

1. Log into Azure portal, and create/open an Azure Web Services console. Tested under Stack: .NET .NET 5 (Early Access) using pricing tier f1 - free - dev / test workloads
2. Under Settings / Configuration, add the above specified Environment variables as Application settings > "name" "value"
3. Under Settings panel on left, click on WebJobs
4. Select + Add to add this job
5. In the Add WebJob panel, fill out:

• Name: enter any name for this job
• File Upload: Upload the run.bat file (azure-app-service-webjobs/run.bat)
• Type: "continuous"

6. Save

The job should immediately begin. View logs to see output.

Troubleshooting:

1. The maximum size of data sent to log-to-eventhub is limited by azure to approx 200000 chars. So the body size in policy.xml must be limited to below that limit. Log-to-Eventhub truncates at that limit.
2. Ensure the policy.xml matches the correct version of ApimEventProcessor.
3. The Checkpoint to azure storage occurs only after CHECKPOINT_MINIMUM_INTERVAL_MINUTES (5 mins) has elapsed and after new event is received. If this program is restarted prior to checkpoint, all events after last checkpoint are sent to Moesif. This may lead to duplicate events in Moesif.
4. Enable more detailed logs by setting APIMEVENTS-LOG-LEVEL environment variable to debug or info from default warn