topic Re: March Developer Challenge - CloudEvents: Week 2 in Application Development and Automation Discussions

March Developer Challenge - CloudEvents: Week 2

ajmaradiaga — Thu, 22 May 2025 06:35:39 GMT

As we learned last week, CloudEvents is a specification for describing event data in common formats and the goal is to provide interoperability across services, platforms and systems. This week we will expand on what we learnt last week and we will create our first CloudEvent programmatically.

Links to March's developer challenge:
Week 1: https://community.sap.com/t5/application-development-discussions/march-developer-challenge-cloudevents-week-1/td-p/13629129
Week 2: https://community.sap.com/t5/application-development-discussions/march-developer-challenge-cloudevents-week-2/m-p/13635719
Week 3: https://community.sap.com/t5/application-development-discussions/march-developer-challenge-cloudevents-week-3/td-p/13642145
Week 4: https://community.sap.com/t5/application-development-discussions/march-developer-challenge-cloudevents-week-4/td-p/13648232

CloudEvent format

Event Formats specify how to serialize a CloudEvent with certain encoding formats. Depending on our requirements it is possible that we might need to use a specific format to encode our CloudEvent message. Maybe we have a requirement where we need to send the data in something different than the JSON format, e.g. AVRO, Protobuf. Check out the specification document if you want to learn more about these different formats.

For simplicity purposes we will stick to the JSON Event format as it is the most common and easiest to interact with.

Now that we are familiar with what a CloudEvent is, what a CloudEvent message looks like, and the different Event Formats available, let's see how we can create one programmatically.

CloudEvents SDK

There are language-specific SDKs that can be used to create a message that complies with the CloudEvents standard. Below is a list of the different languages that there's an SDK for:

You might be thinking, why would I need an SDK when I can create the message "manually" as well? Using an SDK allows us to easily create a CloudEvent message, ensure that it follows the guidelines defined in the standard, and simplify generating the output format. Not only that but it can also be used to parse a CloudEvent message that our application consumes. As an example, I will use the Python SDK to create the CloudEvent message for the Ticket Management System that I used as an example previously.

from cloudevents.http import CloudEvent from cloudevents.conversion import to_binary import requests ticket_id = "IT00010232" # Create a CloudEvent attributes = { "type": "com.ajmaradiaga.tms.Ticket.Created.v1", "source": "https://tms-prod.ajmaradiaga.com/tickets", "subject": ticket_id, } data = { "ID": ticket_id, "Description": "Install ColdTurkey to block distracting websites.", "Urgency": { "ID": 1, "Description": "High" } } event = CloudEvent(attributes, data) # Creates the HTTP request representation of the CloudEvent in binary content mode headers, body = to_binary(event) print(body)

Week 2 challenge - Create a CloudEvent using an SDK

👉 Your task for this week is: Pick your favourite language from the list above and create the message that you shared as part of week's 1 challenge but this time instead of doing it manually, you will do it using an SDK. To complete this week's challenge, share the code you used to create the CloudEvent message and a screenshot of your program's output.

What if there is no SDK available for your favourite language? Not a problem, you can create the message structure "manually". Just share the code used to generate a message in your programming language and a screenshot of the program's output.

Re: March Developer Challenge - CloudEvents: Week 2

ajmaradiaga — Tue, 12 Mar 2024 14:35:15 GMT

Using as a reference my solution for week 1, I will use the CloudEvents Python SDK.

Code

import json from cloudevents.conversion import to_structured from cloudevents.http import CloudEvent import requests # Create a CloudEvent # - The CloudEvent "id" is generated if omitted. "specversion" defaults to "1.0". attributes = { "type": "com.ajmaradiaga.tms.Ticket.Created.v1", "source": "https://tms-prod.ajmaradiaga.com/tickets", } data = { "id": "IT00010232", "description": "Install ColdTurkey to block distracting websites.", "urgency": { "id": 1, "description": "High" } } event = CloudEvent(attributes, data) # Creates the HTTP request representation of the CloudEvent in structured content mode headers, body = to_structured(event) print(headers) json_body = json.loads(body) # Pretty print json print(json.dumps(json_body, indent=2))

Screenshot of the program running

Week 2 solution

Re: March Developer Challenge - CloudEvents: Week 2

r00k13d3v — Tue, 12 Mar 2024 15:25:40 GMT

Here is my submission 🖖

Code JS:

const { CloudEvent, HTTP } = require("cloudevents"); const ce = new CloudEvent({ specversion: "1.0", type: "com.example.iot.device.event.v1", source: "https://iot-prod.example.com/devices", subject: "device12345-temperature-alert", id: "e241f360-4b3f-4c9b-a5e4-d35456b27f62", time: "2024-03-06 08:34:00", datacontenttype: "application/json", data: { device_id: "Device12345", event_type: "temperature-alert", description: "Temperature threshold exceeded.", data: { temperature: 75, threshold: 70, units: "Celsius", }, }, }); const { headers, body } = HTTP.structured(ce); console.log("Headers:"); console.log(JSON.stringify(headers, null, 2) + "\n"); console.log("Body:"); console.log(JSON.stringify(JSON.parse(body), null, 2) + "\n");

Result:

Re: March Developer Challenge - CloudEvents: Week 2

Alpesa1990 — Tue, 12 Mar 2024 17:05:23 GMT

My reference for week 1:

https://community.sap.com/t5/application-development-discussions/march-developer-challenge-cloudevents-week-1/td-p/13629129#:~:text=%7B%0A%22specversion%22%3A%20%221.0%22%2C%0A%22id%22%3A%20%2262706ed3%2D3f4c%2D4a48%2Da2e7%2D8f201301822b%22%2C%0A%22type%22%3A%20%22.com.alpesadevcha.v1%22%2C%0A%22source%22%3A%20%22/alpesadev/test%22%2C%0A%22time%22%3A%20%222024%2D03%2D07T08%3A00%3A00Z%22%2C%0A%22datacontenttype%22%3A%20%22application/json%22%2C%0A%22data%22%3A%20%7B%0A%09%22employee%22%3A%20%2280001000%22%0A%09%7D%0A%7D

My JS code:

const { CloudEvent, HTTP} = require("cloudevents"); // Create a new CloudEvent const ce = new CloudEvent({ "specversion": "1.0", "id": "62706ed3-3f4c-4a48-a2e7-8f201301822b", "type": ".com.alpesadevcha.v1", "source": "/alpesadev/test", "time": "2024-03-07T08:00:00Z", "datacontenttype": "application/json", "data": { "employee": "80001000" } }); // const { headers, body } = HTTP.structured(ce); console.log( "Headers:", "\n", JSON.stringify(headers, null, 2), "\n", "Body:", "\n", JSON.stringify(JSON.parse(body), null, 2));

Output:

Headers: { "content-type": "application/cloudevents+json; charset=utf-8" } Body: { "id": "62706ed3-3f4c-4a48-a2e7-8f201301822b", "time": "2024-03-07T08:00:00.000Z", "type": ".com.alpesadevcha.v1", "source": "/alpesadev/test", "specversion": "1.0", "datacontenttype": "application/json", "data": { "employee": "80001000" } }

Re: March Developer Challenge - CloudEvents: Week 2

emiliocampo — Tue, 12 Mar 2024 18:30:22 GMT

My previous solution Week 1

Code

Screenshot

Re: March Developer Challenge - CloudEvents: Week 2

r00k13d3v — Tue, 12 Mar 2024 20:37:57 GMT

Code PWS:

$cloudEvent = New-CloudEvent ` -Type 'com.example.iot.device.event.v1' ` -Source 'https://iot-prod.example.com/devices' ` -Id 'e241f360-4b3f-4c9b-a5e4-d35456b27f62' ` -Time '2024-03-06 08:34:00' ` $cloudEvent | Set-CloudEventJsonData -Data @{ specversion = "1.0" type = "com.example.iot.device.event.v1" source = "https://iot-prod.example.com/devices" subject = "device12345-temperature-alert" id = "e241f360-4b3f-4c9b-a5e4-d35456b27f62" time = "2024-03-06 08:34:00" datacontenttype = "application/json" data = @{ device_id = "Device12345" event_type = "temperature-alert" description = "Temperature threshold exceeded." data = @{ temperature = 75 threshold = 70 units = "Celsius" } } } > $null $cloudEventStructuredHttpMessage = $cloudEvent | ConvertTo-HttpMessage -ContentMode Structured Write-Host Write-Host "Headers:" -ForegroundColor Green $cloudEventStructuredHttpMessage.Headers Write-Host Write-Host "Body:" -ForegroundColor Green Read-CloudEventData -CloudEvent $cloudEvent

Result:

Re: March Developer Challenge - CloudEvents: Week 2

ajmaradiaga — Wed, 13 Mar 2024 05:42:31 GMT

@r00k13d3v Absolutely love this.... it never crossed my mind that someone would share something using the Powershell SDK... AMAZING!

Re: March Developer Challenge - CloudEvents: Week 2

ajmaradiaga — Wed, 13 Mar 2024 05:55:28 GMT

@emiliocampo Thanks for sharing the to_binary representation, so others can see what the difference is when outputting to_structured and to_binary. Great example!

Re: March Developer Challenge - CloudEvents: Week 2

PriyankaChak — Wed, 13 Mar 2024 11:37:41 GMT

from cloudevents.conversion import to_structured from cloudevents.http import CloudEvent import json attributes = { "type": "com.servicechannel.WorkOrder.Created.v1", "source": "https://test.servicechannel.com/workorders", } data = { "purchaseNumber": "84409626", "status": { "primary": "open" } } event = CloudEvent(attributes, data) headers, body = to_structured(event) print(f"Content-Type: {headers['content-type']}\n") json_body = json.loads(body) print(f"Sample Cloud Event: \n{json.dumps(json_body, indent=2)}")

Re: March Developer Challenge - CloudEvents: Week 2

xavisanse — Wed, 13 Mar 2024 16:02:30 GMT

//Importing Cloud Event libraries. const { CloudEvent, HTTP } = require("cloudevents"); const type = "com.awesome_company.sales_order.Updated.v1" const source = "https://prod.illidian.awesome_company.com/sales_orders" const salesOrderID = "9024000013" const company = "AWO01" const year = 2024 const statusSO = "Shipped" const subject = company + salesOrderID + year const data = { "salesOrder": salesOrderID, "company": company, "year": year, "status": statusSO } //creating and calling event const soEvent = new CloudEvent({type,source,subject,data}) const { headers, body } = HTTP.structured(soEvent); //print the log console.log("### March Developer Challenge - CloudEvents: Week 2 ###\n"); console.log("- HTTP Event Headers - \n") for (const key in headers) { console.log(`Key: "${key}", Value: "${headers[key]}"`); } console.log("\n - HTTP Event Body - \n"); console.log(JSON.stringify(JSON.parse(body), null, 1) + "\n");

JS!

Re: March Developer Challenge - CloudEvents: Week 2

Dan_Wroblewski — Wed, 13 Mar 2024 16:41:46 GMT

Re: March Developer Challenge - CloudEvents: Week 2

r00k13d3v — Wed, 13 Mar 2024 20:29:16 GMT

I don't want to lie... I tried because it's something that blows my mind, 🤣

Re: March Developer Challenge - CloudEvents: Week 2

fjaviergar07 — Wed, 13 Mar 2024 21:40:17 GMT

Why not creating the CloudEvent in Groovy if we want to use Integration Suite for that?

import com.sap.gateway.ip.core.customdev.util.Message import java.util.HashMap import java.text.SimpleDateFormat def Message processData(Message message) { //read properties def properties = message.getProperties() specversion = properties.get("specversion") type = properties.get("type") source = properties.get("source") id = properties.get("id") //create timestamp def date = new Date() def sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss") //read data from body def data = message.getBody(String) //create CloudEvent message.setBody("{\r\n\"specversion\": \"" + specversion +"\",\r\n\"type\": \""+ type +"\",\r\n\"source\": \""+ source +"\",\r\n\"id\": \""+ id +"\",\r\n\"time\": \""+ sdf.format(date) +"\",\r\n\"datacontenttype\": \"application/json\",\r\n\"data\":" + data + "}") return message }

Re: March Developer Challenge - CloudEvents: Week 2

ceedee666 — Thu, 14 Mar 2024 09:30:16 GMT

import json from cloudevents.conversion import to_json from cloudevents.http import CloudEvent attributes = { "type": "sap.s4.beh.productionorder.v1.ProductionOrder.Created.v1", "source": "https://m32z.ucc.ovgu.de/", } data = { "ProductionOrder": "1000206", "ProductionOrderType": "PP01", "ProductionPlant": "HD00", } event = CloudEvent(attributes, data) print(json.dumps(json.loads(to_json(event)), indent=2))

Re: March Developer Challenge - CloudEvents: Week 2

pamoli_banerjee — Thu, 14 Mar 2024 09:46:35 GMT

Hello ,

Here is my Week1 response.

Below is my JS code to populate the same Cloud Event :

const { CloudEvent, HTTP } = require("cloudevents");

const CloudEvent = new CloudEvent({

type: "com.example.iot.device.event.v1",

specversion: "1.0",

source: "/default/sap.s4.beh/SXXXXXX",

id: "a590d392-80be-1ede-a598-d34338408017",

time: "2023-12-07T06:05:25Z",

datacontenttype: "application/json",

data: {

SalesOrder: "9999",

EventRaisedDateTime: "2023-12-07T06:05:19.578802Z",

SalesOrderType: "TA",

SalesOrganization: "1710",

DistributionChannel: "10",

OrganizationDivision: "00",

SoldToParty: "17100001",

});

const { body } = HTTP.structured(CloudEvent);

console.log(JSON.stringify(JSON.parse(body), null, 2) + "\n");

Here is the output :

Re: March Developer Challenge - CloudEvents: Week 2

SyambabuAllu — Thu, 14 Mar 2024 10:04:15 GMT

Here is my submission

const { CloudEvent, HTTP } = require("cloudevents"); const ce = new CloudEvent({ specversion: "1.0", type: "sap.s4.beh.centralrequestforquotation.v1.CentralRequestForQuotation.SuccssrDocCrted.v1", source: "/default/sap.s4.beh/s4hc", id: "QgEK7wzuHtqdeJwqCS+VOA==", time: "2024-03-11T13:00:00Z", datacontenttype: "application/json", data: { CentralRequestForQuotation: "7500000012" }, }); const { headers, body } = HTTP.structured(ce); console.log("Headers:"); console.log(JSON.stringify(headers, null, 2) + "\n"); console.log("Body:"); console.log(JSON.stringify(JSON.parse(body), null, 2) + "\n");

Headers: { "content-type": "application/cloudevents+json; charset=utf-8" } Body: { "id": "QgEK7wzuHtqdeJwqCS+VOA==", "time": "2024-03-11T13:00:00.000Z", "type": "sap.s4.beh.centralrequestforquotation.v1.CentralRequestForQuotation.SuccssrDocCrted.v1", "source": "/default/sap.s4.beh/s4hc", "specversion": "1.0", "datacontenttype": "application/json", "data": { "CentralRequestForQuotation": "7500000012" } }

Re: March Developer Challenge - CloudEvents: Week 2

ajos — Thu, 14 Mar 2024 11:56:35 GMT

Re: March Developer Challenge - CloudEvents: Week 2

Ruthiel — Thu, 14 Mar 2024 14:15:57 GMT

This is the reference for my week 1 proposal:

Re: March Developer Challenge - CloudEvents: Week 2

amitcruz — Fri, 15 Mar 2024 05:06:38 GMT

Here is my submission for Week 2:

Re: March Developer Challenge - CloudEvents: Week 2

tobiasz_h — Fri, 15 Mar 2024 11:25:37 GMT

Hello,

My solution for week 1: week-1-solution , I will use python sdk

Code:

import json from cloudevents.conversion import to_structured from cloudevents.http import CloudEvent # Create a CloudEvent # - The CloudEvent "id" is generated if omitted. "specversion" defaults to "1.0". attributes = { "type": "sap.s4.beh.product.v1.Product.Changed.v1", "source": "../dictionary", "subject": "productId:123", } data = { "Product": "123", "ProductCategory": "TELE", "ProductType": "LCD" } event = CloudEvent(attributes, data) # Creates the HTTP request representation of the CloudEvent in structured content mode headers, body = to_structured(event) print("headers:") print(headers) print() json_body = json.loads(body) # Pretty print json print("body:") print(json.dumps(json_body, indent=2))

Screenshot of the output: