When migrating off IBM Cloud Features, IBM Cloud Code Engine is likely one of the attainable deployment targets. Code Engine provides apps, jobs and (lately operate) that you would be able to (or want) to choose from. On this put up, we offer some dialogue factors and share suggestions and tips on the right way to work with Code Engine capabilities.
IBM Cloud Code Engine is a completely managed, serverless platform to (not solely) run your containerized workloads. It has evolved a lot since March 2021, after I revealed the weblog put up “Migrating Cloud Functions Code to Code Engine.” In 2021, there have been solely Code Engine apps and jobs. Earlier this year, Code Engine added support for functions (Features-as-a-Service, or FaaS).
On this put up, I’m going to take a recent have a look at that matter and talk about the choices on the right way to transfer from IBM Cloud Functions to Code Engine.
Apps, jobs and capabilities
IBM Cloud Code Engine options three different ways to run your business logic:
- An app is a constantly run course of that solutions to HTTP requests.
- A job runs to deal with a process after which terminates.
- A operate is a stateless code snippet that’s invoked by an HTTP request and, after producing a response, terminates. Furthermore, jobs often run considerably longer than capabilities (“batch processing”).
There are numerous extra characteristics that help distinguish between apps, jobs and capabilities. In brief, apps are an excellent match if you wish to craft a REST API or deploy an online software with backend/frontend performance. You’ve gotten full management over the HTTP server and its sources.
Jobs, alternatively, are long-running processes that don’t require any person interplay. They may very well be typical batch actions, analytics processing and even AI mannequin coaching.
Lastly, capabilities can react to incoming HTTP requests in a short time. They serve low-latency use circumstances nicely, like chatbot integrations or webhooks. In distinction to apps, you don’t and can’t outline and configure the HTTP server.
When coming from Cloud Features, you will have skilled that there are various use cases supported by Cloud Functions. Equally, a operate could have totally different attributes which can be essential relying on the case:
- The invocation or start-up time (chilly begin) is likely to be essential, resulting in an total brief response time.
- In different circumstances, the price (billing) might need been the aggressive issue.
- The simplicity and agility, brought on by a operate as unit for improvement and deployment in a DevSecOps course of leads some initiatives to go for capabilities.
Typically, it’s a mixture of the above that results in folks preferring capabilities (FaaS) over different runtime or compute choices.
From Cloud Features to Code Engine
When shifting from Cloud Features to Code Engine, the next operate traits have to be taken into consideration when deciding to on an app, a job or a Code Engine operate:
- Is an http endpoint wanted to invoke the code?
- Is the processing triggered by an occasion?
- What programming language is used for the present operate and the way huge are the required libraries?
- How lengthy does the processing take, what compute sources are wanted, is parallel processing desired?
The information Migrating IBM Cloud Functions to Code Engine has an in depth overview with Code Engine app, job and performance traits. They provide help to to pick out the perfect entity to your present workload. Moreover, the present Code Engine function limitations and the overall limits and quotas for Code Engine have to be taken into consideration. The part Migrating IBM Cloud Functions Actions to Code Engine Functions FAQ may provide help to resolve the right way to migrate.
Ideas and tips for Code Engine capabilities
The next suggestions and tips are based mostly on my experiences with shifting present code from Cloud Features to Code Engine capabilities. They assist in chopping down deployment cycles by first using native assessments to implement comparable performance in combining Code Engine capabilities and jobs and designing built-in APIs by making use of Code Engine system variables.
Native testing of capabilities
Apps are common internet functions, jobs are like scripts, and each might be examined domestically in a number of methods. As a result of capabilities are code snippets, some wrapper is required to show them into packages. The next strategy has served me nicely thus far.
With the operate code in a subdirectory “func,” I make the most of both the Python or Node.js wrapper code proven beneath and place it within the father or mother listing. There, I additionally preserve recordsdata with take a look at configurations as JSON objects, similar to what is passed by Code Engine to the function on invocation. For testing, I run the wrapper together with the configuration file as parameter. The wrappers for Python and Node.js are proven beneath:
# syntax: python wrapper.py params.json
# import the Code Engine operate: func/__main__.py
from func.__main__ import foremost
import sys, json
if __name__ == "__main__":
# open file, learn JSON config
with open(str(sys.argv[1])) as confFile:
params=json.load(confFile)
# invoke the CE operate and print the end result
print(foremost(params))// syntax: node wrapper.js params.json
// require the Code Engine operate: func/foremost.js
var func=require('./func/foremost.js')
// learn the file with operate parameters
const fs = require("fs");
const knowledge = fs.readFileSync(course of.argv[2]);
// invoke the CE operate and log the end result
console.log(func.foremost(JSON.parse(knowledge)));Job-like capabilities
Typically, you may want the HTTP endpoint of a operate and the probably longer execution time of a job. In that case, create each a operate and a job. Then, make the most of the Code Engine API to create a job run from inside the operate. On this hybrid strategy, the operate can get referred to as by way of its HTTP endpoint and it terminates after kicking off the job run. A job may then run as much as 24 hours and profit from the parallel job processing capabilities in Code Engine. You will discover a pattern implementation of this sample within the Code Engine code examples.
Surroundings variables and API design
For designing your API and capabilities namespace, you may make the most of Code Engine-injected environment variables like __ce_path and __ce_method. The previous holds the trail part of the requested URL like “/object”, and the latter has the HTTP methodology like GET or POST. By switching on the provided values for these variables, you may serve a number of API capabilities from the identical Code Engine operate. The profit is a single base URL.
Relying in your challenge and code administration, you may even need to mix this strategy with separating every API operate implementation into its personal file—much like the wrapper strategy proven above.
Conclusions
IBM Cloud Functions have many use circumstances and properties, so there isn’t a simple mapping to a selected Code Engine entity (i.e., app, job or operate). By evaluating an present (Cloud Features) operate’s attribute to these of the Code Engine entities, you may decide the perfect match. In lots of circumstances, a Code Engine operate is likely to be a good selection. For these circumstances, we shared suggestions and tips that you should utilize to your Features-as-a-Service challenge with Code Engine.
Use the next IBM Cloud Code Engine documentation to get began:
When you have suggestions, solutions, or questions on this put up, please attain out to me on Twitter (@data_henrik), Mastodon (@data_henrik@mastodon.social) or LinkedIn.
