Companies are under mounting pressure to continuously release new applications and features. And as software development life cycles become more iterative, continuous integration and continuous delivery (CI/CD) has become a necessary ingredient to enable more rapid deployments.
Many development teams now embrace DevOps, but fully automating a CI/CD pipeline from source code to production deployment is no easy task. For one, the number of tools in use continues to balloon, meaning CI/CD poses an ongoing maintenance hurdle. Furthermore, CI/CD tools often adopt varying formats to describe their events. A CI/CD pipeline, a form of event-driven architecture, may require a lot of special “glue” to patch events together if the output from each tool is not in a standardized format.
Interestingly, CDEvents, an emerging open source standard from the Continous Delivery Foundation (CDF), is working to standardize the root semantics of how CI/CD tools describe the payloads of their events with more granularity than CloudEvents. The project aims to establish schemas for how common CI/CD events are described, easing integration and providing more actionable data surrounding the CI/CD pipeline.
I recently met with Andrea Frittoli, open source developer advocate at IBM, to understand why the CDEvents project exists, how it works and what they’re hoping to achieve. According to Frittoli, who is also co-creator of the CDEvents project and a member of the CDF Technical Oversight Committee, CDEvents has the potential to bring much-needed interoperability to the sprawling CI/CD tooling ecosystem. Below, we’ll investigate where the project is and consider where it’s heading.
The Problem With CI/CD
At its core, the problem CDEvents is trying to solve is a lack of interoperability in the CI/CD field, explained Frittoli. As it stands today, DevOps engineers must routinely make point-to-point integrations between CI/CD tools. “No single tool will take you entirely from managing source code to production,” he said. A single development team could be using up to 15 unique components in one pipeline, and tooling preferences can vary dramatically across teams, he adds, further complicating CI/CD interoperability.
Although CloudEvents has made inroads as a specification to describe event data, nothing has yet existed specifically for describing CI/CD events. According to Frittoli, CloudEvents falls short here, as it’s agnostic about what is inserted into the payload.
Understanding CDEvents
CDEvents is “a common specification for Continuous Delivery events.” Frittoli describes it as a shared dictionary or shared semantics for common events. These events could be a change in source code, running a test, or a code execution or deploy. CDEvents uses JSON object schemas to describe the event types and can work alongside CloudEvents as an attribute. “CDEvents is a standard format for the payload as well, not only for the envelope,” said Frittoli.
As Frittoli explains, the CDF special interest group is still drafting the CDEvent specification’s exact semantics and common names. Currently, CDEvent organizes these objects into four main buckets: Core events, source code version control, CD events and CI events.
While the group is still finalizing the format of events as they work toward the initial release, the example below is an approximation of what the final format will look like:
"meta": {
"version" : "draft",
"event_id" : "A234-1234-1234",
"source" : "/staging/tekton/",
"type" : "dev.cdevents.taskrun.started",
"timestamp" : "2018-04-05T17:31:00Z"
},
"subject": {
"id": "/namespace/taskrun-123",
"type": "taskrun",
"content": {
"URL": ...
"pipelinerun": ...
}
},
"extensions": [{
"name": ,
"content": ...}
],
"links": [{
...
}]
Benefits of CI/CD Event Standardization
So, why is it necessary to define the format of CI/CD event data? What benefits does this bring to developers and the business as a whole? Well, Frittoli sees two potential primary use cases. First off, CDEvents could reduce the effort spent writing and maintaining glue code between common DevOps tools like Spinnaker, Argo or Flux. “This will allow a smoother integration between all the parts,” said Frittoli. Alleviating this could help scale CI/CD initiatives and increase overall agility.
Another positive side effect is collecting more detailed information about workloads and their performances. If all these components generate similarly-formatted events, Frittoli explained, then you can begin to create a true end-to-end visualization of the entire CI/CD pipeline. Then, you can start to measure things such as deployment frequency, failure rate, time to change and other metrics.
If events begin to use a common language, you could do many interesting things with that data, says Frittoli. Event data could help ascertain the root cause of incidents and aid debugging. One could even foresee some AIOps potential to further automate operations and increase observability around CI/CD.
Final Thoughts and Ways to Participate
CDEvents emerged at a time when iterative software development has become commonplace. A slew of helpful CI/CD tools is at our disposal to enable niche operations. Yet, the space still requires a standard way to operate between them. CDEvents is an exciting prospect, yet the project is still in its early stages. It has yet to reach a full release or any production use and proofs-of-concept are still being developed.
Of course, encouraging a vendor-neutral specification requires the tooling community to get on board. “It’s vital for the different tools to implement CDEvents for it to be successful,” said Frittoli. He encourages the tooling community to join the working group to collaborate in building proofs-of-concept. The SIG plans to continue working on finalizing the first version of the specification. In the meantime, the group has produced a proof-of-concept using Tekton and keptn and the project has its future sights set on Knative and Jenkins.
The CDEvents project is in incubating mode and maintained by the Events Special Interest Group (SIG) at the CDF. For more information, you can peruse the CDEvents documentation here or become involved with the community here. The Events SIG also holds biweekly meetings and a CDEvents Community Summit will be part of the upcoming CDcon.
