Realising the Feedback Loop
Information Technology Solution Delivery in Enterprise Environments
Going Beyond Sprint Zero.
Continuous Delivery to Shift-Left
While the DevOps Feedback-Loop, along with finding issues early by moving production-like environments closer to the developer (Shift-Left), are key principles, there is commonly no tangible way of achieving this.
In the typically incremental progression of continuous delivery implementations, eventually automation is built to deliver to production, and typically, that is where the story ends.
Before describing the realisation of the feedback loop, it’s important to highlight the underlying framework approaches that make this possible, which are:
- Release Portability : the output of the build (Continuous Integration) process is a single, self-contained, deployable artefact
- Loose Coupling : delivery orchestration does not use any proprietary mechanisms to deploy, the pipeline tool simply calls the deployable artefact
- Artefact Registry : a store of immutable artefacts, not code (repository). These are strictly versioned and ideally offer the ability to download the latest version.
In my Sprint Zero approach, I espouse the creation of an end-to-end, do-nothing pipeline before any development begins. The final stage of this pipeline should be to push the deployable artefact to the Artefact Registry.
By doing this, a known production state is available as feedback to the developers and testers, by getting the latest version from the Artefact Registry.
Consistent Ways of Working
If this approach is applied consistently between your infrastructure, configuration management and software developers, an automated view of the Production environment is automatically available, without having to inspect the current state of each contributing pipeline.
By combining these deployable assets, users have the ability to create a full-stack, production-like environment on demand. This could be wrapped in a graphical user interface or simply run from the command-line.
Artefact Registries
Each registry vendor has different names for general purpose stores, in Azure DevOps it’s called Universal, in GitLab it’s called Generic and in Nexus it’s called Raw.
Closing note: in the above example provided, there is an Infrastructure-as-Code (IaC)/configuration management deployment package (AZT) and software deployment package (KAT). The software deployment package is a manifest driven, desired state, deployment of containers, the container image publication is not captured in the artefact store as the image build pipeline does not reflect any target environment state.