X: @systemcraftsman | 🦋: @systemcraftsman.com Building Kubernetes Operators in Rust: A New Operator SDK Plugin Aykut M. Bulgu Principal Software Engineer @ Red Hat @SystemCraftsman 

X: @systemcraftsman | 🦋: @systemcraftsman.com About Me #oc apply -f aykutbulgu.yaml apiVersion: redhat/v7 kind: Principal Software Engineer metadata: name: Aykut Bulgu namespace: Red Hat Ansible Engineering (previously Kafka) annotations: twitter: @SystemCraftsman bsky: @SystemCraftsman.com email: - [email protected] - [email protected] ex-organizer: Software Craftsmanship Turkey founder: System Craftsman labels: married: yes children: 2 interests: - basketball/nba/rockets - gamification - stoicism spec: replicas: 1 containers: - image: aykut:latest 

X: @systemcraftsman | 🦋: @systemcraftsman.com Schedule ● Operators ● Developing Operators ○ Kubebuilder ○ Operator SDK ● Why Not Rust? ● Why Rust? ● Developing Operators with Rust ○ Kube-rs ○ Rust Operator SDK Plugin ● Demo 

X: @systemcraftsman | 🦋: @systemcraftsman.com Operators 

X: @systemcraftsman | 🦋: @systemcraftsman.com The Control Loop In robotics and automation, a control loop is a non-terminating loop that regulates the state of a system. In Kubernetes, controllers are control loops that watch the state of your cluster, then make or request changes where needed. 

X: @systemcraftsman | 🦋: @systemcraftsman.com The Controller Pattern Observe Analyze Act 

X: @systemcraftsman | 🦋: @systemcraftsman.com The Operator Pattern https://kubernetes.io/docs/concepts/extend-kubernetes/operator/ 

X: @systemcraftsman | 🦋: @systemcraftsman.com OperatorHub.io 

X: @systemcraftsman | 🦋: @systemcraftsman.com An example: Strimzi Kafka Operator 

X: @systemcraftsman | 🦋: @systemcraftsman.com Developing Operators 

X: @systemcraftsman | 🦋: @systemcraftsman.com Ways of Developing Operators ● Calling the API directly => 🥷🥷🥷 ● Using the Clients => 🥷🥷 ● Using Operator Development Frameworks => 🥷 

X: @systemcraftsman | 🦋: @systemcraftsman.com Calling the API (Pure Bash) 

X: @systemcraftsman | 🦋: @systemcraftsman.com Kubernetes Clients 

X: @systemcraftsman | 🦋: @systemcraftsman.com Operator Development Frameworks ● Kubebuilder ● Operator SDK ● Metacontroller ● Charmed Operator SDK ● KubeOps 

X: @systemcraftsman | 🦋: @systemcraftsman.com Kubebuilder 

X: @systemcraftsman | 🦋: @systemcraftsman.com Kubebuilder $ kubebuilder init … Kubebuilder is a framework for building Kubernetes APIs using custom resource definitions (CRDs). 

X: @systemcraftsman | 🦋: @systemcraftsman.com Kubebuilder as a Library https://github.com/kubernetes-sigs/kubebuilder 

X: @systemcraftsman | 🦋: @systemcraftsman.com Operator SDK 

X: @systemcraftsman | 🦋: @systemcraftsman.com Operator SDK 

X: @systemcraftsman | 🦋: @systemcraftsman.com Operator SDK ● Ansible ● Helm ● Go ● Java (Quarkus) Java Operator SDK (with Quarkus Extension) 

X: @systemcraftsman | 🦋: @systemcraftsman.com Operator SDK $ operator-sdk init … … --plugins helm … --plugins ansible … --plugins quarkus 

X: @systemcraftsman | 🦋: @systemcraftsman.com Why Not Rust? 

X: @systemcraftsman | 🦋: @systemcraftsman.com Why Rust? 

X: @systemcraftsman | 🦋: @systemcraftsman.com Rust is Fast! ● Zero-cost abstractions: Rust compiles high-level constructs down to efficient machine code without runtime overhead. ● No garbage collector: Unlike Go, Rust has no GC pauses. This is critical in latency-sensitive workloads like operators or controllers managing many custom resources. ● Predictable performance: No hidden allocations, background threads, or GC behavior makes Rust predictable in both throughput and latency. 

X: @systemcraftsman | 🦋: @systemcraftsman.com Rust is Safe ● Ownership model: Eliminates entire classes of bugs like use-after-free, null pointer dereferencing, and data races at compile time. ● Concurrency safety: Thread safety is enforced by the type system, making it harder to write racy code even in multithreaded operators. ● Immutable-by-default: Encourages safe patterns by default, reducing unexpected side effects during reconciliations or retries. 

X: @systemcraftsman | 🦋: @systemcraftsman.com Rust is Sane ● Strong static typing + pattern matching: Leads to clearer, more expressive logic in state machines like reconcile loops. ● Excellent tooling: cargo, clippy, rust-analyzer, and fmt provide a top-tier developer experience out of the box. ● Compiler as a mentor: The Rust compiler guides developers toward better code. The errors are verbose but educational. 

X: @systemcraftsman | 🦋: @systemcraftsman.com Rust in CNCF 

X: @systemcraftsman | 🦋: @systemcraftsman.com Developing Operators with Rust 

X: @systemcraftsman | 🦋: @systemcraftsman.com kube-rs 

X: @systemcraftsman | 🦋: @systemcraftsman.com Kube-rs Crates 

X: @systemcraftsman | 🦋: @systemcraftsman.com Spec and API Access 

X: @systemcraftsman | 🦋: @systemcraftsman.com Controller and Reconciliation 

X: @systemcraftsman | 🦋: @systemcraftsman.com Using the Clients => 🥷🥷 Using Operator Development Frameworks => 🥷 

X: @systemcraftsman | 🦋: @systemcraftsman.com Recalling the Operator SDK ● Ansible ● Helm ● Go ● Java (Quarkus) 

X: @systemcraftsman | 🦋: @systemcraftsman.com Rust Operator SDK Plugin 

X: @systemcraftsman | 🦋: @systemcraftsman.com Rust Operator SDK Plugin 

X: @systemcraftsman | 🦋: @systemcraftsman.com Initializing the Operator 

X: @systemcraftsman | 🦋: @systemcraftsman.com Creating the API and Reconcilers 

X: @systemcraftsman | 🦋: @systemcraftsman.com Talk is Cheap, Let’s See the Demo! 

X: @systemcraftsman | 🦋: @systemcraftsman.com Demo on GitHub 

X: @systemcraftsman | 🦋: @systemcraftsman.com What’s Next? ● Moving to Operator SDK org. ● RBAC files ● Release pipeline (artifacts only) ● Webhooks ● … Feel free to contribute! 

X: @systemcraftsman | 🦋: @systemcraftsman.com Thank You! Xwitter: @systemcraftsman 🦋Bluesky: @systemcraftsman.com Email: [email protected] Linkedin: https://www.linkedin.com/in/mabulgu/ Website: https://www.systemcraftsman.com/ GitHub: https://github.com/mabulgu