aldoborrero

Golang concurrency patterns. Use when writing or reviewing concurrent Go code involving goroutines, channels, select, locks, sync primitives, errgroup, singleflight, worker pools, or fan-out/fan-in pipelines. Also triggers when you detect goroutine leaks,…

Idiomatic context.Context usage in Golang — propagation through API boundaries, cancellation, timeouts and deadlines, request-scoped values, context.WithoutCancel for background work outliving requests. Apply when designing context propagation across layers,…

Idiomatic Golang error handling — creation, wrapping with %w, errors.Is/As, errors.Join, custom error types, sentinel errors, panic/recover, the single handling rule, structured logging with slog, HTTP request logging middleware, and samber/oops for…

Linting best practices and golangci-lint configuration for Golang projects — running linters, configuring .golangci.yml, suppressing warnings with nolint directives, interpreting lint output, and selecting linters. Use when configuring golangci-lint, asking…

Modernize Golang code to use recent language features, standard library improvements, and idiomatic patterns. Trigger proactively when writing or reviewing Go code and old-style patterns are detected, or when encountering a deprecation warning. Also use when…

Go (Golang) naming conventions — covers packages, constructors, structs, interfaces, constants, enums, errors, booleans, receivers, getters/setters, functional options, acronyms, test functions, and subtest names. Use this skill when writing new Go code,…

Golang performance optimization patterns and methodology - if X bottleneck, then apply Y. Covers allocation reduction, CPU efficiency, memory layout, GC tuning, pooling, caching, and hot-path optimization. Use when profiling or benchmarks have identified a…

Defensive Golang coding to prevent panics, silent data corruption, and subtle runtime bugs. Use when encountering nil panics, append aliasing, map concurrent access, float comparison pitfalls, or zero-value design questions. Also use when reviewing code for…

House-style scaffold for new Nix-flake projects (Go, Python, or other languages) — numtide/blueprint with prefix="nix", direnv .envrc, numtide devshell with in-repo toolchain caches, treefmt formatter, two-file package (default.nix shim + nixpkgs-style…

treefmt-nix formatter for Nix flakes — `formatter.nix` via `treefmt-nix.lib.evalModule` (build.wrapper + build.check), lint→format ordering with priorities (deadnix→nixfmt, shellcheck→shfmt, ruff-check→ruff-format), and the format check wired into `nix flake…

numtide/blueprint — Nix flake framework that maps a fixed directory structure to flake outputs with zero glue code. Apply when a repo's flake.nix calls `inputs.blueprint { ... }`; when deciding where a package, devshell, host, module, check or template file…

Building and publishing OCI/Docker container images from Nix — dockerTools.buildLayeredImage over a buildEnv (app + cacert), non-root numeric User for Kubernetes runAsNonRoot, version-derived tags, and pushing with skopeo (docker-archive → OCI) to registries…

Secrets in NixOS flakes with sops-nix + age (+ age-plugin-yubikey) — .sops.yaml recipients and creation_rules, a centralized sops.secrets declaration module, and runtime consumption from /run/secrets. Apply when adding, editing or rotating an encrypted…

Adding or provisioning a NixOS host in a blueprint-based config flake — hosts/<name>/default.nix escape hatch wiring input modules (disko, sops-nix, nixos-hardware, nixos-facter), declarative partitioning with disko (GPT ESP+root, ext4 or btrfs subvolumes),…

Expert guidance for numtide/blueprint — an opinionated Nix flake library that maps a standard folder structure to flake outputs. Use this skill whenever the user asks about blueprint in any Nix context: setting up a new project with blueprint, understanding…

Automate interactive CLI programs with persistent sessions using pexpect-cli and pueue. Use when needing to automate programs that require interactive input/output (SSH sessions, database CLIs, vim/editors, interactive shells, or any program with prompts).…

Use when writing, editing, validating, debugging, or extending a configarr.yml — the single declarative YAML that configarr uses to manage Radarr, Sonarr, Prowlarr, Bazarr, and SABnzbd. Triggers when: (1) creating or changing a configarr.yml; (2) adding a…