tonyandrewmeyer

Known-good Juju bundle shapes (COS Lite, 12-Factor + COS, Identity Platform, Charmed Kubeflow) — canonical app lists and relation edges

Implementing Juju actions for operational tasks in charms. WHEN: add Juju actions to a charm, implement backup / rotate-credentials / restore actions, declare actions in charmcraft.yaml, write action handlers, test actions with Scenario, run actions with juju run.

Adding and validating charm configuration options. WHEN: add charm configuration options, declare config in charmcraft.yaml, validate config values in config-changed, apply config to a Pebble layer, apply config to a machine charm, write Scenario tests for config.

End-to-end workflow for building ops-framework charms for custom applications (K8s and machine). WHEN: build a custom Juju charm, write src/charm.py with Pebble, write a machine charm with systemd, decide K8s vs machine substrate, scaffold a non-paas-charm with charmcraft init, customise the ops framework charm lifecycle.

Workflow for charming infrastructure software (databases, caches, message brokers, proxies, monitoring). WHEN: charm infrastructure software, charm a database / cache / message broker / proxy / monitoring system, implement peer relations, leader election, primary/replica failover, backup and restore actions, clustering.

Expert guidance for developing, building, testing, and publishing Juju charms using charmcraft. WHEN: edit charmcraft.yaml, run charmcraft pack, run charmcraft init, manage charm libraries, publish a charm to Charmhub, set up multi-base builds, configure relations / config options, set up storage or containers.

Migrating deprecated ops.testing.Harness tests to state-transition (Scenario) tests. WHEN: migrate ops.testing.Harness tests to Scenario, modernise legacy Juju charm unit tests, rewrite Harness-based tests as state-transition tests, port relation_changed / pebble_ready / action tests off Harness.

Writing integration tests for charms with Jubilant + pytest-jubilant. WHEN: write integration tests for a Juju charm, use Jubilant + pytest-jubilant, deploy charms in a test, relate to postgresql or COS, run actions in tests, write cross-model COS Lite smoke tests.

Find bugs in Canonical Charm Tech Go repositories (pebble, concierge, and other Go charm ecosystem code). Use when asked to "find bugs", "audit code", "review for bugs", "check for issues", or review Go code in Juju charm infrastructure projects. Specialized for charm ecosystem Go patterns including concurrency/deadlocks, nil map panics, error handling, resource leaks, idempotency, snap API interaction, and Pebble service management. Built from analysis of 143 historical bug fixes across 2 Go repos.

Find bugs in Canonical Charm Tech Python repositories (operator/ops, charmlibs, jubilant, pytest-jubilant, operator-libs-linux, and other Python charm code). Use when asked to "find bugs", "audit code", "review for bugs", "check for issues", or review Python code in any Juju charm framework repository. Specialized for charm ecosystem bug patterns including data mutability, falsy value confusion, relation data, secrets, Pebble containers, testing-production divergence, and snap/Juju CLI interactions. Built from analysis of 344 historical bug fixes across 8 Python repos.

Find bugs in Juju charm operator repositories. Use when asked to "find bugs", "audit code", "review for bugs", "check for issues", "security review", or review Python code in any Juju charm. Specialized for charm-specific bug patterns including Pebble container management, relation data handling, TLS certificate lifecycle, status management, config handling, ingress/networking, Grafana dashboard wiring, and Juju interaction. Built from analysis of 6,116 historical bug fixes across 134 charm repositories spanning 10 teams (Data, Observability, MLOps, IS, Identity, Telco, Commercial Systems, K8s, BootStack, Charm-Tech).

Find bugs in the canonical/operator (ops) Python framework for Juju charms. Use when asked to "find bugs in operator", "audit ops code", "review operator for bugs", "check ops for issues", "find bugs in this charm framework code", or review ops/, testing/, or pebble code for correctness issues. Specialized for Juju operator framework bug patterns including relation data, secrets, Pebble containers, data mutability, and testing-production divergence.

Operate a Juju controller — deploy, configure, integrate, scale, debug, and manage charms on Kubernetes and machine models. Use when asked to "deploy a charm", "add a model", "check status", "debug a unit", "integrate applications", "scale up/down", "manage secrets", "configure an app", "run an action", "destroy a model", or any Juju CLI operation. Keywords include juju, deploy, integrate, relate, model, controller, status, debug-log, config, action, expose, storage, secrets, ssh, scale.

Migrate charm integration tests to Jubilant and pytest-jubilant 2.0. Handles migration from pytest-operator (python-libjuju) or from pytest-jubilant 1.x. Covers async removal, fixture replacement, API translation, dependency updates, and verification. license: Apache-2.0 compatibility: any version of pytest-operator, or v1.x of pytest-jubilant allowed-tools: Read

Expert assistant for validating Juju deployments using juju-doctor. Use when running deployment diagnostics, writing probes, creating rulesets, validating deployment health, or debugging deployment issues offline. Keywords include juju-doctor, probe, ruleset, deployment validation, diagnostics, health check, offline validation, sosreport.

Standard linting and testing commands for Juju charms. Use when setting up a charm project's test infrastructure, CI, or tox/make configuration. Defines the required command names and their meanings.

Develop and test against a real Juju controller

Remote control tmux sessions for interactive CLIs (python, gdb, etc.) by sending keystrokes and scraping pane output.

Expert assistant for developing Juju charms using charmcraft. Use when initializing charm projects, building charms, managing charm libraries, publishing to Charmhub, running tests, or working with charmcraft.yaml configuration. Keywords include charmcraft, Juju, charm development, Charmhub publishing, charm libraries, pack, build, upload, release, init, extensions.