kevinveenbirkenbachandClaude Opus 5.5
45d956e5ea
A Redis sidecar whose consumer declares no services.redis.mem_limit
runs in a container that inherits the consumer's primary entity limit.
Since the lookup replaced the old filter, maxmemory followed that limit
and rose from 204 MiB to between 819 and 3276 MiB in 17 roles.
lookup('service_memory_mb', ..., provider=<role>) caps the result at
the same share of the provider's own limit when the application does
not declare one for that service. A declared limit is not capped, and a
container smaller than the provider keeps its own share. The Redis
sidecar passes provider='svc-db-redis': those 17 roles get 409 MiB, the
seven with a 256 MiB container stay at 204.
The lookup now rejects unknown options and a provider that is no role
or declares no limit for the service, so a misspelled option fails
instead of silently lifting the cap.
The memcached sidecar's literal -m 64 takes the same lookup and keeps
its value.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Ansible Plugins (plugins/) 🧩
This document is the central reference for plugin types and plugin placement in Infinito.Nexus.
Not to be confused with application addons. This
plugins/directory holds Ansible plugins (action / filter / lookup) that extend the automation engine itself. Some applications also call their own extensions "plugins" (e.g. Nextcloud, WordPress). Those application-level extensions, whatever the app calls them natively, are declared through the unifiedmeta/addons/contract, documented in Unified Addons. An app "plugin" is an addon; an Ansible plugin lives here.
Current Project Layout 🗂️
plugins/
├── action/ # custom action plugins
├── filter/ # custom Jinja2 filters
└── lookup/ # custom lookup plugins
Configured plugin paths in this repository are defined in ansible.cfg:
action_plugins = ./plugins/actionfilter_plugins = ./plugins/filterlookup_plugins = ./plugins/lookup
All Common Ansible Plugin Types 📚
The table below summarizes common Ansible plugin types and their conventional directory names.
| Emoji | Plugin Type | Conventional Directory | Purpose |
|---|---|---|---|
| ⚙️ | action |
action_plugins/ or plugins/action/ |
Wrap/extend module execution behavior at task runtime. |
| 🔐 | become |
become_plugins/ |
Implement privilege escalation methods. |
| 💾 | cache |
cache_plugins/ |
Persist gathered facts and cached data between runs. |
| 📣 | callback |
callback_plugins/ |
React to play/task events (logging, reporting, notifications). |
| 🖧 | cliconf |
cliconf_plugins/ |
Define CLI command transport behavior (mainly network platforms). |
| 🔌 | connection |
connection_plugins/ |
Control how Ansible connects to targets (ssh, local, etc.). |
| 🔍 | filter |
filter_plugins/ or plugins/filter/ |
Add Jinja2 filters for data transformation. |
| 🌐 | httpapi |
httpapi_plugins/ |
API transport layer over HTTP(S), mainly for network devices. |
| 🧭 | inventory |
inventory_plugins/ |
Build dynamic inventories from APIs, services, or files. |
| 👉 | lookup |
lookup_plugins/ or plugins/lookup/ |
Resolve dynamic values during playbook processing. |
| 🛰️ | netconf |
netconf_plugins/ |
NETCONF transport integration for network automation. |
| 🐚 | shell |
shell_plugins/ |
Adjust shell command wrapping/execution behavior. |
| 🧠 | strategy |
strategy_plugins/ |
Customize task scheduling/execution strategy. |
| ✅ | test |
test_plugins/ |
Add Jinja2 tests used in conditions and templates. |
| 📦 | vars |
vars_plugins/ |
Load variables from custom sources. |
Which Plugin Type to Use 🧭
action ⚙️
Use when task execution behavior itself must be changed or wrapped.
Examples:
- centralized retry logic (
uri_retry.py), - argument normalization before module dispatch,
- pre/post task orchestration.
filter 🔍
Use for pure data transformation in Jinja2 expressions.
Examples:
- mapping/normalizing dictionaries,
- deriving computed fields for templates,
- deterministic formatting helpers.
lookup 👉
Use when a value must be dynamically resolved at runtime.
Examples:
- computing IDs from role metadata,
- resolving paths/version data,
- reading structured project data for templates/tasks.
callback 📣
Use to hook into execution events and shape output/reporting.
inventory 🧭
Use when host/group data should come from a dynamic source.
strategy 🧠
Use to alter how tasks are scheduled/executed across hosts.
vars 📦
Use to load variables from custom backends.
connection, become, shell 🔌🔐🐚
Use to customize low-level execution and privilege mechanics.
cache 💾
Use to persist facts/results across runs for performance and consistency.
cliconf, httpapi, netconf 🖧🌐🛰️
Use in network automation contexts requiring protocol-specific transport behavior.
test ✅
Use to add custom Jinja2 test operators for conditional logic.
Best Practices 🧪
- Keep plugin interfaces explicit and stable.
- Keep plugin logic focused; move shared logic to
utils/. - Add unit tests for plugin behavior and integration tests for end-to-end flows.
- Prefer deterministic outputs and avoid hidden global state.
- Document any plugin-specific task arguments in the plugin docstring and README.
References 🔗
- Ansible plugin development: docs.ansible.com
- Ansible plugin index (all types): docs.ansible.com
- Ansible
ansible-docplugin types:ansible-doc -t ...