feat(domain-architecture): add code style guides and Galaxy structure for image_build_manager

docs/README.rst

@@ -1,6 +1,17 @@
 Omnia Documentation
 -------------------
 
-**Omnia** is an open source project hosted on `GitHub <https://github.com/dell/omnia>`_. Go to `GitHub <https://github.com/dell/omnia>`_ to view the source, open issues, ask questions, and participate in the project.
+**Omnia** is an open source project hosted on `GitHub <https://github.com/dell/omnia>`_.
 
-The Omnia docs are hosted here: https://omnia.readthedocs.io/en/latest/index.html and are written in reStructuredText (`.rst`).
+This directory contains **generic** Omnia documentation shared across all domains.
+Domain-specific docs live inside each domain (e.g. ``src/image_build_manager/docs/``).
+
+::
+
+  docs/
+  ├── code-style/                   Code style guides (Ansible, Python, Jinja2)
+  ├── design/                       Cross-domain design documents
+  │   ├── ansible-collections-migration.md
+  │   ├── omnia-domain-repo-design.md
+  │   └── test-automation-design.md
+  └── logos/                        Omnia branding assets

docs/code-style/README.md

@@ -0,0 +1,20 @@
+# Code Style Guides — Image Build Manager
+
+Coding standards per language/tool. All code PRs are reviewed against these guides.
+Based on [Dell Omnia Code Style Guides](https://github.com/dell/omnia).
+
+| Guide | What It Covers |
+|-------|---------------|
+| [ansible.md](ansible.md) | Playbook structure, FQCN modules, role layout, linting |
+| [python.md](python.md) | Naming, docstrings, pylint rules, Ansible module patterns |
+| [jinja2.md](jinja2.md) | Template syntax, filters, whitespace, error prevention |
+| [general.md](general.md) | Copyright headers, readability, consistency, documentation |
+
+## Validated Environment
+
+| Component | Minimum Version | Validated Version |
+|-----------|----------------|-------------------|
+| Python | 3.12+ | 3.12.8 |
+| Ansible Core | 2.20+ | 2.20.0 |
+| RHEL | 10.0+ | 10.0 |
+| Podman | 5.0+ | 5.3.1 |

docs/code-style/ansible.md

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+# Ansible / YAML Style Guide — Image Build Manager
+
+Based on [Dell Omnia Ansible Style Guide](https://github.com/dell/omnia).
+
+## 1. File Conventions
+
+### 1.1 File Headers
+- Every YAML file SHALL start with the Dell Apache 2.0 copyright header (see `general.md`)
+- Copyright header SHALL be followed by `---`
+- Every playbook SHALL have a descriptive `name:` in the play definition
+
+### 1.2 File Naming
+- Playbooks: `<component>.yml` (e.g., `image_build_manager.yml`)
+- Role tasks: `main.yml`, `<action>.yml` (e.g., `validate_tags.yml`, `load_config.yml`)
+- Variables: `main.yml` in `defaults/` and `vars/`
+- Templates: `<name>.j2` in `templates/`
+
+### 1.3 Indentation
+- **2-space indentation** for all YAML files
+- No tabs — spaces only
+- No trailing whitespace
+
+## 2. Playbook Standards
+
+### 2.1 Play Structure
+```yaml
+---
+# playbook_name.yml — Brief description of purpose
+- name: Descriptive play name
+  hosts: localhost
+  connection: local
+  gather_facts: false
+
+  roles:
+    - role_name
+```
+
+### 2.2 Entry Point Rules
+- `src/<domain>.yml` MUST contain only `roles:` and `import_playbook:` — NO inline `tasks:`.
+- All `hosts:` MUST be `localhost` with `connection: local`.
+- Each play must have a step comment (`# Step N: ...`).
+
+### 2.3 Task Standards
+- Every task SHALL have a descriptive `name:` field
+- Use **FQCN** (Fully Qualified Collection Names): `ansible.builtin.copy`, not `copy`
+- Use `become: true` explicitly — never rely on implicit privilege escalation
+- Set `changed_when` for all `command`/`shell` tasks
+- Set `failed_when` for tasks with non-standard failure conditions
+
+### 2.4 Example Task
+```yaml
+- name: Ensure log directory exists
+  ansible.builtin.file:
+    path: "{{ log_dir }}"
+    state: directory
+    mode: "0755"
+  become: true
+
+- name: Check if service is running
+  ansible.builtin.command:
+    cmd: systemctl is-active minio
+  register: service_status
+  changed_when: false
+  failed_when: false
+```
+
+## 3. Role Structure
+
+```
+roles/<role_name>/
+├── defaults/main.yml      # Default variables (overridable)
+├── vars/main.yml           # Role variables (internal) — ALL error messages here
+├── tasks/
+│   ├── main.yml            # Entry point (include other task files)
+│   ├── validate_tags.yml   # Tag validation
+│   ├── load_config.yml     # Configuration loading
+│   └── validate_prereqs.yml # Prerequisite validation
+├── templates/              # Jinja2 templates
+├── files/                  # Static files
+├── handlers/main.yml       # Handlers (restart/reload)
+└── meta/main.yml           # Role metadata and dependencies
+```
+
+## 4. Variable Standards
+
+### 4.1 Naming
+- Use **snake_case** for all variable names
+- Prefix private variables with `_`: `_prereq_checks`, `_pulp_cert_check`
+- Use descriptive names: `repo_manager_output_dir`, not `dir`
+
+### 4.2 Defaults vs Vars
+- `defaults/main.yml` — Values the user CAN override
+- `vars/main.yml` — Internal values the user SHOULD NOT change
+- **ALL error messages** go in `vars/main.yml` — never inline
+
+### 4.3 Boolean Values
+- Use `true` / `false` — never `yes` / `no`
+
+### 4.4 String Quoting
+- Always quote strings that could be misinterpreted as booleans or numbers
+- Always quote strings with special characters: `{{ }}`, `:`, `#`
+
+### 4.5 Fact Caching
+- Use `cacheable: true` on `set_fact` when the fact is needed across plays
+- Use `verbosity: 1` or `2` on debug tasks (not shown by default)
+- Use `quiet: true` on assert tasks to suppress verbose output
+
+## 5. Error Handling
+
+### 5.1 Block/Rescue/Always
+```yaml
+- name: Deploy component with error handling
+  block:
+    - name: Install packages
+      ansible.builtin.dnf:
+        name: "{{ packages }}"
+        state: present
+  rescue:
+    - name: Log failure
+      ansible.builtin.debug:
+        msg: "Deployment failed: {{ ansible_failed_result.msg }}"
+```
+
+### 5.2 Assertions
+- Use `ansible.builtin.assert` for prerequisite validation
+- Provide actionable `fail_msg` messages defined in `vars/main.yml`
+
+## 6. Linting
+
+### 6.1 Required Tools
+- **ansible-lint** with production profile
+- **yamllint** for raw YAML files
+
+### 6.2 Enforced Rules
+- No unnamed tasks
+- No bare variables in `when:` clauses
+- Use FQCN for `ansible.builtin.*` modules
+- No `command`/`shell` when a module exists
+
+### 6.3 Collection Requirements
+Required collections in `requirements.yml`:
+- `ansible.utils` (IP validation)
+- `containers.podman` (container management)
+- `community.crypto` (certificate handling)
+- `community.general` (general utilities)
+
+## 7. Idempotency
+
+- All roles SHALL be idempotent — running twice produces no changes on second run
+- Use `creates:` parameter for `command` tasks that generate files
+- Use `stat` + `when` for conditional execution
+- Never use `shell` with `rm -rf` without explicit guards
+
+## 8. Secrets Management
+
+- **Never** hardcode credentials in playbooks or variable files
+- Use Ansible Vault for sensitive data
+- Reference secrets via `{{ vault_secret_name }}`
+
+## 9. Validated Environment
+
+| Component | Minimum | Validated |
+|-----------|---------|-----------|
+| Ansible Core | 2.20+ | 2.20.0 |
+| Python | 3.12+ | 3.12.8 |
+| RHEL | 10.0+ | 10.0 |

docs/code-style/general.md

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+# General Code Style — Image Build Manager
+
+Based on [Dell Omnia General Style Guide](https://github.com/dell/omnia).
+
+## 1. Copyright Header
+
+Every source file (`.yml`, `.py`, `.sh`) SHALL include this header. `.j2` templates are excluded (the parent role carries the header):
+
+```
+# Copyright 2026 Dell Inc. or its subsidiaries. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+```
+
+## 2. Principles
+
+- **Readability**: Code should read like prose — clear variable names, step comments
+- **Consistency**: Follow project conventions, not personal preference
+- **Simplicity**: Prefer simple over clever
+- **Maintainability**: Write for the next developer
+- **Documentation**: Document the *why*, not just the *what*
+
+## 3. File Organization
+
+- Group related files in directories
+- Use descriptive file names in `snake_case`
+- Keep files focused on a single responsibility
+- Maximum file length: ~300 lines (split if larger)
+
+## 4. Version Control
+
+- One logical change per commit
+- Clear, descriptive commit messages
+- Branch naming: `feature/<name>` or `fix/<name>`

docs/code-style/jinja2.md

@@ -0,0 +1,50 @@
+# Jinja2 Template Style Guide — Image Build Manager
+
+Based on [Dell Omnia Jinja2 Style Guide](https://github.com/dell/omnia).
+
+## 1. File Conventions
+
+- Template files SHALL use `.j2` extension
+- Name SHALL match the target file: `slurm.conf.j2` → `slurm.conf`
+- Store in role's `templates/` directory
+- Start with `# {{ ansible_managed }}` comment
+- **No copyright header in templates** — the role carries it
+
+## 2. Syntax
+
+| Delimiter | Purpose | Example |
+|-----------|---------|---------|
+| `{{ }}` | Variable output | `{{ admin_nic_ip }}` |
+| `{% %}` | Logic (if/for) | `{% if enable_gpu %}` |
+| `{# #}` | Comments | `{# Registry config #}` |
+
+## 3. Variables
+
+- Use dot notation: `{{ node.hostname }}`
+- Bracket notation for special chars: `{{ config['my-key'] }}`
+- Always provide defaults for optional variables:
+  ```jinja
+  {{ telemetry_port | default(9090) }}
+  ```
+
+## 4. Whitespace Control
+
+- Use `{%-` and `-%}` for clean output in loops
+- Use standard `{% %}` when whitespace is acceptable
+
+## 5. Filters
+
+| Filter | Purpose |
+|--------|---------|
+| `default(val)` | Fallback value |
+| `join(',')` | List to string |
+| `to_yaml` | Dict to YAML |
+| `bool` | Convert to boolean |
+| `int` | Convert to integer |
+| `lower` / `upper` | Case conversion |
+
+## 6. Error Prevention
+
+- Use `{{ var }}` without `default()` for required variables
+- Use `{{ var | default(omit) }}` to skip optional Ansible parameters
+- Use `| int` when arithmetic is needed