ci: Add test plan that runs CI tests and customize it for each role

* Calculate number of managed nodes with this formula:
    (( number_of_test_playbooks / 10 + 1 ))
* Add README explaining how to run the plan locally and remotely

Signed-off-by: Sergei Petrosian <spetrosi@redhat.com>

.codespellrc

@@ -5,4 +5,6 @@ check-hidden = true
 ignore-multiline-regex = codespell:ignore-begin.*codespell:ignore-end
 ignore-words = .codespell_ignores
 # skip-file is not available https://github.com/codespell-project/codespell/pull/2759
+# .pandoc_template.html5 contains a typo in Licence that we shouldn't edit
+# .README.html is generated from README.md automatically - no need to check spelling
 skip = .pandoc_template.html5,.README.html,./tests/files/client.key.nocrypt,./tests/files/client.pem

plans/README-plans.md

@@ -0,0 +1,55 @@
+# Introduction CI Testing Plans
+
+Linux System Roles CI runs [tmt](https://tmt.readthedocs.io/en/stable/index.html) test plans in [Testing farm](https://docs.testing-farm.io/Testing%20Farm/0.1/index.html) with the [tft.yml](https://github.com/linux-system-roles/network/blob/main/.github/workflows/tft.yml) GitHub workflow.
+
+The `plans/test_playbooks_parallel.fmf` plan is a test plan that runs test playbooks in parallel on multiple managed nodes.
+`plans/test_playbooks_parallel.fmf` is generated centrally from `https://github.com/linux-system-roles/.github/`.
+The automation calculates the number of managed nodes to provision with this formula:
+
+```plain
+number-of-test-playbooks / 10 + 1
+```
+
+The `plans/test_playbooks_parallel.fmf` plan does the following steps:
+
+1. Provisions systems to be used as a control node and as managed nodes.
+2. Does the required preparation on systems.
+3. For the given role and the given PR, runs the general test from [test.sh](https://github.com/linux-system-roles/tft-tests/blob/main/tests/general/test.sh).
+
+The [tft.yml](https://github.com/linux-system-roles/network/blob/main/.github/workflows/tft.yml) workflow runs the above plan and uploads the results to our Fedora storage for public access.
+This workflow uses Testing Farm's Github Action [Schedule tests on Testing Farm](https://github.com/marketplace/actions/schedule-tests-on-testing-farm).
+
+## Running Tests
+
+You can run tests locally with the `tmt try` cli or remotely in Testing Farm.
+
+### Running Tests Locally
+
+1. Install `tmt` as described in [Installation](https://tmt.readthedocs.io/en/stable/stories/install.html).
+2. Change to the role repository directory.
+3. Modify `plans/test_playbooks_parallel.fmf` to suit your requirements:
+    1. Due to [issue #3138](https://github.com/teemtee/tmt/issues/3138), comment out all managed nodes except for one.
+    2. Optionally modify environment variables to, e.g. run only specified test playbooks by modifying `SYSTEM_ROLES_ONLY_TESTS`.
+4. Enter `tmt try -p plans/test_playbooks_parallel <platform>`.
+    This command identifies the `plans/test_playbooks_parallel.fmf` plan and provisions local VMs, a control node and a managed node.
+5. `tmt try` is in development and does not identify tests from URL automatically, so after provisioning the machines, you must type `t`, `p`, `t` from the interactive prompt to identify tests, run preparation steps, and run the tests.
+
+### Running in Testing Farm
+
+1. Install `testing-farm` as described in [Installation](https://gitlab.com/testing-farm/cli/-/blob/main/README.adoc#user-content-installation).
+2. Change to the role repository directory.
+3. If you want to run tests with edits in your branch, you need to commit and push changes first to some branch.
+4. You can uncomment "Inject your ssh public key to test systems" discover step in the plan if you want to troubleshoot tests by SSHing into test systems in Testing Farm.
+5. Enter `testing-farm request`.
+    Edit to your needs.
+
+    ```bash
+    $ TESTING_FARM_API_TOKEN=<your_api_token> \
+        testing-farm request --pipeline-type="tmt-multihost" \
+        --plan-filter="tag:playbooks_parallel" \
+        --git-url "https://github.com/<my_user>/network" \
+        --git-ref "<my_branch>" \
+        --compose CentOS-Stream-9 \
+        -e "SYSTEM_ROLES_ONLY_TESTS=tests_default.yml" \
+        --no-wait
+    ```

plans/test_playbooks_parallel.fmf

@@ -51,11 +51,18 @@ provision:
       network:
         - type: eth
         - type: eth
+  - name: managed-node7
+    role: managed_node
+    connection: system
+    hardware:
+      network:
+        - type: eth
+        - type: eth
 environment:
   ANSIBLE_VER: 2.17
   REPO_NAME: network
   PYTHON_VERSION: 3.12
-  SYSTEM_ROLES_ONLY_TESTS: ""
+  SYSTEM_ROLES_ONLY_TESTS: ""  # tests_default.yml
   TEST_LOCAL_CHANGES: true
   PR_NUM: ""
   LINUXSYSTEMROLES_USER: ""
@@ -82,8 +89,6 @@ prepare:
       fi
       yum install epel-release yum-utils -y
       yum-config-manager --enable epel epel-debuginfo epel-source
-  - name: Test NICs
-    script: lshw -C network
 discover:
   - name: Prepare managed node
     how: fmf