Merge pull request #22 from ajdecon/update-readme

Expand documentation in README

README.md

@@ -2,6 +2,15 @@
 
 An Ansible role to install the NVIDIA driver from the NVIDIA CUDA repositories.
 
+## Requirements
+
+In the process of installing the NVIDIA driver, this role will reboot the nodes where it runs.
+Because of this, we strongly recommend that you run `ansible-playbook` from a separate node than the GPU nodes where you are installing the driver.
+
+If you attempt to run Ansible on the same node where you are installing the driver, this role will either:
+
+* Refuse to proceed with an error like `Running reboot with local connection would reboot the control node` (if running with the `local` connection)
+* Reboot the node you're running on, interrupting the playbook execution! (if running the an `ssh` connection against localhost)
 
 ## Installing
 
@@ -11,6 +20,44 @@ This role can be installed using [Ansible Galaxy](https://galaxy.ansible.com/nvi
 $ ansible-galaxy install nvidia.nvidia_driver
 ```
 
+## Role variables
+
+
+| Variable | Default value | Description |
+| -------- | ------------- | ----------- |
+| `nvidia_driver_package_state` | `"present"` | Package state for NVIDIA driver packages |
+| `nvidia_driver_package_version` | `""` | Package version to install. Note that this should match the actual version of the deb or RPM package to be installed. |
+| `nvidia_driver_persistence_mode_on` | `yes` | Whether to enable persistence mode (boolean) |
+| `nvidia_driver_skip_reboot` | `no` | Whether to skip rebooting the node during the install |
+| `nvidia_driver_module_file` | `"/etc/modprobe.d/nvidia.conf"` | Filename to use for NVIDIA driver parameters |
+| `nvidia_driver_module_params` | `""` | Parameters to pass to the NVIDIA driver |
+
+### Red Hat specific variables
+
+
+| Variable | Default value | Description |
+| -------- | ------------- | ----------- |
+| `nvidia_driver_rhel_epel_repo_baseurl` | `"https://download.fedoraproject.org/pub/epel/$releasever/$basearch/"` | Base URL to use for EPEL repo |
+| `nvidia_driver_rhel_epel_repo_gpgkey` | `"https://epel.mirror.constant.com//RPM-GPG-KEY-EPEL-{{ ansible_distribution_major_version }}"` | GPG key for the EPEL repo |
+| `nvidia_driver_rhel_cuda_repo_baseurl` | `"https://developer.download.nvidia.com/compute/cuda/repos/{{ _rhel_repo_dir }}/"` | Base URL to use for CUDA repo |
+| `nvidia_driver_rhel_cuda_repo_gpgkey` | `"https://developer.download.nvidia.com/compute/cuda/repos/{{ _rhel_repo_dir }}/7fa2af80.pub"` | GPG key for the CUDA repo |
+
+### Ubuntu specific variables
+
+
+| Variable | Default value | Description |
+| -------- | ------------- | ----------- |
+| `nvidia_driver_ubuntu_cuda_repo_baseurl` | `"http://developer.download.nvidia.com/compute/cuda/repos/{{ _ubuntu_repo_dir }}"` | Base URL to use for CUDA repo |
+| `nvidia_driver_ubuntu_cuda_repo_gpgkey_url` | `"https://developer.download.nvidia.com/compute/cuda/repos/{{ _ubuntu_repo_dir }}/7fa2af80.pub"` | GPG key for the CUDA repo |
+| `nvidia_driver_ubuntu_cuda_repo_gpgkey_id` | `"7fa2af80"` | GPG key ID for the CUDA repo |
+
+## Example playbook
+
+```
+- hosts: gpu_nodes
+  roles:
+  - nvidia.nvidia_driver
+```
 
 ## Supported distributions