Initial draft of Self-Hosted GitHub onboarding

Author: Spikatrix

docs/integrations/self-hosted-github.md

@@ -0,0 +1,135 @@
+---
+title: CodeRabbit for Self-Managed GitHub
+description: Integrate CodeRabbit with your Self-Managed GitHub instance.
+sidebar_label: Self-Managed GitHub
+---
+
+This page guides you through the process of integrating your Self-Managed GitHub with CodeRabbit.
+
+To initiate the integration, we require specific information. This is essential
+for the initial setup of CodeRabbit within your domain. Once this setup is
+complete, you can log in directly using the OAuth2 flow.
+
+### **Step 1: Getting Started**
+
+**Visit CodeRabbit:** Visit our [Login](https://coderabbit.ai/login) page and 
+select Self-Hosted GitHub
+
+![login-page](./images/login-page.png)![alt text](image.png)
+
+### Step 2: Enter your Self-Managed GitHub URL
+
+On this page, enter the URL of your self-managed GitHub instance and click
+submit. Once, you submit, we check our database for a record of your
+organization and if we find an existing one, we will start the login process.
+
+![Untitled](./images/self-hosted-github-host-url.png)
+
+If the self-managed GitHub instance is not found, we initiate the onboarding process, which can be either manual or automated.
+
+### **Step 3: Onboarding**
+
+#### Creating an OAuth App
+
+Navigate to your GitHub Self-Hosted Instance and follow the steps below to [create an OAuth App](https://docs.github.com/en/enterprise-server@latest/apps/oauth-apps/building-oauth-apps/creating-an-oauth-app):
+
+1. Sign in to your GitHub Enterprise account.
+2. In the upper-right corner of any page, click your profile photo, then click **Settings**.
+3. In the left sidebar, click **Developer settings** > **OAuth Apps**.
+4. Click **New OAuth App**.
+5. Set the following fields:
+   - **Application name**: `CodeRabbit OAuth`
+   - **Homepage URL**: `https://coderabbit.ai`
+   - **Application description**: `OAuth application for signing into CodeRabbit`
+   - **Authorization callback URL**: `https://app.coderabbit.ai/login`
+6. Click **Register application**.
+
+![GitHub Create OAuth App](./images/github-create-oauth-app.png)
+
+Once the OAuth App has been created, click on **Generate a new client secret** under the 'Client secrets' section and copy the secret as it will be visible once only
+
+Keep the following details handy:
+
+- Client ID
+- Client secret
+
+![GitHub OAuth Client ID & Secret](./images/github-oauth-client-id-secret.png)
+
+#### Creating a GitHub App**
+
+Navigate to your GitHub Self-Hosted Instance and follow the steps below to [create a GitHub App](https://docs.github.com/en/enterprise-server@latest/apps/creating-github-apps/registering-a-github-app/registering-a-github-app):
+
+1. Sign in to your GitHub Enterprise account.
+2. In the upper-right corner of any page, click your profile photo, then click **Settings**.
+3. In the left sidebar, click **Developer settings** > **GitHub Apps**
+4. Click **New GitHub App**.
+5. Set the following fields:
+   - **GitHub App name**: `CodeRabbit GitHub App`
+   - **Description**: `GitHub App for CodeRabbit`
+   - **Homepage URL**: `https://coderabbit.ai`
+   - **Callback URL**: `https://app.coderabbit.ai/login`
+   - **Request user authorization (OAuth) during installation**: `true`
+   - **Webhook Active**: `true`
+   - **Webhook URL**: `https://app.coderabbit.ai/githubHandler`
+   - **Webhook secret**: Use a secure string and keep it handy.
+   - **Permissions**:
+     - **Repository permissions**:
+       - **Checks**: Read-only
+       - **Contents**: Read and write
+       - **Discussions**: Read-only
+       - **Issues**: Read and write
+       - **Metadata**: Read-only
+       - **Pull requests**: Read and write
+     - **Organization permissions**:
+       **Members**: Read-only
+     - **Events**:
+       - Meta
+       - Issue comment
+       - Issues
+       - Label
+       - Public
+       - Pull request
+       - Pull request review
+       - Pull request review comment
+       - Pull request review thread
+       - Push
+       - Release
+6. Click **Create GitHub App**.
+
+Once the GitHub App has been created, click on **Generate a new client secret** under the 'Client secrets' section and copy the secret as it will be visible once only.
+
+Scroll down and click on **Generate a private key** under the 'Private keys' section and download the PEM file.
+
+Keep the following details handy:
+
+- App ID
+- Client ID
+- Client secret
+- Webhook secret
+- Private key
+
+![GitHub App Client ID & Secret](./images/github-app-client-id-secret.png)
+
+### **Step 4: CodeRabbit UI Onboarding**
+
+Submit the details that were accumulated:
+
+- Host URL of your GitHub instance
+- OAuth Client ID
+- OAuth Client Secret
+- GitHub App ID
+- GitHub App Client ID
+- GitHub App Client Secret
+- GitHub App Webhook Secret
+- GitHub App Private Key
+
+Click on Submit and the login process will be initiated. 
+On subsequent visits, your setup will be automatically detected, allowing for direct login.
+
+### **Step 5: Whitelist CodeRabbit IP address**
+
+Use this CodeRabbit IP if your instance requires IP whitelisting
+`35.222.179.152/32`
+
+VPN tunneling is available as an add-on package. Please reach out to us at
+[[email protected]](mailto:[email protected]) if you are interested.