doc: add docs for gcp app connection

docs/integrations/app-connections/gcp.mdx

@@ -0,0 +1,88 @@
+---
+title: "GCP Connection"
+description: "Learn how to configure a GCP Connection for Infisical."
+---
+
+Infisical supports [service account impersonation](https://cloud.google.com/iam/docs/service-account-impersonation) to connect with your GCP projects.
+
+<Accordion title="Self-Hosted Instance">
+    Using the GCP integration on a self-hosted instance of Infisical requires configuring a service account on GCP and
+    configuring your instance to use it.
+
+    <Steps>
+        <Step title="Navigate to IAM & Admin > Service Accounts in Google Cloud Console">
+            ![Service Account Page](/images/app-connections/gcp/service-account-overview.png)
+        </Step>
+        <Step title="Create a Service Account">
+            Create a new service account that will be used to impersonate other GCP service accounts for your app connections.
+            ![Service Account Page](/images/app-connections/gcp/create-instance-service-account.png)
+        </Step>
+        <Step title="Generate Service Account Key">
+            Download the JSON key file for your service account. This will be used to authenticate your instance with GCP.
+            ![Service Account Page](/images/app-connections/gcp/create-service-account-credential.png)
+        </Step>
+        <Step title="Configure Your Instance">
+            1. Copy the entire contents of the downloaded JSON key file.
+            2. Set it as a string value for the `INF_APP_CONNECTION_GCP_SERVICE_ACCOUNT_CREDENTIAL` environment variable.
+            3. Restart your Infisical instance to apply the changes.
+            4. You can now use GCP integration with service account impersonation.
+        </Step>
+    </Steps>
+
+</Accordion>
+
+## Configure Service Account for Infisical
+
+<Steps>
+    <Step title="Navigate to IAM & Admin > Service Accounts in Google Cloud Console">
+        ![Service Account Page](/images/app-connections/gcp/service-account-overview.png)
+    </Step>
+    <Step title="Create Service Account">
+        Create a new service account with an ID that follows this requirement:
+        
+        Your service account ID must start with the first two sections of your Infisical organization ID.
+        
+        Example:
+        - Infisical organization ID: `df92581a-0fe9-42b5-b526-0a1e88ec8085`
+        - Required service account ID prefix: `df92581a-0fe9`
+
+        ![Create Service Account](/images/app-connections/gcp/create-service-account.png)
+    </Step>
+    <Step title="Configure Service Account Permissions">
+        <Tabs>
+            <Tab title="Secret Sync">
+                Add the required permissions for secret syncs:
+                ![Assign Service Account Permission](/images/app-connections/gcp/service-account-secret-sync-permission.png)
+            </Tab>
+        </Tabs>
+    </Step>
+    <Step title="Enable Service Account Impersonation">
+        On the newly created service account, assign the `Service Account Token Creator` role to the Infisical instance's service account. This allows the instance to impersonate this service account.
+        ![Service Account Page](/images/app-connections/gcp/service-account-grant-access.png)
+    </Step>
+
+</Steps>
+
+## Setup GCP Connection in Infisical
+
+<Steps>
+  <Step title="Navigate to the App Connections">
+    Navigate to the **App Connections** tab on the **Organization Settings**
+    page. ![App Connections
+    Tab](/images/app-connections/general/add-connection.png)
+  </Step>
+  <Step title="Add Connection">
+    Select the **GCP Connection** option from the connection options modal.
+    ![Select GCP
+    Connection](/images/app-connections/gcp/select-gcp-connection.png)
+  </Step>
+  <Step title="Authorize Connection">
+    Select the **Service Account Impersonation** method and click **Connect to
+    GCP**. ![Connect via GCP
+    impersonation](/images/app-connections/gcp/create-gcp-impersonation-method.png)
+  </Step>
+  <Step title="Connection Created">
+    Your **GCP Connection** is now available for use. ![Impersonation GCP
+    Connection](/images/app-connections/gcp/gcp-app-impersonation-connection.png)
+  </Step>
+</Steps>

docs/mint.json

@@ -351,7 +351,8 @@
           "group": "Connections",
           "pages": [
             "integrations/app-connections/aws",
-            "integrations/app-connections/github"
+            "integrations/app-connections/github",
+            "integrations/app-connections/gcp"
           ]
         }
       ]
@@ -798,7 +799,8 @@
           "pages": [
             "api-reference/endpoints/app-connections/list",
             "api-reference/endpoints/app-connections/options",
-            { "group":  "AWS",
+            {
+              "group": "AWS",
               "pages": [
                 "api-reference/endpoints/app-connections/aws/list",
                 "api-reference/endpoints/app-connections/aws/available",
@@ -809,7 +811,8 @@
                 "api-reference/endpoints/app-connections/aws/delete"
               ]
             },
-            { "group":  "GitHub",
+            {
+              "group": "GitHub",
               "pages": [
                 "api-reference/endpoints/app-connections/github/list",
                 "api-reference/endpoints/app-connections/github/available",
@@ -827,7 +830,8 @@
           "pages": [
             "api-reference/endpoints/secret-syncs/list",
             "api-reference/endpoints/secret-syncs/options",
-            { "group":  "AWS Parameter Store",
+            {
+              "group": "AWS Parameter Store",
               "pages": [
                 "api-reference/endpoints/secret-syncs/aws-parameter-store/list",
                 "api-reference/endpoints/secret-syncs/aws-parameter-store/get-by-id",
@@ -840,7 +844,8 @@
                 "api-reference/endpoints/secret-syncs/aws-parameter-store/remove-secrets"
               ]
             },
-            { "group":  "GitHub",
+            {
+              "group": "GitHub",
               "pages": [
                 "api-reference/endpoints/secret-syncs/github/list",
                 "api-reference/endpoints/secret-syncs/github/get-by-id",