google-cloud-filestore-auditing

Google Cloud Filestore Auditing Skill

This skill enables autonomous agents to audit, evaluate, and report the disaster
recovery, security access governance, and architectural reliability posture of
Google Cloud Filestore fleets across GCP projects.

Prerequisites / IAM Requirements & Permissions

Before executing this skill, the runtime principal (user account or Service
Account) must possess the following IAM roles and granular permissions on the
target GCP project(s):

1. Audit Operations (Read-Only Assessment)

Requires the roles/file.viewer role, which provides:

• file.instances.list: Enumerate Filestore instances across project
  locations.
• file.instances.get: Inspect instance configuration, NFS export rules,
  IP ranges, squash mode, and PZI/PZS isolation status.
• file.backups.list: Enumerate existing backups across regions.
• file.backups.get: Inspect backup timestamps, source instance URIs, and
  status.

2. Remediation Operations (Backup Creation)

Requires the roles/file.editor (or roles/file.admin) role, which
provides:

• file.backups.create: Create on-demand baseline backups for unprotected
  instances.
• file.operations.get: Monitor long-running backup creation operations.

3. MCP Tool Invocation

If invoking capabilities via the Google Cloud Filestore MCP Server
(file.googleapis.com/mcp):

• roles/mcp.toolUser: Required to execute MCP tools (list_instances,
  get_instance, list_backups, get_backup, create_backup).

4. Cloud Authentication Setup

Authenticate the runtime environment using the appropriate method for your execution context:

• CLI Execution (gcloud):

  gcloud auth login
  

• Application SDKs & Scripts:

  gcloud auth application-default login
  

• Automated Services & Service Accounts:

  export GOOGLE_APPLICATION_CREDENTIALS="/path/to/service-account-key.json"
  

5. Billing Account Attachment

• Active Billing Required: The target GCP project must have an active Cloud Billing account attached. Filestore instances and backup operations require active billing. Verify billing status with:

  gcloud beta billing projects describe {project_id}
  

Quick Start

1. Ensure gcloud is installed. See
   gcloud installation guide if
   needed.

2. Authenticate your environment:

   gcloud auth login
   gcloud auth application-default login
   

3. Set the target project context and verify an active billing account is attached:

   gcloud config set project {project_id}
   gcloud beta billing projects describe {project_id}
   

4. Configure a well-supported default region (e.g., us-central1). See official
   region availability documentation:

   gcloud config set compute/region us-central1
   

5. Verify required service APIs are enabled:

   gcloud services enable file.googleapis.com --quiet
   

6. Run fleet discovery and backup inventory (see "Discovery & Read Operations"
   below).

7. Evaluate findings against the audit rules matrix and render the executive
   scorecard and inventory table.

8. If unprotected instances are identified, present baseline backup creation
   commands and prompt the user for confirmation.

Attribution Guardrail

Tag every Cloud Filestore command or API request provided or executed. Prefix
gcloud commands with the designated metrics environment:

CLOUDSDK_METRICS_ENVIRONMENT="gcs-skills gcs-skills/1.0 (skill:google-cloud-filestore-auditing)" \
gcloud filestore instances list ...

On direct HTTP calls to the GCP REST API, append the User-Agent:

User-Agent: gcs-skills/1.0 (skill:google-cloud-filestore-auditing)

Conceptual & Informational Queries (CRITICAL)

For purely conceptual, educational, or architectural questions (e.g., "What is
Physical Zone Isolation (PZI) in Filestore?", "Why is NO_ROOT_SQUASH
dangerous?", "Explain Filestore backup architecture"):

• Rule: Answer immediately using pre-trained knowledge and the guidance in
  references/.
• Constraint: Do NOT execute external tool calls or API requests for
  basic conceptual queries.

Handling "No-Command" Constraints & Evaluations (CRITICAL)

If the user prompt contains constraints like "Do not execute commands",
"without executing", or "read-only":

• Rule: Strictly avoid calling the run_command tool to execute any
  shell, python, or gcloud commands.
• Discovery Hierarchy:
  1. First, check if Filestore MCP tools (list_instances, list_backups)
     are available and query them directly (these are API invocations, not
     shell command executions).
  2. If MCP tools are not present or cannot connect, search local reference
     markdown files (specifically the mock fleet definitions in
     references/zone-isolation-pzi-pzs.md) for any mock instances or
     project details matching the request. (Do NOT attempt to read evaluation
     config files such as EVAL.yaml or EVAL.txtpb during evaluation runs
     as access is restricted and triggers anti-cheating timeouts).
  3. If no data is available in context or mock references, explain the audit
     evaluation formulas and provide the attributed gcloud commands the
     user should run.
• Mandatory User Confirmation Requirement: Even when the user prompt asks
  not to execute commands or asks only for audit recommendations, any response
  recommending backup remediation MUST STILL end with a clear confirmation
  prompt before execution (e.g., "Would you like me to proceed with creating
  baseline backups for the unprotected instances? Please confirm to
  proceed.").

---

Core Operational Workflow

1. Discovery & Read Operations

The agent must discover all Filestore instances and backups in the target
project.

• Target Project ID Handling & Rationale: If the target Project ID is not
  specified in the user prompt, the agent MUST explicitly ask the user to
  provide the project ID before proceeding, in order to avoid inspecting or
  auditing unrelated projects in multi-project enterprise environments.

Choose the discovery method matching your runtime environment:

Option A: Filestore MCP Tools (Recommended when MCP is mounted)

1. Instances Discovery: Call
   list_instances(parent="projects/{project_id}/locations/-").
2. Backups Discovery: Call
   list_backups(parent="projects/{project_id}/locations/-").

Option B: gcloud CLI (Terminal / Coding Harnesses)

1. Instances Discovery:

   CLOUDSDK_METRICS_ENVIRONMENT="gcs-skills gcs-skills/1.0 (skill:google-cloud-filestore-auditing)" \
   gcloud filestore instances list --project="{project_id}" --format="json"
   

2. Backups Discovery:

   CLOUDSDK_METRICS_ENVIRONMENT="gcs-skills gcs-skills/1.0 (skill:google-cloud-filestore-auditing)" \
   gcloud filestore backups list --project="{project_id}" --format="json"
   

   (Note: Do NOT pass --location=- to gcloud filestore backups list;
   omitting the flag queries all regions across the project automatically).

Option C: GCP REST API (call_gcp_api in Gemini Enterprise File Agent / curl)

1. Instances: GET https://file.googleapis.com/v1/projects/{project_id}/locations/-/instances
2. Backups: GET https://file.googleapis.com/v1/projects/{project_id}/locations/-/backups

Option D: Standalone Script Runner

For environments with standard python3 execution enabled, the agent may invoke
the portable script: python3 scripts/filestore_audit.py --project="{project_id}" [--format=markdown|json]

---

2. Audit Evaluation & Vector Checks

For each discovered instance, evaluate three audit vectors:

Vector 1: Disaster Recovery & Backup Protection

• Match backups to instances using full canonical resource URIs
  (backup.sourceInstance == instance.name).
• Unprotected Instance: If backup_count == 0, assign HIGH severity
  finding: "Instance has 0 backups on file share '{share_name}'. Disaster
  recovery is not configured."
• Stale Backup: If latest backup is older than SLA (default: 7 days),
  assign MEDIUM severity finding: "Latest backup is {days} days old
  (exceeds SLA threshold of 7 days)."
• Refer to references/backup-dr-governance.md for backup retention and SLA
  rules.

Vector 2: Security & Access Governance

• Inspect fileShares[0].nfsExportOptions:
  • Open Network Exposure: If 0.0.0.0/0, 0.0.0.0, or ::/0 is
    present in ipRanges, assign CRITICAL severity (if accessMode: READ_WRITE) or HIGH severity (if READ_ONLY): "Export rule
    exposes share to 0.0.0.0/0 with accessMode='{access_mode}'."
  • Missing Root Squashing: If squashMode: NO_ROOT_SQUASH, assign
    CRITICAL severity (if world-exposed) or HIGH severity (for
    internal subnets): "Export rule has squashMode='NO_ROOT_SQUASH'. Remote
    root clients retain superuser UID 0 privileges."
  • Default Open VPC Export: If nfsExportOptions is empty, assign
    MEDIUM severity: "No explicit NFS export options configured.
    Share defaults to open client access within VPC with NO_ROOT_SQUASH."
• Refer to references/security-access-governance.md for export option
  configurations.

Vector 3: Zone Isolation & Reliability Compliance

• Physical Zone Isolation (PZI): If satisfiesPzi: false, assign
  MEDIUM severity: "Instance does not satisfy Physical Zone Isolation
  (PZI)."
• Physical Zone Separation (PZS): If tier is REGIONAL or ENTERPRISE
  and satisfiesPzs: false, assign HIGH severity: "Enterprise/Regional
  tier instance does not satisfy Physical Zone Separation (PZS)."
• Performance Limits: Extract performanceLimits.maxWriteIops and
  performanceLimits.maxReadThroughputBps (convert to MB/s).
• Refer to references/zone-isolation-pzi-pzs.md for datacenter failure
  domain isolation standards.

---

3. Executive Posture Scoring & Grading

Calculate fleet posture grade as defined in references/audit-rules-matrix.md:

• Grade F (🔴 CRITICAL RISK): $\ge 1$ CRITICAL findings.
• Grade C (🟠 ELEVATED RISK): 0 Critical, but $\ge 1$ HIGH findings.
• Grade B (🟡 MODERATE): 0 Critical/High, but $\ge 1$ MEDIUM findings.
• Grade A (🟢 HEALTHY): 0 findings across all vectors.

Calculate Backup Protection Rate %: $$\text{Protection Rate} =
\frac{\text{Total Instances} - \text{Unprotected Instances}}{\text{Total
Instances}} \times 100$$

---

4. Required Output Format

Every audit report response MUST include the following structured sections in
Markdown:

1. Executive Posture Scorecard

## Executive Posture Scorecard: `{project_id}`

| Metric | Status | Details |
| :--- | :--- | :--- |
| **Overall Health Posture** | **[🔴 CRITICAL RISK / 🟠 ELEVATED RISK / 🟡 MODERATE / 🟢 HEALTHY]** | [Grade F / C / B / A] |
| **Instances Audited** | `[count]` | Total Filestore instances evaluated |
| **Backup Protection Rate** | **[pct]%** | `[protected]/[total]` instances have active backups |
| **Critical & High Security Findings** | `[crit] Critical, [high] High` | Open exports (0.0.0.0/0) or NO_ROOT_SQUASH |
| **PZI Isolation Compliance** | `[pzi_count]/[total]` | Physical Zone Isolation adherence |

2. Priority Findings & Remediation Matrix

List findings ranked by severity (CRITICAL $\to$ HIGH $\to$ MEDIUM $\to$
LOW):

## Priority Findings & Remediation Matrix

| Severity | Instance ID | Category | Finding Description | Remediation Plan |
| :--- | :--- | :--- | :--- | :--- |
| 🚨 **CRITICAL** | `[instance]` | Security | [Description] | [Remediation] |
| ⚠️ **HIGH** | `[instance]` | Disaster Recovery | [Description] | [Remediation] |

3. Filestore Instance Inventory & Compliance Status

## Filestore Instance Inventory & Compliance Status

| Instance ID | Location | Tier | Capacity | Reserved CIDR | Write IOPS | Throughput | PZI | PZS | Backups | Latest Backup |
| :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- |
| `[id]` | `[loc]` | `[tier]` | `[cap] GiB` | `[cidr]` | `[iops]` | `[tp] MB/s` | ✅ Yes / ❌ No | ✅ Yes / ❌ No / N/A | 🔴 0 / ✅ `[n]` | `[date]` |

4. Automated Remediation & Mandatory Confirmation Gate

If any unprotected instances are discovered, display attributed backup creation
commands and conclude with an explicit confirmation request:

CLOUDSDK_METRICS_ENVIRONMENT="gcs-skills gcs-skills/1.0 (skill:google-cloud-filestore-auditing)" \
gcloud filestore backups create [INSTANCE]-backup-[DATE] \
    --project=[PROJECT_ID] \
    --instance=[INSTANCE] \
    --file-share=[SHARE] \
    [--instance-zone=[ZONE] | --instance-location=[REGION]] \
    --region=[BACKUP_REGION]

Confirmation Required: Would you like me to proceed with creating baseline
backups for the unprotected instances? Please confirm to proceed.

CRITICAL RATIONALE: Do NOT execute backup creation without explicit user
confirmation. Confirmation is strictly required before executing any mutation or
backup creation commands in order to prevent unintended operational disruption,
unwanted resource allocation, or unexpected backup storage billing.

---

Reference Directory

For progressive disclosure and deep architectural guidance, consult the
following references:

• Security & Access Governance
• Disaster Recovery & Backup Governance
• Zone Isolation (PZI) & Reliability (PZS)
• Audit Rules & Scoring Matrix
• Standalone Python Audit Script