GCP DrawIO Diagram Generator

Generates professional DrawIO XML diagrams for Google Cloud Platform architectures.

Capabilities

1. Extract - Analyze existing DrawIO XML files to identify GCP shapes, connections, and structure
2. Identify - Recognize GCP service icons from architecture diagram images
3. Generate - Create valid DrawIO XML from images or text descriptions
4. Convert - Transform GCP architecture diagrams into editable DrawIO format

Quick Reference

GCP Shape Pattern

shape=mxgraph.gcp2.{service_name}

Note: GCP uses snake_case for shape names (e.g., cloud_run, cloud_sql, cloud_storage).

Icon Pattern: Unlike AWS, GCP uses a single icon pattern for all services — there is no service vs instance icon distinction. The same shape=mxgraph.gcp2.{name} is used whether labeling the service itself ("Cloud Run") or a specific instance ("Cloud Run (API Handler)"). Differentiate by label text only.

Common GCP Services

Service	Shape Code
Cloud Run	mxgraph.gcp2.cloud_run
BigQuery	mxgraph.gcp2.bigquery
Cloud Storage	mxgraph.gcp2.cloud_storage
Vertex AI	mxgraph.gcp2.cloud_machine_learning
Cloud Scheduler	mxgraph.gcp2.cloud_scheduler
Apigee	mxgraph.gcp2.apigee_api_platform
Pub/Sub	mxgraph.gcp2.cloud_pubsub
Cloud SQL	mxgraph.gcp2.cloud_sql
GKE	mxgraph.gcp2.compute_engine
Cloud Functions	mxgraph.gcp2.cloud_functions

GCP Container Types

Container	Use Case
gcp_project	Main project boundary (two-cell pattern)
gcp_vpc_sc	VPC Service Controls perimeter (green border)
gcp_region	Regional grouping
gcp_zone	Zone grouping
logical_group_dashed	Logical grouping with dashed border
logical_group_solid	Solid border grouping
subnet	Subnet boundary
firewall_rules	Firewall rules grouping
instance_group	Instance group container

---

Task 1: Analyze a DrawIO File

Use this workflow to extract and document all components from an existing DrawIO file.

Steps

1. Read the file - Load the .drawio XML file
2. Parse structure - Extract all <mxCell> elements
3. Identify shapes - Find cells with vertex="1"
4. Identify connections - Find cells with edge="1"
5. Extract styles - Parse style strings for each element
6. Map hierarchy - Build container/child relationships using parent attribute
7. Generate report - Output findings in structured format

Input

• Path to .drawio file

Output

Generate a Markdown report with:

# DrawIO Analysis Report

## Summary
- Total shapes: X
- Total connections: Y
- Containers: Z

## Shape Inventory

| ID | Label | Type | Position | Parent |
|----|-------|------|----------|--------|
| abc | Cloud Run | mxgraph.gcp2.cloud_run | (100,200) | vpc1 |

## Connection Matrix

| From | To | Label | Type |
|------|-----|-------|------|
| Cloud Run | BigQuery | API | solid |

## Container Hierarchy

- VPC-SC (vpc1)
  - Cloud Run (run1)
  - Cloud Run (run2)
  - BigQuery (bq1)

## Style Analysis

### Unique Shapes Found
- mxgraph.gcp2.cloud_run (4 instances)
- mxgraph.gcp2.bigquery (2 instances)

---

Task 2: Convert Image to DrawIO

Use this workflow to recreate a GCP architecture diagram from an image.

Steps

1. Analyze image - Identify all visual elements:

   • GCP service icons (shape, color, label)
   • Containers/boundaries (color, border style)
   • Connections (solid, dashed, arrows)
   • Labels and text

2. Map to library - For each identified element:

   • Look up in assets/gcp-icons.json by visual signature or label
   • Match containers to assets/containers.json
   • Note any unrecognized elements

3. Estimate layout - Determine positions:

   • Identify container boundaries first
   • Place icons within containers
   • Estimate x,y coordinates and dimensions
   • Standard icon size: 50x50 pixels

4. Generate XML - Build the DrawIO structure:

   • Start with base template from assets/templates/drawio-base.xml
   • Add containers first (they become parents)
   • Add service icons with correct parent references
   • Add connections between shapes

5. Create confidence report - Document accuracy:

   • List all identified components
   • Note any uncertain matches
   • Flag potential issues

Input

• GCP architecture diagram image (PNG/JPG)

Output

1. Valid .drawio XML file
2. Confidence report (Markdown)

Confidence Report Format

# Conversion Confidence Report

## Overall Confidence: 85%

## Identified Components

### High Confidence (>90%)
- Cloud Run x4 - Clear icon match
- BigQuery x2 - Clear icon match
- VPC-SC container - Green border, correct label

### Medium Confidence (70-90%)
- Vertex AI Search - Icon similar, label confirms

### Low Confidence (<70%)
- Unknown icon at position (300, 400) - Mapped to generic service

## Connection Accuracy
- 12/14 connections clearly visible
- 2 connections inferred from layout

## Notes
- "Same Instance" dashed container identified
- Bidirectional arrows on 3 connections

---

Task 3: Create DrawIO from Description

Use this workflow to generate a new GCP diagram from text specifications.

Steps

1. Parse requirements - Extract from description:

   • Required GCP services
   • Container/grouping needs
   • Connection requirements
   • Layout preferences

2. Select components - From libraries:

   • Look up services in assets/gcp-icons.json
   • Choose containers from assets/containers.json
   • Select connection styles

3. Plan layout - Design the arrangement:

   • Determine canvas size
   • Position containers first
   • Arrange services logically (left-to-right data flow, top-to-bottom hierarchy)
   • Standard spacing: 100px between 50x50 icons

4. Generate XML - Build the diagram:

   • Use assets/templates/drawio-base.xml as starting point
   • Add elements in order: containers, services, connections
   • Assign unique IDs to all elements

5. Validate - Check the output:

   • All requested components present
   • Connections reference valid IDs
   • Layout is logical and readable

Input

• Text description of desired GCP architecture

Output

• Valid .drawio XML file

Example Input

Create a GCP architecture with:
- VPC-SC container
- Cloud Scheduler triggering Cloud Run
- Cloud Run connecting to BigQuery and Cloud Storage
- Vertex AI Search connected to BigQuery

Example Output Structure

<mxfile ...>
  <diagram name="GCP Architecture">
    <mxGraphModel ...>
      <root>
        <mxCell id="0" />
        <mxCell id="1" parent="0" />
        <!-- VPC-SC Container -->
        <mxCell id="vpc" value="VPC-SC" style="..." vertex="1" parent="1">
          <mxGeometry x="50" y="50" width="700" height="400" />
        </mxCell>
        <!-- Cloud Scheduler -->
        <mxCell id="sched" value="Cloud Scheduler" style="...mxgraph.gcp2.cloud_scheduler" vertex="1" parent="vpc">
          <mxGeometry x="50" y="100" width="50" height="50" />
        </mxCell>
        <!-- More shapes... -->
        <!-- Connections -->
        <mxCell id="conn1" edge="1" source="sched" target="run" style="..." />
      </root>
    </mxGraphModel>
  </diagram>
</mxfile>

---

Shape Library Reference

Looking Up a GCP Service

1. Open assets/gcp-icons.json
2. Search by service_name or recognition_keywords
3. Use the drawio_shape.full_style for complete styling
4. Or construct style using shape=mxgraph.gcp2.{shape_name}

Service Coverage:

• 46 GCP services across 11 categories
• 40 exact matches, 6 fallback icons
• Categories: compute, database, storage, networking, ai_ml, integration, operations, api_management, data_analytics, devops, security

Note: 6 services use fallback icons (Workflows, Eventarc, Artifact Registry, Cloud Deploy, Secret Manager, Identity Platform) as they're newer services not yet in DrawIO's mxgraph.gcp2 stencil. See references/ICON-COMPATIBILITY.md for complete validation details.

GCP Service Categories

Category	Services
compute	Cloud Run, Compute Engine, GKE, Cloud Functions, App Engine
database	BigQuery, Cloud SQL, Firestore, Spanner, Bigtable, Memorystore
storage	Cloud Storage, Filestore, Persistent Disk
networking	VPC, Load Balancing, CDN, DNS, Armor, Cloud NAT
ai_ml	Vertex AI, AI Platform, Vision, NLP, Speech-to-Text
integration	Pub/Sub, Cloud Tasks, Workflows, Eventarc, Scheduler
operations	Logging, Monitoring, Trace, Error Reporting
api_management	Apigee, API Gateway
data_analytics	Dataflow, Dataproc, Cloud Composer
devops	Cloud Build, Artifact Registry, Container Registry, Cloud Deploy
security	Cloud KMS, Secret Manager, Identity Platform

---

Visual Best Practices (Summary)

For detailed visual design guidelines, see references/DIAGRAM-BEST-PRACTICES.md.

GCP Project Zone (Two-Cell Pattern)

The GCP Project container uses two cells, not one:

1. Container cell: Plain rectangle with fillColor=#F6F6F6;strokeColor=none; and HTML value <b>Google </b>Cloud Platform
2. Logo child cell: shape=mxgraph.gcp2.google_cloud_platform at 23x20px with relative=1 geometry

See assets/templates/node-template.xml for the exact template.

Font Colors

• Service icon labels: fontColor=#424242 (dark gray)
• GCP Project zone text: fontColor=#717171
• VPC-SC container title: fontColor=#2E7D32 (dark green)
• Dashed group labels: fontColor=#424242

Icon Spacing

• Icon size: 50x50 pixels
• Standard spacing: 100px between icons
• Container padding: 20-30px

Connection Labels

Always add these properties to labeled connections:

labelBackgroundColor=#FFFFFF;fontSize=10;fontColor=#333333;

Connection Best Practices

• Standard width: strokeWidth=1 for most connections
• Thick width: strokeWidth=2 only for primary data paths (use sparingly - max 1-3 per diagram)
• Orthogonal routing: edgeStyle=orthogonalEdgeStyle for professional appearance
• When 3+ connections cross same corridor: consolidate into single connection

---

XML Structure Quick Reference

For complete XML examples and detailed structure, see references/xml-examples.md.

The key building blocks:

• Shape: <mxCell id="..." value="Label" style="..." vertex="1" parent="1"> with <mxGeometry>
• Connection: <mxCell id="..." edge="1" source="..." target="..." style="...">
• Container: Shape with container=1 in style; children set parent to container ID
• Root cells: Every diagram needs <mxCell id="0"/> and <mxCell id="1" parent="0"/>

For XML parsing and extraction techniques, see references/xml-parser-guide.md.

---

Troubleshooting

Icon Not Displaying

• Verify shape name matches exactly: mxgraph.gcp2.cloud_run (underscore, not hyphen)
• Check references/ICON-COMPATIBILITY.md for correct shape names
• Ensure vertex="1" is present
• Check that <mxGeometry> has valid width/height (50x50)
• For Workflows/Eventarc, note these don't have exact icon matches in DrawIO's library

Connection Not Rendering

• Verify source and target IDs exist
• Ensure edge="1" is set
• Check that source/target shapes are vertices

Shapes Not Inside Container

• Set child's parent attribute to container's ID
• Ensure container has container=1 in style
• Position child coordinates relative to container (not absolute)

Label Not Showing

• Check value attribute is set
• Verify fontSize is reasonable (11-14)
• Ensure fontColor=#424242 is set

File Won't Open in DrawIO

• Validate XML structure (proper closing tags)
• Ensure id="0" and id="1" root cells exist
• Check for special characters in labels (use 
 for newlines)

---

Desktop Integration

After generating a .drawio file, you can validate and preview it:

1. Validate: python scripts/validate-drawio.py output.drawio --verbose
2. Analyze: python scripts/analyze-existing.py output.drawio --markdown
3. Validate Icons: python scripts/validate-gcp-icons.py
4. Export PNG: ./scripts/export-diagram.sh output.drawio png
5. Open in DrawIO: ./scripts/open-diagram.sh output.drawio

Requires DrawIO Desktop. Install on macOS: brew install drawio

---

Files in This Skill

File	Purpose
SKILL.md	This file - main instructions
Assets
assets/gcp-icons.json	GCP service icon database (46 services)
assets/containers.json	GCP container and connection styles
assets/templates/drawio-base.xml	Base XML template
assets/templates/node-template.xml	Shape insertion template
assets/templates/connection-template.xml	Connection template
References
references/ICON-COMPATIBILITY.md	Icon validation reference
references/DIAGRAM-BEST-PRACTICES.md	Visual design and layout guidelines
references/xml-parser-guide.md	Detailed XML parsing reference
references/xml-examples.md	Copy-paste XML examples
references/coordinate-system.md	Positioning and layout guide
references/style-guide.md	Style string reference
Scripts
scripts/validate-drawio.py	Validate .drawio XML structure
scripts/validate-gcp-icons.py	Validate GCP icon compatibility
scripts/fix-gcp-icons.py	Auto-fix icon shape names
scripts/fix-drawio-icons.py	Bulk fix icon references in .drawio files
scripts/extract-shape-names.py	Extract available shapes from DrawIO stencil
scripts/analyze-existing.py	Extract shapes/connections from .drawio files
scripts/export-diagram.sh	Export to PNG/PDF via DrawIO Desktop CLI
scripts/open-diagram.sh	Open .drawio file in DrawIO Desktop