53 KiB
Propagate-Changes Workflow Failure - Investigation Report
Date: January 30, 2026
Investigator: Planning Agent
Status: 🔴 ROOT CAUSE IDENTIFIED - Configuration file blocking workflow changes
Executive Summary
Investigation of workflow run #21532969700 reveals that the propagate-changes workflow completed successfully but did NOT create a PR because .github/workflows/ is still listed in the sensitive_paths configuration file, causing all workflow file changes to be blocked from propagation.
Root Cause: Mismatch between workflow code comment (claiming .github/workflows/ was removed from sensitive paths) and the actual configuration file (.github/propagate-config.yml) which still blocks workflow paths.
1. Root Cause Analysis
🔴 CRITICAL: Configuration File Still Blocks Workflow Changes
Evidence from .github/propagate-config.yml:
sensitive_paths:
- scripts/history-rewrite/
- data/backups
- docs/plans/history_rewrite.md
- .github/workflows/ # <-- THIS BLOCKS ALL WORKFLOW CHANGES
- scripts/history-rewrite/preview_removals.sh
- scripts/history-rewrite/clean_history.sh
Contradicting Comment in Workflow (line 84-85):
// NOTE: .github/workflows/ was removed from defaults - workflow updates SHOULD propagate
// to ensure downstream branches have correct CI/CD configurations
Logic Flow That Caused the Skip
- Push made to
mainbranch (triggering workflow) - Workflow compared
maintodevelopment - Found files changed included
.github/workflows/*paths - Loaded
.github/propagate-config.ymlwhich contains.github/workflows/ - Matched sensitive path →
core.info()logged skip message - PR creation skipped, workflow exits with green status ✅
2. Other Potential Causes Eliminated
| Potential Cause | Verdict | Evidence |
|---|---|---|
| Push by github-actions[bot] | ❌ Unlikely | User-triggered push would have different actor |
github.event.pusher == null |
❌ Unlikely | Push events always have pusher context |
| Main already synced with dev | ❌ No | Workflow CI changes would create diff |
| Existing open PR | ❌ Unknown | Would need gh pr list to verify |
| Sensitive path blocking | ✅ ROOT CAUSE | .github/workflows/ in config file |
3. Recommended Fix
Option A: Remove .github/workflows/ from Sensitive Paths (Recommended)
Edit .github/propagate-config.yml:
sensitive_paths:
- scripts/history-rewrite/
- data/backups
- docs/plans/history_rewrite.md
# REMOVED: .github/workflows/ - workflow updates should propagate
- scripts/history-rewrite/preview_removals.sh
- scripts/history-rewrite/clean_history.sh
Rationale:
- CI/CD changes SHOULD propagate to keep all branches in sync
- The original intent (documented in workflow comment) was to allow this
- Downstream branches with outdated workflows cause CI failures
Option B: Add Specific Exclusions Instead
If certain workflows should NOT propagate, use specific paths:
sensitive_paths:
- scripts/history-rewrite/
- data/backups
- docs/plans/history_rewrite.md
- .github/workflows/propagate-changes.yml # Only block self-propagation
- scripts/history-rewrite/preview_removals.sh
- scripts/history-rewrite/clean_history.sh
4. Additional Findings
Workflow Logic Analysis
The workflow has robust logic for:
- ✅ Checking existing PRs before creating duplicates
- ✅ Comparing commits (ahead_by check)
- ✅ Loading external config file for sensitive paths
- ✅ Proper error handling with
core.warning()
Potential Edge Case: Skip Condition
if: github.actor != 'github-actions[bot]' && github.event.pusher != null
This condition is generally safe, but:
- If a merge is performed by GitHub's merge queue or rebase,
pushercontext may vary - Consider adding logging to track when this condition fails
5. Verification Steps After Fix
- Apply fix to
.github/propagate-config.yml - Push a test change to
mainthat includes workflow modifications - Verify PR creation in GitHub Actions logs
- Check
core.info()messages for:"Checking propagation from main to development...""Created PR #XXX to merge main into development"
6. Previous Investigation (Archived)
The following sections document a previous investigation into Renovate and Playwright configuration issues.
Renovate and Playwright Configuration Issues - Investigation Report (Archived)
Date: January 30, 2026
Investigator: Planning Agent
Status: ⚠️ CRITICAL - Multiple configuration issues found
Executive Summary (Archived)
Investigation reveals that both Renovate and Playwright workflows have incorrect configurations that deviate from the user's required behavior. The Renovate configuration is missing feature branch support and has incorrect automerge settings. The Playwright workflow is missing push event triggers.
1. Renovate Configuration Issues
File Locations
- Primary Config:
.github/renovate.json(154 lines) - Workflow:
.github/workflows/renovate.yml(31 lines)
🔴 CRITICAL ISSUE #1: Missing Feature Branch Support
Current State (BROKEN):
"baseBranches": [
"development"
]
- Line:
.github/renovate.json:9 - Problem: Only targets
developmentbranch - Impact: Feature branches (
feature/*) receive NO Renovate updates
Required State:
"baseBranches": [
"development",
"feature/*"
]
🔴 CRITICAL ISSUE #2: Automerge Enabled Globally
Current State (BROKEN):
"automerge": true,
"automergeType": "pr",
"platformAutomerge": true,
- Lines:
.github/renovate.json:28-30 - Problem: All non-major updates auto-merge immediately
- Impact: Updates merge before compatibility is proven
Required State:
- Feature Branches: Manual approval required (automerge: false)
- Development Branch: Let PRs sit until proven compatible
- Major Updates: Already correctly set to manual review (line 148)
🟡 ISSUE #3: Grouped Updates Configuration
Current State (PARTIALLY CORRECT):
{
"description": "THE MEGAZORD: Group ALL non-major updates (NPM, Docker, Go, Actions) into one weekly PR",
"matchPackagePatterns": ["*"],
"matchUpdateTypes": [
"minor",
"patch",
"pin",
"digest"
],
"groupName": "weekly-non-major-updates",
"automerge": true
}
- Lines:
.github/renovate.json:116-127 - Status: ✅ Grouping behavior is CORRECT
- Problem: ❌ Automerge should be conditional on branch
🟢 CORRECT Configuration
These are working as intended:
- ✅ Major updates are separate and require manual review (line 145-148)
- ✅ Weekly schedule (Monday 8am, line 23-25)
- ✅ Grouped minor/patch updates (line 116-127)
- ✅ Custom managers for Dockerfile, scripts (lines 32-113)
2. Playwright Workflow Issues
File Locations
- Primary Workflow:
.github/workflows/playwright.yml(319 lines) - Alternative E2E:
.github/workflows/e2e-tests.yml(533 lines)
🔴 CRITICAL ISSUE #4: Missing Push Event Triggers
Current State (BROKEN):
on:
workflow_run:
workflows: ["Docker Build, Publish & Test"]
types:
- completed
workflow_dispatch:
inputs:
pr_number:
description: 'PR number to test (optional)'
required: false
type: string
- Lines:
.github/workflows/playwright.yml:4-15 - Problem: Only runs after
docker-build.ymlcompletes, NOT on direct pushes - Impact: User pushed code and Playwright tests did NOT run
Root Cause Analysis:
The workflow uses workflow_run trigger which:
- Waits for "Docker Build, Publish & Test" to finish
- Only triggers if that workflow was triggered by
pull_requestorpush - BUT the condition on line 28-30 filters execution:
if: >- github.event_name == 'workflow_dispatch' || ((github.event.workflow_run.event == 'pull_request' || github.event.workflow_run.event == 'push') && github.event.workflow_run.conclusion == 'success')
Required State:
on:
push:
branches:
- main
- development
- 'feature/**'
paths:
- 'frontend/**'
- 'backend/**'
- 'tests/**'
- 'playwright.config.js'
- '.github/workflows/playwright.yml'
pull_request:
branches:
- main
- development
- 'feature/**'
workflow_run:
workflows: ["Docker Build, Publish & Test"]
types:
- completed
workflow_dispatch:
inputs:
pr_number:
description: 'PR number to test (optional)'
required: false
type: string
🟡 ISSUE #5: Alternative E2E Workflow Exists
Discovery:
- File:
.github/workflows/e2e-tests.yml - Lines 31-50: Has CORRECT push/PR triggers:
on: pull_request: branches: - main - development - 'feature/**' paths: - 'frontend/**' - 'backend/**' - 'tests/**' - 'playwright.config.js' - '.github/workflows/e2e-tests.yml' push: branches: - main - development - 'feature/**'
Question: Are there TWO Playwright workflows?
playwright.yml- Runs after Docker build (BROKEN triggers)e2e-tests.yml- Runs on push/PR (CORRECT triggers)
Impact: Confusion about which workflow should be the primary E2E test runner
3. Required Changes Summary
Renovate Configuration Changes
File: .github/renovate.json
Change #1: Add Feature Branch Support
"baseBranches": [
- "development"
+ "development",
+ "feature/*"
],
- Line: 9
- Priority: 🔴 CRITICAL
Change #2: Conditional Automerge by Branch
- "automerge": true,
- "automergeType": "pr",
- "platformAutomerge": true,
Replace with:
"packageRules": [
{
"description": "Feature branches: Require manual approval",
"matchBaseBranches": ["feature/*"],
"automerge": false
},
{
"description": "Development branch: Automerge after compatibility proven",
"matchBaseBranches": ["development"],
"automerge": true,
"automergeType": "pr",
"platformAutomerge": true,
"minimumReleaseAge": "3 days"
}
]
- Lines: 28-30 (delete) + add to packageRules section
- Priority: 🔴 CRITICAL
Change #3: Update Grouped Updates Rule
{
"description": "THE MEGAZORD: Group ALL non-major updates (NPM, Docker, Go, Actions) into one weekly PR",
"matchPackagePatterns": ["*"],
"matchUpdateTypes": [
"minor",
"patch",
"pin",
"digest"
],
"groupName": "weekly-non-major-updates",
- "automerge": true
}
- Lines: 116-127
- Priority: 🟡 HIGH (automerge now controlled by branch-specific rules)
Playwright Workflow Changes
File: .github/workflows/playwright.yml
Option A: Add Direct Push Triggers (Recommended)
on:
+ push:
+ branches:
+ - main
+ - development
+ - 'feature/**'
+ paths:
+ - 'frontend/**'
+ - 'backend/**'
+ - 'tests/**'
+ - 'playwright.config.js'
+ - '.github/workflows/playwright.yml'
+
+ pull_request:
+ branches:
+ - main
+ - development
+ - 'feature/**'
+
workflow_run:
workflows: ["Docker Build, Publish & Test"]
types:
- completed
- Lines: 4 (insert after)
- Priority: 🔴 CRITICAL
Option B: Consolidate Workflows
Alternative Solution:
- Delete
playwright.yml(post-docker workflow) - Keep
e2e-tests.ymlas the primary E2E test runner - Update documentation to reference
e2e-tests.yml
Pros:
e2e-tests.ymlalready has correct triggers- Includes sharding and coverage collection
- More comprehensive test execution
Cons:
- Requires updating CI documentation
- May have different artifact/image handling
4. Verification Steps
After Applying Renovate Changes
-
Create test feature branch:
git checkout -b feature/test-renovate-config -
Manually trigger Renovate:
# Via GitHub Actions UI # Or via API gh workflow run renovate.yml -
Verify Renovate creates PRs against feature branch
-
Verify automerge behavior:
- Feature branch: PR should NOT automerge
- Development branch: PR should automerge after 3 days
After Applying Playwright Changes
-
Create test commit on feature branch:
git checkout -b feature/test-playwright-trigger # Make trivial change to frontend git commit -am "test: trigger playwright" git push origin feature/test-playwright-trigger -
Verify Playwright workflow runs immediately on push
-
Check GitHub Actions UI:
- Workflow should appear in "Actions" tab
- Status should show "running" or "completed"
- Should NOT wait for docker-build workflow
5. Root Cause Analysis
Why These Changes Occurred
Hypothesis: Another AI model likely:
- Simplified baseBranches to reduce complexity
- Enabled automerge globally to reduce manual PR overhead
- Removed direct push triggers to avoid duplicate test runs
Problems with this approach:
- Violates user's explicit requirements for manual feature branch approval
- Creates risk by auto-merging untested updates
- Breaks CI/CD by preventing push-triggered tests
6. Implementation Priority
Immediate (Block Development)
- 🔴 Renovate: Add feature branch support (
.github/renovate.json:9) - 🔴 Playwright: Add push triggers (
.github/workflows/playwright.yml:4)
High Priority (Block Production)
- 🟡 Renovate: Fix automerge behavior (branch-specific rules)
Medium Priority (Technical Debt)
- 🟢 Consolidate: Decide on single E2E workflow (playwright.yml vs e2e-tests.yml)
7. Configuration Comparison Table
| Setting | Current (Broken) | Required | Priority |
|---|---|---|---|
| Renovate baseBranches | ["development"] |
["development", "feature/*"] |
🔴 CRITICAL |
| Renovate automerge | Global true |
Conditional by branch | 🔴 CRITICAL |
| Renovate grouping | ✅ Weekly grouped | ✅ Weekly grouped | 🟢 OK |
| Renovate major updates | ✅ Manual review | ✅ Manual review | 🟢 OK |
| Playwright triggers | workflow_run only |
push + pull_request + workflow_run |
🔴 CRITICAL |
| E2E workflow count | 2 workflows | 1 workflow (consolidate) | 🟡 HIGH |
8. Next Steps
- Review this specification with the user
- Apply critical changes to Renovate and Playwright configs
- Test changes on feature branch before merging
- Document decision on e2e-tests.yml vs playwright.yml consolidation
- Update CI/CD documentation to reflect correct workflow triggers
Appendix: File References
Renovate Configuration
- Primary Config:
.github/renovate.json- Line 9:
baseBranches(NEEDS FIX) - Lines 28-30: Global
automerge(NEEDS FIX) - Lines 116-127: Grouped updates (NEEDS UPDATE)
- Lines 145-148: Major updates (CORRECT)
- Line 9:
Playwright Workflows
-
Primary:
.github/workflows/playwright.yml- Lines 4-15:
on:triggers (NEEDS FIX) - Lines 28-30: Execution condition (REVIEW)
- Lines 4-15:
-
Alternative:
.github/workflows/e2e-tests.yml- Lines 31-50:
on:triggers (CORRECT - consider as model)
- Lines 31-50:
End of Investigation Report 2. Docker Run (One Command) 3. Alternative: GitHub Container Registry
Code Sample:
services:
charon:
image: wikid82/charon:latest
container_name: charon
restart: unless-stopped
Verdict: Zero mention of standalone binaries, native installation, or platform-specific installers.
3. Distribution Method ✅
Source: docs/getting-started.md (Lines 1-150)
Supported Installation:
- Docker Hub:
wikid82/charon:latest - GitHub Container Registry:
ghcr.io/wikid82/charon:latest
Migration Commands:
docker exec charon /app/charon migrate
Verdict: All documentation assumes Docker runtime.
4. GoReleaser Configuration ⚠️
Source: .goreleaser.yaml (Lines 1-122)
Current Build Targets:
builds:
- id: linux
goos: [linux]
goarch: [amd64, arm64]
- id: windows
goos: [windows]
goarch: [amd64]
- id: darwin
goos: [darwin]
goarch: [amd64, arm64]
Observations:
- Builds binaries for
linux,windows,darwin - Creates archives (
.tar.gz,.zip) - Generates Debian/RPM packages
- These artifacts are never referenced in user documentation
- No installation instructions for standalone binaries
Verdict: Unnecessary build targets creating unused artifacts.
5. Release Workflow Analysis ✅
Source: .github/workflows/release-goreleaser.yml
What Gets Published:
- ✅ Docker images (multi-platform:
linux/amd64,linux/arm64) - ✅ SBOM (Software Bill of Materials)
- ✅ SLSA provenance attestation
- ✅ Cryptographic signatures (Cosign)
- ⚠️ Standalone binaries (unused)
- ⚠️ Archives (
.tar.gz,.zip- unused) - ⚠️ Debian/RPM packages (unused)
Verdict: Docker images are the primary (and only documented) distribution method.
6. Dockerfile Base Image ✅
Source: Dockerfile (Lines 1-50)
# renovate: datasource=docker depName=debian versioning=docker
ARG CADDY_IMAGE=debian:trixie-slim@sha256:...
Verdict: Debian-based Linux container. No Windows/macOS container images exist.
7. User Base & Use Cases ✅
Source: ARCHITECTURE.md
Target Audience:
"Simplify website and application hosting for home users and small teams"
Deployment Model:
"Monolithic architecture packaged as a single Docker container"
Verdict: Docker-first design with no enterprise/cloud-native multi-platform requirements.
Current Issue: Disk Space Implementation
Original Problem:
// backend/internal/models/systemmetrics.go
func UpdateDiskMetrics(db *gorm.DB) error {
// TODO: Cross-platform disk space implementation
// Currently hardcoded to "/" for Linux
// Need platform detection for Windows (C:\) and macOS
}
Why This Is Complex:
- Windows uses drive letters (
C:\,D:\) - macOS uses
/System/Volumes/Data - Windows requires
golang.org/x/sys/windowssyscalls - macOS requires
golang.org/x/sys/unixwith special mount handling - Testing requires platform-specific CI runners
Why This Is Unnecessary:
- Charon only runs in Linux containers (Debian base image)
- The host OS (Windows/macOS) is irrelevant - Docker abstracts it
- The disk space check should monitor
/app/data(container filesystem)
Old Plan Context (Now Superseded)
Previous Problem Description
The GetAvailableSpace() method in backend/internal/services/backup_service.go (lines 363-394) used Unix-specific syscalls that blocked Windows cross-compilation. This was mistakenly interpreted as requiring platform-specific implementations.
Why The Problem Was Misunderstood
- Assumption: Users need to run Charon natively on Windows/macOS
- Reality: Charon is Docker-only, runs in Linux containers regardless of host OS
- Root Cause: GoReleaser configured to build unused Windows/macOS binaries
Recommended Solution
Simple Solution: Remove Unnecessary Build Targets
Changes to .goreleaser.yaml:
builds:
- id: linux
dir: backend
main: ./cmd/api
binary: charon
env:
- CGO_ENABLED=0
goos:
- linux
goarch:
- amd64
- arm64
ldflags:
- -s -w
- -X github.com/Wikid82/charon/backend/internal/version.Version={{.Version}}
- -X github.com/Wikid82/charon/backend/internal/version.GitCommit={{.Commit}}
- -X github.com/Wikid82/charon/backend/internal/version.BuildTime={{.Date}}
archives:
- formats:
- tar.gz
id: linux
ids:
- linux
name_template: >-
{{ .ProjectName }}_
{{- .Version }}_
{{- .Os }}_
{{- .Arch }}
files:
- LICENSE
- README.md
nfpms:
- id: packages
ids:
- linux
package_name: charon
vendor: Charon
homepage: https://github.com/Wikid82/charon
maintainer: Wikid82
description: "Charon - A powerful reverse proxy manager"
license: MIT
formats:
- deb
- rpm
Removals:
- ❌
windowsbuild ID (lines 23-35) - ❌
darwinbuild ID (lines 37-51) - ❌ Windows archive format
Benefits:
- ✅ Faster CI builds (no cross-compilation overhead)
- ✅ Smaller release artifacts
- ✅ Clearer distribution model (Docker-only)
- ✅ Reduced maintenance burden
- ✅ No platform-specific disk space code needed
Simplified Disk Space Implementation
File: backend/internal/services/backup_service.go
Current Implementation (already Linux-compatible):
func (s *BackupService) GetAvailableSpace() (int64, error) {
var stat syscall.Statfs_t
if err := syscall.Statfs(s.BackupDir, &stat); err != nil {
return 0, fmt.Errorf("failed to get disk space: %w", err)
}
bsize := stat.Bsize
bavail := stat.Bavail
if bsize < 0 {
return 0, fmt.Errorf("invalid block size %d", bsize)
}
if bavail > uint64(math.MaxInt64) {
return math.MaxInt64, nil
}
available := int64(bavail) * int64(bsize)
return available, nil
}
Recommended Change: Monitor /app/data instead of / for more accurate container volume metrics:
func (s *BackupService) GetAvailableSpace() (int64, error) {
// Monitor the container data volume (or fallback to root)
dataPath := "/app/data"
var stat syscall.Statfs_t
if err := syscall.Statfs(dataPath, &stat); err != nil {
// Fallback to root filesystem if data mount doesn't exist
if err := syscall.Statfs("/", &stat); err != nil {
return 0, fmt.Errorf("failed to get disk space: %w", err)
}
}
// Existing overflow protection logic...
bsize := stat.Bsize
bavail := stat.Bavail
if bsize < 0 {
return 0, fmt.Errorf("invalid block size %d", bsize)
}
if bavail > uint64(math.MaxInt64) {
return math.MaxInt64, nil
}
available := int64(bavail) * int64(bsize)
return available, nil
}
Rationale:
- Monitors
/app/data(user's persistent volume) - Falls back to
/if volume not mounted - No platform detection needed
- Works in all Docker environments (Linux host, macOS Docker Desktop, Windows WSL2)
Decision Matrix
| Approach | Pros | Cons | Recommendation |
|---|---|---|---|
| Remove Windows/macOS targets | ✅ Aligns with actual architecture ✅ Faster CI builds ✅ Simpler codebase ✅ No cross-platform complexity |
⚠️ Can't distribute standalone binaries (never documented anyway) | ✅ RECOMMENDED |
| Keep all platforms | ⚠️ "Future-proofs" for potential pivot | ❌ Wastes CI resources ❌ Adds complexity ❌ Misleads users ❌ No documented use case |
❌ NOT RECOMMENDED |
Implementation Tasks
Task 1: Update GoReleaser Configuration
File: .goreleaser.yaml
Changes:
- Remove
windowsanddarwinbuild definitions - Remove Windows archive format (zip)
- Keep only
linux/amd64andlinux/arm64 - Update
nfpmsto reference onlylinuxbuild ID
Estimated Effort: 15 minutes
Task 2: Remove Zig Cross-Compilation from CI
File: .github/workflows/release-goreleaser.yml
Changes:
- Remove
Install Cross-Compilation Tools (Zig)step (lines 52-56) - No longer needed for Linux-only builds
Estimated Effort: 5 minutes
Task 3: Simplify Disk Metrics (Optional Enhancement)
File: backend/internal/models/systemmetrics.go
Changes:
- Update
UpdateDiskMetrics()to monitor/app/datainstead of/ - Add fallback to
/if data volume not mounted - Update comments to clarify Docker-only scope
Estimated Effort: 10 minutes
Task 4: Update Documentation
Files:
ARCHITECTURE.md- Add note about Docker-only distribution in "Build & Release Process" sectionCONTRIBUTING.md- Remove any Windows/macOS build instructions
Estimated Effort: 10 minutes
Validation Checklist
After implementation:
- CI release workflow completes successfully
- Docker images build for
linux/amd64andlinux/arm64 - No Windows/macOS binaries in GitHub releases
backend/internal/services/backup_service.gostill compiles- E2E tests pass against built image
- Documentation reflects Docker-only distribution model
Future Considerations
If standalone binary distribution is needed in the future:
-
Revisit Architecture:
- Extract backend into CLI tool
- Bundle frontend as embedded assets
- Provide platform-specific installers (
.exe,.dmg,.deb)
-
Update Documentation:
- Add installation guides for each platform
- Provide troubleshooting for native installs
-
Re-add Build Targets:
- Restore
windowsanddarwinin.goreleaser.yaml - Implement platform detection for disk metrics with build tags
- Add CI runners for each platform (Windows Server, macOS)
- Restore
Current Priority: None. Docker-only distribution meets all documented use cases.
Conclusion
Charon is explicitly designed, documented, and distributed as a Docker-only application. The Windows and macOS build targets in GoReleaser serve no purpose and should be removed.
Recommended Next Steps:
- Remove unused build targets from
.goreleaser.yaml - Remove Zig cross-compilation step from release workflow
- (Optional) Update disk metrics to monitor
/app/datavolume - Update documentation to clarify Docker-only scope
- Proceed with simplified implementation (no platform detection needed)
Plan Status: Ready for Implementation
Confidence Level: High (100% - all evidence aligns)
Risk Assessment: Low (removing unused features)
Total Estimated Effort: 40 minutes (configuration changes + testing)
Archived: Old Plan (Platform-Specific Build Tags)
The previous plan assumed cross-platform binary support was needed and proposed implementing platform-specific disk space checks using build tags. This approach is no longer necessary given the Docker-only distribution model.
Key Insight from Research:
- Charon runs in Linux containers regardless of host OS
- Windows/macOS users run Docker Desktop (which uses Linux VMs internally)
- The container always sees a Linux filesystem
- No platform detection needed
Historical Context:
}
// Safe to convert now
availBlocks := int64(bavail)
blockSize := int64(bsize)
// Check for multiplication overflow
if availBlocks > 0 && blockSize > math.MaxInt64/availBlocks {
return math.MaxInt64, nil
}
return availBlocks * blockSize, nil
}
**Key Points:**
- Preserves existing overflow protection logic
- Maintains gosec compliance (G115)
- No functional changes from current implementation
---
### Phase 3: Windows Implementation
#### File: `backup_service_disk_windows.go`
```go
//go:build windows
package services
import (
"fmt"
"math"
"path/filepath"
"strings"
"golang.org/x/sys/windows"
)
// getAvailableSpace returns the available disk space in bytes for the given directory.
// Windows implementation using GetDiskFreeSpaceExW with long path support.
func getAvailableSpace(dir string) (int64, error) {
// Normalize path for Windows
cleanPath := filepath.Clean(dir)
// Handle long paths (>260 chars) by prepending \\?\ prefix
// This enables paths up to 32,767 characters on Windows
if len(cleanPath) > 260 && !strings.HasPrefix(cleanPath, `\\?\`) {
// Convert to absolute path first
absPath, err := filepath.Abs(cleanPath)
if err != nil {
return 0, fmt.Errorf("failed to resolve absolute path for '%s': %w", dir, err)
}
// Add long path prefix
cleanPath = `\\?\` + absPath
}
// Convert to UTF-16 for Windows API
utf16Ptr, err := windows.UTF16PtrFromString(cleanPath)
if err != nil {
return 0, fmt.Errorf("failed to convert path '%s' to UTF16: %w", dir, err)
}
var freeBytesAvailable, totalBytes, totalFreeBytes uint64
err = windows.GetDiskFreeSpaceEx(
utf16Ptr,
&freeBytesAvailable,
&totalBytes,
&totalFreeBytes,
)
if err != nil {
return 0, fmt.Errorf("failed to get disk space for path '%s': %w", dir, err)
}
// freeBytesAvailable already accounts for quotas and user restrictions
// Check if value exceeds max int64
if freeBytesAvailable > uint64(math.MaxInt64) {
return math.MaxInt64, nil
}
return int64(freeBytesAvailable), nil
}
Key Points:
-
API Choice:
GetDiskFreeSpaceExvsGetDiskFreeSpaceGetDiskFreeSpaceExrespects disk quotas (correct behavior)- Returns bytes directly (no block size calculation needed)
- Supports paths > 260 characters with proper handling
-
Path Handling:
- Converts Go string to UTF-16 (Windows native format)
- Handles Unicode paths correctly
- Windows Long Path Support: For paths > 260 characters, automatically prepends
\\?\prefix - Normalizes forward slashes to backslashes for Windows API compatibility
-
Overflow Protection:
- Maintains same logic as Unix version
- Caps at
math.MaxInt64for consistency
-
Return Value:
- Uses
freeBytesAvailable(nottotalFreeBytes) - Correctly accounts for user quotas and restrictions
- Uses
Phase 4: Refactor Main File
File: backup_service.go
Modification:
// BEFORE (lines 363-394): Direct implementation
// AFTER: Delegate to platform-specific function
func (s *BackupService) GetAvailableSpace() (int64, error) {
return getAvailableSpace(s.BackupDir)
}
Changes:
- Remove
var stat syscall.Statfs_tand all calculation logic - Replace with single call to platform-specific
getAvailableSpace() - Platform selection handled at compile-time via build tags
Benefits:
- Simplified main file
- No runtime conditionals
- Zero performance overhead
- Same API for all callers
Phase 5: Dependency Management
5.1 Add Windows Dependency
Command:
cd backend
go get golang.org/x/sys/windows@latest
go mod tidy
Expected go.mod Change:
require (
// ... existing deps ...
golang.org/x/sys v0.40.0 // existing
)
Note: golang.org/x/sys is already present in go.mod (line 95), but we need to ensure windows subpackage is available. It's part of the same module, so no new direct dependency needed.
5.2 Verify Build Tags
Test Matrix:
# Test Unix build
GOOS=linux GOARCH=amd64 go build ./cmd/api
# Test Darwin build
GOOS=darwin GOARCH=arm64 go build ./cmd/api
# Test Windows build (this currently fails)
GOOS=windows GOARCH=amd64 go build ./cmd/api
Phase 6: Testing Strategy
6.1 Unit Tests
New Test Files:
backend/internal/services/
├── backup_service_disk_unix_test.go
└── backup_service_disk_windows_test.go
Unix Test (backup_service_disk_unix_test.go):
//go:build unix
package services
import (
"os"
"testing"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
)
func TestGetAvailableSpace_Unix(t *testing.T) {
// Test with temp directory
tmpDir := t.TempDir()
space, err := getAvailableSpace(tmpDir)
require.NoError(t, err)
assert.Greater(t, space, int64(0), "Available space should be positive")
// Test with invalid directory
space, err = getAvailableSpace("/nonexistent/path")
assert.Error(t, err)
assert.Equal(t, int64(0), space)
}
func TestGetAvailableSpace_UnixRootFS(t *testing.T) {
// Test with root filesystem
space, err := getAvailableSpace("/")
require.NoError(t, err)
assert.Greater(t, space, int64(0))
}
func TestGetAvailableSpace_UnixPermissionDenied(t *testing.T) {
// Test permission denied scenario
// Try to stat a path we definitely don't have access to
if os.Getuid() == 0 {
t.Skip("Test requires non-root user")
}
// Most Unix systems have restricted directories
restrictedPaths := []string{"/root", "/lost+found"}
for _, path := range restrictedPaths {
if _, err := os.Stat(path); os.IsNotExist(err) {
continue // Path doesn't exist on this system
}
space, err := getAvailableSpace(path)
if err != nil {
// Expected: permission denied
assert.Contains(t, err.Error(), "failed to get disk space")
assert.Equal(t, int64(0), space)
return // Test passed
}
}
t.Skip("No restricted paths found to test permission denial")
}
func TestGetAvailableSpace_UnixSymlink(t *testing.T) {
// Test symlink resolution - statfs follows symlinks
tmpDir := t.TempDir()
targetDir := filepath.Join(tmpDir, "target")
symlinkPath := filepath.Join(tmpDir, "link")
err := os.Mkdir(targetDir, 0755)
require.NoError(t, err)
err = os.Symlink(targetDir, symlinkPath)
require.NoError(t, err)
// Should follow symlink and return space for target
space, err := getAvailableSpace(symlinkPath)
require.NoError(t, err)
assert.Greater(t, space, int64(0))
// Compare with direct target query (should match filesystem)
targetSpace, err := getAvailableSpace(targetDir)
require.NoError(t, err)
assert.Equal(t, targetSpace, space, "Symlink should resolve to same filesystem")
}
Windows Test (backup_service_disk_windows_test.go):
//go:build windows
package services
import (
"os"
"testing"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
)
func TestGetAvailableSpace_Windows(t *testing.T) {
// Test with temp directory
tmpDir := t.TempDir()
space, err := getAvailableSpace(tmpDir)
require.NoError(t, err)
assert.Greater(t, space, int64(0), "Available space should be positive")
// Test with C: drive (usually exists on Windows)
space, err = getAvailableSpace("C:\\")
require.NoError(t, err)
assert.Greater(t, space, int64(0))
}
func TestGetAvailableSpace_WindowsInvalidPath(t *testing.T) {
// Test with invalid drive letter
space, err := getAvailableSpace("Z:\\nonexistent\\path")
// May error or return 0 depending on Windows version
if err != nil {
assert.Equal(t, int64(0), space)
}
}
func TestGetAvailableSpace_WindowsLongPath(t *testing.T) {
// Test long path handling (>260 characters)
tmpBase := t.TempDir()
// Create a deeply nested directory structure to exceed MAX_PATH
longPath := tmpBase
for i := 0; i < 20; i++ {
longPath = filepath.Join(longPath, "verylongdirectorynamewithlotsofcharacters")
}
err := os.MkdirAll(longPath, 0755)
require.NoError(t, err, "Should create long path with \\\\?\\ prefix support")
// Test disk space check on long path
space, err := getAvailableSpace(longPath)
require.NoError(t, err, "Should query disk space for paths >260 chars")
assert.Greater(t, space, int64(0), "Available space should be positive")
}
func TestGetAvailableSpace_WindowsUnicodePath(t *testing.T) {
// Test Unicode path handling to ensure UTF-16 conversion works correctly
tmpBase := t.TempDir()
// Create directory with Unicode characters (emoji, CJK, Arabic)
unicodeDirName := "test_🚀_测试_اختبار"
unicodePath := filepath.Join(tmpBase, unicodeDirName)
err := os.Mkdir(unicodePath, 0755)
require.NoError(t, err, "Should create directory with Unicode name")
// Test disk space check on Unicode path
space, err := getAvailableSpace(unicodePath)
require.NoError(t, err, "Should handle Unicode path names")
assert.Greater(t, space, int64(0), "Available space should be positive")
}
func TestGetAvailableSpace_WindowsPermissionDenied(t *testing.T) {
// Test permission denied scenario
// On Windows, system directories like C:\System Volume Information
// typically deny access to non-admin users
space, err := getAvailableSpace("C:\\System Volume Information")
if err != nil {
// Expected: access denied error
assert.Contains(t, err.Error(), "failed to get disk space")
assert.Equal(t, int64(0), space)
} else {
// If no error (running as admin), space should still be valid
assert.GreaterOrEqual(t, space, int64(0))
}
}
6.2 Integration Testing
Existing Tests Impact:
backend/internal/services/backup_service_test.goshould work unchanged- If tests mock disk space, update mocks to use new signature
- Add CI matrix testing for Windows builds
CI/CD Testing:
Add platform-specific test matrix to ensure all implementations are validated:
# .github/workflows/go-tests.yml
name: Go Tests
on:
pull_request:
paths:
- 'backend/**/*.go'
- 'backend/go.mod'
- 'backend/go.sum'
push:
branches:
- main
jobs:
test-cross-platform:
name: Test on ${{ matrix.os }}
runs-on: ${{ matrix.os }}
strategy:
fail-fast: false
matrix:
os: [ubuntu-latest, macos-latest, windows-latest]
go-version: ['1.25.6']
steps:
- name: Checkout code
uses: actions/checkout@v4
- name: Set up Go
uses: actions/setup-go@v5
with:
go-version: ${{ matrix.go-version }}
cache: true
cache-dependency-path: backend/go.sum
- name: Run platform-specific tests
working-directory: backend
run: |
go test -v -race -coverprofile=coverage.txt -covermode=atomic ./internal/services/...
- name: Upload coverage
uses: codecov/codecov-action@v4
with:
files: ./backend/coverage.txt
flags: ${{ matrix.os }}
token: ${{ secrets.CODECOV_TOKEN }}
verify-cross-compilation:
name: Cross-compile for ${{ matrix.goos }}/${{ matrix.goarch }}
runs-on: ubuntu-latest
strategy:
matrix:
include:
- goos: linux
goarch: amd64
- goos: linux
goarch: arm64
- goos: darwin
goarch: amd64
- goos: darwin
goarch: arm64
- goos: windows
goarch: amd64
steps:
- name: Checkout code
uses: actions/checkout@v4
- name: Set up Go
uses: actions/setup-go@v5
with:
go-version: '1.25.6'
- name: Build for ${{ matrix.goos }}/${{ matrix.goarch }}
working-directory: backend
env:
GOOS: ${{ matrix.goos }}
GOARCH: ${{ matrix.goarch }}
CGO_ENABLED: 0
run: |
go build -v -o /tmp/charon-${{ matrix.goos }}-${{ matrix.goarch }} ./cmd/api
6.3 Manual Testing Checklist
Unix/Linux:
- Backup creation succeeds with sufficient space
- Backup creation fails gracefully with insufficient space
- Log messages show correct available space
Windows:
- Binary compiles successfully
- Same functionality as Unix version
- Handles UNC paths (\server\share)
- Respects disk quotas
Phase 7: Documentation Updates
7.1 Code Documentation
File-level comments:
// backup_service_disk_unix.go
// Platform-specific implementation of disk space queries for Unix-like systems.
// This file is compiled only on Linux, macOS, BSD, and other Unix variants.
// backup_service_disk_windows.go
// Platform-specific implementation of disk space queries for Windows.
// Uses Win32 API GetDiskFreeSpaceEx to query filesystem statistics.
7.2 Architecture Documentation
Update ARCHITECTURE.md:
- Add section on platform-specific implementations
- Document build tag strategy
- List platform-specific files
Update docs/development/building.md (if exists):
- Cross-compilation requirements
- Platform-specific testing instructions
7.3 Developer Guidance
Create docs/development/platform-specific-code.md:
# Platform-Specific Code Guidelines
## When to Use Build Tags
Use build tags when:
- Accessing OS-specific APIs (syscalls, Win32, etc.)
- Functionality differs by platform
- No cross-platform abstraction exists
## Build Tag Reference
- `//go:build unix` - Linux, macOS, BSD, Solaris
- `//go:build windows` - Windows
- `//go:build darwin` - macOS only
- `//go:build linux` - Linux only
## File Naming Convention
Pattern: `{feature}_{platform}.go`
Examples:
- `backup_service_disk_unix.go`
- `backup_service_disk_windows.go`
Phase 8: Configuration Updates
8.1 Codecov Configuration
Current codecov.yml (line 15-31):
ignore:
- "**/*_test.go"
- "**/testdata/**"
- "**/mocks/**"
No changes needed:
- Platform-specific files are production code
- Should be included in coverage
- Tests run on each platform will cover respective implementation
Rationale:
- Unix tests run on Linux CI runners → cover
*_unix.go - Windows tests run on Windows CI runners → cover
*_windows.go - Combined coverage shows full platform coverage
8.2 .gitignore Updates
Current .gitignore:
No changes needed for source files.
Verify exclusions:
# Already covered:
*.test
*.out
backend/bin/
8.3 Linter Configuration
Verify gopls/staticcheck:
- Build tags are standard Go feature
- No linter configuration changes needed
- GoReleaser will compile each platform separately
Build Validation
Pre-Merge Checklist
Compilation Tests:
# Unix targets
GOOS=linux GOARCH=amd64 go build -o /dev/null ./backend/cmd/api
GOOS=darwin GOARCH=arm64 go build -o /dev/null ./backend/cmd/api
# Windows target (currently fails)
GOOS=windows GOARCH=amd64 go build -o /dev/null ./backend/cmd/api
Post-Implementation: All three commands should succeed with exit code 0.
Unit Test Validation:
# Run on each platform
go test ./backend/internal/services/... -v
# Expected output includes:
# - TestGetAvailableSpace_Unix (on Unix)
# - TestGetAvailableSpace_Windows (on Windows)
GoReleaser Integration
.goreleaser.yaml (lines 23-35):
- id: windows
dir: backend
main: ./cmd/api
binary: charon
env:
- CGO_ENABLED=0 # ✅ Maintained: static binary
goos:
- windows
goarch:
- amd64
Expected Behavior After Fix:
- GoReleaser snapshot builds succeed
- Windows binary in
dist/windows_windows_amd64_v1/ - Binary size similar to Linux/Darwin variants
Risk Assessment & Mitigation
Risks
| Risk | Likelihood | Impact | Mitigation |
|---|---|---|---|
| Windows API fails on network drives | Medium | Medium | Document UNC path limitations, add error handling |
| Path encoding issues (Unicode) | Low | Medium | UTF-16 conversion with error handling |
| Quota calculation differs | Low | Low | Use freeBytesAvailable (quota-aware) |
| Missing test coverage on Windows | Medium | Low | Add CI Windows runner for tests |
| Breaking existing Unix behavior | Low | High | Preserve existing logic byte-for-byte |
Rollback Plan
If Windows implementation causes issues:
- Revert to Unix-only with build tag exclusion:
//go:build !windows - Update GoReleaser to skip Windows target temporarily
- File issue to investigate Windows-specific failures
Revert Complexity: Low (isolated files, no API changes)
Timeline & Effort Estimate
Breakdown
| Phase | Task | Effort | Dependencies |
|---|---|---|---|
| 1 | File structure refactoring | 30 min | None |
| 2 | Unix implementation | 15 min | Phase 1 |
| 3 | Windows implementation | 1 hour | Phase 1, research |
| 4 | Main file refactor | 15 min | Phase 2, 3 |
| 5 | Dependency management | 10 min | None |
| 6 | Unit tests (both platforms) | 1.5 hours | Phase 2, 3 |
| 7 | Documentation | 45 min | Phase 4 |
| 8 | Configuration updates | 15 min | Phase 6 |
| Total | ~4.5 hours |
Milestones
- ✅ M1: Unix implementation compiles (Phase 1-2)
- ✅ M2: Windows implementation compiles (Phase 3)
- ✅ M3: All platforms compile successfully (Phase 4-5)
- ✅ M4: Tests pass on Unix (Phase 6)
- ✅ M5: Tests pass on Windows (Phase 6)
- ✅ M6: Documentation complete (Phase 7)
- ✅ M7: Ready for merge (Phase 8)
Success Criteria
Functional Requirements
GOOS=windows GOARCH=amd64 go buildsucceeds without errorsGetAvailableSpace()returns accurate values on Windows- Existing Unix behavior unchanged (byte-for-byte identical)
- All existing tests pass without modification
- New platform-specific tests added and passing
Non-Functional Requirements
- Zero runtime performance overhead (compile-time selection)
- No new external dependencies (uses existing
golang.org/x/sys) - Codecov shows >85% coverage for new files
- GoReleaser nightly builds include Windows binaries
- Documentation updated for platform-specific code patterns
Quality Gates
- No gosec findings on new code
- staticcheck passes on all platforms
- golangci-lint passes
- No breaking API changes
- Windows binary size < 50MB (similar to Linux)
Known Limitations & Platform-Specific Behavior
Disk Quotas
Windows:
GetDiskFreeSpaceExrespects user disk quotas configured via NTFSfreeBytesAvailablereflects quota-limited space (correct behavior)- If user has 10GB quota on 100GB volume with 50GB free, returns ~10GB
Unix:
syscall.Statfsreturns filesystem-level statistics- Does NOT account for user quotas set via
quota,edquota, or XFS project quotas - Returns physical available space regardless of quota limits
- Recommendation: For quota-aware backups on Unix, implement separate quota checking via
quotactl()syscall (future enhancement)
Mount Points and Virtual Filesystems
Both Platforms:
- Query operates on the filesystem containing the path, not the path's parent
- If backup dir is
/mnt/backupon separate mount, returns that mount's space - Virtual filesystems (tmpfs, ramfs, procfs) return valid stats but may not reflect persistent storage
Unix Specific:
/proc,/sys,/devreturn non-zero space (virtual filesystems)- Network mounts (NFS, CIFS) return remote filesystem stats (may be stale)
- Bind mounts resolve to underlying filesystem
Windows Specific:
- UNC paths (
\\server\share) supported but require network access - Mounted volumes (NTFS junctions, symbolic links) follow to target
- Drive letters always resolve to root of volume
Symlink Behavior
Unix:
syscall.Statfsfollows symlinks to target directory- If
/backup→/mnt/external/backup, queries/mnt/externalfilesystem - Broken symlinks return error ("no such file or directory")
Windows:
GetDiskFreeSpaceExfollows junction points and symbolic links- Reparse points (directory symlinks) resolve to target volume
- Hard links not applicable to directories (Windows limitation)
Path Length Limits
Unix:
- No practical path length limit on modern systems (Linux: 4096 bytes, macOS: 1024 bytes)
- Individual filename component limit: 255 bytes
Windows:
- Legacy applications: MAX_PATH = 260 characters (including drive and null terminator)
- Long path support: Up to 32,767 characters with
\\?\prefix (handled automatically in our implementation) - Registry requirement:
Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\FileSystem\LongPathsEnabled= 1 (Windows 10 1607+) - Limitation: Some third-party backup tools may not support long paths
Error Handling Edge Cases
Permission Denied:
- Unix: Returns
syscall.EACCESwrapped in error - Windows: Returns
syscall.ERROR_ACCESS_DENIEDwrapped in error - Behavior: Backup creation should fail gracefully with clear error message
Path Does Not Exist:
- Unix: Returns
syscall.ENOENT - Windows: Returns
syscall.ERROR_FILE_NOT_FOUNDorERROR_PATH_NOT_FOUND - Behavior: Create parent directories before calling space check
Network Timeouts:
- Both platforms: Network filesystem queries can hang indefinitely
- Mitigation: Document that network paths may cause slow backup starts
- Future: Add timeout context to space check calls
Overflow and Large Filesystems
Both Platforms:
- Cap return value at
math.MaxInt64(9,223,372,036,854,775,807 bytes ≈ 8 exabytes) - Filesystems larger than 8EB report max value (edge case, unlikely until 2030s)
- Block size calculation protected against multiplication overflow
Concurrent Access
Both Platforms:
- Space check is a snapshot at query time, not transactional
- Available space may decrease between check and backup write
- Mitigation: Pre-flight check provides best-effort validation; backup write handles actual out-of-space errors
Future Enhancements
Out of Scope (This PR)
-
UNC Path Support: Full support for Windows network paths (
\\server\share)- Current implementation supports basic UNC paths via Win32 API
- Advanced scenarios (DFS, mapped drives) deferred
-
Disk Quota Management: Proactive quota warnings
- Could add separate endpoint for quota information
- Requires additional Win32 API calls
-
Real-time Space Monitoring: Filesystem watcher for space changes
- Would require platform-specific event listeners
- Significant scope expansion
-
Cross-Platform Backup Restoration: Handling Windows vs Unix path separators in archives
- Archive format already uses forward slashes (zip standard)
- No changes needed for basic compatibility
Technical Debt
None identified. This implementation:
- Follows Go best practices for platform-specific code
- Uses standard library and official
golang.org/xextensions - Maintains backward compatibility
- Adds no unnecessary complexity
References
Go Documentation
Windows API
Similar Implementations
- Go stdlib:
os.Stat()uses build tags for platform-specificSys()implementation - Docker: Uses
golang.org/x/sysfor platform-specific volume operations - Prometheus: Platform-specific collectors via build tags
Project Files
- GoReleaser config:
.goreleaser.yaml(lines 23-35) - Nightly CI:
.github/workflows/nightly-build.yml(lines 268-285) - Backend go.mod:
backend/go.mod(line 95:golang.org/x/sys v0.40.0)
Appendix: Build Tag Examples in Codebase
Current Usage (from analysis):
backend/integration/*_test.go- Use//go:build integrationfor integration testsbackend/internal/api/handlers/security_handler_test_fixed.go- Uses build tags
Pattern Established: Build tags are already in use for test isolation. This PR extends the pattern to platform-specific production code.
Implementation Order
Recommended Sequence:
- Create
backup_service_disk_unix.go(copy existing logic) - Test Unix compilation:
GOOS=linux go build - Create
backup_service_disk_windows.go(new implementation) - Test Windows compilation:
GOOS=windows go build - Refactor
backup_service.goto delegate - Add unit tests for both platforms
- Update documentation
- Verify GoReleaser builds all targets
Critical Path: Phase 3 (Windows implementation) is the longest and most complex. Start research on Win32 API early.
Plan Version: 1.1 Created: 2026-01-30 Updated: 2026-01-30 Author: Planning Agent Status: Ready for Implementation
Plan Revision History
v1.1 (2026-01-30)
- ✅ Added Windows long path support with
\\?\prefix for paths > 260 characters - ✅ Removed unused
syscallandunsafeimports from Windows implementation - ✅ Added missing test cases: long paths, Unicode paths, permission denied, symlinks
- ✅ Added detailed CI/CD matrix configuration with actual workflow YAML
- ✅ Documented limitations: quotas, mount points, symlinks, path lengths
- ✅ Enhanced error messages with path context in all error returns
- ✅ Removed out-of-scope sections: GoReleaser v2 migration, SQLite driver changes (separate issue)
v1.0 (2026-01-30)
- Initial plan for cross-platform disk space check implementation
Out of Scope
The following items are explicitly excluded from this implementation plan and may be addressed in separate issues:
1. GoReleaser v1 → v2 Migration
- Rationale: Cross-platform disk space check is independent of release tooling
- Status: Tracked in separate issue for GoReleaser configuration updates
- Priority: Can be addressed after disk space check implementation
2. SQLite Driver Migration
- Rationale: Database driver choice is independent of disk space queries
- Status: Current CGO-based SQLite driver works for all platforms
- Priority: Performance optimization, not a blocking issue for Windows compilation
3. Nightly Build CI/CD Issues
- Rationale: CI/CD pipeline fixes are separate from source code changes
- Status: Tracked in separate workflow configuration issues
- Priority: Can be addressed in parallel or after implementation