Improve loading large replays. Fix Docker image build.

[SteamNimmersatt]

• Improve loading of large replays by using chunk loading
• Fix Docker image build and startup

[fank]

Code Review

Issues Found

1. Security Risk: Disabled Server Timeouts (cmd/main.go:44-47)

e.Server.ReadTimeout = 0  // No read timeout for large files
e.Server.WriteTimeout = 0 // No write timeout for large files

Setting timeouts to 0 disables them entirely, making the server vulnerable to:

• Slowloris attacks - malicious clients can hold connections open indefinitely
• Resource exhaustion - slow clients can exhaust server file descriptors

Recommendation: Use generous but finite timeouts (e.g., 30+ minutes) rather than disabling them:

e.Server.ReadTimeout = 30 * time.Minute
e.Server.WriteTimeout = 30 * time.Minute

2. Bug: Duplicate Content-Length Header (server/handler.go)

Content-Length is set twice:

• In GetCapture(): c.Response().Header().Set("Content-Length", ...)
• In streamFile(): c.Response().Header().Set("Content-Length", ...)

The second call is redundant and should be removed from streamFile().

3. Variable Shadowing (server/handler.go:339)

func (h *Handler) streamFile(c echo.Context, filepath string) error {

The parameter filepath shadows the imported path/filepath package. Rename to filePath or path.

4. Missing 404 Error Handling (server/handler.go:230-233)

fileInfo, statErr := os.Stat(upath)
if statErr != nil {
    return statErr  // Returns raw OS error, not HTTP 404
}

Should return a proper 404:

if os.IsNotExist(statErr) {
    return echo.ErrNotFound
}
return statErr

5. Aggressive Cache Headers (low priority)

c.Response().Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")

This forces redownload every time. For large replay files, you might want to allow some caching. Not critical, just something to consider.

---

The core streaming improvement is valuable for handling large replays, but the disabled timeouts are a security concern that should be addressed before merging.

[fank]

Suggestion: Consider splitting this PR into two separate PRs:

1. Docker image fixes - The Dockerfile changes (Alpine → Debian, ca-certificates)
2. Large replay loading improvements - The streaming changes and timeout adjustments

This would make it easier to review and merge the Docker fixes independently, and allows more focused discussion on the streaming/timeout changes.

[fank]

I fixed the docker build issues, also added PR checks to ensure stability before merging a PR.

[SteamNimmersatt]

I have tested this PR more in the last few days:

• Medium sized recordings (16 MB zipped, 690 MB raw) can be viewed with both Firefox and Chrome/Chromium.
• Large replays (32 MB zipped, 1.2 GB raw) load forever on Firefox, Chromium runs into error "SIGTRAP".

-> This PR does really improve loading large replays. Fixing this would require a lot more effort and time.
-> PR will be abandoned. If anyone wants to continue working on this please reopen.

[fank]

@SteamNimmersatt could you provide me a large replay?
I would like to test something.

[SteamNimmersatt]

@fank Here is a 6h22min replay on the map "Pulau". I've tested it with the changes from this PR. On Firefox the recording loads forever, on Chrome loading fails immediately.
https://file.kiwi/01dbbc7f#gzi6ywrzQsU2BvXKidIMNg

[fank]

@SteamNimmersatt contact me on discord, I got my first prototype working with your recording: