fix(dev): make just recipes WSL2-friendly #858
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When running under WSL2, Windows Chrome can't reach QUIC/UDP via localhost forwarding. Auto-select the WSL IP for the hang demo and override relay bind/cert generation only in WSL.
WalkthroughThe pull request modifies the justfile to improve web server and relay command functionality. The web task replaces direct URL invocation with "auto" URL resolution that handles both WSL and non-WSL environments. The relay command adds WSL-specific logic that binds the server to 0.0.0.0:4443 and generates TLS certificates using local IP, while preserving existing behavior outside WSL. The web server is configured to bind to 0.0.0.0 with environment-conditional URL resolution for localhost or host IP address. 🚥 Pre-merge checks | ✅ 3✅ Passed checks (3 passed)
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Actionable comments posted: 2
🤖 Fix all issues with AI agents
In `@justfile`:
- Around line 36-41: The WSL branch sets ip="$(hostname -I | awk '{print $1}')"
then passes it to --tls-generate which can produce an invalid SAN when empty;
add a guard that checks the ip variable before invoking cargo: if ip is empty,
print an error and exit (fast-fail) rather than continuing to run
TOKIO_CONSOLE_BIND=... cargo run --bin moq-relay -- dev/relay.toml ...
--tls-generate "localhost,$ip". Ensure the check lives in the same justfile WSL
block so the variables (ip, TOKIO_CONSOLE_BIND) and the invocation of moq-relay
are only executed when ip is non-empty.
- Around line 269-279: The web recipe currently always appends "--host 0.0.0.0"
which exposes the Vite server to the LAN; change the invocation in the web
recipe (the line that runs: cd js/hang-demo && VITE_RELAY_URL="$url" bun run dev
-- --host 0.0.0.0) to only include "--host 0.0.0.0" when running under WSL
(WSL_DISTRO_NAME present) or when an explicit opt-in flag/env (e.g.,
DEV_HOST_ALL or similar) is set; otherwise omit the --host flag (or use --host
localhost) to keep the server bound to loopback. Ensure the conditional uses the
existing WSL_DISTRO_NAME check or a new opt-in env and updates the command
construction accordingly.
| @if [ -n "${WSL_DISTRO_NAME:-}" ]; then \ | ||
| ip="$(hostname -I | awk '{print $1}')"; \ | ||
| TOKIO_CONSOLE_BIND=127.0.0.1:6680 cargo run --bin moq-relay -- dev/relay.toml \ | ||
| --server-bind "0.0.0.0:4443" \ | ||
| --tls-generate "localhost,$ip" \ | ||
| {{args}}; \ |
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Add a guard for empty WSL IP detection.
If hostname -I returns nothing, TLS SAN becomes invalid and the relay may fail or generate a bad cert. Consider a fast-fail check.
🛠️ Suggested guard
- ip="$(hostname -I | awk '{print $1}')"; \
+ ip="$(hostname -I | awk '{print $1}')"; \
+ if [ -z "$ip" ]; then \
+ echo "Error: unable to detect WSL IP" >&2; \
+ exit 1; \
+ fi; \📝 Committable suggestion
‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.
| @if [ -n "${WSL_DISTRO_NAME:-}" ]; then \ | |
| ip="$(hostname -I | awk '{print $1}')"; \ | |
| TOKIO_CONSOLE_BIND=127.0.0.1:6680 cargo run --bin moq-relay -- dev/relay.toml \ | |
| --server-bind "0.0.0.0:4443" \ | |
| --tls-generate "localhost,$ip" \ | |
| {{args}}; \ | |
| `@if` [ -n "${WSL_DISTRO_NAME:-}" ]; then \ | |
| ip="$(hostname -I | awk '{print $1}')"; \ | |
| if [ -z "$ip" ]; then \ | |
| echo "Error: unable to detect WSL IP" >&2; \ | |
| exit 1; \ | |
| fi; \ | |
| TOKIO_CONSOLE_BIND=127.0.0.1:6680 cargo run --bin moq-relay -- dev/relay.toml \ | |
| --server-bind "0.0.0.0:4443" \ | |
| --tls-generate "localhost,$ip" \ | |
| {{args}}; \ |
🤖 Prompt for AI Agents
In `@justfile` around lines 36 - 41, The WSL branch sets ip="$(hostname -I | awk
'{print $1}')" then passes it to --tls-generate which can produce an invalid SAN
when empty; add a guard that checks the ip variable before invoking cargo: if ip
is empty, print an error and exit (fast-fail) rather than continuing to run
TOKIO_CONSOLE_BIND=... cargo run --bin moq-relay -- dev/relay.toml ...
--tls-generate "localhost,$ip". Ensure the check lives in the same justfile WSL
block so the variables (ip, TOKIO_CONSOLE_BIND) and the invocation of moq-relay
are only executed when ip is non-empty.
| web url="auto": | ||
| @url="{{url}}"; \ | ||
| if [ "$url" = "auto" ]; then \ | ||
| if [ -n "${WSL_DISTRO_NAME:-}" ]; then \ | ||
| ip="$(hostname -I | awk '{print $1}')"; \ | ||
| url="http://$ip:4443/anon"; \ | ||
| else \ | ||
| url="http://localhost:4443/anon"; \ | ||
| fi; \ | ||
| fi; \ | ||
| cd js/hang-demo && VITE_RELAY_URL="$url" bun run dev -- --host 0.0.0.0 |
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Avoid binding Vite to all interfaces outside WSL.
--host 0.0.0.0 on non-WSL exposes the dev server to the LAN by default. Consider limiting it to WSL only (or making it opt-in) to keep the previous security posture.
🔒 Suggested conditional host binding
web url="auto":
`@url`="{{url}}"; \
+ host="127.0.0.1"; \
if [ "$url" = "auto" ]; then \
if [ -n "${WSL_DISTRO_NAME:-}" ]; then \
ip="$(hostname -I | awk '{print $1}')"; \
url="http://$ip:4443/anon"; \
+ host="0.0.0.0"; \
else \
url="http://localhost:4443/anon"; \
fi; \
fi; \
- cd js/hang-demo && VITE_RELAY_URL="$url" bun run dev -- --host 0.0.0.0
+ cd js/hang-demo && VITE_RELAY_URL="$url" bun run dev -- --host "$host"📝 Committable suggestion
‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.
| web url="auto": | |
| @url="{{url}}"; \ | |
| if [ "$url" = "auto" ]; then \ | |
| if [ -n "${WSL_DISTRO_NAME:-}" ]; then \ | |
| ip="$(hostname -I | awk '{print $1}')"; \ | |
| url="http://$ip:4443/anon"; \ | |
| else \ | |
| url="http://localhost:4443/anon"; \ | |
| fi; \ | |
| fi; \ | |
| cd js/hang-demo && VITE_RELAY_URL="$url" bun run dev -- --host 0.0.0.0 | |
| web url="auto": | |
| `@url`="{{url}}"; \ | |
| host="127.0.0.1"; \ | |
| if [ "$url" = "auto" ]; then \ | |
| if [ -n "${WSL_DISTRO_NAME:-}" ]; then \ | |
| ip="$(hostname -I | awk '{print $1}')"; \ | |
| url="http://$ip:4443/anon"; \ | |
| host="0.0.0.0"; \ | |
| else \ | |
| url="http://localhost:4443/anon"; \ | |
| fi; \ | |
| fi; \ | |
| cd js/hang-demo && VITE_RELAY_URL="$url" bun run dev -- --host "$host" |
🤖 Prompt for AI Agents
In `@justfile` around lines 269 - 279, The web recipe currently always appends
"--host 0.0.0.0" which exposes the Vite server to the LAN; change the invocation
in the web recipe (the line that runs: cd js/hang-demo && VITE_RELAY_URL="$url"
bun run dev -- --host 0.0.0.0) to only include "--host 0.0.0.0" when running
under WSL (WSL_DISTRO_NAME present) or when an explicit opt-in flag/env (e.g.,
DEV_HOST_ALL or similar) is set; otherwise omit the --host flag (or use --host
localhost) to keep the server bound to loopback. Ensure the conditional uses the
existing WSL_DISTRO_NAME check or a new opt-in env and updates the command
construction accordingly.
|
@fcancela I thought you said |
2 participants
Summary
Fix WSL2 + Windows Chrome local dev where WebTransport (QUIC/UDP) to
localhostfails, causing a WebSocket fallback.Problem / symptoms
Failed to establish a connection to https://localhost:4443/anon: net::ERR_CONNECTION_RESET... using WebSocket fallback; the user experience may be degradedhttp://.../anonshows400 Connection header did not include 'upgrade'(expected;/anonis not an HTTP endpoint).Root cause (validated)
http://<wsl-ip>:4443/certificate.sha256worked (HTTP/TCP reachability ok)ws://<wsl-ip>:4443/anonworked (WebSocket/TCP ok)https://localhost:4443/...failed (WSL2 localhost forwarding doesn’t reliably support UDP/QUIC)Fix
Dev tooling now:
localhostfor the relay URL when in WSL (just web auto/just dev)--server-bind 0.0.0.0:4443(QUIC reachable from Windows)--tls-generate localhost,<wsl-ip>(WebTransport upgrades tohttps://…; cert SAN must match the IP host)--host 0.0.0.0so Windows can open the dev server via the WSL IP.Test plan
just devERR_CONNECTION_RESET, no WebSocket fallback warning)