test(traefik): add local base-path routing fixture

Add a local Traefik docker-compose setup that builds spa-to-http from the repository and routes only base-path requests to the SPA service.

Support environment-driven test configuration via SPA_BASE_PATH and SPA_MODE, and route non-base-path traffic to whoami to emulate production path segregation.

Document the fixture usage and verification flow in development docs, and link it from deployment docs.

Author: mamchurovskyy

docs/deployment.md

@@ -65,4 +65,5 @@ So either notation works in deployment config.
 
 - [Configuration](configuration.md) — Environment variables and CLI flags
 - [Getting Started](getting-started.md) — Install, build, and run
+- [Development](development.md) — Includes a local Traefik fixture for testing `/qwerty` base-path routing
 - [Benchmarks](benchmarks.md) — spa-to-http vs Nginx

docs/development.md

@@ -85,6 +85,40 @@ docker run --rm -p 8080:8080 -v $(pwd)/test/frontend/dist:/code devforth/spa-to-
 
 Open `http://localhost:8080` in your browser.
 
+## Prod-like Local Test: Traefik + Base Path `/qwerty`
+
+Use the local fixture at `test/traefik/docker-compose.base-path.yml` to emulate production routing:
+- `spa-to-http` serves only `${SPA_BASE_PATH}` paths (default: `/qwerty`)
+- non-base-path requests are routed to a different backend (`whoami`)
+- `spa-to-http` image is built locally from this repository
+
+Run from repository root:
+
+```bash
+SPA_BASE_PATH=/qwerty SPA_MODE=true \
+docker compose -f test/traefik/docker-compose.base-path.yml up --build
+```
+
+Verify behavior:
+
+```bash
+# SPA (should return your app index)
+curl -i http://localhost:8081/qwerty
+
+# SPA asset under base path (should be served by spa-to-http)
+curl -i http://localhost:8081/qwerty/vite.svg
+
+# Not SPA (should be routed to whoami, not your app)
+curl -i http://localhost:8081/
+curl -i http://localhost:8081/anything
+```
+
+Stop:
+
+```bash
+docker compose -f test/traefik/docker-compose.base-path.yml down
+```
+
 ## See Also
 
 - [Getting Started](getting-started.md) — Fast Docker onboarding

test/traefik/docker-compose.base-path.yml

@@ -0,0 +1,35 @@
+services:
+  traefik:
+    image: traefik:v2.11
+    command:
+      - "--providers.docker=true"
+      - "--providers.docker.exposedbydefault=false"
+      - "--entrypoints.web.address=:8081"
+    ports:
+      - "8081:8081"
+    volumes:
+      - "/var/run/docker.sock:/var/run/docker.sock:ro"
+
+  spa:
+    image: spa-to-http-local:test
+    build:
+      context: ../..
+      dockerfile: Dockerfile
+    command: --base-path ${SPA_BASE_PATH:-/qwerty} --directory /code --spa=${SPA_MODE:-true}
+    volumes:
+      - "../frontend/dist:/code:ro"
+    labels:
+      - "traefik.enable=true"
+      - "traefik.http.routers.spa.rule=Host(`localhost`) && (Path(`${SPA_BASE_PATH:-/qwerty}`) || PathPrefix(`${SPA_BASE_PATH:-/qwerty}/`))"
+      - "traefik.http.routers.spa.entrypoints=web"
+      - "traefik.http.routers.spa.priority=100"
+      - "traefik.http.services.spa.loadbalancer.server.port=8080"
+
+  other:
+    image: traefik/whoami:v1.10
+    labels:
+      - "traefik.enable=true"
+      - "traefik.http.routers.other.rule=Host(`localhost`) && PathPrefix(`/`)"
+      - "traefik.http.routers.other.entrypoints=web"
+      - "traefik.http.routers.other.priority=1"
+      - "traefik.http.services.other.loadbalancer.server.port=80"