Middleware never responds to client

[KetchupBomb]

Working without plugin

services:
  whoami:
    command:
      - --verbose
    image: traefik/whoami
    labels:
      traefik.enable: "true"
      traefik.http.routers.http.entrypoints: http
      # traefik.http.routers.http.middlewares: badbotblocker
      traefik.http.routers.http.rule: PathPrefix(`/whoami`)

  traefik:
    command:
      - --entrypoints.http.address=:80
      - --experimental.plugins.traefik-ultimate-bad-bot-blocker.modulename=github.com/discoverygarden/traefik-ultimate-bad-bot-blocker
      - --experimental.plugins.traefik-ultimate-bad-bot-blocker.version=v0.2.0
      - --log.level=INFO
      - --providers.docker.exposedbydefault=false
    image: traefik
    labels:
      traefik.enable: "true"
      traefik.http.middlewares.badbotblocker.plugin.traefik-ultimate-bad-bot-blocker.ipblocklisturls: https://raw.githubusercontent.com/mitchellkrogza/nginx-ultimate-bad-bot-blocker/refs/heads/master/_generator_lists/bad-ip-addresses.list
      traefik.http.middlewares.badbotblocker.plugin.traefik-ultimate-bad-bot-blocker.loglevel: DEBUG
      traefik.http.middlewares.badbotblocker.plugin.traefik-ultimate-bad-bot-blocker.useragentblocklisturls: https://raw.githubusercontent.com/mitchellkrogza/apache-ultimate-bad-bot-blocker/master/_generator_lists/bad-user-agents.list
    ports:
      - 81:80
      - 444:443
    volumes:
      - /docker/traefik/data/plugins-storage:/plugins-storage
      - /var/run/docker.sock:/var/run/docker.sock:ro

Traefik startup log

2025-01-05T22:51:32-08:00 INF Traefik version 3.2.3 built on 2024-12-16T10:31:50Z version=3.2.3
2025-01-05T22:51:32-08:00 INF 
Stats collection is disabled.
Help us improve Traefik by turning this feature on :)
More details on: https://doc.traefik.io/traefik/contributing/data-collection/
2025-01-05T22:51:32-08:00 INF Loading plugins... plugins=["traefik-ultimate-bad-bot-blocker"]
2025-01-05T22:51:34-08:00 INF Plugins loaded. plugins=["traefik-ultimate-bad-bot-blocker"]
2025-01-05T22:51:34-08:00 INF Starting provider aggregator *aggregator.ProviderAggregator
2025-01-05T22:51:34-08:00 INF Starting provider *traefik.Provider
2025-01-05T22:51:34-08:00 INF Starting provider *acme.ChallengeTLSALPN
2025-01-05T22:51:34-08:00 INF Starting provider *docker.Provider

Working HTTP request

$ curl -vs localhost:81/whoami
*   Trying 127.0.0.1:81...
* Connected to localhost (127.0.0.1) port 81 (#0)
> GET /whoami HTTP/1.1
> Host: localhost:81
> User-Agent: curl/7.81.0
> Accept: */*
> 
* Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
< Content-Length: 431
< Content-Type: text/plain; charset=utf-8
< Date: Mon, 06 Jan 2025 06:56:24 GMT
< 
Hostname: whoami
IP: 127.0.0.1
IP: ::1
IP: 192.168.223.66
RemoteAddr: 192.168.223.7:36100
GET /whoami HTTP/1.1
Host: localhost:81
User-Agent: curl/7.81.0
Accept: */*
Accept-Encoding: gzip
Traceparent: 00-d44a3cae4ea8888a3e4f49b082efe6f8-e9d9158c416dc4d4-01
X-Forwarded-For: 192.168.223.1
X-Forwarded-Host: localhost:81
X-Forwarded-Port: 81
X-Forwarded-Proto: http
X-Forwarded-Server: traefik
X-Real-Ip: 192.168.223.1

* Connection #0 to host localhost left intact

Enabling plugin causes issues

Once traefik-ultimate-bad-bot-blocker is enabled:

1. the plugin loads in Traefik
2. requests are received by Traefik
3. plugin logging indicates allow/deny decision
   • allowed requests made it to whoami -- whoami logs a request (and I assume sends a response)
   • denied requests are logged
4. Traefik, and therefore the client, never receive a response

Code change:

       traefik.http.routers.http.entrypoints: http
-      # traefik.http.routers.http.middlewares: badbotblocker
+      traefik.http.routers.http.middlewares: badbotblocker
       traefik.http.routers.http.rule: PathPrefix(`/whoami`)

Traefik startup log

2025-01-05T23:02:36-08:00 INF Traefik version 3.2.3 built on 2024-12-16T10:31:50Z version=3.2.3
2025-01-05T23:02:36-08:00 INF 
Stats collection is disabled.
Help us improve Traefik by turning this feature on :)
More details on: https://doc.traefik.io/traefik/contributing/data-collection/
2025-01-05T23:02:36-08:00 INF Loading plugins... plugins=["traefik-ultimate-bad-bot-blocker"]
2025-01-05T23:02:37-08:00 INF Plugins loaded. plugins=["traefik-ultimate-bad-bot-blocker"]
2025-01-05T23:02:37-08:00 INF Starting provider aggregator *aggregator.ProviderAggregator
2025-01-05T23:02:37-08:00 INF Starting provider *traefik.Provider
2025-01-05T23:02:37-08:00 INF Starting provider *docker.Provider
2025-01-05T23:02:37-08:00 INF Starting provider *acme.ChallengeTLSALPN
2025/01/05 23:02:37 Bad Bot Blocker INFO: Updating CIDR blocklist
2025/01/05 23:02:37 Bad Bot Blocker INFO: Updating user agent blocklist
2025/01/05 23:02:37 Bad Bot Blocker INFO: Updated block lists. Blocked CIDRs:  10000  Duration:  83.531643ms

Stalled HTTP request

$ curl -vs localhost:81/whoami
*   Trying 127.0.0.1:81...
* Connected to localhost (127.0.0.1) port 81 (#0)
> GET /whoami HTTP/1.1
> Host: localhost:81
> User-Agent: curl/7.81.0
> Accept: */*
> 

traefik-ultimate-bad-bot-blocker logging

2025/01/05 23:03:43 Bad Bot Blocker DEBUG: Checking request: CIDR: "192.168.223.1:35018" user agent: "curl/7.81.0"
2025/01/05 23:03:43 Bad Bot Blocker DEBUG: Checked request in 6.33695ms

whoami --verbose logging

2025/01/05 23:05:46 Starting up on port 80
2025/01/05 23:05:59 192.168.223.7:38430 - - [05/Jan/2025:23:05:59 -0800] "GET /whoami HTTP/1.1" - -

Simulated bad request is detected

Simulating a request that should be blocked is logged by the plugin in the logs, but the client still hangs:

Sending bad User-Agent (adstxtcrawlertp)

2025/01/05 23:19:19 Bad Bot Blocker DEBUG: Checking request: CIDR: "192.168.223.1:43476" user agent: "AdsTxtCrawlerTP"
2025/01/05 23:19:19 Bad Bot Blocker INFO: blocked request with user agent adstxtcrawlertp because it contained adstxtcrawlertp
2025/01/05 23:19:19 Bad Bot Blocker DEBUG: Checked request in 5.281855ms

Request still stalls

$ curl -vskLH 'User-Agent: AdsTxtCrawlerTP' localhost:81/whoami
*   Trying 127.0.0.1:81...
* Connected to localhost (127.0.0.1) port 81 (#0)
> GET /whoami HTTP/1.1
> Host: localhost:81
> Accept: */*
> User-Agent: AdsTxtCrawlerTP
> 

Any ideas what would be causing the middleware to not allow the response make it back to the client? Thanks for any help.