How to expose port 53 for traefik/acme-dns

I'm trying to run joohoi/acme-dns behind traefik. It exposes ports 53/tcp, 53/udp, 80, 443.

If I run it under docker (without traefik), it runs as expected. When I run it with traefik, I get the following error:

time="2019-08-27T15:48:40Z" level=debug msg="'502 Bad Gateway' caused by: dial tcp 10.0.3.171:
53: connect: connection refused"

<<docker-compose.yml>>
version: "3.3"
services:

  traefik:
    image: traefik:v2.0 # The official v2.0 Traefik docker image
    container_name: traefik
    restart: always
    command:
#      - "--log=true"
      - "--log.level=DEBUG"
      - "--log.filepath=/shared/traefik.log"
#      - "--accesslog=true"
      - "--accesslog.filepath=/shared/access.log"
      - "--api=true"
      - "--api.dashboard=true"
#      - "--api.entrypoint=traefik"    # Fails when enabled.

      - "--global.sendanonymoususage=true"
      - "--providers.docker=true"
      - "--providers.docker.exposedbydefault=false"
 #     - "--entrypoints.web=true"
      - "--entrypoints.dns.address=:53"
      - "--entrypoints.web.address=:80"
 #     - "--entrypoints.websecure=true"
      - "--entrypoints.websecure.address=:443"
 #     - "--certificatesresolvers.mydns = true"
      - "--certificatesresolvers.mydns.acme.dnsChallenge=true"
      - "--certificatesresolvers.mydns.acme.dnsChallenge.provider=cloudflare"         
      - "--certificatesresolvers.mydns.acme.email=${ACME_EMAIL}"
      - "--certificatesresolvers.mydns.acme.storage=/etc/traefik/acme.json"
      - "--certificatesresolvers.mydns.acme.dnschallenge.delaybeforecheck=30"
      - "--certificatesresolvers.mydns.acme.caserver=https://acme-staging-v02.api.letsencyrpt.org/directory"

    networks:
      - default
      - traefik_proxy
    ports:
      - "80:80"     # The HTTP port
      - "443:443"     # The HTTPS port
      - "8080:8080" # The Dashboard
      # - "53:53/tcp"     # DNS Port
      # - "53:53/udp"     # DNS Port
    environment:
      - CF_API_EMAIL=${CLOUDFLARE_EMAIL}
      - CF_API_KEY=${CLOUDFLARE_API_KEY}
    labels:
      # - "traefik.enable=true"
      # - "traefik.docker.network=traefik_proxy"
       - "traefik.http.routers.traefik1_router_http.entrypoints=web"
#      - "traefik.http.routers.traefik1_router_https.tls=true"
       - "traefik.http.routers.traefik1_router_https.rule=Host(`traefik.${DOMAINNAME}`)"
       - "traefik.http.routers.traefik1_router_https.entrypoints=websecure"
       - "traefik.http.middlewares.https_redirect.redirectscheme.scheme=https"
       - "traefik.http.routers.traefik1_router_http.middlewares=https_redirect"
       - "treafik.http.routers.traefik1_router_https.dns.certresolver=mydns"
#      - "traefik.http.services.traefik1_service.loadbalancer.server.port=8080"
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock:ro # So that Traefik can listen to the Docker events
      - ./traefik:/etc/traefik
      - ./shared:/shared
      - ./certificates:/certificates

  whoami:
    image: "containous/whoami"
    container_name: "whoami"
    networks:
      - traefik_proxy
    labels:
      - "traefik.enable=true"
      # - "traefik.docker.network=traefik_proxy"
      - "traefik.http.routers.whoami.rule=Host(`whoami.${DOMAINNAME}`,`whoami.docker.localhost`)"
      - "traefik.http.routers.whoami.entrypoints=web"
#      - "traefik.http.routers.whoami.tls.certresolver=mydns"

  acmedns:
    image: joohoi/acme-dns:latest
    container_name: acmedns
    volumes:
      - ./acme:/etc/acme-dns:ro
      - ./acme:/var/lib/acme-dns
      - ./shared:/shared
    networks:
      - traefik_proxy
      - default
    labels:
      - "traefik.enable=true"
      - "traefik.docker.network=traefik_proxy"
      - "traefik.http.routers.acmedns.rule=Host(`auth.${DOMAINNAME}`)"
      - "traefik.http.routers.acmedns.entrypoints=web,websecure"
      - "traefik.tcp.routers.acmedns.entrypoints=dns"

networks:
  traefik_proxy:
    external:
      name: traefik_proxy
  default:
    driver: bridge

::::::::::::::
shared/access.log
::::::::::::::
172.23.0.1 - - [27/Aug/2019:15:48:40 +0000] "GET / HTTP/1.1" 200 353 "-" "-" 1 "whoami@docker"
 "http://10.0.3.170:80" 1ms
172.23.0.1 - - [27/Aug/2019:15:48:40 +0000] "GET / HTTP/1.1" 200 339 "-" "-" 2 "whoami@docker"
 "http://10.0.3.170:80" 0ms
172.16.88.1 - - [27/Aug/2019:15:48:40 +0000] "POST /register HTTP/1.1" 502 11 "-" "-" 3 "acmed
ns@docker" "http://10.0.3.171:53" 0ms
::::::::::::::
shared/traefik.log
::::::::::::::
time="2019-08-27T15:48:30Z" level=info msg="Traefik version 2.0.0-rc1 built on 2019-08-26T17:4
7:29Z"
time="2019-08-27T15:48:30Z" level=debug msg="Static configuration loaded {\"global\":{\"checkN
ewVersion\":true,\"sendAnonymousUsage\":true},\"serversTransport\":{\"maxIdleConnsPerHost\":20
0},\"entryPoints\":{\"dns\":{\"address\":\":53\",\"transport\":{\"lifeCycle\":{\"graceTimeOut\
":10000000000},\"respondingTimeouts\":{\"idleTimeout\":180000000000}},\"forwardedHeaders\":{}}
,\"traefik\":{\"address\":\":8080\",\"transport\":{\"lifeCycle\":{\"graceTimeOut\":10000000000
},\"respondingTimeouts\":{\"idleTimeout\":180000000000}},\"forwardedHeaders\":{}},\"web\":{\"a
ddress\":\":80\",\"transport\":{\"lifeCycle\":{\"graceTimeOut\":10000000000},\"respondingTimeo
uts\":{\"idleTimeout\":180000000000}},\"forwardedHeaders\":{}},\"websecure\":{\"address\":\":4
43\",\"transport\":{\"lifeCycle\":{\"graceTimeOut\":10000000000},\"respondingTimeouts\":{\"idl
eTimeout\":180000000000}},\"forwardedHeaders\":{}}},\"providers\":{\"providersThrottleDuration
\":2000000000,\"docker\":{\"watch\":true,\"endpoint\":\"unix:///var/run/docker.sock\",\"defaul
tRule\":\"Host(`{{ normalize .Name }}`)\",\"swarmModeRefreshSeconds\":15000000000}},\"api\":{\
"dashboard\":true},\"log\":{\"level\":\"DEBUG\",\"filePath\":\"/shared/traefik.log\",\"format\
":\"common\"},\"accessLog\":{\"filePath\":\"/shared/access.log\",\"format\":\"common\",\"filte
rs\":{},\"fields\":{\"defaultMode\":\"keep\",\"headers\":{\"defaultMode\":\"drop\"}}},\"certif
icatesResolvers\":{\"mydns\":{\"acme\":{\"email\":\"admin@myexample.com\",\"caServer\":\"https://a
cme-staging-v02.api.letsencyrpt.org/directory\",\"storage\":\"/etc/traefik/acme.json\",\"keyTy
pe\":\"RSA4096\",\"dnsChallenge\":{\"provider\":\"cloudflare\",\"delayBeforeCheck\":3000000000
0}}}}}"
time="2019-08-27T15:48:30Z" level=info msg="\nStats collection is enabled.\nMany thanks for co
ntributing to Traefik's improvement by allowing us to receive anonymous information from your
configuration.\nHelp us improve Traefik by leaving this feature on :)\nMore details on: https:
//docs.traefik.io/basics/#collected-data\n"
time="2019-08-27T15:48:30Z" level=debug msg="No default certificate, generating one"
time="2019-08-27T15:48:30Z" level=info msg="Starting provider aggregator.ProviderAggregator {}
"
time="2019-08-27T15:48:30Z" level=debug msg="Start TCP Server" entryPointName=websecure
time="2019-08-27T15:48:30Z" level=debug msg="Start TCP Server" entryPointName=dns
time="2019-08-27T15:48:30Z" level=info msg="Starting provider *acme.Provider {\"email\":\"admi
n@myexample.com\",\"caServer\":\"https://acme-staging-v02.api.letsencyrpt.org/directory\",\"storag
e\":\"/etc/traefik/acme.json\",\"keyType\":\"RSA4096\",\"dnsChallenge\":{\"provider\":\"cloudf
lare\",\"delayBeforeCheck\":30000000000},\"ResolverName\":\"mydns\",\"store\":{},\"ChallengeSt
ore\":{}}"
time="2019-08-27T15:48:30Z" level=info msg="Testing certificate renew..." providerName=mydns.a
cme
time="2019-08-27T15:48:30Z" level=debug msg="Start TCP Server" entryPointName=web
time="2019-08-27T15:48:30Z" level=info msg="Starting provider *docker.Provider {\"watch\":true
,\"endpoint\":\"unix:///var/run/docker.sock\",\"defaultRule\":\"Host(`{{ normalize .Name }}`)\
",\"swarmModeRefreshSeconds\":15000000000}"
time="2019-08-27T15:48:30Z" level=debug msg="Start TCP Server" entryPointName=traefik
time="2019-08-27T15:48:30Z" level=debug msg="Configuration received from provider mydns.acme:
{\"http\":{},\"tls\":{}}" providerName=mydns.acme
time="2019-08-27T15:48:30Z" level=debug msg="No default certificate, generating one"
time="2019-08-27T15:48:30Z" level=debug msg="Provider connection established with docker 19.03
.1 (API 1.40)" providerName=docker
time="2019-08-27T15:48:30Z" level=debug msg="Filtering disabled container" container=traefik_d
ocker-9a95d6293c72d360c31069576de4afcd700f7a03483c840682f0f76e0df990eb providerName=docker
time="2019-08-27T15:48:30Z" level=error msg="Empty rule" providerName=docker routerName=acmedn
s container=acmedns_docker-31fce2f40eb801d00f683d181daeb85569e0b2004a33754f4593483d1657bf91
time="2019-08-27T15:48:30Z" level=debug msg="Configuration received from provider docker: {\"h
ttp\":{\"routers\":{\"acmedns\":{\"entryPoints\":[\"web\",\"websecure\"],\"service\":\"acmedns
_docker\",\"rule\":\"Host(`auth.myexample.com`)\"},\"whoami\":{\"entryPoints\":[\"web\"],\"service
\":\"whoami_docker\",\"rule\":\"Host(`whoami.myexample.com`,`whoami.docker.localhost`)\"}},\"servi
ces\":{\"acmedns_docker\":{\"loadBalancer\":{\"servers\":[{\"url\":\"http://10.0.3.171:53\"}],
\"passHostHeader\":true}},\"whoami_docker\":{\"loadBalancer\":{\"servers\":[{\"url\":\"http://
10.0.3.170:80\"}],\"passHostHeader\":true}}}},\"tcp\":{\"services\":{\"acmedns_docker\":{\"loa
dBalancer\":{\"servers\":[{\"address\":\"10.0.3.171:53\"}]}}}}}" providerName=docker
time="2019-08-27T15:48:30Z" level=debug msg="Creating middleware" serviceName=acmedns_docker m
iddlewareName=pipelining middlewareType=Pipelining entryPointName=websecure routerName=acmedns
@docker
time="2019-08-27T15:48:30Z" level=debug msg="Creating load-balancer" serviceName=acmedns_docke
r entryPointName=websecure routerName=acmedns@docker
time="2019-08-27T15:48:30Z" level=debug msg="Creating server 0 http://10.0.3.171:53" serviceNa
me=acmedns_docker serverName=0 entryPointName=websecure routerName=acmedns@docker
time="2019-08-27T15:48:30Z" level=debug msg="Added outgoing tracing middleware acmedns_docker"
 routerName=acmedns@docker middlewareName=tracing middlewareType=TracingForwarder entryPointNa
me=websecure
time="2019-08-27T15:48:30Z" level=debug msg="Creating middleware" entryPointName=websecure mid
dlewareName=traefik-internal-recovery middlewareType=Recovery
time="2019-08-27T15:48:30Z" level=debug msg="Creating middleware" routerName=whoami@docker ent
ryPointName=web serviceName=whoami_docker middlewareName=pipelining middlewareType=Pipelining
time="2019-08-27T15:48:30Z" level=debug msg="Creating load-balancer" routerName=whoami@docker
entryPointName=web serviceName=whoami_docker
time="2019-08-27T15:48:30Z" level=debug msg="Creating server 0 http://10.0.3.170:80" serviceNa
me=whoami_docker serverName=0 routerName=whoami@docker entryPointName=web
time="2019-08-27T15:48:30Z" level=debug msg="Added outgoing tracing middleware whoami_docker"
middlewareType=TracingForwarder routerName=whoami@docker middlewareName=tracing entryPointName
=web
time="2019-08-27T15:48:30Z" level=debug msg="Creating middleware" middlewareType=Recovery entr
yPointName=web middlewareName=traefik-internal-recovery
time="2019-08-27T15:48:30Z" level=debug msg="No default certificate, generating one"
time="2019-08-27T15:48:40Z" level=debug msg="vulcand/oxy/roundrobin/rr: begin ServeHttp on req
uest" Request="{\"Method\":\"GET\",\"URL\":{\"Scheme\":\"\",\"Opaque\":\"\",\"User\":null,\"Ho
st\":\"\",\"Path\":\"/\",\"RawPath\":\"\",\"ForceQuery\":false,\"RawQuery\":\"\",\"Fragment\":
\"\"},\"Proto\":\"HTTP/1.1\",\"ProtoMajor\":1,\"ProtoMinor\":1,\"Header\":{\"Accept\":[\"*/*\"
],\"User-Agent\":[\"curl/7.64.0\"],\"X-Forwarded-Host\":[\"whoami.docker.localhost\"],\"X-Forw
arded-Port\":[\"80\"],\"X-Forwarded-Proto\":[\"http\"],\"X-Forwarded-Server\":[\"9a95d6293c72\
"],\"X-Real-Ip\":[\"172.23.0.1\"]},\"ContentLength\":0,\"TransferEncoding\":null,\"Host\":\"wh
oami.docker.localhost\",\"Form\":null,\"PostForm\":null,\"MultipartForm\":null,\"Trailer\":nul
l,\"RemoteAddr\":\"172.23.0.1:50752\",\"RequestURI\":\"/\",\"TLS\":null}"
time="2019-08-27T15:48:40Z" level=debug msg="vulcand/oxy/roundrobin/rr: Forwarding this reques
t to URL" ForwardURL="http://10.0.3.170:80" Request="{\"Method\":\"GET\",\"URL\":{\"Scheme\":\
"\",\"Opaque\":\"\",\"User\":null,\"Host\":\"\",\"Path\":\"/\",\"RawPath\":\"\",\"ForceQuery\"
:false,\"RawQuery\":\"\",\"Fragment\":\"\"},\"Proto\":\"HTTP/1.1\",\"ProtoMajor\":1,\"ProtoMin
or\":1,\"Header\":{\"Accept\":[\"*/*\"],\"User-Agent\":[\"curl/7.64.0\"],\"X-Forwarded-Host\":
[\"whoami.docker.localhost\"],\"X-Forwarded-Port\":[\"80\"],\"X-Forwarded-Proto\":[\"http\"],\
"X-Forwarded-Server\":[\"9a95d6293c72\"],\"X-Real-Ip\":[\"172.23.0.1\"]},\"ContentLength\":0,\
"TransferEncoding\":null,\"Host\":\"whoami.docker.localhost\",\"Form\":null,\"PostForm\":null,
\"MultipartForm\":null,\"Trailer\":null,\"RemoteAddr\":\"172.23.0.1:50752\",\"RequestURI\":\"/
\",\"TLS\":null}"
time="2019-08-27T15:48:40Z" level=debug msg="vulcand/oxy/roundrobin/rr: completed ServeHttp on
 request" Request="{\"Method\":\"GET\",\"URL\":{\"Scheme\":\"\",\"Opaque\":\"\",\"User\":null,
\"Host\":\"\",\"Path\":\"/\",\"RawPath\":\"\",\"ForceQuery\":false,\"RawQuery\":\"\",\"Fragmen
t\":\"\"},\"Proto\":\"HTTP/1.1\",\"ProtoMajor\":1,\"ProtoMinor\":1,\"Header\":{\"Accept\":[\"*
/*\"],\"User-Agent\":[\"curl/7.64.0\"],\"X-Forwarded-Host\":[\"whoami.docker.localhost\"],\"X-
Forwarded-Port\":[\"80\"],\"X-Forwarded-Proto\":[\"http\"],\"X-Forwarded-Server\":[\"9a95d6293
c72\"],\"X-Real-Ip\":[\"172.23.0.1\"]},\"ContentLength\":0,\"TransferEncoding\":null,\"Host\":
\"whoami.docker.localhost\",\"Form\":null,\"PostForm\":null,\"MultipartForm\":null,\"Trailer\"
:null,\"RemoteAddr\":\"172.23.0.1:50752\",\"RequestURI\":\"/\",\"TLS\":null}"
time="2019-08-27T15:48:40Z" level=debug msg="vulcand/oxy/roundrobin/rr: begin ServeHttp on req
uest" Request="{\"Method\":\"GET\",\"URL\":{\"Scheme\":\"\",\"Opaque\":\"\",\"User\":null,\"Ho
st\":\"\",\"Path\":\"/\",\"RawPath\":\"\",\"ForceQuery\":false,\"RawQuery\":\"\",\"Fragment\":
\"\"},\"Proto\":\"HTTP/1.1\",\"ProtoMajor\":1,\"ProtoMinor\":1,\"Header\":{\"Accept\":[\"*/*\"
],\"User-Agent\":[\"curl/7.64.0\"],\"X-Forwarded-Host\":[\"whoami.myexample.com\"],\"X-Forwarded-P
ort\":[\"80\"],\"X-Forwarded-Proto\":[\"http\"],\"X-Forwarded-Server\":[\"9a95d6293c72\"],\"X-
Real-Ip\":[\"172.23.0.1\"]},\"ContentLength\":0,\"TransferEncoding\":null,\"Host\":\"whoami.21
9er.xyz\",\"Form\":null,\"PostForm\":null,\"MultipartForm\":null,\"Trailer\":null,\"RemoteAddr
\":\"172.23.0.1:50758\",\"RequestURI\":\"/\",\"TLS\":null}"
time="2019-08-27T15:48:40Z" level=debug msg="vulcand/oxy/roundrobin/rr: Forwarding this reques
t to URL" Request="{\"Method\":\"GET\",\"URL\":{\"Scheme\":\"\",\"Opaque\":\"\",\"User\":null,
\"Host\":\"\",\"Path\":\"/\",\"RawPath\":\"\",\"ForceQuery\":false,\"RawQuery\":\"\",\"Fragmen
t\":\"\"},\"Proto\":\"HTTP/1.1\",\"ProtoMajor\":1,\"ProtoMinor\":1,\"Header\":{\"Accept\":[\"*
/*\"],\"User-Agent\":[\"curl/7.64.0\"],\"X-Forwarded-Host\":[\"whoami.myexample.com\"],\"X-Forward
ed-Port\":[\"80\"],\"X-Forwarded-Proto\":[\"http\"],\"X-Forwarded-Server\":[\"9a95d6293c72\"],
\"X-Real-Ip\":[\"172.23.0.1\"]},\"ContentLength\":0,\"TransferEncoding\":null,\"Host\":\"whoam
i.myexample.com\",\"Form\":null,\"PostForm\":null,\"MultipartForm\":null,\"Trailer\":null,\"Remote
Addr\":\"172.23.0.1:50758\",\"RequestURI\":\"/\",\"TLS\":null}" ForwardURL="http://10.0.3.170:
80"
time="2019-08-27T15:48:40Z" level=debug msg="vulcand/oxy/roundrobin/rr: completed ServeHttp on
 request" Request="{\"Method\":\"GET\",\"URL\":{\"Scheme\":\"\",\"Opaque\":\"\",\"User\":null,
\"Host\":\"\",\"Path\":\"/\",\"RawPath\":\"\",\"ForceQuery\":false,\"RawQuery\":\"\",\"Fragmen
t\":\"\"},\"Proto\":\"HTTP/1.1\",\"ProtoMajor\":1,\"ProtoMinor\":1,\"Header\":{\"Accept\":[\"*
/*\"],\"User-Agent\":[\"curl/7.64.0\"],\"X-Forwarded-Host\":[\"whoami.myexample.com\"],\"X-Forward
ed-Port\":[\"80\"],\"X-Forwarded-Proto\":[\"http\"],\"X-Forwarded-Server\":[\"9a95d6293c72\"],
\"X-Real-Ip\":[\"172.23.0.1\"]},\"ContentLength\":0,\"TransferEncoding\":null,\"Host\":\"whoam
i.myexample.com\",\"Form\":null,\"PostForm\":null,\"MultipartForm\":null,\"Trailer\":null,\"Remote
Addr\":\"172.23.0.1:50758\",\"RequestURI\":\"/\",\"TLS\":null}"
time="2019-08-27T15:48:40Z" level=debug msg="vulcand/oxy/roundrobin/rr: begin ServeHttp on req
uest" Request="{\"Method\":\"POST\",\"URL\":{\"Scheme\":\"\",\"Opaque\":\"\",\"User\":null,\"H
ost\":\"\",\"Path\":\"/register\",\"RawPath\":\"\",\"ForceQuery\":false,\"RawQuery\":\"\",\"Fr
agment\":\"\"},\"Proto\":\"HTTP/1.1\",\"ProtoMajor\":1,\"ProtoMinor\":1,\"Header\":{\"Accept\"
:[\"*/*\"],\"User-Agent\":[\"curl/7.64.0\"],\"X-Forwarded-Host\":[\"auth.myexample.com\"],\"X-Forw
arded-Port\":[\"80\"],\"X-Forwarded-Proto\":[\"http\"],\"X-Forwarded-Server\":[\"9a95d6293c72\
"],\"X-Real-Ip\":[\"172.16.88.1\"]},\"ContentLength\":0,\"TransferEncoding\":null,\"Host\":\"a
uth.myexample.com\",\"Form\":null,\"PostForm\":null,\"MultipartForm\":null,\"Trailer\":null,\"Remo
teAddr\":\"172.16.88.1:45240\",\"RequestURI\":\"/register\",\"TLS\":null}"
time="2019-08-27T15:48:40Z" level=debug msg="vulcand/oxy/roundrobin/rr: Forwarding this reques
t to URL" Request="{\"Method\":\"POST\",\"URL\":{\"Scheme\":\"\",\"Opaque\":\"\",\"User\":null
,\"Host\":\"\",\"Path\":\"/register\",\"RawPath\":\"\",\"ForceQuery\":false,\"RawQuery\":\"\",
\"Fragment\":\"\"},\"Proto\":\"HTTP/1.1\",\"ProtoMajor\":1,\"ProtoMinor\":1,\"Header\":{\"Acce
pt\":[\"*/*\"],\"User-Agent\":[\"curl/7.64.0\"],\"X-Forwarded-Host\":[\"auth.myexample.com\"],\"X-
Forwarded-Port\":[\"80\"],\"X-Forwarded-Proto\":[\"http\"],\"X-Forwarded-Server\":[\"9a95d6293
c72\"],\"X-Real-Ip\":[\"172.16.88.1\"]},\"ContentLength\":0,\"TransferEncoding\":null,\"Host\"
:\"auth.myexample.com\",\"Form\":null,\"PostForm\":null,\"MultipartForm\":null,\"Trailer\":null,\"
RemoteAddr\":\"172.16.88.1:45240\",\"RequestURI\":\"/register\",\"TLS\":null}" ForwardURL="htt
p://10.0.3.171:53"
time="2019-08-27T15:48:40Z" level=debug msg="'502 Bad Gateway' caused by: dial tcp 10.0.3.171:
53: connect: connection refused"
time="2019-08-27T15:48:40Z" level=debug msg="vulcand/oxy/roundrobin/rr: completed ServeHttp on
 request" Request="{\"Method\":\"POST\",\"URL\":{\"Scheme\":\"\",\"Opaque\":\"\",\"User\":null
,\"Host\":\"\",\"Path\":\"/register\",\"RawPath\":\"\",\"ForceQuery\":false,\"RawQuery\":\"\",
\"Fragment\":\"\"},\"Proto\":\"HTTP/1.1\",\"ProtoMajor\":1,\"ProtoMinor\":1,\"Header\":{\"Acce
pt\":[\"*/*\"],\"User-Agent\":[\"curl/7.64.0\"],\"X-Forwarded-Host\":[\"auth.myexample.com\"],\"X-
Forwarded-Port\":[\"80\"],\"X-Forwarded-Proto\":[\"http\"],\"X-Forwarded-Server\":[\"9a95d6293
c72\"],\"X-Real-Ip\":[\"172.16.88.1\"]},\"ContentLength\":0,\"TransferEncoding\":null,\"Host\"
:\"auth.myexample.com\",\"Form\":null,\"PostForm\":null,\"MultipartForm\":null,\"Trailer\":null,\"
RemoteAddr\":\"172.16.88.1:45240\",\"RequestURI\":\"/register\",\"TLS\":null}"
time="2019-08-27T15:48:46Z" level=warning msg="Could not retrieve CanonizedHost, rejecting "
time="2019-08-27T15:48:46Z" level=warning msg="Could not retrieve CanonizedHost, rejecting "


I also have no idea what is triggering the warning message "Could not retrieve CanonizedHost, rejecting"