# Traefik with docker swarm as loadbalancer -\> Bad Gateway **URL:** \ **Category:** Traefik v2\ **Tags:** docker-swarm\ **Created:** [October 23, 2019, 5:28pm UTC](https://community.traefik.io/t/traefik-with-docker-swarm-as-loadbalancer-bad-gateway/2558 "2019-10-23T17:28:22Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![Stargate](https://avatars.discourse-cdn.com/v4/letter/s/9d8465/32.png) [@Stargate](https://community.traefik.io/u/Stargate)\ **Post date:** [October 23, 2019, 5:28pm UTC](https://community.traefik.io/t/traefik-with-docker-swarm-as-loadbalancer-bad-gateway/2558/1 "2019-10-23T17:28:22Z")
Hello, im new to Traefik and i want to setup a docker swarm cluster with Traefik as loadbalancer. my Traefik docker-compose file looks like that: ```auto version: '3.5' services: traefik: image: traefik:v2.0.2 ports: - 8510:8510 - 8511:443 - 8512:8080 deploy: replicas: 1 placement: constraints: - node.role == manager preferences: - spread: node.id labels: - traefik.port=8512 - traefik.docker.network=traefik-proxy volumes: - /var/run/docker.sock:/var/run/docker.sock command: > --accesslog=true --log.level=info --api.insecure=true --providers.docker=true --providers.docker.swarmmode=true --providers.docker.exposedbydefault=false --entrypoints.http.address=:8510 networks: - traefik-proxy networks: traefik-proxy: external: true ``` then in the next step i deployed a spring boot application (myApp) in global mode on 2 servers lets call it myAppServer1 and myAppServer2. Now if i call traefikUrl:8510/myApp it should route me to one of the the 2 myApp Servers and remove the myApp prefix. For Example if i call treafikUrl:8510/myApp/site2 it should remove "myApp" and route me to "myAppServer2/site2" but all i get is Bad Gateway.. The traefik-proxy network is an overlay network (docker network create --driver=overlay traefik-proxy) ```auto version: '3.5' services: myApp: image: "myApp:v1.0" networks: - traefik-proxy deploy: labels: - traefik.enable=true - traefik.http.routers.myapp_router.entrypoints=http - traefik.http.routers.myapp_router.rule=PathPrefix(`/myApp`) - traefik.http.middlewares.myapp-stripprefix.stripprefix.prefixes=/myApp - "traefik.http.routers.myapp_router.middlewares=myapp-stripprefix@docker" - traefik.docker.network=traefik-proxy - traefik.port=8515 - traefik.http.services.myapp_service.loadbalancer.server.port=8515 mode: global update_config: parallelism: 1 delay: 1m order: stop-first restart_policy: condition: any environment: - "SPRING_PROFILES_ACTIVE=docker" networks: traefik-proxy: external: true ``` ---
**Author:** ![dduportal](https://sea2.discourse-cdn.com/flex020/user_avatar/community.traefik.io/dduportal/32/4_2.png) [@dduportal](https://community.traefik.io/u/dduportal)\ **Post date:** [October 24, 2019, 8:05am UTC](https://community.traefik.io/t/traefik-with-docker-swarm-as-loadbalancer-bad-gateway/2558/2 "2019-10-24T08:05:41Z")
Hi @Stargate, there are a few things to fix to have this working: - First of all, remove all labels `traefik.port` as this label does not exist anymore in Traefik v2.0 (you can validate this assumption with the reference documentation for dynamic configuration for Docker e.g. "labels": [https://docs.traefik.io/v2.0/reference/dynamic-configuration/docker/](https://docs.traefik.io/v2.0/reference/dynamic-configuration/docker/)) - What is the port on which the Spring app is listening to (and exposed by the Docker images)? As you specified the label `- traefik.http.services.myapp_service.loadbalancer.server.port=8515`, then it means that Traefik contacts the docker container of "myApp" to its port 8515: Spring must be listening to this port (instead of the default 8080). - You should not expose Traefik's dashboard without protection: you might want to remove the published port `8512:8080` from Traefik's container, and add the right labels to traefik's container to expose the dashboard in secured mode, which implies removing the flag `--api.insecure` as well.(reference: [https://docs.traefik.io/v2.0/operations/dashboard/#secure-mode](https://docs.traefik.io/v2.0/operations/dashboard/#secure-mode)). If you are not able to make it work, can you provide the full Traefik's container logs with debug enabled here so we can dive in the errors? ---
**Author:** ![Stargate](https://avatars.discourse-cdn.com/v4/letter/s/9d8465/32.png) [@Stargate](https://community.traefik.io/u/Stargate)\ **Post date:** [October 24, 2019, 9:57am UTC](https://community.traefik.io/t/traefik-with-docker-swarm-as-loadbalancer-bad-gateway/2558/3 "2019-10-24T09:57:58Z")
Hi, thanks for your help. i have updated my config: ```auto version: '3.5' services: traefik: image: traefik:v2.0.2 ports: - 8600:8600 - 8510:8510 - 8511:443 - 8512:8080 deploy: replicas: 1 placement: constraints: - node.role == manager preferences: - spread: node.id labels: - traefik.docker.network=traefik-proxy volumes: - /var/run/docker.sock:/var/run/docker.sock command: > --accesslog=true --log.level=info --api.insecure=true --providers.docker=true --providers.docker.swarmmode=true --providers.docker.exposedbydefault=false --entrypoints.http.address=:8510 --entrypoints.myapp-ws.address=:8600 networks: - traefik-proxy networks: traefik-proxy: external: true ``` ```auto version: '3.5' services: myApp: image: "myApp:v1.0" ports: - 8515:8080 networks: - traefik-proxy deploy: labels: - traefik.enable=true - traefik.http.routers.myapp_router.entrypoints=http - traefik.http.routers.myapp_router.rule=PathPrefix(`/`) - traefik.docker.network=traefik-proxy - traefik.http.services.myapp_service.loadbalancer.server.port=8080 mode: global update_config: parallelism: 1 delay: 1m order: stop-first restart_policy: condition: any environment: - "SPRING_PROFILES_ACTIVE=docker" networks: traefik-proxy: external: true ``` i have removd the traefik.port labels and i added a port to the myApp Application (8515:8080) and i changed the traefik.http.services.myapp\_service.loadbalancer.server.port to 8080. Which port is the right for the loadbalancer label is it the internal container port "8080" or the exposed 8515 ? it seems to work with port 8080. Now if i call traefikUrl:8600 it will route me to myApp1:8080 or myApp2:8080 ---
**Author:** ![dduportal](https://sea2.discourse-cdn.com/flex020/user_avatar/community.traefik.io/dduportal/32/4_2.png) [@dduportal](https://community.traefik.io/u/dduportal)\ **Post date:** [October 24, 2019, 12:41pm UTC](https://community.traefik.io/t/traefik-with-docker-swarm-as-loadbalancer-bad-gateway/2558/4 "2019-10-24T12:41:19Z")
- First of all, you only have to deal with exposed ports (aka. private only) between Traefik and the backend services: you can remove the directive ```auto ports: - 8515:8080 ``` from the service `myApp`. - Your configuration seems right for the label `traefik.http.services.myapp_service.loadbalancer.server.port` : `8080` seems like the default port which Spring is listening on, hence the private port exposed by the container on the private network. Traefik will forward requests from the outside to this port. Are you facing issues now or is it working? (I'm not sure if I understood correctly) ---
**Author:** ![Stargate](https://avatars.discourse-cdn.com/v4/letter/s/9d8465/32.png) [@Stargate](https://community.traefik.io/u/Stargate)\ **Post date:** [October 24, 2019, 1:35pm UTC](https://community.traefik.io/t/traefik-with-docker-swarm-as-loadbalancer-bad-gateway/2558/5 "2019-10-24T13:35:44Z")
Hi, yes it worked now. But i have currently a problem with the dashboard in secure mode. If i enter traefikUrl:8512/dashboard (the basic auth did not work) i cann see the dashboard screen but all is grayed out and i can not see the services and routers.. the config looks like that: ```auto version: '3.5' services: traefik: image: traefik:v2.0.2 ports: - 8510:8510 - 8512:8512 - 8600:8600 deploy: replicas: 1 placement: constraints: - node.role == manager preferences: - spread: node.id labels: - traefik.docker.network=traefik-proxy - traefik.http.routers.api.entrypoints=api - traefik.http.routers.api.rule=PathPrefix(`/api`) || PathPrefix(`/dashboard`) - traefik.http.routers.api.service=api@internal - traefik.http.routers.api.middlewares=auth - traefik.http.middlewares.auth.basicauth.users=user:pw volumes: - /var/run/docker.sock:/var/run/docker.sock command: > --accesslog=true --log.level=info --api=true --api.dashboard=true --providers.docker=true --providers.docker.swarmmode=true --providers.docker.exposedbydefault=false --entrypoints.http.address=:8510 --entrypoints.myapp-ws.address=:8600 --entrypoints.api.address=:8512 networks: - traefik-proxy networks: traefik-proxy: external: true ``` ---
**Author:** ![dduportal](https://sea2.discourse-cdn.com/flex020/user_avatar/community.traefik.io/dduportal/32/4_2.png) [@dduportal](https://community.traefik.io/u/dduportal)\ **Post date:** [October 24, 2019, 3:51pm UTC](https://community.traefik.io/t/traefik-with-docker-swarm-as-loadbalancer-bad-gateway/2558/6 "2019-10-24T15:51:09Z")
Hi Stargate, as stated in the documentation ([https://docs.traefik.io/v2.0/operations/dashboard/](https://docs.traefik.io/v2.0/operations/dashboard/)) , you have to add a trailing slash: `htrtp://traefikUrl:8512/dashboard/`. The reason of the "grayed out" is because your web browser already have the HTML/JS/CSS of the dashboard in its local cache, but there is an issue when contacting the backend to update data: clean up your cache. If you still have an issue, I'll need the following elements to help: - The result of the command `curl --verbose --location --insecure -o /dev/null http://traefikUrl:8512/dashboard/` - The logs (with debug enabled) from Traefik's container ---
**Author:** ![Stargate](https://avatars.discourse-cdn.com/v4/letter/s/9d8465/32.png) [@Stargate](https://community.traefik.io/u/Stargate)\ **Post date:** [October 25, 2019, 2:02pm UTC](https://community.traefik.io/t/traefik-with-docker-swarm-as-loadbalancer-bad-gateway/2558/7 "2019-10-25T14:02:03Z")
Hi, i have cleard my cache but when i enter [http://traefik:8512/dashboard/](http://traefik:8512/dashboard/) i get a "404 page not found". the log shows only hundreds of this entries: ```auto traefik.1.1crqzz4fgpk6@server | 10.255.0.3 - - [25/Oct/2019:13:57:39 +0000] "GET /api/overview HTTP/1.1" - - "-" "-" 3818 - - 0ms traefik.1.1crqzz4fgpk6@server | 10.255.0.3 - - [25/Oct/2019:13:57:39 +0000] "GET /api/providers HTTP/1.1" - - "-" "-" 3819 - - 0ms traefik.1.1crqzz4fgpk6@server | 10.255.0.3 - - [25/Oct/2019:13:57:39 +0000] "GET /api/providers HTTP/1.1" - - "-" "-" 3820 - - 0ms traefik.1.1crqzz4fgpk6@server | 10.255.0.3 - - [25/Oct/2019:13:57:40 +0000] "GET /api/entrypoints HTTP/1.1" - - "-" "-" 3821 - - 0ms traefik.1.1crqzz4fgpk6@server | 10.255.0.3 - - [25/Oct/2019:13:57:40 +0000] "GET /api/overview HTTP/1.1" - - "-" "-" 3822 - - 0ms traefik.1.1crqzz4fgpk6@server | 10.255.0.3 - - [25/Oct/2019:13:57:41 +0000] "GET /api/providers HTTP/1.1" - - "-" "-" 3823 - - 0ms traefik.1.1crqzz4fgpk6@server | 10.255.0.3 - - [25/Oct/2019:13:57:41 +0000] "GET /api/providers HTTP/1.1" - - "-" "-" 3824 - - 0ms traefik.1.1crqzz4fgpk6@server | 10.255.0.3 - - [25/Oct/2019:13:57:41 +0000] "GET /api/providers HTTP/1.1" - - "-" "-" 3825 - - 0ms traefik.1.1crqzz4fgpk6@server | 10.255.0.3 - - [25/Oct/2019:13:57:41 +0000] "GET /api/providers HTTP/1.1" - - "-" "-" 3826 - - 0ms traefik.1.1crqzz4fgpk6@server | 10.255.0.3 - - [25/Oct/2019:13:57:41 +0000] "GET /api/providers HTTP/1.1" - - "-" "-" 3827 - - 0ms traefik.1.1crqzz4fgpk6@server | 10.255.0.3 - - [25/Oct/2019:13:57:41 +0000] "GET /api/providers HTTP/1.1" - - "-" "-" 3828 - - 0ms traefik.1.1crqzz4fgpk6@server | 10.255.0.3 - - [25/Oct/2019:13:57:42 +0000] "GET /dashboard/ HTTP/1.1" - - "-" "-" 3829 - - 0ms ``` the only dashboard related entry is: ```auto traefik.1.1crqzz4fgpk6@server | 10.255.0.3 - - [25/Oct/2019:13:57:42 +0000] "GET /dashboard/ HTTP/1.1" - - "-" "-" 3829 - - 0ms ``` is it correct that i set --entrypoints.api.address=:8512 and - traefik.http.routers.api.entrypoints=api ? and the curl result: ```auto curl --verbose --location --insecure -o /dev/null http://traefikUrl:8512/dashboard/ % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0* About to connect() to traefikUrl port 8512 (#0) * Trying 10.10.3.218... * Connected to traefikUrl (10.10.3.218) port 8512 (#0) > GET /dashboard/ HTTP/1.1 > User-Agent: curl/7.29.0 > Host: traefikUrl:8512 > Accept: */* > < HTTP/1.1 404 Not Found < Content-Type: text/plain; charset=utf-8 < X-Content-Type-Options: nosniff < Date: Fri, 25 Oct 2019 13:59:23 GMT < Content-Length: 19 < { [data not shown] 100 19 100 19 0 0 3550 0 --:--:-- --:--:-- --:--:-- 3800 * Connection #0 to host traefikUrl left intact ``` ---
**Author:** ![Stargate](https://avatars.discourse-cdn.com/v4/letter/s/9d8465/32.png) [@Stargate](https://community.traefik.io/u/Stargate)\ **Post date:** [October 29, 2019, 11:27am UTC](https://community.traefik.io/t/traefik-with-docker-swarm-as-loadbalancer-bad-gateway/2558/8 "2019-10-29T11:27:44Z")
Hi, it seems this guy ([https://github.com/containous/traefik/issues/5457](https://github.com/containous/traefik/issues/5457)) has the same error "404 page not found". it works only if i set the insecure flag ---
**Author:** ![dduportal](https://sea2.discourse-cdn.com/flex020/user_avatar/community.traefik.io/dduportal/32/4_2.png) [@dduportal](https://community.traefik.io/u/dduportal)\ **Post date:** [October 29, 2019, 3:30pm UTC](https://community.traefik.io/t/traefik-with-docker-swarm-as-loadbalancer-bad-gateway/2558/9 "2019-10-29T15:30:45Z")
Hi @Stargate, I tried to reproduce you case and caught 2 errors in the docker service of Traefik: * * * First: ```auto traefik_traefik.1.wdn1uhibsxbi@docker-desktop | time="2019-10-26T09:41:52Z" level=warning msg="Could not find network named 'traefik-proxy' for container 'traefik_traefik.1'! Maybe you're missing the project's prefix in the label? Defaulting to first available network." container=traefik-traefik-wdn1uhibsxbio80neggxkglg6 serviceName=traefik-traefik providerName=docker ``` =\> You might not have this error: it is related to the space between the last line of the `command: >` yaml node and `networks:`. When checking the Docker API, I saw that the Traefik container was not attached to the network `traedfik-proxy`. By removing the empty line and redeploying, this error went away * * * Second: ```auto --providers.docker.exposedbydefault=false ``` This flag means that Traefik takes in account only the containers which have the label `traefik.enable` set to `true`. But Traefik itself do not have this label in your snippet, so it ignores itself and the configuration is never created. =\> Add the label `- traefik.enable=true` to Traefik itself. * * * Third: When using Swarm, Traefik cannot determines the exposed port automatically as how it does with Docker Engine. It is mandatory to specify this port as if there were multiple ports. I don't know why (yet) but you must create a "dummy" service with a port, which won't be used but is still required. =\> Add the label `traefik.http.services.api-dummy.loadbalancer.server.port=99999` to the Traefik service. With these 3 elements you should be ready to go 🙂 ---
**Author:** ![Stargate](https://avatars.discourse-cdn.com/v4/letter/s/9d8465/32.png) [@Stargate](https://community.traefik.io/u/Stargate)\ **Post date:** [October 30, 2019, 12:00pm UTC](https://community.traefik.io/t/traefik-with-docker-swarm-as-loadbalancer-bad-gateway/2558/10 "2019-10-30T12:00:25Z")
Hi dduportal, it worked now 🙂 thanks a lot for your help. But i have hopefully a last question 🙂 i need for my app a sticky session. So that a second request goes to the same server. Is it enough to add this label: - traefik.http.services.myapp\_service.loadbalancer.sticky=true to my myApp yml ? Becaus this configuration did not work for me. EDIT: The myApp Application is in this case a Vaadin Application and i use websockets. I ---
**Author:** ![Stargate](https://avatars.discourse-cdn.com/v4/letter/s/9d8465/32.png) [@Stargate](https://community.traefik.io/u/Stargate)\ **Post date:** [October 30, 2019, 5:34pm UTC](https://community.traefik.io/t/traefik-with-docker-swarm-as-loadbalancer-bad-gateway/2558/11 "2019-10-30T17:34:59Z")
Hi, i have added "- traefik.http.services.myapp\_service.loadbalancer.sticky.cookie.name=StickyCookie" to my config and now its working. But i have a last error in my logs: time="2019-10-30T17:30:19Z" level=error msg="port is missing" providerName=docker container=myApp-6nybt4u2572n9wkxj38py1ngd All is working fine but i have no idea why the message "port ist missing" appears. ```auto version: '3.5' services: myApp: image: "myApp:v1.0" ports: - "8515:8080" networks: - traefik-proxy deploy: labels: - traefik.enable=true - traefik.http.routers.myapp_router.entrypoints=http - traefik.http.routers.myapp_router.rule=PathPrefix(`/`) - traefik.docker.network=traefik-proxy - traefik.http.services.myapp_service.loadbalancer.server.port=8080 - traefik.http.services.persistence_service.loadbalancer.healthcheck.path=/admin/health - traefik.http.services.persistence_service.loadbalancer.healthcheck.headers.Authorization=Basic 1234 - traefik.http.services.persistence_service.loadbalancer.healthcheck.interval=10s mode: global update_config: parallelism: 1 delay: 1m order: stop-first restart_policy: condition: any environment: - "SPRING_PROFILES_ACTIVE=docker" networks: traefik-proxy: external: true ``` ---
**Author:** ![ldez](https://sea2.discourse-cdn.com/flex020/user_avatar/community.traefik.io/ldez/32/5_2.png) [@ldez](https://community.traefik.io/u/ldez)\ **Post date:** [October 30, 2019, 8:29pm UTC](https://community.traefik.io/t/traefik-with-docker-swarm-as-loadbalancer-bad-gateway/2558/12 "2019-10-30T20:29:37Z")
small typo in your configuration `myapp_service` -\> `persistence_service` ---
**Author:** ![Stargate](https://avatars.discourse-cdn.com/v4/letter/s/9d8465/32.png) [@Stargate](https://community.traefik.io/u/Stargate)\ **Post date:** [October 31, 2019, 9:05am UTC](https://community.traefik.io/t/traefik-with-docker-swarm-as-loadbalancer-bad-gateway/2558/13 "2019-10-31T09:05:55Z")
Hi Idez, sorry i have copied the wrong code. Here is no typo. ```auto version: '3.5' services: myApp: image: "myApp:v1.0" ports: - "8515:8080" networks: - traefik-proxy deploy: labels: - traefik.enable=true - traefik.http.routers.myapp_router.entrypoints=http - traefik.http.routers.myapp_router.rule=PathPrefix(`/`) - traefik.docker.network=traefik-proxy - traefik.http.services.myapp_service.loadbalancer.server.port=8080 - traefik.http.services.myapp_service.loadbalancer.healthcheck.path=/admin/health - traefik.http.services.myapp_service.loadbalancer.healthcheck.headers.Authorization=Basic 1234 - traefik.http.services.myapp_service.loadbalancer.healthcheck.interval=10s mode: global update_config: parallelism: 1 delay: 1m order: stop-first restart_policy: condition: any environment: - "SPRING_PROFILES_ACTIVE=docker" ``` but i get still two different error messages with "port ist missing" but so far this message has no effect all works fine. But i dont know why this message appears ```auto traefik | time="2019-10-31T09:00:50Z" level=error msg="port is missing" providerName=docker container=myApp-6nybt4u2572n9wkxj38py1ngd traefik | time="2019-10-31T09:00:50Z" level=error msg="port is missing" providerName=docker container=myApp-ozw4no2nvv249ij1jra4bfo1a traefik | time="2019-10-31T09:01:05Z" level=error msg="port is missing" container=myApp-6nybt4u2572n9wkxj38py1ngd providerName=docker traefik | time="2019-10-31T09:01:05Z" level=error msg="port is missing" container=myApp-ozw4no2nvv249ij1jra4bfo1a providerName=docker ``` here is a similar bug but i have set a loadbalancer port: "traefik.http.services.myapp\_service.loadbalancer.server.port=8080" > > > Do you want to request a feature or report a bug? > Bug > What did you do? > I tried to run traefik in a docker... ---
**Author:** ![dduportal](https://sea2.discourse-cdn.com/flex020/user_avatar/community.traefik.io/dduportal/32/4_2.png) [@dduportal](https://community.traefik.io/u/dduportal)\ **Post date:** [October 31, 2019, 11:58am UTC](https://community.traefik.io/t/traefik-with-docker-swarm-as-loadbalancer-bad-gateway/2558/14 "2019-10-31T11:58:59Z")
Hi @Stargate can you check that you do not have dangling containers? (You can share here the results of `docker service ls`)