traefik/docs/content/migration/v1-to-v2.md
2019-09-20 16:44:04 +02:00

970 lines
No EOL
26 KiB
Markdown

# Migration Guide: From v1 to v2
How to Migrate from Traefik v1 to Traefik v2.
{: .subtitle }
The version 2 of Traefik introduces a number of breaking changes,
which require one to update their configuration when they migrate from v1 to v2.
The goal of this page is to recapitulate all of these changes, and in particular to give examples,
feature by feature, of how the configuration looked like in v1, and how it now looks like in v2.
!!! Note "Migration Helper"
We created a tool to help during the migration: [traefik-migration-tool](https://github.com/containous/traefik-migration-tool)
This tool allows to:
- convert `Ingress` to Traefik `IngressRoute` resources.
- convert `acme.json` file from v1 to v2 format.
## Frontends and Backends Are Dead... <br/>... Long Live Routers, Middlewares, and Services
During the transition from v1 to v2, a number of internal pieces and components of Traefik were rewritten and reorganized.
As such, the combination of core notions such as frontends and backends has been replaced with the combination of [routers](../routing/routers/index.md), [services](../routing/services/index.md), and [middlewares](../middlewares/overview.md).
Typically, a router replaces a frontend, and a service assumes the role of a backend, with each router referring to a service.
However, even though a backend was in charge of applying any desired modification on the fly to the incoming request,
the router defers that responsibility to another component.
Instead, a dedicated middleware is now defined for each kind of such modification.
Then any router can refer to an instance of the wanted middleware.
!!! example "One frontend with basic auth and one backend, become one router, one service, and one basic auth middleware."
!!! info "v1"
```yaml tab="Docker"
labels:
- "traefik.frontend.rule=Host:test.localhost;PathPrefix:/test"
- "traefik.frontend.auth.basic.users=test:$apr1$H6uskkkW$IgXLP6ewTrSuBkTrqE8wj/,test2:$apr1$d9hr9HBB$4HxwgUir3HP4EsggP/QNo0"
```
```yaml tab="K8s Ingress"
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: traefik
namespace: kube-system
annotations:
kubernetes.io/ingress.class: traefik
traefik.ingress.kubernetes.io/rule-type: PathPrefix
spec:
rules:
- host: test.locahost
http:
paths:
- path: /test
backend:
serviceName: server0
servicePort: 80
- path: /test
backend:
serviceName: server1
servicePort: 80
```
```toml tab="File (TOML)"
[frontends]
[frontends.frontend1]
entryPoints = ["http"]
backend = "backend1"
[frontends.frontend1.routes]
[frontends.frontend1.routes.route0]
rule = "Host:test.localhost"
[frontends.frontend1.routes.route0]
rule = "PathPrefix:/test"
[frontends.frontend1.auth]
[frontends.frontend1.auth.basic]
users = [
"test:$apr1$H6uskkkW$IgXLP6ewTrSuBkTrqE8wj/",
"test2:$apr1$d9hr9HBB$4HxwgUir3HP4EsggP/QNo0",
]
[backends]
[backends.backend1]
[backends.backend1.servers.server0]
url = "http://10.10.10.1:80"
[backends.backend1.servers.server1]
url = "http://10.10.10.2:80"
[backends.backend1.loadBalancer]
method = "wrr"
```
!!! info "v2"
```yaml tab="Docker"
labels:
- "traefik.http.routers.router0.rule=Host(`bar.com`) && PathPrefix(`/test`)"
- "traefik.http.routers.router0.middlewares=auth"
- "traefik.http.middlewares.auth.basicauth.users=test:$apr1$H6uskkkW$IgXLP6ewTrSuBkTrqE8wj/,test2:$apr1$d9hr9HBB$4HxwgUir3HP4EsggP/QNo0"
```
```yaml tab="K8s IngressRoute"
# The definitions below require the definitions for the Middleware and IngressRoute kinds.
# https://docs.traefik.io/v2.0/providers/kubernetes-crd/#traefik-ingressroute-definition
apiVersion: traefik.containo.us/v1alpha1
kind: Middleware
metadata:
name: basicauth
namespace: foo
spec:
basicAuth:
users:
- test:$apr1$H6uskkkW$IgXLP6ewTrSuBkTrqE8wj/
- test2:$apr1$d9hr9HBB$4HxwgUir3HP4EsggP/QNo0
---
apiVersion: traefik.containo.us/v1alpha1
kind: IngressRoute
metadata:
name: ingressroutebar
spec:
entryPoints:
- http
routes:
- match: Host(`test.localhost`) && PathPrefix(`/test`)
kind: Rule
services:
- name: server0
port: 80
- name: server1
port: 80
middlewares:
- name: basicauth
namespace: foo
```
```toml tab="File (TOML)"
[http.routers]
[http.routers.router0]
rule = "Host(`test.localhost`) && PathPrefix(`/test`)"
middlewares = ["auth"]
service = "my-service"
[http.services]
[[http.services.my-service.loadBalancer.servers]]
url = "http://10.10.10.1:80"
[[http.services.my-service.loadBalancer.servers]]
url = "http://10.10.10.2:80"
[http.middlewares]
[http.middlewares.auth.basicAuth]
users = [
"test:$apr1$H6uskkkW$IgXLP6ewTrSuBkTrqE8wj/",
"test2:$apr1$d9hr9HBB$4HxwgUir3HP4EsggP/QNo0",
]
```
```yaml tab="File (YAML)"
http:
routers:
router0:
rule: "Host(`test.localhost`) && PathPrefix(`/test`)"
service: my-service
middlewares:
- auth
services:
my-service:
loadBalancer:
servers:
- url: http://10.10.10.1:80
- url: http://10.10.10.2:80
middlewares:
auth:
basicAuth:
users:
- "test:$apr1$H6uskkkW$IgXLP6ewTrSuBkTrqE8wj/"
- "test2:$apr1$d9hr9HBB$4HxwgUir3HP4EsggP/QNo0"
```
## TLS configuration is now dynamic, per router.
TLS parameters used to be specified in the static configuration, as an entryPoint field.
With Traefik v2, a new dynamic TLS section at the root contains all the desired TLS configurations.
Then, a [router's TLS field](../routing/routers/index.md#tls) can refer to one of the [TLS configurations](../https/tls.md) defined at the root, hence defining the [TLS configuration](../https/tls.md) for that router.
!!! example "TLS on web-secure entryPoint becomes TLS option on Router-1"
!!! info "v1"
```toml tab="File (TOML)"
# static configuration
[entryPoints]
[entryPoints.web-secure]
address = ":443"
[entryPoints.web-secure.tls]
minVersion = "VersionTLS12"
cipherSuites = [
"TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256",
"TLS_RSA_WITH_AES_256_GCM_SHA384"
]
[[entryPoints.web-secure.tls.certificates]]
certFile = "path/to/my.cert"
keyFile = "path/to/my.key"
```
```bash tab="CLI"
--entryPoints='Name:web-secure Address::443 TLS:path/to/my.cert,path/to/my.key TLS.MinVersion:VersionTLS12 TLS.CipherSuites:TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA384'
```
!!! info "v2"
```toml tab="File (TOML)"
# dynamic configuration
[http.routers]
[http.routers.Router-1]
rule = "Host(`bar.com`)"
service = "service-id"
# will terminate the TLS request
[http.routers.Router-1.tls]
options = "myTLSOptions"
[[tls.certificates]]
certFile = "/path/to/domain.cert"
keyFile = "/path/to/domain.key"
[tls.options]
[tls.options.default]
minVersion = "VersionTLS12"
[tls.options.myTLSOptions]
minVersion = "VersionTLS13"
cipherSuites = [
"TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256",
"TLS_RSA_WITH_AES_256_GCM_SHA384"
]
```
```yaml tab="File (YAML)"
http:
routers:
Router-1:
rule: "Host(`bar.com`)"
service: service-id
# will terminate the TLS request
tls:
options: myTLSOptions
tls:
certificates:
- certFile: /path/to/domain.cert
keyFile: /path/to/domain.key
options:
myTLSOptions:
minVersion: VersionTLS13
cipherSuites:
- TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
- TLS_RSA_WITH_AES_256_GCM_SHA384
```
```yaml tab="K8s IngressRoute"
# The definitions below require the definitions for the TLSOption and IngressRoute kinds.
# https://docs.traefik.io/v2.0/providers/kubernetes-crd/#traefik-ingressroute-definition
apiVersion: traefik.containo.us/v1alpha1
kind: TLSOption
metadata:
name: mytlsoption
namespace: default
spec:
minVersion: VersionTLS13
cipherSuites:
- TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
- TLS_RSA_WITH_AES_256_GCM_SHA384
---
apiVersion: traefik.containo.us/v1alpha1
kind: IngressRoute
metadata:
name: ingressroutebar
spec:
entryPoints:
- web
routes:
- match: Host(`bar.com`)
kind: Rule
services:
- name: whoami
port: 80
tls:
options:
name: mytlsoption
namespace: default
```
```yaml tab="Docker"
labels:
# myTLSOptions must be defined by another provider, in this instance in the File Provider.
# see the cross provider section
- "traefik.http.routers.router0.tls.options=myTLSOptions@file"
```
## HTTP to HTTPS Redirection is now configured on Routers
Previously on Traefik v1, the redirection was applied on an entry point or on a frontend.
With Traefik v2 it is applied on a [Router](../routing/routers/index.md).
To apply a redirection, one of the redirect middlewares, [RedirectRegex](../middlewares/redirectregex.md) or [RedirectScheme](../middlewares/redirectscheme.md), has to be configured and added to the router middlewares list.
!!! example "HTTP to HTTPS redirection"
!!! info "v1"
```toml tab="File (TOML)"
# static configuration
defaultEntryPoints = ["http", "https"]
[entryPoints]
[entryPoints.http]
address = ":80"
[entryPoints.http.redirect]
entryPoint = "https"
[entryPoints.https]
address = ":443"
[entryPoints.https.tls]
[[entryPoints.https.tls.certificates]]
certFile = "examples/traefik.crt"
keyFile = "examples/traefik.key"
```
```bash tab="CLI"
--entrypoints=Name:web Address::80 Redirect.EntryPoint:web-secure
--entryPoints='Name:web-secure Address::443 TLS:path/to/my.cert,path/to/my.key'
```
!!! info "v2"
```yaml tab="Docker"
labels:
- traefik.http.routers.web.rule=Host(`foo.com`)
- traefik.http.routers.web.entrypoints=web
- traefik.http.routers.web.middlewares=redirect@file
- traefik.http.routers.web-secured.rule=Host(`foo.com`)
- traefik.http.routers.web-secured.entrypoints=web-secure
- traefik.http.routers.web-secured.tls=true
```
```yaml tab="K8s IngressRoute"
apiVersion: traefik.containo.us/v1alpha1
kind: IngressRoute
metadata:
name: http-redirect-ingressRoute
spec:
entryPoints:
- web
routes:
- match: Host(`foo.com`)
kind: Rule
services:
- name: whoami
port: 80
middlewares:
- name: redirect
---
apiVersion: traefik.containo.us/v1alpha1
kind: IngressRoute
metadata:
name: https-ingressRoute
spec:
entryPoints:
- web-secure
routes:
- match: Host(`foo`)
kind: Rule
services:
- name: whoami
port: 80
tls: {}
---
apiVersion: traefik.containo.us/v1alpha1
kind: Middleware
metadata:
name: redirect
spec:
redirectScheme:
scheme: https
```
```toml tab="File (TOML)"
## static configuration
# traefik.toml
[entryPoints.web]
address = ":80"
[entryPoints.web-secure]
address = ":443"
##---------------------##
## dynamic configuration
# dymanic-conf.toml
[http.routers]
[http.routers.router0]
rule = "Host(`foo.com`)"
service = "my-service"
entrypoints = "web"
middlewares = ["redirect"]
[http.routers.router1]
rule = "Host(`foo.com`)"
service = "my-service"
entrypoints = "web-secure"
[http.routers.router1.tls]
[http.services]
[[http.services.my-service.loadBalancer.servers]]
url = "http://10.10.10.1:80"
[[http.services.my-service.loadBalancer.servers]]
url = "http://10.10.10.2:80"
[http.middlewares]
[http.middlewares.redirect.redirectScheme]
scheme = "https"
[[tls.certificates]]
certFile = "/path/to/domain.cert"
keyFile = "/path/to/domain.key"
```
```yaml tab="File (YAML)"
## static configuration
# traefik.yml
entryPoints:
web:
address: ":80"
web-secure:
address: ":443"
##---------------------##
## dynamic configuration
# dymanic-conf.yml
http:
routers:
router0:
rule: "Host(`foo.com`)"
entryPoints:
- web
middlewares:
- redirect
service: my-service
router1:
rule: "Host(`foo.com`)"
entryPoints:
- web-secure
service: my-service
tls: {}
services:
my-service:
loadBalancer:
servers:
- url: http://10.10.10.1:80
- url: http://10.10.10.2:80
middlewares:
redirect:
redirectScheme:
scheme: https
tls:
certificates:
- certFile: /app/certs/server/server.pem
keyFile: /app/certs/server/server.pem
```
## ACME (LetsEncrypt)
[ACME](../https/acme.md) is now a certificate resolver (under a certificatesResolvers section) but remains in the static configuration.
!!! example "ACME from provider to a specific Certificate Resolver"
!!! info "v1"
```toml tab="File (TOML)"
# static configuration
defaultEntryPoints = ["web-secure","web"]
[entryPoints.web]
address = ":80"
[entryPoints.web.redirect]
entryPoint = "webs"
[entryPoints.web-secure]
address = ":443"
[entryPoints.https.tls]
[acme]
email = "your-email-here@my-awesome-app.org"
storage = "acme.json"
entryPoint = "web-secure"
onHostRule = true
[acme.httpChallenge]
entryPoint = "web"
```
```bash tab="CLI"
--defaultentrypoints=web-secure,web
--entryPoints=Name:web Address::80 Redirect.EntryPoint:web-secure
--entryPoints=Name:web-secure Address::443 TLS
--acme.email=your-email-here@my-awesome-app.org
--acme.storage=acme.json
--acme.entryPoint=web-secure
--acme.onHostRule=true
--acme.httpchallenge.entrypoint=http
```
!!! info "v2"
```toml tab="File (TOML)"
# static configuration
[entryPoints]
[entryPoints.web]
address = ":80"
[entryPoints.web-secure]
address = ":443"
[certificatesResolvers.sample.acme]
email = "your-email@your-domain.org"
storage = "acme.json"
[acme.httpChallenge]
# used during the challenge
entryPoint = "web"
```
```yaml tab="File (YAML)"
entryPoints:
web:
address: ":80"
web-secure:
address: ":443"
certificatesResolvers:
sample:
acme:
email: your-email@your-domain.org
storage: acme.json
httpChallenge:
# used during the challenge
entryPoint: web
```
```bash tab="CLI"
--entryPoints.web.address=":80"
--entryPoints.websecure.address=":443"
--certificatesResolvers.sample.acme.email: your-email@your-domain.org
--certificatesResolvers.sample.acme.storage: acme.json
--certificatesResolvers.sample.acme.httpChallenge.entryPoint: web
```
## Traefik Logs
In the v2, all the [log configuration](../observability/logs.md) remains in the static part but are unified under a `log` section.
There is no more log configuration at the root level.
!!! example "Simple log configuration"
!!! info "v1"
```toml tab="File (TOML)"
# static configuration
logLevel = "DEBUG"
[traefikLog]
filePath = "/path/to/traefik.log"
format = "json"
```
```bash tab="CLI"
--logLevel="DEBUG"
--traefikLog.filePath="/path/to/traefik.log"
--traefikLog.format="json"
```
!!! info "v2"
```toml tab="File (TOML)"
# static configuration
[log]
level = "DEBUG"
filePath = "/path/to/log-file.log"
format = "json"
```
```yaml tab="File (YAML)"
# static configuration
log:
level: DEBUG
filePath: /path/to/log-file.log
format: json
```
```bash tab="CLI"
--log.level="DEBUG"
--log.filePath="/path/to/traefik.log"
--log.format="json"
```
## Tracing
Traefik v2 retains OpenTracing support. The `backend` root option from the v1 is gone, you just have to set your [tracing configuration](../observability/tracing/overview.md).
!!! example "Simple Jaeger tracing configuration"
!!! info "v1"
```toml tab="File (TOML)"
# static configuration
[tracing]
backend = "jaeger"
servicename = "tracing"
[tracing.jaeger]
samplingParam = 1.0
samplingServerURL = "http://12.0.0.1:5778/sampling"
samplingType = "const"
localAgentHostPort = "12.0.0.1:6831"
```
```bash tab="CLI"
--tracing.backend="jaeger"
--tracing.servicename="tracing"
--tracing.jaeger.localagenthostport="12.0.0.1:6831"
--tracing.jaeger.samplingparam="1.0"
--tracing.jaeger.samplingserverurl="http://12.0.0.1:5778/sampling"
--tracing.jaeger.samplingtype="const"
```
!!! info "v2"
```toml tab="File (TOML)"
# static configuration
[tracing]
servicename = "tracing"
[tracing.jaeger]
samplingParam = 1.0
samplingServerURL = "http://12.0.0.1:5778/sampling"
samplingType = "const"
localAgentHostPort = "12.0.0.1:6831"
```
```yaml tab="File (YAML)"
# static configuration
tracing:
servicename: tracing
jaeger:
samplingParam: 1
samplingServerURL: 'http://12.0.0.1:5778/sampling'
samplingType: const
localAgentHostPort: '12.0.0.1:6831'
```
```bash tab="CLI"
--tracing.servicename="tracing"
--tracing.jaeger.localagenthostport="12.0.0.1:6831"
--tracing.jaeger.samplingparam="1.0"
--tracing.jaeger.samplingserverurl="http://12.0.0.1:5778/sampling"
--tracing.jaeger.samplingtype="const"
```
## Metrics
The v2 retains metrics tools and allows metrics to be configured for the entrypoints and/or services.
For a basic configuration, the [metrics configuration](../observability/metrics/overview.md) remains the same.
!!! example "Simple Prometheus metrics configuration"
!!! info "v1"
```toml tab="File (TOML)"
# static configuration
[metrics.prometheus]
buckets = [0.1,0.3,1.2,5.0]
entryPoint = "traefik"
```
```bash tab="CLI"
--metrics.prometheus.buckets=[0.1,0.3,1.2,5.0]
--metrics.prometheus.entrypoint="traefik"
```
!!! info "v2"
```toml tab="File (TOML)"
# static configuration
[metrics.prometheus]
buckets = [0.1,0.3,1.2,5.0]
entryPoint = "metrics"
```
```yaml tab="File (YAML)"
# static configuration
metrics:
prometheus:
buckets:
- 0.1
- 0.3
- 1.2
- 5
entryPoint: metrics
```
```bash tab="CLI"
--metrics.prometheus.buckets=[0.1,0.3,1.2,5.0]
--metrics.prometheus.entrypoint="metrics"
```
## No more root level key/values
To avoid any source of confusion, there are no more configuration at the root level.
Each root item has been moved to a related section or removed.
!!! example "From root to dedicated section"
!!! info "v1"
```toml tab="File (TOML)"
# static configuration
checkNewVersion = false
sendAnonymousUsage = true
logLevel = "DEBUG"
insecureSkipVerify = true
rootCAs = [ "/mycert.cert" ]
maxIdleConnsPerHost = 200
providersThrottleDuration = "2s"
AllowMinWeightZero = true
debug = true
defaultEntryPoints = ["web", "web-secure"]
keepTrailingSlash = false
```
```bash tab="CLI"
--checknewversion=false
--sendanonymoususage=true
--loglevel="DEBUG"
--insecureskipverify=true
--rootcas="/mycert.cert"
--maxidleconnsperhost=200
--providersthrottleduration="2s"
--allowminweightzero=true
--debug=true
--defaultentrypoints="web","web-secure"
--keeptrailingslash=true
```
!!! info "v2"
```toml tab="File (TOML)"
# static configuration
[global]
checkNewVersion = true
sendAnonymousUsage = true
[log]
level = "DEBUG"
[serversTransport]
insecureSkipVerify = true
rootCAs = [ "/mycert.cert" ]
maxIdleConnsPerHost = 42
[providers]
providersThrottleDuration = 42
```
```yaml tab="File (YAML)"
# static configuration
global:
checkNewVersion: true
sendAnonymousUsage: true
log:
level: DEBUG
serversTransport:
insecureSkipVerify: true
rootCAs:
- /mycert.cert
maxIdleConnsPerHost: 42
providers:
providersThrottleDuration: 42
```
```bash tab="CLI"
--global.checknewversion=true
--global.sendanonymoususage=true
--log.level="DEBUG"
--serverstransport.insecureskipverify=true
--serverstransport.rootcas="/mycert.cert"
--serverstransport.maxidleconnsperhost=42
--providers.providersthrottleduration=42
```
## Dashboard
You need to activate the [API](../operations/dashboard.md#enabling-the-dashboard) to access the dashboard.
As the dashboard access is now secured by default you can either:
* define a [specific router](../operations/api.md#configuration) with the `api@internal` service and one authentication middleware like the following example
* or use the [unsecure](../operations/api.md#insecure) option of the API
!!! note "Dashboard with k8s and dedicated router"
As `api@internal` is not a Kubernetes service, you have to use the file provider or the `insecure` API option.
!!! example "Activate and access the dashboard"
!!! info "v1"
```toml tab="File (TOML)"
## static configuration
# traefik.toml
[entryPoints.web-secure]
address = ":443"
[entryPoints.web-secure.tls]
[entryPoints.web-secure.auth]
[entryPoints.web-secure.auth.basic]
users = [
"test:$apr1$H6uskkkW$IgXLP6ewTrSuBkTrqE8wj/"
]
[api]
entryPoint = "web-secure"
```
```bash tab="CLI"
--entryPoints='Name:web-secure Address::443 TLS Auth.Basic.Users:test:$apr1$H6uskkkW$IgXLP6ewTrSuBkTrqE8wj/'
--api
```
!!! info "v2"
```yaml tab="Docker"
# dynamic configuration
labels:
- "traefik.http.routers.api.rule=Host(`traefik.docker.localhost`)"
- "traefik.http.routers.api.entrypoints=web-secured"
- "traefik.http.routers.api.service=api@internal"
- "traefik.http.routers.api.middlewares=myAuth"
- "traefik.http.routers.api.tls"
- "traefik.http.middlewares.myAuth.basicauth.users=test:$apr1$H6uskkkW$IgXLP6ewTrSuBkTrqE8wj/"
```
```toml tab="File (TOML)"
## static configuration
# traefik.toml
[entryPoints.web-secure]
address = ":443"
[api]
[providers.file]
filename = "/dymanic-conf.toml"
##---------------------##
## dynamic configuration
# dymanic-conf.toml
[http.routers.api]
rule = "Host(`traefik.docker.localhost`)"
entrypoints = ["web-secure"]
service = "api@internal"
middlewares = ["myAuth"]
[http.routers.api.tls]
[http.middlewares.myAuth.basicAuth]
users = [
"test:$apr1$H6uskkkW$IgXLP6ewTrSuBkTrqE8wj/"
]
```
```yaml tab="File (YAML)"
## static configuration
# traefik.yaml
entryPoints:
web-secure:
address: ':443'
api: {}
providers:
file:
filename: /dymanic-conf.yaml
##---------------------##
## dynamic configuration
# dymanic-conf.yaml
http:
routers:
api:
rule: Host(`traefik.docker.localhost`)
entrypoints:
- web-secure
service: api@internal
middlewares:
- myAuth
tls: {}
middlewares:
myAuth:
basicAuth:
users:
- 'test:$apr1$H6uskkkW$IgXLP6ewTrSuBkTrqE8wj/'
```
## Providers
Supported [providers](../providers/overview.md), for now:
* [ ] Azure Service Fabric
* [ ] BoltDB
* [ ] Consul
* [ ] Consul Catalog
* [x] Docker
* [ ] DynamoDB
* [ ] ECS
* [ ] Etcd
* [ ] Eureka
* [x] File
* [x] Kubernetes Ingress (without annotations)
* [x] Kubernetes IngressRoute
* [x] Marathon
* [ ] Mesos
* [x] Rancher
* [x] Rest
* [ ] Zookeeper
## Some Tips You Should Known
* Different sources of static configuration (file, CLI flags, ...) cannot be [mixed](../getting-started/configuration-overview.md#the-static-configuration).
* Now, configuration elements can be referenced between different providers by using the provider namespace notation: `@<provider>`.
For instance, a router named `myrouter` in a File Provider can refer to a service named `myservice` defined in Docker Provider with the following notation: `myservice@docker`.
* Middlewares are applied in the same order as their declaration in router.
* If you have any questions feel free to join our [community forum](https://community.containo.us).