Traefik & Consul Catalog¶
A Story of Tags, Services & Instances
Attach tags to your services and let Traefik do the rest!
Configuration Examples¶
Configuring Consul Catalog & Deploying / Exposing Services
Enabling the consul catalog provider
providers:
consulCatalog: {}[providers.consulCatalog]--providers.consulcatalog=trueAttaching tags to services
- traefik.http.routers.my-router.rule=Host(`example.com`)Routing Configuration¶
See the dedicated section in routing.
Provider Configuration¶
refreshInterval¶
Optional, Default=15s
Defines the polling interval.
providers:
consulCatalog:
refreshInterval: 30s
# ...[providers.consulCatalog]
refreshInterval = "30s"
# ...--providers.consulcatalog.refreshInterval=30s
# ...prefix¶
required, Default="traefik"
The prefix for Consul Catalog tags defining Traefik labels.
providers:
consulCatalog:
prefix: test
# ...[providers.consulCatalog]
prefix = "test"
# ...--providers.consulcatalog.prefix=test
# ...requireConsistent¶
Optional, Default=false
Forces the read to be fully consistent.
It is more expensive due to an extra round-trip but prevents ever performing a stale read.
For more information, see the consul documentation on consistency.
providers:
consulCatalog:
requireConsistent: true
# ...[providers.consulCatalog]
requireConsistent = true
# ...--providers.consulcatalog.requireConsistent=true
# ...stale¶
Optional, Default=false
Use stale consistency for catalog reads.
This makes reads very fast and scalable at the cost of a higher likelihood of stale values.
For more information, see the consul documentation on consistency.
providers:
consulCatalog:
stale: true
# ...[providers.consulCatalog]
stale = true
# ...--providers.consulcatalog.stale=true
# ...cache¶
Optional, Default=false
Use local agent caching for catalog reads.
providers:
consulCatalog:
cache: true
# ...[providers.consulCatalog]
cache = true
# ...--providers.consulcatalog.cache=true
# ...endpoint¶
Defines the Consul server endpoint.
address¶
Defines the address of the Consul server.
Optional, Default="127.0.0.1:8500"
providers:
consulCatalog:
endpoint:
address: 127.0.0.1:8500
# ...[providers.consulCatalog]
[providers.consulCatalog.endpoint]
address = "127.0.0.1:8500"
# ...--providers.consulcatalog.endpoint.address=127.0.0.1:8500
# ...scheme¶
Optional, Default=""
Defines the URI scheme for the Consul server.
providers:
consulCatalog:
endpoint:
scheme: https
# ...[providers.consulCatalog]
[providers.consulCatalog.endpoint]
scheme = "https"
# ...--providers.consulcatalog.endpoint.scheme=https
# ...datacenter¶
Optional, Default=""
Defines the datacenter to use. If not provided in Traefik, Consul uses the default agent datacenter.
providers:
consulCatalog:
endpoint:
datacenter: test
# ...[providers.consulCatalog]
[providers.consulCatalog.endpoint]
datacenter = "test"
# ...--providers.consulcatalog.endpoint.datacenter=test
# ...token¶
Optional, Default=""
Token is used to provide a per-request ACL token which overwrites the agent's default token.
providers:
consulCatalog:
endpoint:
token: test
# ...[providers.consulCatalog]
[providers.consulCatalog.endpoint]
token = "test"
# ...--providers.consulcatalog.endpoint.token=test
# ...endpointWaitTime¶
Optional, Default=""
Limits the duration for which a Watch can block. If not provided, the agent default values will be used.
providers:
consulCatalog:
endpoint:
endpointWaitTime: 15s
# ...[providers.consulCatalog]
[providers.consulCatalog.endpoint]
endpointWaitTime = "15s"
# ...--providers.consulcatalog.endpoint.endpointwaittime=15s
# ...httpAuth¶
Optional
Used to authenticate the HTTP client using HTTP Basic Authentication.
username¶
Optional, Default=""
Username to use for HTTP Basic Authentication.
providers:
consulCatalog:
endpoint:
httpAuth:
username: test[providers.consulCatalog.endpoint.httpAuth]
username = "test"--providers.consulcatalog.endpoint.httpauth.username=testpassword¶
Optional, Default=""
Password to use for HTTP Basic Authentication.
providers:
consulCatalog:
endpoint:
httpAuth:
password: test[providers.consulCatalog.endpoint.httpAuth]
password = "test"--providers.consulcatalog.endpoint.httpauth.password=testtls¶
Optional
Defines the TLS configuration used for the secure connection to Consul Catalog.
ca¶
Optional
ca is the path to the certificate authority used for the secure connection to Consul Catalog,
it defaults to the system bundle.
providers:
consulCatalog:
endpoint:
tls:
ca: path/to/ca.crt[providers.consulCatalog.endpoint.tls]
ca = "path/to/ca.crt"--providers.consulcatalog.endpoint.tls.ca=path/to/ca.crtcert¶
Optional
cert is the path to the public certificate used for the secure connection to Consul Catalog.
When using this option, setting the key option is required.
providers:
consulCatalog:
endpoint:
tls:
cert: path/to/foo.cert
key: path/to/foo.key[providers.consulCatalog.endpoint.tls]
cert = "path/to/foo.cert"
key = "path/to/foo.key"--providers.consulcatalog.endpoint.tls.cert=path/to/foo.cert
--providers.consulcatalog.endpoint.tls.key=path/to/foo.keykey¶
Optional
key is the path to the private key used for the secure connection to Consul Catalog.
When using this option, setting the cert option is required.
providers:
consulCatalog:
endpoint:
tls:
cert: path/to/foo.cert
key: path/to/foo.key[providers.consulCatalog.endpoint.tls]
cert = "path/to/foo.cert"
key = "path/to/foo.key"--providers.consulcatalog.endpoint.tls.cert=path/to/foo.cert
--providers.consulcatalog.endpoint.tls.key=path/to/foo.keyinsecureSkipVerify¶
Optional, Default=false
If insecureSkipVerify is true, the TLS connection to Consul accepts any certificate presented by the server regardless of the hostnames it covers.
providers:
consulCatalog:
endpoint:
tls:
insecureSkipVerify: true[providers.consulCatalog.endpoint.tls]
insecureSkipVerify = true--providers.consulcatalog.endpoint.tls.insecureskipverify=trueexposedByDefault¶
Optional, Default=true
Expose Consul Catalog services by default in Traefik.
If set to false, services that don't have a traefik.enable=true tag will be ignored from the resulting routing configuration.
For additional information, refer to Restrict the Scope of Service Discovery.
providers:
consulCatalog:
exposedByDefault: false
# ...[providers.consulCatalog]
exposedByDefault = false
# ...--providers.consulcatalog.exposedByDefault=false
# ...defaultRule¶
Optional, Default=Host(`{{ normalize .Name }}`)
The default host rule for all services.
For a given service, if no routing rule was defined by a tag, it is defined by this defaultRule instead.
The defaultRule must be set to a valid Go template,
and can include sprig template functions.
The service name can be accessed with the Name identifier,
and the template has access to all the labels (i.e. tags beginning with the prefix) defined on this service.
The option can be overridden on an instance basis with the traefik.http.routers.{name-of-your-choice}.rule tag.
providers:
consulCatalog:
defaultRule: "Host(`{{ .Name }}.{{ index .Labels \"customLabel\"}}`)"
# ...[providers.consulCatalog]
defaultRule = "Host(`{{ .Name }}.{{ index .Labels \"customLabel\"}}`)"
# ...--providers.consulcatalog.defaultRule='Host(`{{ .Name }}.{{ index .Labels "customLabel"}}`)'
# ...Default rule and Traefik service
The exposure of the Traefik container, combined with the default rule mechanism, can lead to create a router targeting itself in a loop. In this case, to prevent an infinite loop, Traefik adds an internal middleware to refuse the request if it comes from the same router.
connectAware¶
Optional, Default=false
Enable Consul Connect support.
If set to true, Traefik will be enabled to communicate with Connect services.
[providers.consulCatalog]
connectAware = true
# ...providers:
consulCatalog:
connectAware: true
# ...--providers.consulcatalog.connectAware=true
# ...connectByDefault¶
Optional, Default=false
Consider every service as Connect capable by default.
If set to true, Traefik will consider every Consul Catalog service to be Connect capable by default.
The option can be overridden on an instance basis with the traefik.consulcatalog.connect tag.
[providers.consulCatalog]
connectByDefault = true
# ...providers:
consulCatalog:
connectByDefault: true
# ...--providers.consulcatalog.connectByDefault=true
# ...serviceName¶
Optional, Default="traefik"
Name of the Traefik service in Consul Catalog.
[providers.consulCatalog]
serviceName = "test"
# ...providers:
consulCatalog:
serviceName: test
# ...--providers.consulcatalog.serviceName=test
# ...constraints¶
Optional, Default=""
The constraints option can be set to an expression that Traefik matches against the service tags to determine whether
to create any route for that service. If none of the service tags match the expression, no route for that service is
created. If the expression is empty, all detected services are included.
The expression syntax is based on the Tag(`tag`), and TagRegex(`tag`) functions,
as well as the usual boolean logic, as shown in examples below.
Constraints Expression Examples
# Includes only services having the tag `a.tag.name=foo`
constraints = "Tag(`a.tag.name=foo`)"# Excludes services having any tag `a.tag.name=foo`
constraints = "!Tag(`a.tag.name=foo`)"# With logical AND.
constraints = "Tag(`a.tag.name`) && Tag(`another.tag.name`)"# With logical OR.
constraints = "Tag(`a.tag.name`) || Tag(`another.tag.name`)"# With logical AND and OR, with precedence set by parentheses.
constraints = "Tag(`a.tag.name`) && (Tag(`another.tag.name`) || Tag(`yet.another.tag.name`))"# Includes only services having a tag matching the `a\.tag\.t.+` regular expression.
constraints = "TagRegex(`a\.tag\.t.+`)"providers:
consulCatalog:
constraints: "Tag(`a.tag.name`)"
# ...[providers.consulCatalog]
constraints = "Tag(`a.tag.name`)"
# ...--providers.consulcatalog.constraints="Tag(`a.tag.name`)"
# ...For additional information, refer to Restrict the Scope of Service Discovery.
namespaces¶
Optional, Default=""
The namespaces option defines the namespaces in which the consul catalog services will be discovered.
When using the namespaces option, the discovered configuration object names will be suffixed as shown below:
<resource-name>@consulcatalog-<namespace>Warning
The namespaces option only works with Consul Enterprise, which provides the Namespaces feature.
Warning
One should only define either the namespaces option or the namespace option.
providers:
consulCatalog:
namespaces:
- "ns1"
- "ns2"
# ...[providers.consulCatalog]
namespaces = ["ns1", "ns2"]
# ...--providers.consulcatalog.namespaces=ns1,ns2
# ...strictChecks¶
Optional, Default="passing,warning"
Define which Consul Service health checks are allowed to take on traffic.
providers:
consulCatalog:
strictChecks:
- "passing"
- "warning"
# ...[providers.consulCatalog]
strictChecks = ["passing", "warning"]
# ...--providers.consulcatalog.strictChecks=passing,warning
# ...watch¶
Optional, Default=false
When set to true, watches for Consul changes (Consul watches checks).
providers:
consulCatalog:
watch: true
# ...[providers.consulCatalog]
watch = true
# ...--providers.consulcatalog.watch=true
# ...