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Contour Configuration Reference

Overview

There are various ways to configure Contour, flags, the configuration file, as well as environment variables. Contour has a precedence of configuration for contour serve, meaning anything configured in the config file is overridden by environment vars which are overridden by cli flags.

Serve Flags

The contour serve command is the main command which is used to watch for Kubernetes resource and process them into Envoy configuration which is then streamed to any Envoy via its xDS gRPC connection. There are a number of flags that can be passed to this command which further configures how Contour operates. Many of these flags are mirrored in the Contour Configuration File.

Flag NameDescription
--config-pathPath to base configuration
--inclusterUse in cluster configuration
--kubeconfig=</path/to/file>Path to kubeconfig (if not in running inside a cluster)
--xds-address=<ipaddr>xDS gRPC API address
--xds-port=<port>xDS gRPC API port
--stats-address=<ipaddr>Envoy /stats interface address
--stats-port=<port>Envoy /stats interface port
--debug-http-address=<address>Address the debug http endpoint will bind to.
--debug-http-port=<port>Port the debug http endpoint will bind to
--http-address=<ipaddr>Address the metrics HTTP endpoint will bind to
--http-port=<port>Port the metrics HTTP endpoint will bind to.
--health-address=<ipaddr>Address the health HTTP endpoint will bind to
--health-port=<port>Port the health HTTP endpoint will bind to
--contour-cafile=</path/to/file|CONTOUR_CERT_FILE>CA bundle file name for serving gRPC with TLS
--contour-cert-file=</path/to/file|CONTOUR_CERT_FILE>Contour certificate file name for serving gRPC over TLS
--contour-key-file=</path/to/file|CONTOUR_KEY_FILE>Contour key file name for serving gRPC over TLS
--insecureAllow serving without TLS secured gRPC
--root-namespaces=<ns,ns>Restrict contour to searching these namespaces for root ingress routes
--ingress-class-name=<name>Contour IngressClass name
--ingress-status-address=<address>Address to set in Ingress object status
--envoy-http-access-log=</path/to/file>Envoy HTTP access log
--envoy-https-access-log=</path/to/file>Envoy HTTPS access log
--envoy-service-http-address=<ipaddr>Kubernetes Service address for HTTP requests
--envoy-service-https-address=<ipaddr>Kubernetes Service address for HTTPS requests
--envoy-service-http-port=<port>Kubernetes Service port for HTTP requests
--envoy-service-https-port=<port>Kubernetes Service port for HTTPS requests
--envoy-service-name=<name>Name of the Envoy service to inspect for Ingress status details.
--envoy-service-namespace=<namespace>Envoy Service Namespace
--use-proxy-protocolUse PROXY protocol for all listeners
--accesslog-format=<envoy|json>Format for Envoy access logs
--disable-leader-electionDisable leader election mechanism
-d, --debugEnable debug logging
--kubernetes-debug=<log level>Enable Kubernetes client debug logging

Configuration File

A configuration file can be passed to the --config-path argument of the contour serve command to specify additional configuration to Contour. In most deployments, this file is passed to Contour via a ConfigMap which is mounted as a volume to the Contour pod.

The Contour configuration file is optional. In its absence, Contour will operate with reasonable defaults. Where Contour settings can also be specified with command-line flags, the command-line value takes precedence over the configuration file.

Field NameTypeDefaultDescription
accesslog-formatstringenvoyThis key sets the global access log format for Envoy. Valid options are envoy or json.
debugbooleanfalseEnables debug logging.
default-http-versionsstring arrayHTTP/1.1
HTTP/2
This array specifies the HTTP versions that Contour should program Envoy to serve. HTTP versions are specified as strings of the form “HTTP/x”, where “x” represents the version number.
disableAllowChunkedLengthbooleanfalseIf this field is true, Contour will disable the RFC-compliant Envoy behavior to strip the Content-Length header if Transfer-Encoding: chunked is also set. This is an emergency off-switch to revert back to Envoy’s default behavior in case of failures.
disablePermitInsecurebooleanfalseIf this field is true, Contour will ignore PermitInsecure field in HTTPProxy documents.
envoy-service-namestringenvoyThis sets the service name that will be inspected for address details to be applied to Ingress objects.
envoy-service-namespacestringprojectcontourThis sets the namespace of the service that will be inspected for address details to be applied to Ingress objects. If the CONTOUR_NAMESPACE environment variable is present, Contour will populate this field with its value.
ingress-status-addressstringNoneIf present, this specifies the address that will be copied into the Ingress status for each Ingress that Contour manages. It is exclusive with envoy-service-name and envoy-service-namespace.
inclusterbooleanfalseThis field specifies that Contour is running in a Kubernetes cluster and should use the in-cluster client access configuration.
json-fieldsstring arrayfieldsThis is the list the field names to include in the JSON access log format.
kubeconfigstring$HOME/.kube/configPath to a Kubernetes kubeconfig file for when Contour is executed outside a cluster.
leaderelectionleaderelectionThe leader election configuration.
policyPolicyConfigThe default policy configuration.
tlsTLSThe default TLS configuration.
timeoutsTimeoutConfigThe timeout configuration.
clusterClusterConfigThe cluster configuration.
networkNetworkConfigThe network configuration.
listenerListenerConfigThe listener configuration.
serverServerConfigThe server configuration for contour serve command.
gatewayGatewayConfigThe gateway-api Gateway configuration.
rateLimitServiceRateLimitServiceConfigThe rate limit service configuration.

TLS Configuration

The TLS configuration block can be used to configure default values for how Contour should provision TLS hosts.

Field NameTypeDefaultDescription
minimum-protocol-versionstring1.2This field specifies the minimum TLS protocol version that is allowed. Valid options are 1.2 (default) and 1.3. Any other value defaults to TLS 1.2.
fallback-certificateFallback certificate configuration.
envoy-client-certificateClient certificate configuration for Envoy.
cipher-suites[]stringSee config package documentationThis field specifies the TLS ciphers to be supported by TLS listeners when negotiating TLS 1.2. This parameter should only be used by advanced users. Note that this is ignored when TLS 1.3 is in use. The set of ciphers that are allowed is a superset of those supported by default in stock, non-FIPS Envoy builds and FIPS builds as specified here. Custom ciphers not accepted by Envoy in a standard build are not supported.

Fallback Certificate

Field NameTypeDefaultDescription
namestring""This field specifies the name of the Kubernetes secret to use as the fallback certificate.
namespacestring""This field specifies the namespace of the Kubernetes secret to use as the fallback certificate.

Envoy Client Certificate

Field NameTypeDefaultDescription
namestring""This field specifies the name of the Kubernetes secret to use as the client certificate and private key when establishing TLS connections to the backend service.
namespacestring""This field specifies the namespace of the Kubernetes secret to use as the client certificate and private key when establishing TLS connections to the backend service.

Leader Election Configuration

The leader election configuration block configures how a deployment with more than one Contour pod elects a leader. The Contour leader is responsible for updating the status field on Ingress and HTTPProxy documents. In the vast majority of deployments, only the configmap-name and configmap-namespace fields should require any configuration.

Field NameTypeDefaultDescription
configmap-namestringleader-electThe name of the ConfigMap that Contour leader election will lease.
configmap-namespacestringprojectcontourThe namespace of the ConfigMap that Contour leader election will lease. If the CONTOUR_NAMESPACE environment variable is present, Contour will populate this field with its value.
lease-durationduration15sThe duration of the leadership lease.
renew-deadlineduration10sThe length of time that the leader will retry refreshing leadership before giving up.
retry-periodduration2sThe interval at which Contour will attempt to the acquire leadership lease.

Timeout Configuration

The timeout configuration block can be used to configure various timeouts for the proxies. All fields are optional; Contour/Envoy defaults apply if a field is not specified.

Field NameTypeDefaultDescription
request-timeoutstringnone*This field specifies the default request timeout. Note that this is a timeout for the entire request, not an idle timeout. Must be a valid Go duration string, or omitted or set to infinity to disable the timeout entirely. See the Envoy documentation for more information.

Note: A value of 0s previously disabled this timeout entirely. This is no longer the case. Use infinity or omit this field to disable the timeout.
connection-idle-timeoutstring60sThis field defines how long the proxy should wait while there are no active requests (for HTTP/1.1) or streams (for HTTP/2) before terminating an HTTP connection. Must be a valid Go duration string, or infinity to disable the timeout entirely. See the Envoy documentation for more information.
stream-idle-timeoutstring5m*This field defines how long the proxy should wait while there is no request activity (for HTTP/1.1) or stream activity (for HTTP/2) before terminating the HTTP request or stream. Must be a valid Go duration string, or infinity to disable the timeout entirely. See the Envoy documentation for more information.
max-connection-durationstringnone*This field defines the maximum period of time after an HTTP connection has been established from the client to the proxy before it is closed by the proxy, regardless of whether there has been activity or not. Must be a valid Go duration string, or omitted or set to infinity for no max duration. See the Envoy documentation for more information.
delayed-close-timeoutstring1s*Note: this is an advanced setting that should not normally need to be tuned.

This field defines how long envoy will wait, once connection close processing has been initiated, for the downstream peer to close the connection before Envoy closes the socket associated with the connection. Setting this timeout to ‘infinity’ will disable it. See the Envoy documentation for more information.
connection-shutdown-grace-periodstring5s*This field defines how long the proxy will wait between sending an initial GOAWAY frame and a second, final GOAWAY frame when terminating an HTTP/2 connection. During this grace period, the proxy will continue to respond to new streams. After the final GOAWAY frame has been sent, the proxy will refuse new streams. Must be a valid Go duration string. See the Envoy documentation for more information.

This is Envoy’s default setting value and is not explicitly configured by Contour.

Cluster Configuration

The cluster configuration block can be used to configure various parameters for Envoy clusters.

Field NameTypeDefaultDescription
dns-lookup-familystringautoThis field specifies the dns-lookup-family to use for upstream requests to externalName type Kubernetes services from an HTTPProxy route. Values are: auto, v4, v6`

Network Configuration

The network configuration block can be used to configure various parameters network connections.

Field NameTypeDefaultDescription
num-trusted-hopsint0Configures the number of additional ingress proxy hops from the right side of the x-forwarded-for HTTP header to trust.

Listener Configuration

The listener configuration block can be used to configure various parameters for Envoy listener.

Field NameTypeDefaultDescription
connection-balancerstring""This field specifies the listener connection balancer. If the value is exact, the listener will use the exact connection balancer to balance connections between threads in a single Envoy process. See the Envoy documentation for more information.

Server Configuration

The server configuration block can be used to configure various settings for the contour serve command.

Field NameTypeDefaultDescription
xds-server-typestringcontourThis field specifies the xDS Server to use. Options are contour or envoy.

Gateway Configuration

The gateway configuration block is used to configure which gateway-api Gateway Contour should configure:

Field NameTypeDefaultDescription
controllerNamestringGateway Class controller name (i.e. projectcontour.io/projectcontour/contour).
namestringcontourThis field specifies the name of a Gateway.
namespacestringprojectcontourThis field specifies the namespace of a Gateway.

Policy Configuration

The Policy configuration block can be used to configure default policy values that are set if not overridden by the user.

The request-headers field is used to rewrite headers on a HTTP request, and the response-headers field is used to rewrite headers on a HTTP response.

Field NameTypeDefaultDescription
request-headersHeaderPolicynoneThe default request headers set or removed on all service routes if not overridden in the object
response-headersHeaderPolicynoneThe default response headers set or removed on all service routes if not overridden in the object

HeaderPolicy

The set field sets an HTTP header value, creating it if it doesn’t already exist but not overwriting it if it does. The remove field removes an HTTP header.

Field NameTypeDefaultDescription
setmap[string]stringnoneMap of headers to set on all service routes if not overridden in the object
remove[]stringnoneList of headers to remove on all service routes if not overridden in the object

Note: the values of entries in the set and remove fields can be overridden in HTTPProxy objects but it it not possible to remove these entries.

Rate Limit Service Configuration

The rate limit service configuration block is used to configure an optional global rate limit service:

Field NameTypeDefaultDescription
extensionServicestringThis field identifies the extension service defining the rate limit service, formatted as /.
domainstringcontourThis field defines the rate limit domain value to pass to the rate limit service. Acts as a container for a set of rate limit definitions within the RLS.
failOpenboolfalseThis field defines whether to allow requests to proceed when the rate limit service fails to respond with a valid rate limit decision within the timeout defined on the extension service.
enableXRateLimitHeadersboolfalseThis field defines whether to include the X-RateLimit headers X-RateLimit-Limit, X-RateLimit-Remaining, and X-RateLimit-Reset (as defined by the IETF Internet-Draft https://tools.ietf.org/id/draft-polli-ratelimit-headers-03.html), on responses to clients when the Rate Limit Service is consulted for a request.

Configuration Example

The following is an example ConfigMap with configuration file included:

apiVersion: v1
kind: ConfigMap
metadata:
  name: contour
  namespace: projectcontour
data:
  contour.yaml: |
    #
    # server:
    #   determine which XDS Server implementation to utilize in Contour.
    #   xds-server-type: contour
    #
    # specify the gateway-api Gateway Contour should configure
    # gateway:
    #   controllerName: projectcontour.io/projectcontour/contour
    #   name: contour
    #   namespace: projectcontour
    #
    # should contour expect to be running inside a k8s cluster
    # incluster: true
    #
    # path to kubeconfig (if not running inside a k8s cluster)
    # kubeconfig: /path/to/.kube/config
    #
    # Disable RFC-compliant behavior to strip "Content-Length" header if
    # "Tranfer-Encoding: chunked" is also set.
    # disableAllowChunkedLength: false
    # Disable HTTPProxy permitInsecure field
    disablePermitInsecure: false
    tls:
    # minimum TLS version that Contour will negotiate
    # minimum-protocol-version: "1.2"
    # TLS ciphers to be supported by Envoy TLS listeners when negotiating
    # TLS 1.2.
    # cipher-suites:
    # - '[ECDHE-ECDSA-AES128-GCM-SHA256|ECDHE-ECDSA-CHACHA20-POLY1305]'
    # - '[ECDHE-RSA-AES128-GCM-SHA256|ECDHE-RSA-CHACHA20-POLY1305]'
    # - 'ECDHE-ECDSA-AES256-GCM-SHA384'
    # - 'ECDHE-RSA-AES256-GCM-SHA384'
    # Defines the Kubernetes name/namespace matching a secret to use
    # as the fallback certificate when requests which don't match the
    # SNI defined for a vhost.
      fallback-certificate:
    #   name: fallback-secret-name
    #   namespace: projectcontour
      envoy-client-certificate:
    #   name: envoy-client-cert-secret-name
    #   namespace: projectcontour
    # The following config shows the defaults for the leader election.
    # leaderelection:
    #   configmap-name: leader-elect
    #   configmap-namespace: projectcontour
    ### Logging options
    # Default setting
    accesslog-format: envoy
    # To enable JSON logging in Envoy
    # accesslog-format: json
    # The default fields that will be logged are specified below.
    # To customise this list, just add or remove entries.
    # The canonical list is available at
    # https://godoc.org/github.com/projectcontour/contour/internal/envoy#JSONFields
    # json-fields:
    #   - "@timestamp"
    #   - "authority"
    #   - "bytes_received"
    #   - "bytes_sent"
    #   - "downstream_local_address"
    #   - "downstream_remote_address"
    #   - "duration"
    #   - "method"
    #   - "path"
    #   - "protocol"
    #   - "request_id"
    #   - "requested_server_name"
    #   - "response_code"
    #   - "response_flags"
    #   - "uber_trace_id"
    #   - "upstream_cluster"
    #   - "upstream_host"
    #   - "upstream_local_address"
    #   - "upstream_service_time"
    #   - "user_agent"
    #   - "x_forwarded_for"
    #
    # default-http-versions:
    # - "HTTP/2"
    # - "HTTP/1.1"
    #
    # The following shows the default proxy timeout settings.
    # timeouts:
    #   request-timeout: infinity
    #   connection-idle-timeout: 60s
    #   stream-idle-timeout: 5m
    #   max-connection-duration: infinity
    #   connection-shutdown-grace-period: 5s
    #
    # Envoy cluster settings.
    # cluster:
    #   configure the cluster dns lookup family
    #   valid options are: auto (default), v4, v6
    #   dns-lookup-family: auto   
    #
    # network:
    #   Configure the number of additional ingress proxy hops from the
    #   right side of the x-forwarded-for HTTP header to trust.
    #   num-trusted-hops: 0
    #
    # Configure an optional global rate limit service.
    # rateLimitService:
    #   Identifies the extension service defining the rate limit service,
    #   formatted as <namespace>/<name>.
    #   extensionService: projectcontour/ratelimit
    #   Defines the rate limit domain to pass to the rate limit service.
    #   Acts as a container for a set of rate limit definitions within
    #   the RLS.
    #   domain: contour
    #   Defines whether to allow requests to proceed when the rate limit
    #   service fails to respond with a valid rate limit decision within
    #   the timeout defined on the extension service.
    #   failOpen: false
    # Defines whether to include the X-RateLimit headers X-RateLimit-Limit,
    # X-RateLimit-Remaining, and X-RateLimit-Reset (as defined by the IETF
    # Internet-Draft linked below), on responses to clients when the Rate
    # Limit Service is consulted for a request.
    # ref. https://tools.ietf.org/id/draft-polli-ratelimit-headers-03.html
    #   enableXRateLimitHeaders: false
    #
    # Global Policy settings.
    # policy:
    #   # Default headers to set on all requests (unless set/removed on the HTTPProxy object itself)
    #   request-headers:
    #     set:
    #       # example: the hostname of the Envoy instance that proxied the request
    #       X-Envoy-Hostname: %HOSTNAME%
    #       # example: add a l5d-dst-override header to instruct Linkerd what service the request is destined for
    #       l5d-dst-override: %CONTOUR_SERVICE_NAME%.%CONTOUR_NAMESPACE%.svc.cluster.local:%CONTOUR_SERVICE_PORT%
    #   # default headers to set on all responses (unless set/removed on the HTTPProxy object itself)
    #   response-headers:
    #     set:
    #       # example: Envoy flags that provide additional details about the response or connection
    #       X-Envoy-Response-Flags: %RESPONSE_FLAGS%
    #    

Note: The default example contour includes this file for easy deployment of Contour.

Environment Variables

CONTOUR_NAMESPACE

If present, the value of the CONTOUR_NAMESPACE environment variable is used as:

  1. The value for the contour bootstrap --namespace flag unless otherwise specified.
  2. The value for the contour certgen --namespace flag unless otherwise specified.
  3. The value for the contour serve --envoy-service-namespace flag unless otherwise specified.
  4. The value for the leaderelection.configmap-namespace config file setting for contour serve unless otherwise specified.

The CONTOUR_NAMESPACE environment variable is set via the Downward API in the Contour example manifests.

Bootstrap Config File

The bootstrap configuration file is generated by an initContainer in the Envoy daemonset which runs the contour bootstrap command to generate the file. This configuration file configures the Envoy container to connect to Contour and receive configuration via xDS.

The next section outlines all the available flags that can be passed to the contour bootstrap command which are used to customize the configuration file to match the environment in which Envoy is deployed.

Flags

There are flags that can be passed to contour bootstrap that help configure how Envoy connects to Contour:

FlagDefaultDescription
–resources-dir""Directory where resource files will be written.
–admin-address127.0.0.1Address the Envoy admin webpage will listen on.
–admin-port9001Port the Envoy admin webpage will listen on.
–xds-address127.0.0.1Address to connect to Contour xDS server on.
–xds-port8001Port to connect to Contour xDS server on.
–envoy-cafile""CA filename for Envoy secure xDS gRPC communication.
–envoy-cert-file""Client certificate filename for Envoy secure xDS gRPC communication.
–envoy-key-file""Client key filename for Envoy secure xDS gRPC communication.
–namespaceprojectcontourNamespace the Envoy container will run, also configured via ENV variable “CONTOUR_NAMESPACE”. Namespace is used as part of the metric names on static resources defined in the bootstrap configuration file.
–xds-resource-versionv3Currently, the only valid xDS API resource version is v3.
–dns-lookup-familyautoDefines what DNS Resolution Policy to use for Envoy -> Contour cluster name lookup. Either v4, v6 or auto.

Ready to try Contour?

Read our getting started documentation.