Traffic Route
New to Kuma? Don’t use this, check the
MeshHTTPRoute
orMeshTCPRoute
policy policies instead.
Traffic Route is an outbound policy. Dataplanes whose configuration is modified are in the
sources
matcher.
This policy lets you configure routing rules for the traffic in the mesh. It supports weighted routing and can be used to implement versioning across services or to support deployment strategies such as blue/green or canary.
Note the following:
- The configuration must specify the data plane proxies for the routing rules.
- The
spec.destinations
field supports onlykuma.io/service
. - All available tags are supported for
spec.conf
. - This is an outbound connection policy. Make sure that your data plane proxy configuration includes the appropriate tags.
Kong Mesh also supports locality aware load balancing.
Default TrafficRoute
The control plane creates a default TrafficRoute
every time a new Mesh
is created. The default TrafficRoute
enables the traffic between all the services in the mesh.
apiVersion: kuma.io/v1alpha1
kind: TrafficRoute
mesh: default
metadata:
name: route-all-default
spec:
sources:
- match:
kuma.io/service: '*'
destinations:
- match:
kuma.io/service: '*'
conf:
loadBalancer:
roundRobin: {}
destination:
kuma.io/service: '*'
Usage
Here is a full example of TrafficRoute
policy
apiVersion: kuma.io/v1alpha1
kind: TrafficRoute
mesh: default
metadata:
name: full-example
spec:
sources:
- match:
kuma.io/service: backend_default_svc_80
destinations:
- match:
kuma.io/service: redis_default_svc_6379
conf:
http:
- match:
method: # one of either "prefix", "exact" or "regex" is allowed
exact: GET
regex: "^POST|PUT$"
path: # one of either "prefix", "exact" or "regex" is allowed
prefix: /users
exact: /users/user-1
regex: "^users$"
headers:
some-header: # one of either "prefix", "exact" or "regex" will be allowed
exact: some-value
prefix: some-
regex: "^users$"
modify: # optional section
path: # one of "rewritePrefix" or "regex" is allowed
rewritePrefix: /not-users # rewrites previously matched prefix
regex: # (example to change the path from "/service/foo/v1/api" to "/v1/api/instance/foo")
pattern: "^/service/([^/]+)(/.*)$"
substitution: '\2/instance/\1'
host: # one of "value" or "fromPath" is allowed
value: "XYZ"
fromPath: # (example to extract "envoyproxy.io" host header from "/envoyproxy.io/some/path" path)
pattern: "^/(.+)/.+$"
substitution: '\1'
requestHeaders:
add:
- name: x-custom-header
value: xyz
append: true # if true then if there is x-custom-header already, it will append xyz to the value
remove:
- name: x-something
responseHeaders:
add:
- name: x-custom-header
value: xyz
append: true
remove:
- name: x-something
destination: # one of "destination", "split" is allowed
kuma.io/service: redis_default_svc_6379
split:
- weight: 100
destination:
kuma.io/service: redis_default_svc_6379
destination: # one of "destination", "split" is allowed
kuma.io/service: redis_default_svc_6379
split:
- weight: 100
destination:
kuma.io/service: redis_default_svc_6379
loadBalancer: # one of "roundRobin", "leastRequest", "ringHash", "random", "maglev" is allowed
roundRobin: {}
leastRequest:
choiceCount: 8
ringHash:
hashFunction: "MURMUR_HASH_2"
minRingSize: 64
maxRingSize: 1024
random: {}
maglev: {}
Kong Mesh utilizes positive weights in the TrafficRoute
policy and not percentages, therefore Kong Mesh does not check if the total adds up to 100. If we want to stop sending traffic to a destination service we change the weight
for that service to 0.
L4 Traffic Split
We can use TrafficRoute
to split a TCP traffic between services with different tags implementing A/B testing or canary deployments.
Here is an example of a TrafficRoute
that splits the traffic over the two different versions of the application.
90% of the connections from backend_default_svc_80
service will be initiated to redis_default_svc_6379
with tag version: 1.0
and 10% of the connections will be initiated to version: 2.0
apiVersion: kuma.io/v1alpha1
kind: TrafficRoute
mesh: default
metadata:
name: split-traffic
spec:
sources:
- match:
kuma.io/service: backend_default_svc_80
destinations:
- match:
kuma.io/service: redis_default_svc_6379
conf:
split:
- weight: 90
destination:
kuma.io/service: redis_default_svc_6379
version: '1.0'
- weight: 10
destination:
kuma.io/service: redis_default_svc_6379
version: '2.0'
L4 Traffic Rerouting
We can use TrafficRoute
to fully reroute a TCP traffic to different version of a service or even completely different service.
Here is an example of a TrafficRoute
that redirects the traffic to another-redis_default_svc_6379
when backend_default_svc_80
is trying to consume redis_default_svc_6379
.
apiVersion: kuma.io/v1alpha1
kind: TrafficRoute
mesh: default
metadata:
name: reroute-traffic
spec:
sources:
- match:
kuma.io/service: backend_default_svc_80
destinations:
- match:
kuma.io/service: redis_default_svc_6379
conf:
destination:
kuma.io/service: another-redis_default_svc_6379
L7 Traffic Split
We can use TrafficRoute
to split an HTTP traffic between services with different tags implementing A/B testing or canary deployments.
Here is an example of a TrafficRoute
that splits the traffic from frontend_default_svc_80
to backend_default_svc_80
between versions,
but only on endpoints starting with /api
. All other endpoints will go to version: 1.0
apiVersion: kuma.io/v1alpha1
kind: TrafficRoute
mesh: default
metadata:
name: api-split
spec:
sources:
- match:
kuma.io/service: frontend_default_svc_80
destinations:
- match:
kuma.io/service: backend_default_svc_80
conf:
http:
- match:
path:
prefix: "/api"
split:
- weight: 90
destination:
kuma.io/service: backend_default_svc_80
version: '1.0'
- weight: 10
destination:
kuma.io/service: backend_default_svc_80
version: '2.0'
destination: # default rule is applied when endpoint does not match any rules in http section
kuma.io/service: backend_default_svc_80
version: '1.0'
In order to use L7 Traffic Split, we need to mark the destination service with
kuma.io/protocol: http
.
L7 Traffic Modification
We can use TrafficRoute
to modify outgoing requests, by setting new path or changing request and response headers.
Here is an example of a TrafficRoute
that adds x-custom-header
with value xyz
when frontend_default_svc_80
tries to consume backend_default_svc_80
.
apiVersion: kuma.io/v1alpha1
kind: TrafficRoute
mesh: default
metadata:
name: add-header
spec:
sources:
- match:
kuma.io/service: frontend_default_svc_80
destinations:
- match:
kuma.io/service: backend_default_svc_80
conf:
http:
- match:
path:
prefix: "/"
modify:
requestHeader:
add:
- name: x-custom-header
value: xyz
destination:
kuma.io/service: backend_default_svc_80
destination:
kuma.io/service: backend_default_svc_80
In order to use L7 Traffic Modification, we need to mark the destination service with
kuma.io/protocol: http
.
L7 Traffic Rerouting
We can use TrafficRoute
to modify outgoing requests, by setting new path or changing request and response headers.
Here is an example of a TrafficRoute
that redirect traffic to offers_default_svc_80
when frontend_default_svc_80
is trying to consume backend_default_svc_80
on /offers
endpoint.
apiVersion: kuma.io/v1alpha1
kind: TrafficRoute
mesh: default
metadata:
name: http-reroute
spec:
sources:
- match:
kuma.io/service: frontend_default_svc_80
destinations:
- match:
kuma.io/service: backend_default_svc_80
conf:
http:
- match:
path:
prefix: "/offers"
destination:
kuma.io/service: offers_default_svc_80
destination:
kuma.io/service: backend_default_svc_80
In order to use L7 Traffic Rerouting, we need to mark the destination service with
kuma.io/protocol: http
.
Load balancer types
There are different load balancing algorithms that can be used to determine how traffic is routed to the destinations. By default TrafficRoute
uses the roundRobin
load balancer, but more options are available:
-
roundRobin
is a simple algorithm in which each available upstream host is selected in round robin order.Example:
loadBalancer: roundRobin: {}
-
leastRequest
uses different algorithms depending on whether the hosts have the same or different weights. It has a single configuration fieldchoiceCount
, which denotes the number of random healthy hosts from which the host with the fewer active requests will be chosen.Example:
loadBalancer: leastRequest: choiceCount: 8
-
ringHash
implements consistent hashing to the upstream hosts. It has the following fields:-
hashFunction
the hash function used to hash the hosts onto the ketama ring. Can beXX_HASH
orMURMUR_HASH_2
. -
minRingSize
minimum hash ring size. -
maxRingSize
maximum hash ring size.
Example:
loadBalancer: ringHash: hashFunction: "MURMUR_HASH_2" minRingSize: 64 maxRingSize: 1024
-
-
random
selects a random available host.Example:
loadBalancer: random: {}
-
maglev
implements consistent hashing to upstream hostsExample:
loadBalancer: maglev: {}
All options
$schema: http://json-schema.org/draft-04/schema#
$ref: #/definitions/TrafficRoute
definitions
TrafficRoute
- ## Traffic Route
- TrafficRoute defines routing rules for the traffic in the mesh.
- Type:
object
- This schema accepts additional properties.
- Properties
- sources
- List of selectors to match data plane proxies that are sources of traffic.
- Type:
array
- Items
- $ref: #/definitions/kuma.mesh.v1alpha1.Selector
- destinations
- List of selectors to match services that are destinations of traffic. Notice the difference between sources and destinations. While the source of traffic is always a data plane proxy within a mesh, the destination is a service that could be either within or outside of a mesh.
- Type:
array
- Items
- $ref: #/definitions/kuma.mesh.v1alpha1.Selector
- conf
- Configuration for the route.
- $ref: #/definitions/kuma.mesh.v1alpha1.TrafficRoute.Conf
- sources
kuma.mesh.v1alpha1.Selector
- ## Selector
- Selector defines structure for selecting tags for given dataplane
- Type:
object
- This schema accepts additional properties.
- Properties
- match
- Tags to match, can be used for both source and destinations
- Type:
object
- This schema accepts additional properties.
- Properties
- match
kuma.mesh.v1alpha1.TrafficRoute.Conf
- ## Conf
- Conf defines the destination configuration.
- Type:
object
- This schema accepts additional properties.
- Properties
- split
- List of destinations with weights assigned to them. When used, "destination" is not allowed.
- Type:
array
- load_balancer
- Load balancer configuration for given "split" or "destination"
- $ref: #/definitions/kuma.mesh.v1alpha1.TrafficRoute.LoadBalancer
- destination
- One destination that the traffic will be redirected to. When used, "split" is not allowed.
- Type:
object
- This schema accepts additional properties.
- Properties
- http
- Configuration of HTTP traffic. Traffic is matched one by one with the order defined in the list. If the request does not match any criteria then "split" or "destination" outside of "http" section is executed.
- Type:
array
- split
kuma.mesh.v1alpha1.TrafficRoute.Http
- ## Http
- Http defines configuration for HTTP traffic.
- Type:
object
- This schema accepts additional properties.
- Properties
- match
- If request matches against defined criteria then "split" or "destination" is executed.
- $ref: #/definitions/kuma.mesh.v1alpha1.TrafficRoute.Http.Match
- modify
- Modifications to the traffic matched by the match section.
- $ref: #/definitions/kuma.mesh.v1alpha1.TrafficRoute.Http.Modify
- split
- List of destinations with weights assigned to them. When used, "destination" is not allowed.
- Type:
array
- destination
- One destination that the traffic will be redirected to. When used, "split" is not allowed.
- Type:
object
- This schema accepts additional properties.
- Properties
- match
kuma.mesh.v1alpha1.TrafficRoute.Http.Match
- ## Match
- Match defines a series of matching criteria to apply modification and reroute the traffic.
- Type:
object
- This schema accepts additional properties.
- Properties
- method
- Method matches method of HTTP request.
- $ref: #/definitions/kuma.mesh.v1alpha1.TrafficRoute.Http.Match.StringMatcher
- path
- Path matches HTTP path.
- $ref: #/definitions/kuma.mesh.v1alpha1.TrafficRoute.Http.Match.StringMatcher
- headers
- Headers match HTTP request headers.
- Type:
object
- This schema accepts additional properties.
- Properties
- method
kuma.mesh.v1alpha1.TrafficRoute.Http.Match.StringMatcher
- ## String Matcher
- StringMatcher matches the string value.
- Type:
object
- This schema accepts additional properties.
- Properties
- prefix
- Prefix matches the string against defined prefix.
- Type:
string
- exact
- Exact checks that strings are equal to each other.
- Type:
string
- regex
- Regex checks the string using RE2 syntax. https://github.com/google/re2/wiki/Syntax
- Type:
string
- prefix
kuma.mesh.v1alpha1.TrafficRoute.Http.Modify
- ## Modify
- Modify defines modifications of matched HTTP messages.
- Type:
object
- This schema accepts additional properties.
- Properties
- path
- Path modifications.
- $ref: #/definitions/kuma.mesh.v1alpha1.TrafficRoute.Http.Modify.Path
- host
- Host modifications.
- $ref: #/definitions/kuma.mesh.v1alpha1.TrafficRoute.Http.Modify.Host
- requestHeaders
- Request headers modifications.
- $ref: #/definitions/kuma.mesh.v1alpha1.TrafficRoute.Http.Modify.Headers
- responseHeaders
- Response headers modifications.
- $ref: #/definitions/kuma.mesh.v1alpha1.TrafficRoute.Http.Modify.Headers
- path
kuma.mesh.v1alpha1.TrafficRoute.Http.Modify.Headers
- ## Headers
- Headers defines modification of HTTP headers.
- Type:
object
- This schema accepts additional properties.
- Properties
- add
- List of add header operations.
- Type:
array
- remove
- List of remove header operations.
- Type:
array
- add
kuma.mesh.v1alpha1.TrafficRoute.Http.Modify.Headers.Add
- ## Add
- Add defines operation of adding new HTTP header.
- Type:
object
- This schema accepts additional properties.
- Properties
- name
- Name of the header.
- Type:
string
- value
- Value of the header.
- Type:
string
- append
- If true, it appends the value if there is already a value. Otherwise, value of existing header will be replaced.
- Type:
boolean
- name
kuma.mesh.v1alpha1.TrafficRoute.Http.Modify.Headers.Remove
- ## Remove
- Remove defines operation of removing an HTTP header.
- Type:
object
- This schema accepts additional properties.
- Properties
- name
- Name of the header to remove.
- Type:
string
- name
kuma.mesh.v1alpha1.TrafficRoute.Http.Modify.Host
- ## Host
- Host defines modification of the HTTP Host header
- Type:
object
- This schema accepts additional properties.
- Properties
- value
- Value replaces the host header with given value.
- Type:
string
- fromPath
- FromPath replaces the host header from path using regex.
- $ref: #/definitions/kuma.mesh.v1alpha1.TrafficRoute.Http.Modify.RegexReplace
- value
kuma.mesh.v1alpha1.TrafficRoute.Http.Modify.Path
- ## Path
- Path defines modification of path of the HTTP request.
- Type:
object
- This schema accepts additional properties.
- Properties
- rewritePrefix
- RewritePrefix rewrites previously matched prefix in match section.
- Type:
string
- regex
- Regex rewrites prefix using regex with substitution.
- $ref: #/definitions/kuma.mesh.v1alpha1.TrafficRoute.Http.Modify.RegexReplace
- rewritePrefix
kuma.mesh.v1alpha1.TrafficRoute.Http.Modify.RegexReplace
- ## Regex Replace
- RegexReplace defines a way to match string using regex and build a new one using substitution section.
- Type:
object
- This schema accepts additional properties.
- Properties
- pattern
- Pattern of the regex using RE2 syntax. https://github.com/google/re2/wiki/Syntax
- Type:
string
- substitution
- Substitution using regex groups. E.g. use \1 as a first matched group.
- Type:
string
- pattern
kuma.mesh.v1alpha1.TrafficRoute.LoadBalancer
- ## Load Balancer
- LoadBalancer defines the load balancing policy and configuration.
- Type:
object
- This schema accepts additional properties.
- Properties
- round_robin
- least_request
- ring_hash
- random
- maglev
kuma.mesh.v1alpha1.TrafficRoute.LoadBalancer.LeastRequest
- ## Least Request
- LeastRequest uses different algorithms depending on whether hosts have the same or different weights.
- Type:
object
- This schema accepts additional properties.
- Properties
- choice_count
- The number of random healthy hosts from which the host with the fewest active requests will be chosen. Defaults to 2 so that we perform two-choice selection if the field is not set.
- Type:
integer
- choice_count
kuma.mesh.v1alpha1.TrafficRoute.LoadBalancer.Maglev
- ## Maglev
- Maglev implements consistent hashing to upstream hosts.
- Type:
object
- This schema accepts additional properties.
- Properties
kuma.mesh.v1alpha1.TrafficRoute.LoadBalancer.Random
- ## Random
- Random selects a random available host.
- Type:
object
- This schema accepts additional properties.
- Properties
kuma.mesh.v1alpha1.TrafficRoute.LoadBalancer.RingHash
- ## Ring Hash
- RingHash implements consistent hashing to upstream hosts.
- Type:
object
- This schema accepts additional properties.
- Properties
- hash_function
- The hash function used to hash hosts onto the ketama ring. The value defaults to 'XXHASH'._
- Type:
string
- minringsize
- Minimum hash ring size.
- Type:
string
- maxringsize
- Maximum hash ring size.
- Type:
string
- hash_function
kuma.mesh.v1alpha1.TrafficRoute.LoadBalancer.RoundRobin
- ## Round Robin
- RoundRobin is a simple policy in which each available upstream host is selected in round robin order.
- Type:
object
- This schema accepts additional properties.
- Properties
kuma.mesh.v1alpha1.TrafficRoute.Split
- ## Split
- Split defines a destination with a weight assigned to it.
- Type:
object
- This schema accepts additional properties.
- Properties
- weight
- Weight assigned to that destination. Weights are not percentages. For example two destinations with weights the same weight "1" will receive both same amount of the traffic. 0 means that the destination will be ignored.
- Type:
integer
- destination
- Selector to match individual endpoints that comprise that destination. Notice that an endpoint can be either inside or outside the mesh. In the former case an endpoint corresponds to a data plane proxy, in the latter case an endpoint is an External Service.
- Type:
object
- This schema accepts additional properties.
- Properties
- weight
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