SGTM This method can ensure good compatibility and rich functions
Ling Samuel <lingsamuelgr...@gmail.com> 于2022年8月5日周五 15:07写道： > Background > > The users' environment may be not a simple single K8s cluster, but may be > multiple K8s clusters, a mix of K8s clusters and bare metal machines, or > rely on third-party services. The current ApisixRoute does not support such > complex environments. > > It would be a useful feature if ApisixRoute supports using ExternalName > Service or domain name as a backend directly. > Solution > > APISIX does support setting domain names or IP addresses as upstream nodes. > We can extend our CRD to support this scenario. > > For external service, both the ExternalName service inside the K8s cluster > and the third-party service outside the cluster will only have one node > configured in the translated upstream nodes field, unlike the K8s service > which may have several nodes. > This allows multiple external services to be merged into a single upstream > and gain healthCheck capabilities. > Design > > We add a field named upstream to ApisixRoute, which has the same level as > "backends". The user must fill in at least one of upstream or backends. > The field upstream will refer to an ApisixUpstream CRD, where the external > services are defined in the newly added field externalNode, indicating that > the upstream node is pre-defined and does not need to resolve. > An externalNode must have a name field pointing to the final node location, > which can be a service name pointing to a k8s external name service, an IP > address or a domain name. If it points to a k8s external name service, the > type field should be service, or it should be the default value of direct. > The node can also be configured with an optional load balancing weight, > which defaults to 1. > > apiVersion: apisix.apache.org/v2kind: ApisixRoutemetadata: > name: external-examplespec: > http: > - name: example > match: > hosts: > - external.example.com > paths: > - "/*" > upstreams: > - name: external-example # Refers to ApisixUpstream > weight: 50 > ---apiVersion: apisix.apache.org/v2kind: ApisixUpstreammetadata: > name: external-examplespec: > externalNodes: # Indicates that this upstream doesn't need to resolve > nodes > - name: "httpbin.org" > # could be "domain", "serivce" > # if the value is `service`, the name must refers to a K8s > ExternalName service > type: domain > weight: 1 # default value is 1 > healthCheck: # same as normal ApisixUpstream > # .... > > Using upstream and backends together > > Users can use both upstream and backend. A route-level traffic-split plugin > will be generated normally. > Please note that since APISIX does not support health checks between > multiple upstreams, we will only support health checks within the > upstream.nodes. > This means that the healthCheck section defined in ApisixUpstream is at the > upstream level and its effect is limited to that upstream only, not at the > Route level. >
