Cluster Base Path

# Per-Cluster Upstream Base Path
#
# Prepends a path to the upstream request for the cluster the load balancer
# selected, so one gateway can front several upstreams that each serve the
# same API under their own prefix.
#
# Both models below answer the same client path, /v1/completions. Which
# prefix the upstream needs follows from the cluster selected for the
# request, so nothing before selection can know it: model-a receives
# /grid-models/model-a/v1/completions and model-b receives
# /grid-models/model-b/v1/completions.
#
# The prefix applies to the upstream leg only. Route matching, access logs
# and anything else reading the request path still see the path the client
# sent. A trailing slash on base_path is stripped and a bare "/" is treated
# as unset, so the join never doubles a slash.
#
# base_path is a routing convenience, not an isolation boundary. Do not rely
# on it to confine a request to a subtree: the proxy forwards a percent-encoded
# separator verbatim, and an upstream that decodes it before resolving dot
# segments can leave the prefix.
#
# Not applied to a health check probe, which builds its own request, so
# health_check.path is always the full upstream path. Not applied on the
# response, so an upstream Location or Link header still carries the prefix.
#
# A target that names a path is prefixed: origin-form, absolute-form, and a
# query-only target, which is anchored at the root first. An asterisk-form or
# CONNECT target names no resource and is sent unchanged.
#
# Usage:
#   cargo run -p praxis-proxy -- -c examples/configs/traffic-management/cluster-base-path.yaml
#
#   curl -H "X-Model: model-a" http://localhost:8080/v1/completions
#   curl -H "X-Model: model-b" http://localhost:8080/v1/completions

listeners:
  - name: default
    address: "0.0.0.0:8080"
    filter_chains: [main]

filter_chains:
  - name: main
    filters:
      - filter: router
        routes:
          - path_prefix: "/"
            headers:
              X-Model: "model-a"
            cluster: model-a
          - path_prefix: "/"
            headers:
              X-Model: "model-b"
            cluster: model-b
      - filter: load_balancer
        clusters:
          - name: model-a
            endpoints:
              - "127.0.0.1:9000"
            http:
              base_path: "/grid-models/model-a"
          - name: model-b
            endpoints:
              - "127.0.0.1:9001"
            http:
              base_path: "/grid-models/model-b"

insecure_options:
  allow_private_endpoints: true