Project: APISIX (Orchestration & Management / API Gateway)
File: router-radixtree.md

Title: Router Radixtree <!-- --> is an adaptive radix tree that is implemented in Lua for OpenResty and it is based on FFI for . APISIX uses libradixtree as a route dispatching library. There are several ways to use Libradixtree in APISIX. Let's take a look at a few examples and have an intuitive understanding. ``` /blog/foo ``` It will only match the full path `/blog/foo`. ``` /blog/bar* ``` It will match the path with the prefix `/blog/bar`. For example, `/blog/bar/a`, `/blog/bar/b`, `/blog/bar/c/d/e`, `/blog/bar` etc. Full match has a higher priority than deep prefix matching. Here are the rules: ``` /blog/foo/* /blog/foo/a/* /blog/foo/c/* /blog/foo/bar ``` | path | Match result | ||--| |/blog/foo/bar | `/blog/foo/bar` | |/blog/foo/a/b/c | `/blog/foo/a/*` | |/blog/foo/c/d | `/blog/foo/c/*` | |/blog/foo/gloo | `/blog/foo/*` | |/blog/bar | not match | When different routes have the same `uri`, you can set the priority field of the route to determine which route to match first, or add other matching rules to distinguish different routes. Note: In the matching rules, the `priority` field takes precedence over other rules except `uri`. Different routes have the same `uri` but different `priority` field Create two routes with different `priority` values (the larger the value, the higher the priority). :::note You can fetch the `admin_key` from `config.yaml` and save to an environment variable with the following command: ```bash adminkey=$(yq '.deployment.admin.adminkey[0].key' conf/config.yaml | sed 's/"//g') ``` ::: ```shell $ curl http://127.0.0.1:9180/apisix/admin/routes/1 -H "X-API-KEY: $admin_key" -X PUT -d ' { "upstream": { "nodes": { "127.0.0.1:1980": 1 }, "type": "roundrobin" }, "priority": 3, "uri": "/hello" }' ``` ```shell $ curl http://127.0.0.1:9180/apisix/admin/routes/2 -H "X-API-KEY: $admin_key" -X PUT -d ' { "upstream": { "nodes": { "127.0.0.1:1981": 1 }, "type": "roundrobin" }, "priority": 2, "uri": "/hello" }' ``` Test: ```shell curl http://127.0.0.1:1980/hello 1980 ``` All requests will only hit the route of port `1980` because it has a priority of 3 while the route with the port of `1981` has a priority of 2. Different routes have the same `uri` but different matching conditions To understand this, look at the example of setting host matching rules: ```shell $ curl http://127.0.0.1:9180/apisix/admin/routes/1 -H "X-API-KEY: $admin_key" -X PUT -d ' { "upstream": { "nodes": { "127.0.0.1:1980": 1 }, "type": "roundrobin" }, "hosts": ["localhost.com"], "uri": "/hello" }' ``` ```shell $ curl http://127.0.0.1:9180/apisix/admin/routes/2 -H "X-API-KEY: $admin_key" -X PUT -d ' { "upstream": { "nodes": { "127.0.0.1:1981": 1 }, "type": "roundrobin" }, "hosts": ["test.com"], "uri": "/hello" }' ``` Test: ```shell $ curl http://127.0.0.1:9080/hello -H 'host: localhost.com' 1980 ``` ```shell $ curl http://127.0.0.1:9080/hello -H 'host: test.com' 1981 ``` ```shell $ curl http://127.0.0.1:9080/hello {"error_msg":"404 Route Not Found"} ``` If the `host` rule matches, the request hits the corresponding upstream, and if the `host` does not match, the request returns a 404

When `radixtreeuriwith_parameter` is used, we can match routes with parameters. For example, with configuration: ```yaml apisix: router: http: 'radixtreeuriwith_parameter' ``` route like ``` /blog/:name ``` will match both `/blog/dog` and `/blog/cat`. For more details, see https://github.com/api7/lua-resty-radixtree/#parameters-in-path. Nginx provides a variety of built-in variables that can be used to filter routes based on certain criteria. Here is an example of how to filter routes by Nginx built-in variables: ```shell $ curl http://127.0.0.1:9180/apisix/admin/routes/1 -H "X-API-KEY: $admin_key" -X PUT -i -d ' { "uri": "/index.html", "vars": [ ["http_host", "==", "iresty.com"], ["cookiedeviceid", "==", "a66f0cdc4ba2df8c096f74c9110163a9"], ["arg_name", "==", "json"], ["arg_age", ">", "18"], ["arg_address", "~~", "China.*"] ], "upstream": { "type": "roundrobin", "nodes": { "127.0.0.1:1980": 1 } } }' ``` This route will require the request header `host` equal `iresty.com`, request cookie key `deviceid` equal `a66f0cdc4ba2df8c096f74c9110163a9` etc. You can learn more at . APISIX supports filtering route by POST form attributes with `Content-Type` = `application/x-www-form-urlencoded`. We can define the following route: ```shell $ curl http://127.0.0.1:9180/apisix/admin/routes/1 -H "X-API-KEY: $admin_key" -X PUT -i -d ' { "methods": ["POST", "GET"], "uri": "/_post", "vars": [ ["postargname", "==", "json"] ], "upstream": { "type": "roundrobin", "nodes": { "127.0.0.1:1980": 1 } } }' ``` The route will be matched when the POST form contains `name=json`. APISIX can handle HTTP GET and POST methods. At the same time, the request body can be a GraphQL query string or JSON-formatted content. APISIX supports filtering routes by some attributes of GraphQL. Currently, we support: graphql_operation graphql_name graphqlrootfields For instance, with GraphQL like this: ```graphql query getRepo { owner { name } repo { created } } ``` Where The `graphql_operation` is `query` The `graphql_name` is `getRepo`, The `graphqlrootfields` is `["owner", "repo"]` We can filter such route with: ```shell $ curl http://127.0.0.1:9180/apisix/admin/routes/1 -H "X-API-KEY: $admin_key" -X PUT -i -d ' { "methods": ["POST", "GET"], "uri": "/graphql", "vars": [ ["graphql_operation", "==", "query"], ["graphql_name", "==", "getRepo"], ["graphqlrootfields", "has", "owner"] ], "upstream": { "type": "roundrobin", "nodes": { "127.0.0.1:1980": 1 } } }' ``` We can verify GraphQL matches in the following three ways: GraphQL query strings ```shell $ curl -H 'content-type: application/graphql' -X POST http://127.0.0.1:9080/graphql -d ' query getRepo { owner { name } repo { created } }' ``` JSON format ```shell $ curl -H 'content-type: application/json' -X POST \ http://127.0.0.1:9080/graphql --data '{"query": "query getRepo { owner {name } repo {created}}"}' ``` Try `GET` request match ```shell $ curl -H 'content-type: application/graphql' -X GET \ "http://127.0.0.1:9080/graphql?query=query getRepo { owner {name } repo {created}}" -g ``` To prevent spending too much time reading invalid GraphQL request body, we only read the first 1 MiB data from the request body. This limitation is configured via: ```yaml graphql: max_size: 1048576 ``` If you need to pass a GraphQL body which is larger than the limitation, you can increase the value in `conf/config.yaml`.