The opa
plugin is used to integrate with Open Policy Agent. By using this plugin, users can decouple functions such as authentication and access to services and reduce the complexity of the application system.
Name | Type | Requirement | Default | Valid | Description |
---|---|---|---|---|---|
host | string | required | Open Policy Agent service host (eg. https://localhost:8181) | ||
ssl_verify | boolean | optional | true | Whether to verify the certificate | |
policy | string | required | OPA policy path (It is a combination of package and decision . When you need to use advanced features such as custom response, decision can be omitted) | ||
timeout | integer | optional | 3000ms | [1, 60000]ms | HTTP call timeout. |
keepalive | boolean | optional | true | HTTP keepalive | |
keepalive_timeout | integer | optional | 60000ms | [1000, ...]ms | keepalive idle timeout |
keepalive_pool | integer | optional | 5 | [1, ...]ms | Connection pool limit |
with_route | boolean | optional | false | Whether to send information about the current route. | |
with_service | boolean | optional | false | Whether to send information about the current service. | |
with_consumer | boolean | optional | false | Whether to send information about the current consumer. (It may contain sensitive information such as apikey, so please turn it on only if you are sure it is safe) |
The type
indicates that the request type. (e.g. http
or stream
) The reqesut
is used when the request type is http
, it contains the basic information of the request. (e.g. url, header) The var
contains basic information about this requested connection. (e.g. IP, port, request timestamp) The route
, service
, and consumer
will be sent only after the opa
plugin has enabled the relevant features, and their contents are same as those stored by APISIX in etcd.
{ "type": "http", "request": { "scheme": "http", "path": "\/get", "headers": { "user-agent": "curl\/7.68.0", "accept": "*\/*", "host": "127.0.0.1:9080" }, "query": {}, "port": 9080, "method": "GET", "host": "127.0.0.1" }, "var": { "timestamp": 1701234567, "server_addr": "127.0.0.1", "server_port": "9080", "remote_port": "port", "remote_addr": "ip address" }, "route": {}, "service": {}, "consumer": {} }
In the response, result
is automatically added by OPA. The allow
is indispensable and will indicate whether the request is allowed to be forwarded through the APISIX. The reason
, headers
, and status_code
are optional and are only returned when you need to use a custom response, as you'll see in the next section with the actual use case for it.
{ "result": { "allow": true, "reason": "test", "headers": { "an": "header" }, "status_code": 401 } }
First, you need to launch the Open Policy Agent environment.
$ docker run -d --name opa -p 8181:8181 openpolicyagent/opa:0.35.0 run -s
You can create a basic policy for testing.
$ curl -X PUT '127.0.0.1:8181/v1/policies/example1' \ -H 'Content-Type: text/plain' \ -d 'package example1 import input.request default allow = false allow { # HTTP method must GET request.method == "GET" }'
After that, you can create a route and turn on the opa
plugin.
$ curl -X PUT 'http://127.0.0.1:9080/apisix/admin/routes/r1' \ -H 'X-API-KEY: <api-key>' \ -H 'Content-Type: application/json' \ -d '{ "uri": "/*", "plugins": { "opa": { "host": "http://127.0.0.1:8181", "policy": "example1" } }, "upstream": { "nodes": { "httpbin.org:80": 1 }, "type": "roundrobin" } }'
Try it out.
# Successful request $ curl -i -X GET 127.0.0.1:9080/get HTTP/1.1 200 OK # Failed request $ curl -i -X POST 127.0.0.1:9080/post HTTP/1.1 403 FORBIDDEN
Next, let's think about some more complex scenarios.
When you need to return a custom error message for an incorrect request, you can implement it this way.
$ curl -X PUT '127.0.0.1:8181/v1/policies/example2' \ -H 'Content-Type: text/plain' \ -d 'package example2 import input.request default allow = false allow { request.method == "GET" } # custom response body (Accepts a string or an object, the object will respond as JSON format) reason = "test" { not allow } # custom response header (The data of the object can be written in this way) headers = { "Location": "http://example.com/auth" } { not allow } # custom response status code status_code = 302 { not allow }'
Update the route and set opa
plugin‘s policy
parameter to example2
. Then, let’s try it.
# Successful request $ curl -i -X GET 127.0.0.1:9080/get HTTP/1.1 200 OK # Failed request $ curl -i -X POST 127.0.0.1:9080/post HTTP/1.1 302 FOUND Location: http://example.com/auth test
Let's think about another scenario, when your decision needs to use some APISIX data, such as route
, consumer
, etc., how should we do it?
Create a simple policy echo
, which will return the data sent by APISIX to the OPA service as is, so we can simply see them.
$ curl -X PUT '127.0.0.1:8181/v1/policies/echo' \ -H 'Content-Type: text/plain' \ -d 'package echo allow = false reason = input'
Next, update the config of the route to enable sending route data.
$ curl -X PUT 'http://127.0.0.1:9080/apisix/admin/routes/r1' \ -H 'X-API-KEY: <api-key>' \ -H 'Content-Type: application/json' \ -d '{ "uri": "/*", "plugins": { "opa": { "host": "http://127.0.0.1:8181", "policy": "echo", "with_route": true } }, "upstream": { "nodes": { "httpbin.org:80": 1 }, "type": "roundrobin" } }'
Try it. As you can see, we output this data with the help of the custom response body function described above, along with the data from the route.
$ curl -X GET 127.0.0.1:9080/get { "type": "http", "request": { xxx }, "var": { xxx }, "route": { xxx } }