azure-functions

Metadata for azure-functions plugin provides the functionality for authorization fallback. It defines master_apikey and master_clientid (azure active directory client id) where users (optionally) can define the master API key or Client ID for mission-critical application deployment. So if there are no authorization details found inside the plugin attribute the authorization details present in the metadata kicks in.

The relative priority ordering is as follows:

• First, the plugin looks for x-functions-key or x-functions-clientid keys inside the request header to the APISIX agent.
• If they are not found, the azure-functions plugin checks for the authorization details inside plugin attributes. If present, it adds the respective header to the request sent to the Azure cloud function.
• If no authorization details are found inside plugin attributes, APISIX fetches the metadata config for this plugin and uses the master keys.

To add a new Master APIKEY, make a request to /apisix/admin/plugin_metadata endpoint with the updated metadata as follows:

# enable azure function for a route
curl http://127.0.0.1:9080/apisix/admin/routes/1 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
        "azure-functions": {
            "function_uri": "http://test-apisix.azurewebsites.net/api/HttpTrigger",
            "authorization": {
                "apikey": "<Generated API key to access the Azure-Function>"
            }
        }
    "uri": "/azure"
}'

Now any requests (HTTP/1.1, HTTPS, HTTP2) to URI /azure will trigger an HTTP invocation to the aforesaid function URI and response body along with the response headers and response code will be proxied back to the client. For example ( here azure cloud function just take the name query param and returns Hello $name ) :

For requests where the mode of communication between the client and the Apache APISIX gateway is HTTP/2, the example looks like ( make sure you are running APISIX agent with enable_http2: true for a port in config-default.yaml. You can do it by uncommenting the port 9081 from apisix.node_listen field ) :

$ curl -i -XGET --http2 --http2-prior-knowledge http://localhost:9081/azure\?name=APISIX
HTTP/2 200
content-type: text/plain; charset=utf-8
date: Wed, 17 Nov 2021 14:54:07 GMT
server: APISIX/2.10.2

Azure Faas plugin supports url path forwarding while proxying request to the modified upstream. With that being said, any extension to the path of the base request APISIX gateway URI gets “appended” (path join) to the function_uri specified in the plugin configuration.

Here is an example:

Now any request with path azure/HttpTrigger1 will invoke the azure function. Here the extra path (where the magic character * has been used) up to the query params have been forwarded.

curl -i -XGET http://127.0.0.1:9080/azure/HttpTrigger1\?name\=APISIX
HTTP/1.1 200 OK
Content-Type: text/plain; charset=utf-8
Transfer-Encoding: chunked
Connection: keep-alive
Date: Wed, 01 Dec 2021 14:19:53 GMT
Request-Context: appId=cid-v1:4d4b6221-07f1-4e1a-9ea0-b86a5d533a94
Server: APISIX/2.11.0
Hello, APISIX

Remove the corresponding JSON configuration in the plugin configuration to disable the azure-functions plugin and add the suitable upstream configuration. APISIX plugins are hot-reloaded, therefore no need to restart APISIX.