[Bug] HTTP 415 when creating Automated Rules using multipart/form-data

[andrewazores]

Current Behavior:

POSTing a multipart/form-data to /api/v2/rules always produces an HTTP 415 error response.

Expected Behavior:

The rule should be created whether submitted as multipart/form-data, application/x-www-form-urlencoded, or application/json.

Related to https://github.com/cryostatio/cryostat/pull/1072

Steps To Reproduce:

1. sh run.sh
2. Try to POST a multipart form:

$ curl -vk -F name="firstRule" -F matchExpression="target.labels[\"app\"]==\"jfr-sb-app\"" -F eventSpecifier="template=Profiling,type=TARGET" https://localhost:8181/api/v2/rules -H 'Accept: application/json' -H 'Content-Type: multipart/form-data'
*   Trying 127.0.0.1:8181...
* Connected to localhost (127.0.0.1) port 8181 (#0)
* ALPN: offers h2
* ALPN: offers http/1.1
* TLSv1.0 (OUT), TLS header, Certificate Status (22):
* TLSv1.3 (OUT), TLS handshake, Client hello (1):
* TLSv1.2 (IN), TLS header, Certificate Status (22):
* TLSv1.3 (IN), TLS handshake, Server hello (2):
* TLSv1.2 (IN), TLS handshake, Certificate (11):
* TLSv1.2 (IN), TLS handshake, Server key exchange (12):
* TLSv1.2 (IN), TLS handshake, Server finished (14):
* TLSv1.2 (OUT), TLS header, Certificate Status (22):
* TLSv1.2 (OUT), TLS handshake, Client key exchange (16):
* TLSv1.2 (OUT), TLS header, Finished (20):
* TLSv1.2 (OUT), TLS change cipher, Change cipher spec (1):
* TLSv1.2 (OUT), TLS header, Certificate Status (22):
* TLSv1.2 (OUT), TLS handshake, Finished (20):
* TLSv1.2 (IN), TLS header, Finished (20):
* TLSv1.2 (IN), TLS header, Certificate Status (22):
* TLSv1.2 (IN), TLS handshake, Finished (20):
* SSL connection using TLSv1.2 / ECDHE-RSA-AES256-GCM-SHA384
* ALPN: server did not agree on a protocol. Uses default.
* Server certificate:
*  subject: C=CA; O=Cryostat; CN=cryostat
*  start date: Feb  2 02:03:33 2023 GMT
*  expire date: Feb  2 02:03:33 2024 GMT
*  issuer: C=CA; O=Cryostat; CN=cryostat
*  SSL certificate verify result: self-signed certificate (18), continuing anyway.
* TLSv1.2 (OUT), TLS header, Supplemental data (23):
> POST /api/v2/rules HTTP/1.1
> Host: localhost:8181
> User-Agent: curl/7.85.0
> Accept: application/json
> Content-Length: 419
> Content-Type: multipart/form-data; boundary=------------------------1b58d77f95f35fe9
> 
* TLSv1.2 (OUT), TLS header, Supplemental data (23):
* We are completely uploaded and fine
* TLSv1.2 (IN), TLS header, Supplemental data (23):
* Mark bundle as not supporting multiuse
< HTTP/1.1 415 Unsupported Media Type
< content-type: application/json
< content-length: 87
< 
* Connection #0 to host localhost left intact
{"meta":{"type":"text/plain","status":"Unsupported Media Type"},"data":{"reason":null}}

3. Try the same submission using a urlencoded-form:

$ curl -vk -d name="firstRule" -d matchExpression="target.labels[\"app\"]==\"jfr-sb-app\"" -d eventSpecifier="template=Profiling,type=TARGET" https://localhost:8181/api/v2/rules -H 'Accept: application/json'
*   Trying 127.0.0.1:8181...
* Connected to localhost (127.0.0.1) port 8181 (#0)
* ALPN: offers h2
* ALPN: offers http/1.1
* TLSv1.0 (OUT), TLS header, Certificate Status (22):
* TLSv1.3 (OUT), TLS handshake, Client hello (1):
* TLSv1.2 (IN), TLS header, Certificate Status (22):
* TLSv1.3 (IN), TLS handshake, Server hello (2):
* TLSv1.2 (IN), TLS handshake, Certificate (11):
* TLSv1.2 (IN), TLS handshake, Server key exchange (12):
* TLSv1.2 (IN), TLS handshake, Server finished (14):
* TLSv1.2 (OUT), TLS header, Certificate Status (22):
* TLSv1.2 (OUT), TLS handshake, Client key exchange (16):
* TLSv1.2 (OUT), TLS header, Finished (20):
* TLSv1.2 (OUT), TLS change cipher, Change cipher spec (1):
* TLSv1.2 (OUT), TLS header, Certificate Status (22):
* TLSv1.2 (OUT), TLS handshake, Finished (20):
* TLSv1.2 (IN), TLS header, Finished (20):
* TLSv1.2 (IN), TLS header, Certificate Status (22):
* TLSv1.2 (IN), TLS handshake, Finished (20):
* SSL connection using TLSv1.2 / ECDHE-RSA-AES256-GCM-SHA384
* ALPN: server did not agree on a protocol. Uses default.
* Server certificate:
*  subject: C=CA; O=Cryostat; CN=cryostat
*  start date: Feb  2 02:03:33 2023 GMT
*  expire date: Feb  2 02:03:33 2024 GMT
*  issuer: C=CA; O=Cryostat; CN=cryostat
*  SSL certificate verify result: self-signed certificate (18), continuing anyway.
* TLSv1.2 (OUT), TLS header, Supplemental data (23):
> POST /api/v2/rules HTTP/1.1
> Host: localhost:8181
> User-Agent: curl/7.85.0
> Accept: application/json
> Content-Length: 111
> Content-Type: application/x-www-form-urlencoded
> 
* TLSv1.2 (IN), TLS header, Supplemental data (23):
* Mark bundle as not supporting multiuse
< HTTP/1.1 201 Created
< location: /api/v2/rules/firstRule
< content-type: application/json
< content-length: 85
< 
* Connection #0 to host localhost left intact
{"meta":{"type":"application/json","status":"Created"},"data":{"result":"firstRule"}}

4. Try a submission as JSON:

$ curl -vk -H 'Content-Type: application/json' -d '{"name":"secondRule","matchExpression":"false","eventSpecifier":"template=Profiling,type=TARGET"}' https://localhost:8181/api/v2/rules -H 'Accept: application/json'
*   Trying 127.0.0.1:8181...
* Connected to localhost (127.0.0.1) port 8181 (#0)
* ALPN: offers h2
* ALPN: offers http/1.1
* TLSv1.0 (OUT), TLS header, Certificate Status (22):
* TLSv1.3 (OUT), TLS handshake, Client hello (1):
* TLSv1.2 (IN), TLS header, Certificate Status (22):
* TLSv1.3 (IN), TLS handshake, Server hello (2):
* TLSv1.2 (IN), TLS handshake, Certificate (11):
* TLSv1.2 (IN), TLS handshake, Server key exchange (12):
* TLSv1.2 (IN), TLS handshake, Server finished (14):
* TLSv1.2 (OUT), TLS header, Certificate Status (22):
* TLSv1.2 (OUT), TLS handshake, Client key exchange (16):
* TLSv1.2 (OUT), TLS header, Finished (20):
* TLSv1.2 (OUT), TLS change cipher, Change cipher spec (1):
* TLSv1.2 (OUT), TLS header, Certificate Status (22):
* TLSv1.2 (OUT), TLS handshake, Finished (20):
* TLSv1.2 (IN), TLS header, Finished (20):
* TLSv1.2 (IN), TLS header, Certificate Status (22):
* TLSv1.2 (IN), TLS handshake, Finished (20):
* SSL connection using TLSv1.2 / ECDHE-RSA-AES256-GCM-SHA384
* ALPN: server did not agree on a protocol. Uses default.
* Server certificate:
*  subject: C=CA; O=Cryostat; CN=cryostat
*  start date: Feb  2 02:03:33 2023 GMT
*  expire date: Feb  2 02:03:33 2024 GMT
*  issuer: C=CA; O=Cryostat; CN=cryostat
*  SSL certificate verify result: self-signed certificate (18), continuing anyway.
* TLSv1.2 (OUT), TLS header, Supplemental data (23):
> POST /api/v2/rules HTTP/1.1
> Host: localhost:8181
> User-Agent: curl/7.85.0
> Content-Type: application/json
> Accept: application/json
> Content-Length: 97
> 
* TLSv1.2 (IN), TLS header, Supplemental data (23):
* Mark bundle as not supporting multiuse
< HTTP/1.1 201 Created
< location: /api/v2/rules/secondRule
< content-type: application/json
< content-length: 86
< 
* Connection #0 to host localhost left intact
{"meta":{"type":"application/json","status":"Created"},"data":{"result":"secondRule"}}