Trying to POST the same (name, version) tuple yields a non-obvious 422 error

[nrr]

When trying to POST to /v1/containers with an already existing (name, version) tuple, CatalogIt will barf all over itself and return a 422 to the client with nary any indication as to what really went on:

error   10-May-2017 15:08:28    * About to connect() to catalogit.services.dmtio.net port 80 (#0)
error   10-May-2017 15:08:28    *   Trying 10.61.6.71... connected
error   10-May-2017 15:08:28    > POST /v1/containers HTTP/1.1
error   10-May-2017 15:08:28    > User-Agent: curl/7.22.0 (x86_64-pc-linux-gnu) libcurl/7.22.0 OpenSSL/1.0.1 zlib/1.2.3.4 libidn/1.23 librtmp/2.3
error   10-May-2017 15:08:28    > Host: catalogit.services.dmtio.net
error   10-May-2017 15:08:28    > Accept: */*
error   10-May-2017 15:08:28    > Content-Type: application/json
error   10-May-2017 15:08:28    > Content-Length: 202
error   10-May-2017 15:08:28    > 
error   10-May-2017 15:08:28    } [data not shown]
error   10-May-2017 15:08:28    * upload completely sent off: 202out of 202 bytes
error   10-May-2017 15:08:28    * The requested URL returned error: 422
error   10-May-2017 15:08:28    * Closing connection #0
error   10-May-2017 15:08:28    [ERROR] Posting image to CatalogIt failed.

This makes debugging, e.g., Bamboo build failures kind of a pain when considering CatalogIt itself as a black box.

[wilsonodk]

FWIW, the response object tells you exactly why there was a 422…

$ curl -sSv -XPOST http://catalogit.services.dmtio.net/v1/containers -H'Content-Type: application/json' --data-binary '{"name": "mss-wwise-hello-world", "version": "0.0.1", "image": "registry.services.dmtio.net/mss-wwise-hello-world:0.0.1"}'
*   Trying 10.61.3.25...
* TCP_NODELAY set
* Connected to catalogit.services.dmtio.net (10.61.3.25) port 80 (#0)
> POST /v1/containers HTTP/1.1
> Host: catalogit.services.dmtio.net
> User-Agent: curl/7.51.0
> Accept: */*
> Content-Type: application/json
> Content-Length: 121
>
* upload completely sent off: 121 out of 121 bytes
< HTTP/1.1 422 Unprocessable Entity
< Access-Control-Allow-Origin: *
< Content-Type: application/json; charset=utf-8
< Date: Thu, 11 May 2017 12:19:24 GMT
< ETag: W/"78-IXjtrbBfCwxhgeFVh48Gpw"
< X-Powered-By: Express
< Content-Length: 120
< Connection: keep-alive
<
* Curl_http_done: called premature == 0
* Connection #0 to host catalogit.services.dmtio.net left intact
{"error":"Container Error: There is already a combination of mss-wwise-hello-world:0.0.1. Specify unique combinations."}

I'll can certainly update the returned status code to 409 Conflict if that makes it more obvious.

[nrr]

Yeah, a 409 would actually be a lot more obvious in this case. Our invocation of curl here literally writes only the HTTP status code to stdout so that we can branch based on its value.