/v2 route doesn't exist

[Matt Riedemann]

Looking at the api-ref docs, I'm able to list versions of the image API available in a cloud (I'm using a devstack created from master as of last week):

http://developer.openstack.org/api-ref/image/versions/index.html?expanded=id1-detail#id1

stack@osc:/opt/stack/glance$ git log -1
commit 9bd264cd034f996852372ae0ca988bd67b98cf9a
Merge: 2de3caf ce6cb2d
Author: Jenkins <email address hidden>
Date: Tue Oct 4 02:28:10 2016 +0000

    Merge "[api-ref] configure LogABug feature"
stack@osc:/opt/stack/glance$

I'm able to list versions for the image endpoint:

stack@osc:/opt/stack/glance$ curl -s -H "X-Auth-Token: $OS_TOKEN" http://9.5.127.82:9292 | json_pp
{
   "versions" : [
      {
         "id" : "v2.4",
         "status" : "CURRENT",
         "links" : [
            {
               "rel" : "self",
               "href" : "http://9.5.127.82:9292/v2/"
            }
         ]
      },
      {
         "links" : [
            {
               "rel" : "self",
               "href" : "http://9.5.127.82:9292/v2/"
            }
         ],
         "id" : "v2.3",
         "status" : "SUPPORTED"
      },
      {
         "links" : [
            {
               "rel" : "self",
               "href" : "http://9.5.127.82:9292/v2/"
            }
         ],
         "status" : "SUPPORTED",
         "id" : "v2.2"
      },
      {
         "id" : "v2.1",
         "status" : "SUPPORTED",
         "links" : [
            {
               "rel" : "self",
               "href" : "http://9.5.127.82:9292/v2/"
            }
         ]
      },
      {
         "status" : "SUPPORTED",
         "id" : "v2.0",
         "links" : [
            {
               "href" : "http://9.5.127.82:9292/v2/",
               "rel" : "self"
            }
         ]
      },
      {
         "links" : [
            {
               "href" : "http://9.5.127.82:9292/v1/",
               "rel" : "self"
            }
         ],
         "status" : "DEPRECATED",
         "id" : "v1.1"
      },
      {
         "links" : [
            {
               "rel" : "self",
               "href" : "http://9.5.127.82:9292/v1/"
            }
         ],
         "id" : "v1.0",
         "status" : "DEPRECATED"
      }
   ]
}
stack@osc:/opt/stack/glance$

I'm able to list the v1 route which is just a list of images:

stack@osc:/opt/stack/glance$ curl -s -H "X-Auth-Token: $OS_TOKEN" http://9.5.127.82:9292/v1/ | json_pp {
   "images" : [
      {
         "size" : 25165824,
         "name" : "cirros-0.3.4-x86_64-uec",
         "id" : "c8af19ff-cebc-4112-a237-78dcd19e588c",
         "disk_format" : "ami",
         "checksum" : "eb9139e4942121f22bbc2afc0400b2a4",
         "container_format" : "ami"
      },
      {
         "disk_format" : "ari",
         "container_format" : "ari",
         "checksum" : "be575a2b939972276ef675752936977f",
         "size" : 3740163,
         "name" : "cirros-0.3.4-x86_64-uec-ramdisk",
         "id" : "ff195fc4-c039-43b5-acca-501aba68aba2"
      },
      {
         "size" : 4979632,
         "name" : "cirros-0.3.4-x86_64-uec-kernel",
         "id" : "08463073-3460-4b5f-92cc-ade974936e96",
         "disk_format" : "aki",
         "container_format" : "aki",
         "checksum" : "8a40c862b5735975d82605c1dd395796"
      }
   ]
}

But I'm not able to list the v2 route:

stack@osc:/opt/stack/glance$ curl -s -H "X-Auth-Token: $OS_TOKEN" http://9.5.127.82:9292/v2/
404 Not Found

The resource could not be found.

   stack@osc:/opt/stack/glance$

[Matt Riedemann (mriedem)]

Also, the v1 route lists images, is that by design? I was expecting it to provide details on the v1 API version.

[Sean Dague (sdague)]

In my reading of the api-ref document, there is nothing stating that this is a valid url. I actually think the 404 is correct

[Brian Rosmaita (brian-rosmaita)]

The image-list response for GET v1/ is by design, though it was designed before my time, so I can't tell you what the reasoning was behind it. We'll have to keep it like this.

Looking into the GET v2/ situation now.

[Matt Riedemann (mriedem)]

@Sean, then the root /versions response shouldn't provide links to a busted URL should they? Because they do:

{
         "status" : "SUPPORTED",
         "id" : "v2.0",
         "links" : [
            {
               "href" : "http://9.5.127.82:9292/v2/",
               "rel" : "self"
            }
         ]
      },

[Matt Riedemann (mriedem)]

Also just doing /v2 without the trailing slash doesn't do anything:

stack@osc:/opt/stack/glance$ curl -G -H "X-Auth-Token: $OS_TOKEN" http://9.5.127.82:9292/v2
stack@osc:/opt/stack/glance$

2016-10-12 15:40:07.551 INFO eventlet.wsgi.server [req-806a6004-9d72-4386-b01b-c8db5806a9dd 95802c8f3a424b8d83b898ced6b2bb31 f6e20cc9f34d4c7fafb56e81905df44d] 9.5.127.82 - - [12/Oct/2016 15:40:07] "GET /v2 HTTP/1.1" 302 222 0.047123

There should be a redirect location in the response, but there isn't one.

[Matt Riedemann (mriedem)]

Looking at the code, /v1 routes to /images because of:

https://github.com/openstack/glance/blob/9bd264cd034f996852372ae0ca988bd67b98cf9a/glance/api/v1/router.py#L31

And /v2/ has no such route:

https://github.com/openstack/glance/blob/9bd264cd034f996852372ae0ca988bd67b98cf9a/glance/api/v2/router.py#L35

[Matt Riedemann (mriedem)]

stack@osc:~$ curl -G -i -H "X-Auth-Token: $OS_TOKEN" http://9.5.127.82:9292/v2
HTTP/1.1 302 Found
Content-Type: text/plain; charset=utf8
Location: http://9.5.127.82:9292/v2/
X-Openstack-Request-Id: req-eb53a8f9-a38c-4188-82fb-a8a3d747f395
Content-Length: 0
Date: Wed, 12 Oct 2016 15:51:00 GMT

So that returns a location in the response to the /v2/ route that doesn't exist and will give you a 404. :)

[Brian Rosmaita (brian-rosmaita)]

Here's what we currently see on the v2 endpoint, courtesy of Matt:

stack@osc:~$ curl -G -i -H "X-Auth-Token: $OS_TOKEN" http://9.5.127.82:9292/v2/
HTTP/1.1 404 Not Found
Content-Length: 52
Content-Type: text/plain; charset=UTF-8
X-Openstack-Request-Id: req-76d77d29-9278-4530-b2a1-c44e54cabc32
Date: Wed, 12 Oct 2016 15:50:06 GMT

stack@osc:~$ curl -G -i -H "X-Auth-Token: $OS_TOKEN" http://9.5.127.82:9292/v2
HTTP/1.1 302 Found
Content-Type: text/plain; charset=utf8
Location: http://9.5.127.82:9292/v2/
X-Openstack-Request-Id: req-eb53a8f9-a38c-4188-82fb-a8a3d747f395
Content-Length: 0
Date: Wed, 12 Oct 2016 15:51:00 GMT

So GET v2 gives you a redirect to GET v2/ ... and GET v2/ gives you a 404.

Matt's point is that since the v2/ shows up in the /versions response (see above), you'd expect *something* to be there. Most projects give a version list there.

We need to decide what to do for Glance and document it.

[Brian Rosmaita (brian-rosmaita)]

Here's a summary of the requests/responses

suppose your glance endpoint is g.os.org:9292

(token not required for these)
GET g.os.org:9292 => 300 (Multiple Choices) + "versions" response
GET g.os.org:9292/ => 300 + "versions" response
GET g.os.org:9292/versions => 200 + "versions" response
GET g.os.org:9292/versions/ => 200 + "versions" response

(token required for the following)
GET g.os.org:9292/v1 => 302 (Found) + Location: http://g.os.org:9292/v1/ + no content
GET g.os.org:9292/v1/ => 200 + image-list response for authenticated user
GET g.os.org:9292/v2 => 302 + Location: http://g.os.org:9292/v2/ + no content
GET g.os.org:9292/v2/ => 404

[Brian Rosmaita (brian-rosmaita)]

I must've had this sitting open for a while and completely missed Sean's update.

We discussed this at the glance meeting today and decided to agree with Sean's position, namely that a 404 is appropriate.

It could make sense to have the versions returned, or it could make sense to have a JSON-home type document returned. So we don't want to be precipitate in deciding what (if anything) to return.

[Matt Riedemann (mriedem)]

I'm fine with it not being there, but then why do we even have the links in the root version discovery list? e.g.

        {
            "id": "v2.0",
            "links": [
                {
                    "href": "http://glance.openstack.example.org/v2/",
                    "rel": "self"
                }
            ],
            "status": "SUPPORTED"
        },

If I try to follow that self link it's going to fail - then why have the link in there at all? This at least seems confusing from a version discovery standpoint, and could be made clear in the docs.

[Matt Riedemann (mriedem)]

Another example of the docs saying that a self link refers back to itself here:

http://developer.openstack.org/api-guide/compute/links_and_references.html

And links are used for conveniently showing you where to go - but it shouldn't show you to go somewhere that doesn't exist. It'd be better to not even have the link IMO.