/v2/find with select=private has different behaviour for queries and name searches

[Robert Ancell]

If you do a /v2/find with select=private the behaviour is different when using a query or a name. The name form will return non-private results from the store, but the query only returns results for private snaps.

When using a query only private results are returned, when using a name non-private results are returned. I would have expected only private results to be selected in both cases.

e.g.
$ sudo nc -C -U /run/snapd.socket
GET /v2/find?q=moon-buggy&select=private HTTP/1.1
Host:
Authorization: Macaroon root="..."

HTTP/1.1 200 OK
Content-Type: application/json
Date: Wed, 25 Jan 2017 00:33:55 GMT
Content-Length: 106

{"type":"sync","status-code":200,"status":"OK","result":[],"sources":["store"],"suggested-currency":"USD"}

$ sudo nc -C -U /run/snapd.socket
GET /v2/find?name=moon-buggy&select=private HTTP/1.1
Host:
Authorization: Macaroon root="..."

HTTP/1.1 200 OK
Content-Type: application/json
Date: Wed, 25 Jan 2017 00:34:29 GMT
Content-Length: 1221

{"type":"sync","status-code":200,"status":"OK","result":[{"channel":"","channels":{"beta":{"revision":"12","confinement":"strict","version":"1.0.51.11","channel":"beta","epoch":"0","size":90112},"candidate":{"revision":"12","confinement":"strict","version":"1.0.51.11","channel":"candidate","epoch":"0","size":90112},"edge":{"revision":"12","confinement":"strict","version":"1.0.51.11","channel":"edge","epoch":"0","size":90112},"stable":{"revision":"12","confinement":"strict","version":"1.0.51.11","channel":"stable","epoch":"0","size":90112}},"confinement":"strict","description":"Moon-buggy is a simple character graphics game, where you drive some kind of car across the moon's surface. Unfortunately there are dangerous craters there. Fortunately your car can jump over them!\r\n","developer":"dholbach","download-size":90112,"icon":"https://myapps.developer.ubuntu.com/site_media/appmedia/2015/11/moon-buggy.jpg.png","id":"2kkitQurgOkL3foImG4wDwn9CIANuHlt","name":"moon-buggy","private":false,"resource":"/v2/find?name=moon-buggy\u0026select=private","revision":"12","status":"available","summary":"Drive a car across the moon","type":"app","version":"1.0.51.11"}],"sources":["store"],"suggested-currency":"USD"}

[Robert Ancell (robert-ancell)]

Actually, now I read the docs more closely:

'private: search private snaps (by default, find only searches public snaps). Can't be used with name, only q (for now at least)."

So I think this should be returning an error when this is attempted.

[Robert Ancell (robert-ancell)]

The relevant part of the code is (daemon/api.go):

        query := r.URL.Query()
        q := query.Get("q")
        section := query.Get("section")
        name := query.Get("name")
        private := false
        prefix := false

        if name != "" {
                if q != "" {
                        return BadRequest("cannot use 'q' and 'name' together")
                }

                if name[len(name)-1] != '*' {
                        return findOne(c, r, user, name)
                }

                prefix = true
                q = name[:len(name)-1]
        }

        if sel := query.Get("select"); sel != "" {
                switch sel {
                case "refresh":
                        if prefix {
                                return BadRequest("cannot use 'name' with 'select=refresh'")
                        }
                        if q != "" {
                                return BadRequest("cannot use 'q' with 'select=refresh'")
                        }
                        return storeUpdates(c, r, user)
                case "private":
                        private = true
                }
        }

        theStore := getStore(c)
        found, err := theStore.Find(&store.Search{
                Query: q,
                Section: section,
                Private: private,
                Prefix: prefix,
        }, user)

The main issue seems to be if you pass ?name=&select= no BadRequest is generated because the function returns after findOne().

Also note the 'section' parameter is not documented in https://github.com/snapcore/snapd/wiki/REST-API

[Robert Ancell (robert-ancell)]

I've found the /v2/find to be the hardest part to understand in the REST API due to the interaction between the q, name and select parameters.

The question is, does select=private even need to exist? Since the JSON snap object have a private value, shouldn't all searches return private snaps if authorization is provided? The client can then filter the results if this is required.

Perhaps it would be simpler if select=refresh was replaced with /v2/find/refreshable - this and the above would get rid of the select parameter entirely.

[Seth Arnold (seth-arnold)]

On Wed, Jan 25, 2017 at 02:36:13AM -0000, Robert Ancell wrote:
> The question is, does select=private even need to exist? Since the JSON
> snap object have a private value, shouldn't all searches return private
> snaps if authorization is provided? The client can then filter the
> results if this is required.

What's the intention of the 'private' in 'private snaps'? Is the intention
to keep their existence secret? Or just the contents of the snap?

Thanks

[John Lenton (chipaca)]

So... at this point, what remains to be done is to detect and return an error when 'private' is true and 'name' does not end in a *. That is, just before api.go's searchStore calls out to findOne, it should check for private and bail with a 400.