Arvados

The problem seems to be on collections#list:

$ arv collection list | jq .items[0].created_at
"2020-10-07T19:32:42.993304Z" 
$ arv group list | jq .items[0].created_at
"2020-10-20T22:05:42.392489000Z" 
$ arv container list | jq .items[0].created_at
"2020-10-19T16:35:12.026524000Z" 
$ arv container_request list | jq .items[0].created_at
"2020-10-19T16:35:12.057875000Z" 

There's an explicit test con CollectionsController at services/api/test/functional/arvados/v1/filters_test.rb called 'api responses provide timestamps with nanoseconds' that passes without issues. OTOH, I've just double checked this on ce8i5 and it behaves as reported here.

Making the request directly to railsAPI works OK:

root@d0b854923e28:/# curl  -H "Authorization: OAuth2 xxxxtokenxxxxx" http://localhost:8004/arvados/v1/collections | jq .items[0].created_at
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 10615    0 10615    0     0   334k      0 --:--:-- --:--:-- --:--:--  334k
"2020-10-07T19:32:42.993304000Z" 

looks like it comes from:lib/controller/router/response.go

for k, v := range tmp {
        if strings.HasSuffix(k, "_at") {
            // Format non-nil timestamps as
            // rfc3339NanoFixed (otherwise they
            // would use the default time encoding).
            switch tv := v.(type) {
            case *time.Time:
                if tv == nil {
                    break
                }
                tmp[k] = tv.Format(rfc3339NanoFixed)
            case time.Time:
                if tv.IsZero() {
                    tmp[k] = nil
                } else {
                    tmp[k] = tv.Format(rfc3339NanoFixed)
                }

Ok, so for the record: The original issue of getting a different etag field isn't because controller rewrites the dates in different format, but because the same collection is retrieved via different endpoints, and one of them doesn't include manifest_text so of course the digest changes.

69221de9db77ccb68f8d744e5d2dceeef963ae36 should fix this