lib/controller/router/response.go

   1 // Copyright (C) The Arvados Authors. All rights reserved.
   2 //
   3 // SPDX-License-Identifier: AGPL-3.0
   4
   5 package router
   6
   7 import (
   8         "encoding/json"
   9         "fmt"
  10         "net/http"
  11         "regexp"
  12         "strings"
  13         "time"
  14
  15         "git.arvados.org/arvados.git/sdk/go/arvados"
  16         "git.arvados.org/arvados.git/sdk/go/httpserver"
  17 )
  18
  19 const rfc3339NanoFixed = "2006-01-02T15:04:05.000000000Z07:00"
  20
  21 type responseOptions struct {
  22         Select []string
  23         Count  string
  24 }
  25
  26 func (rtr *router) responseOptions(opts interface{}) (responseOptions, error) {
  27         var rOpts responseOptions
  28         switch opts := opts.(type) {
  29         case *arvados.GetOptions:
  30                 rOpts.Select = opts.Select
  31         case *arvados.ListOptions:
  32                 rOpts.Select = opts.Select
  33                 rOpts.Count = opts.Count
  34         }
  35         return rOpts, nil
  36 }
  37
  38 func applySelectParam(selectParam []string, orig map[string]interface{}) map[string]interface{} {
  39         if len(selectParam) == 0 {
  40                 return orig
  41         }
  42         selected := map[string]interface{}{}
  43         for _, attr := range selectParam {
  44                 if v, ok := orig[attr]; ok {
  45                         selected[attr] = v
  46                 }
  47         }
  48         // Some keys are always preserved, even if not requested
  49         for _, k := range []string{"etag", "kind", "writable_by"} {
  50                 if v, ok := orig[k]; ok {
  51                         selected[k] = v
  52                 }
  53         }
  54         return selected
  55 }
  56
  57 func (rtr *router) sendResponse(w http.ResponseWriter, req *http.Request, resp interface{}, opts responseOptions) {
  58         var tmp map[string]interface{}
  59
  60         if resp, ok := resp.(http.Handler); ok {
  61                 // resp knows how to write its own http response
  62                 // header and body.
  63                 resp.ServeHTTP(w, req)
  64                 return
  65         }
  66
  67         err := rtr.transcode(resp, &tmp)
  68         if err != nil {
  69                 rtr.sendError(w, err)
  70                 return
  71         }
  72
  73         respKind := kind(resp)
  74         if respKind != "" {
  75                 tmp["kind"] = respKind
  76         }
  77         defaultItemKind := ""
  78         if strings.HasSuffix(respKind, "List") {
  79                 defaultItemKind = strings.TrimSuffix(respKind, "List")
  80         }
  81
  82         if items, ok := tmp["items"].([]interface{}); ok {
  83                 for i, item := range items {
  84                         // Fill in "kind" by inspecting UUID/PDH if
  85                         // possible; fall back on assuming each
  86                         // Items[] entry in an "arvados#fooList"
  87                         // response should have kind="arvados#foo".
  88                         item, _ := item.(map[string]interface{})
  89                         infix := ""
  90                         if uuid, _ := item["uuid"].(string); len(uuid) == 27 {
  91                                 infix = uuid[6:11]
  92                         }
  93                         if k := kind(infixMap[infix]); k != "" {
  94                                 item["kind"] = k
  95                         } else if pdh, _ := item["portable_data_hash"].(string); pdh != "" {
  96                                 item["kind"] = "arvados#collection"
  97                         } else if defaultItemKind != "" {
  98                                 item["kind"] = defaultItemKind
  99                         }
 100                         item = applySelectParam(opts.Select, item)
 101                         rtr.mungeItemFields(item)
 102                         items[i] = item
 103                 }
 104                 if opts.Count == "none" {
 105                         delete(tmp, "items_available")
 106                 }
 107         } else {
 108                 tmp = applySelectParam(opts.Select, tmp)
 109                 rtr.mungeItemFields(tmp)
 110         }
 111
 112         w.Header().Set("Content-Type", "application/json")
 113         enc := json.NewEncoder(w)
 114         enc.SetEscapeHTML(false)
 115         enc.Encode(tmp)
 116 }
 117
 118 func (rtr *router) sendError(w http.ResponseWriter, err error) {
 119         code := http.StatusInternalServerError
 120         if err, ok := err.(interface{ HTTPStatus() int }); ok {
 121                 code = err.HTTPStatus()
 122         }
 123         httpserver.Error(w, err.Error(), code)
 124 }
 125
 126 var infixMap = map[string]interface{}{
 127         "4zz18": arvados.Collection{},
 128         "j7d0g": arvados.Group{},
 129 }
 130
 131 var mungeKind = regexp.MustCompile(`\..`)
 132
 133 func kind(resp interface{}) string {
 134         t := fmt.Sprintf("%T", resp)
 135         if !strings.HasPrefix(t, "arvados.") {
 136                 return ""
 137         }
 138         return mungeKind.ReplaceAllStringFunc(t, func(s string) string {
 139                 // "arvados.CollectionList" => "arvados#collectionList"
 140                 return "#" + strings.ToLower(s[1:])
 141         })
 142 }
 143
 144 func (rtr *router) mungeItemFields(tmp map[string]interface{}) {
 145         for k, v := range tmp {
 146                 if strings.HasSuffix(k, "_at") {
 147                         // Format non-nil timestamps as
 148                         // rfc3339NanoFixed (otherwise they would use
 149                         // the default time encoding, which omits
 150                         // trailing zeroes).
 151                         switch tv := v.(type) {
 152                         case *time.Time:
 153                                 if tv == nil || tv.IsZero() {
 154                                         tmp[k] = nil
 155                                 } else {
 156                                         tmp[k] = tv.Format(rfc3339NanoFixed)
 157                                 }
 158                         case time.Time:
 159                                 if tv.IsZero() {
 160                                         tmp[k] = nil
 161                                 } else {
 162                                         tmp[k] = tv.Format(rfc3339NanoFixed)
 163                                 }
 164                         case string:
 165                                 if tv == "" {
 166                                         tmp[k] = nil
 167                                 } else if t, err := time.Parse(time.RFC3339Nano, tv); err != nil {
 168                                         // pass through an invalid time value (?)
 169                                 } else if t.IsZero() {
 170                                         tmp[k] = nil
 171                                 } else {
 172                                         tmp[k] = t.Format(rfc3339NanoFixed)
 173                                 }
 174                         }
 175                 }
 176                 // Arvados API spec says when these fields are empty
 177                 // they appear in responses as null, rather than a
 178                 // zero value.
 179                 switch k {
 180                 case "output_uuid", "output_name", "log_uuid", "description", "requesting_container_uuid", "container_uuid":
 181                         if v == "" {
 182                                 tmp[k] = nil
 183                         }
 184                 case "container_count_max":
 185                         if v == float64(0) {
 186                                 tmp[k] = nil
 187                         }
 188                 }
 189         }
 190 }