SPIN1305: Add custom date range queries (#7)

* add route for cost-explorer date range for GET, expand key for cache to enable multiple date range objects to be cached.

* add comment to add date range unit test, updated README, etc.

* updates, added input cleansing, and good API errors when input is bad

* added endpoint querystring for StartTime, EndTime to readme

* changes per PR review

* cleaned up logic per PR

* cleaned up debug statements

* clean up time to string conversion

* refactored new code into smaller functions, built unit tests for new code

* sort out unwrapping time errors back to client caller, adding tests for dates

* updated with PR suggestions

* nit

* moar nits

README.md

@@ -10,6 +10,7 @@ GET /v1/cost/version
 GET /v1/cost/metrics
 
 GET /v1/cost/{account}/spaces/{spaceid}
+GET /v1/cost/{account}/spaces/{spaceid}[?StartTime=2019-10-01&EndTime=2019-10-30]
 ```
 
 ## Usage

api/handlers_spaces.go

@@ -15,12 +15,59 @@ import (
 	log "github.com/sirupsen/logrus"
 )
 
+// getTimeDefault returns time range from beginning of month to day-of-month now
+func getTimeDefault() (string, string) {
+	// if it's the first day of the month, get today's usage thus far
+	y, m, d := time.Now().Date()
+	if d == 1 {
+		d = 3
+	}
+	return fmt.Sprintf("%d-%02d-01", y, m), fmt.Sprintf("%d-%02d-%02d", y, m, d)
+}
+
+// getTimeAPI returns time parsed from API input
+func getTimeAPI(startTime, endTime string) (string, string, error) {
+	log.Debugf("startTime: %s, endTime: %s ", startTime, endTime)
+
+	// sTmp and eTmp temporary vars to hold time.Time objects
+	sTmp, err := time.Parse("2006-01-02", startTime)
+	if err != nil {
+		return "", "", errors.Wrapf(err, "error parsing StartTime from input")
+	}
+
+	eTmp, err := time.Parse("2006-01-02", endTime)
+	if err != nil {
+		return "", "", errors.Wrapf(err, "error parsing EndTime from input")
+	}
+
+	// if time on the API input is already borked, don't continue
+	// end time is greater than start time, logically
+	timeValidity := eTmp.After(sTmp)
+	if !timeValidity {
+		return "", "", errors.Errorf("endTime should be greater than startTime")
+	}
+
+	// convert time.Time to a string
+	return sTmp.Format("2006-01-02"), eTmp.Format("2006-01-02"), nil
+}
+
 // SpaceGetHandler gets the cost for a space, grouped by the service.  By default,
 // it pulls data from the start of the month until now.
 func (s *server) SpaceGetHandler(w http.ResponseWriter, r *http.Request) {
 	w = LogWriter{w}
+
+	// loop thru and log given API input vars in debug
 	vars := mux.Vars(r)
+	for k, v := range vars {
+		log.Debugf("key=%v, value=%v", k, v)
+	}
+
+	// get vars from the API route
 	account := vars["account"]
+	startTime := vars["StartTime"]
+	endTime := vars["EndTime"]
+	spaceID := vars["space"]
+
 	ceService, ok := s.costExplorerServices[account]
 	if !ok {
 		msg := fmt.Sprintf("cost explorer service not found for account: %s", account)
@@ -37,15 +84,24 @@ func (s *server) SpaceGetHandler(w http.ResponseWriter, r *http.Request) {
 	}
 	log.Debugf("found cost explorer result cache %+v", *resultCache)
 
-	spaceID := vars["space"]
-	log.Debugf("getting costs for space %s", spaceID)
-
-	y, m, d := time.Now().Date()
+	// vars for checking input times parse and are valid
+	var start string
+	var end string
+	var err error
 
-	// if it's the first day of the month, get todays usage thus far
-	if d == 1 {
-		d = 2
+	// Did we get cost-explorer start and end times on the API?
+	// set defaults, else verify times given on API
+	if endTime == "" || startTime == "" {
+		log.Debug("no start or end time given on API input, assigning defaults")
+		start, end = getTimeDefault()
+	} else {
+		start, end, err = getTimeAPI(startTime, endTime)
+		if err != nil {
+			handleError(w, err)
+			return
+		}
 	}
+
 	input := costexplorer.GetCostAndUsageInput{
 		Filter: &costexplorer.Expression{
 			And: []*costexplorer.Expression{
@@ -108,27 +164,33 @@ func (s *server) SpaceGetHandler(w http.ResponseWriter, r *http.Request) {
 			aws.String("USAGE_QUANTITY"),
 		},
 		TimePeriod: &costexplorer.DateInterval{
-			End:   aws.String(fmt.Sprintf("%d-%02d-%02d", y, m, d)),
-			Start: aws.String(fmt.Sprintf("%d-%02d-01", y, m)),
+			Start: aws.String(start),
+			End:   aws.String(end),
 		},
 	}
 
+	// create a cacheKey more unique than spaceID for managing cache objects.
+	// Since we will accept date-range cost exploring, concatenate the spaceID
+	// and the start and end time so we can cache each time-based result
+	cacheKey := fmt.Sprintf("%s_%s_%s", spaceID, startTime, endTime)
+	log.Debugf("cacheKey: %s", cacheKey)
+
 	// the object is not found in the cache, call AWS cost-explorer and set cache
 	var out []*costexplorer.ResultByTime
-	c, expire, ok := resultCache.GetWithExpiration(spaceID)
+	c, expire, ok := resultCache.GetWithExpiration(cacheKey)
 	if !ok || c == nil {
-		log.Debugf("cache empty for org, space: %s, %s, calling cost-explorer", Org, spaceID)
+		log.Debugf("cache empty for org, and space-cacheKey: %s, %s, calling cost-explorer", Org, cacheKey)
 		// call cost-explorer
 		var err error
 		out, err = ceService.GetCostAndUsage(r.Context(), &input)
 		if err != nil {
-			msg := fmt.Sprintf("failed to get costs for space %s: %s", spaceID, err.Error())
+			msg := fmt.Sprintf("failed to get costs for space %s: %s", cacheKey, err.Error())
 			handleError(w, errors.Wrap(err, msg))
 			return
 		}
 
 		// cache results
-		resultCache.SetDefault(spaceID, out)
+		resultCache.SetDefault(cacheKey, out)
 	} else {
 		// cached object was found
 		out = c.([]*costexplorer.ResultByTime)
@@ -147,4 +209,5 @@ func (s *server) SpaceGetHandler(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Type", "application/json")
 	w.WriteHeader(http.StatusOK)
 	w.Write(j)
+
 }

api/handlers_spaces_test.go

@@ -0,0 +1,110 @@
+package api
+
+import (
+	"fmt"
+	"testing"
+	"time"
+)
+
+func TestGetTimeDefault(t *testing.T) {
+	// use defaults derived in code
+	startTime, endTime := getTimeDefault()
+
+	// tests should match defaults from getTimeDefault
+	y, m, d := time.Now().Date()
+	if d == 1 {
+		d = 5
+	}
+
+	sTime := fmt.Sprintf("%d-%02d-01", y, m)
+	eTime := fmt.Sprintf("%d-%02d-%02d", y, m, d)
+
+	if startTime == sTime {
+		t.Logf("got expected default sTime: %s\n", sTime)
+	} else {
+		t.Errorf("got unexpected sTime: %s\n", sTime)
+	}
+	if endTime == eTime {
+		t.Logf("got expected default eTime: %s\n", eTime)
+	} else {
+		t.Errorf("got unexpected eTime: %s\n", eTime)
+	}
+
+	// negative tests for non-matching defaults from getTimeDefault
+	sTime = fmt.Sprint("2006-01-02")
+	eTime = fmt.Sprint("2006-13-40")
+
+	if startTime != sTime {
+		t.Logf("negative test sTime: %s does not match: %s", sTime, startTime)
+	} else {
+		t.Errorf("got unexpected sTime: %s\n", sTime)
+	}
+	if endTime != eTime {
+		t.Logf("negative test eTime: %s does not match: %s", eTime, endTime)
+	} else {
+		t.Errorf("got unexpected eTime: %s\n", eTime)
+	}
+
+}
+
+func TestGetTimeAPI(t *testing.T) {
+	startTime := "2019-11-01"
+	endTime := "2019-11-30"
+
+	startResult, endResult, err := getTimeAPI(startTime, endTime)
+	if err != nil {
+		t.Errorf("got unexpected error: %s", err)
+	}
+	if startResult == startTime {
+		t.Logf("got expected startResult from getTimeAPI: %s", startResult)
+	}
+	if endResult == endTime {
+		t.Logf("got expected endResult from getTimeAPI: %s", endResult)
+	}
+
+	// negative tests for non-matching API inputs from getTimeDefault
+	// bad start time fails
+	sTime := fmt.Sprint("2006-01-022")
+	eTime := fmt.Sprint("2006-12-02")
+
+	neg00startResult, neg00endResult, err := getTimeAPI(sTime, eTime)
+	if err != nil {
+		t.Logf("negative test got expected error: %s", err)
+	}
+	if neg00startResult == startTime {
+		t.Logf("negative test expected neg00_startResult from getTimeAPI: %s", neg00startResult)
+	}
+	if neg00endResult == endTime {
+		t.Logf("negative test got expected neg00_endResult from getTimeAPI: %s", neg00endResult)
+	}
+
+	// bad end time fails
+	sTime = fmt.Sprint("2006-01-02")
+	eTime = fmt.Sprint("2006-12-403")
+
+	neg01startResult, neg01endResult, err := getTimeAPI(sTime, eTime)
+	if err != nil {
+		t.Logf("negative test got expected error: %s", err)
+	}
+	if neg01startResult == "" {
+		t.Logf("negative test expected empty neg01startResult: %s", neg01startResult)
+	}
+	if neg01endResult == endTime {
+		t.Logf("negative test got expected neg01endResult from getTimeAPI: %s", neg01endResult)
+	}
+
+	// start after end fails
+	sTime = fmt.Sprint("2006-01-30")
+	eTime = fmt.Sprint("2006-01-01")
+
+	neg02startResult, neg02endResult, err := getTimeAPI(sTime, eTime)
+	if err != nil {
+		t.Logf("negative test got expected error for start after end : %s", err)
+	}
+	if neg02startResult == startTime {
+		t.Logf("negative test expected neg02startResult from getTimeAPI: %s", neg02startResult)
+	}
+	if neg02endResult == endTime {
+		t.Logf("negative test got expected neg02endResult from getTimeAPI: %s", neg02endResult)
+	}
+}

api/routes.go

@@ -12,5 +12,8 @@ func (s *server) routes() {
 	api.HandleFunc("/version", s.VersionHandler).Methods(http.MethodGet)
 	api.Handle("/metrics", promhttp.Handler()).Methods(http.MethodGet)
 
+	api.HandleFunc("/{account}/spaces/{space}", s.SpaceGetHandler).
+		Queries("EndTime", "{EndTime}", "StartTime", "{StartTime}").
+		Methods(http.MethodGet)
 	api.HandleFunc("/{account}/spaces/{space}", s.SpaceGetHandler).Methods(http.MethodGet)
 }

go.sum

@@ -23,6 +23,7 @@ github.com/jmespath/go-jmespath v0.0.0-20180206201540-c2b33e8439af h1:pmfjZENx5i
 github.com/jmespath/go-jmespath v0.0.0-20180206201540-c2b33e8439af/go.mod h1:Nht3zPeWKUH0NzdCt2Blrr5ys8VGpn0CEB0cQHVjt7k=
 github.com/json-iterator/go v1.1.6/go.mod h1:+SdeFBvtyEkXs7REEP0seUULqWtbJapLOCVDaaPEHmU=
 github.com/julienschmidt/httprouter v1.2.0/go.mod h1:SYymIcj16QtmaHHD7aYtjjsJG7VTCxuUUipMqKk8s4w=
+github.com/konsorten/go-windows-terminal-sequences v1.0.1 h1:mweAR1A6xJ3oS2pRaGiHgQ4OO8tzTaLawm8vnODuwDk=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
 github.com/kr/logfmt v0.0.0-20140226030751-b84e30acd515/go.mod h1:+0opPa2QZZtGFBFZlji/RkVcI2GknAs/DXo4wKdlNEc=
 github.com/matttproud/golang_protobuf_extensions v1.0.1 h1:4hp9jkHxhMHkqkrB3Ix0jegS5sx/RkqARlsWZ6pIwiU=