Merge pull request #2 from leprechaun/region-filtering

feature(regions): Adding support for limiting the regions we query

README.md

@@ -41,6 +41,8 @@ Usage of ./spot-price-exporter:
         Comma separated list of AWS partitions. Accepted values: aws, aws-cn, aws-us-gov (default "aws")
   -product-descriptions string
         Comma separated list of product descriptions. Accepted values: Linux/UNIX, SUSE Linux, Windows, Linux/UNIX (Amazon VPC), SUSE Linux (Amazon VPC), Windows (Amazon VPC) (default "Linux/UNIX")
+  -regions string
+        Comma separated list of AWS regions to get pricing for (defaults to *all*)
 ```
 
 ### Example metrics

exporter/exporter.go

@@ -19,6 +19,7 @@ type Exporter struct {
 	session             *session.Session
 	partitions          []string
 	productDescriptions []string
+	regions []string
 	duration            prometheus.Gauge
 	scrapeErrors        prometheus.Gauge
 	totalScrapes        prometheus.Counter
@@ -36,8 +37,8 @@ type scrapeResult struct {
 	ProductDescription string
 }
 
-// NewExporter returns a new exporter of AWS Autoscaling group metrics.
-func NewExporter(p []string, pds []string) (*Exporter, error) {
+// NewExporter returns a new exporter of AWS Spot Price metrics.
+func NewExporter(p []string, pds []string, regions []string) (*Exporter, error) {
 
 	session, err := session.NewSession()
 	if err != nil {
@@ -49,6 +50,7 @@ func NewExporter(p []string, pds []string) (*Exporter, error) {
 		session:             session,
 		partitions:          p,
 		productDescriptions: pds,
+		regions: regions,
 		duration: prometheus.NewGauge(prometheus.GaugeOpts{
 			Namespace: "aws_spot",
 			Name:      "scrape_duration_seconds",
@@ -123,9 +125,17 @@ func (e *Exporter) scrape(scrapes chan<- scrapeResult) {
 		if !e.inPartitions(p.ID()) {
 			continue
 		}
-		log.Infof("querying spot prices in all regions [partition=%s]", p.ID())
+		log.Infof("querying spot prices in each region [partition=%s]", p.ID())
 		var wg sync.WaitGroup
 		for _, r := range p.Regions() {
+			// Skip regions we don't care about, if we specified any we do
+			if len(e.regions) > 0 {
+				if !e.inRegions(r.ID()) {
+					log.Debugf("Skipping region %s", r.ID())
+					continue
+				}
+			}
+
 			log.Debugf("querying spot prices [region=%s]", r.ID())
 			wg.Add(1)
 			go func(r string) {
@@ -203,3 +213,12 @@ func (e *Exporter) inPartitions(p string) bool {
 	}
 	return false
 }
+
+func (e *Exporter) inRegions(r string) bool {
+	for _, region := range e.regions {
+		if r == region {
+			return true
+		}
+	}
+	return false
+}

main.go

@@ -17,6 +17,7 @@ var (
 	rawLevel            = flag.String("log-level", "info", "log level")
 	partitions          = flag.String("partitions", "aws", "Comma separated list of AWS partitions. Accepted values: aws, aws-cn, aws-us-gov")
 	productDescriptions = flag.String("product-descriptions", "Linux/UNIX", "Comma separated list of product descriptions. Accepted values: Linux/UNIX, SUSE Linux, Windows, Linux/UNIX (Amazon VPC), SUSE Linux (Amazon VPC), Windows (Amazon VPC)")
+	regions = flag.String("regions", "", "Comma separated list of AWS regions to get pricing for (defaults to *all*)")
 )
 
 func init() {
@@ -34,9 +35,10 @@ func main() {
 	log.Infof("Starting AWS Spot Price exporter. [log-level=%s, partitions=%s, product-descriptions=%s]", *rawLevel, *partitions, *productDescriptions)
 	parts := splitAndTrim(*partitions)
 	pds := splitAndTrim(*productDescriptions)
+	regions := splitAndTrim(*regions)
 	validatePartitions(parts)
 	validateProductDesc(pds)
-	exporter, err := exporter.NewExporter(parts, pds)
+	exporter, err := exporter.NewExporter(parts, pds, regions)
 	if err != nil {
 		log.Fatal(err)
 	}