Provide full SD configs to discovery constructors.

Some SD configs may have many options. To be readable and consistent, make
all discovery constructors receive the full config rather than the separate
arguments.

retrieval/discovery/dns.go

@@ -70,11 +70,11 @@ type DNSDiscovery struct {
 }
 
 // NewDNSDiscovery returns a new DNSDiscovery which periodically refreshes its targets.
-func NewDNSDiscovery(names []string, refreshInterval time.Duration) *DNSDiscovery {
+func NewDNSDiscovery(conf *config.DNSSDConfig) *DNSDiscovery {
 	return &DNSDiscovery{
-		names:  names,
+		names:  conf.Names,
 		done:   make(chan struct{}),
-		ticker: time.NewTicker(refreshInterval),
+		ticker: time.NewTicker(time.Duration(conf.RefreshInterval)),
 	}
 }
 

retrieval/discovery/file.go

@@ -44,13 +44,12 @@ type FileDiscovery struct {
 }
 
 // NewFileDiscovery returns a new file discovery for the given paths.
-func NewFileDiscovery(paths []string, interval time.Duration) *FileDiscovery {
-	fd := &FileDiscovery{
-		paths:    paths,
-		interval: interval,
+func NewFileDiscovery(conf *config.FileSDConfig) *FileDiscovery {
+	return &FileDiscovery{
+		paths:    conf.Names,
+		interval: time.Duration(conf.RefreshInterval),
 		done:     make(chan struct{}),
 	}
-	return fd
 }
 
 // Sources implements the TargetProvider interface.

retrieval/discovery/file_test.go

@@ -20,7 +20,11 @@ func TestFileSD(t *testing.T) {
 func testFileSD(t *testing.T, ext string) {
 	// As interval refreshing is more of a fallback, we only want to test
 	// whether file watches work as expected.
-	fsd := NewFileDiscovery([]string{"fixtures/_*" + ext}, 1*time.Hour)
+	var conf config.FileSDConfig
+	conf.Names = []string{"fixtures/_*" + ext}
+	conf.RefreshInterval = config.Duration(1 * time.Hour)
+
+	fsd := NewFileDiscovery(&conf)
 
 	ch := make(chan *config.TargetGroup)
 	go fsd.Run(ch)

retrieval/targetmanager.go

@@ -17,7 +17,6 @@ import (
 	"fmt"
 	"strings"
 	"sync"
-	"time"
 
 	"github.com/golang/glog"
 
@@ -356,13 +355,11 @@ func (tm *TargetManager) targetsFromGroup(tg *config.TargetGroup, cfg *config.Sc
 func ProvidersFromConfig(cfg *config.ScrapeConfig) []TargetProvider {
 	var providers []TargetProvider
 
-	for _, dnscfg := range cfg.DNSSDConfigs {
-		dnsSD := discovery.NewDNSDiscovery(dnscfg.Names, time.Duration(dnscfg.RefreshInterval))
-		providers = append(providers, dnsSD)
+	for _, c := range cfg.DNSSDConfigs {
+		providers = append(providers, discovery.NewDNSDiscovery(c))
 	}
-	for _, filecfg := range cfg.FileSDConfigs {
-		fileSD := discovery.NewFileDiscovery(filecfg.Names, time.Duration(filecfg.RefreshInterval))
-		providers = append(providers, fileSD)
+	for _, c := range cfg.FileSDConfigs {
+		providers = append(providers, discovery.NewFileDiscovery(c))
 	}
 	if len(cfg.TargetGroups) > 0 {
 		providers = append(providers, NewStaticProvider(cfg.TargetGroups))