From 79216011cb72be07ab760ede71bf96c2bc3b4bd1 Mon Sep 17 00:00:00 2001
From: Dan Milstein <milstein.dan@gmail.com>
Date: Thu, 25 Aug 2016 14:36:26 -0400
Subject: [PATCH] Add basic test for TargetManager.targetSet

Verify that if the configs change, target groups are cleaned on
TargetManager.reload (rather than having old ones linger around, even if
they are no longer present in the configs).

This covers the bug fixed in #1907 -- I verified that by checking out
source from before that commit.

This is a start on #1906
---
 retrieval/targetmanager_test.go | 60 +++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)

diff --git a/retrieval/targetmanager_test.go b/retrieval/targetmanager_test.go
index 074fe51ecd..e9d4544c36 100644
--- a/retrieval/targetmanager_test.go
+++ b/retrieval/targetmanager_test.go
@@ -12,3 +12,63 @@
 // limitations under the License.
 
 package retrieval
+
+import (
+	"testing"
+
+	"golang.org/x/net/context"
+	"gopkg.in/yaml.v2"
+
+	"github.com/prometheus/prometheus/config"
+	"github.com/prometheus/prometheus/storage/local"
+)
+
+func TestTargetSetRecreatesTargetGroupsEveryRun(t *testing.T) {
+	scrapeConfig := &config.ScrapeConfig{}
+
+	sOne := `
+job_name: "foo"
+dns_sd_configs:
+- names:
+  - "srv.name.one.example.org"
+`
+	if err := yaml.Unmarshal([]byte(sOne), scrapeConfig); err != nil {
+		t.Fatalf("Unable to load YAML config sOne: %s", err)
+	}
+
+	// Not properly setting it up, but that seems okay
+	mss := &local.MemorySeriesStorage{}
+
+	ts := newTargetSet(scrapeConfig, mss)
+
+	ts.runProviders(context.Background(), providersFromConfig(scrapeConfig))
+
+	verifyPresence(t, ts.tgroups, "dns/0/srv.name.one.example.org", true)
+
+	sTwo := `
+job_name: "foo"
+dns_sd_configs:
+- names:
+  - "srv.name.two.example.org"
+`
+	if err := yaml.Unmarshal([]byte(sTwo), scrapeConfig); err != nil {
+		t.Fatalf("Unable to load YAML config sTwo: %s", err)
+	}
+
+	ts.runProviders(context.Background(), providersFromConfig(scrapeConfig))
+
+	verifyPresence(t, ts.tgroups, "dns/0/srv.name.one.example.org", false)
+	verifyPresence(t, ts.tgroups, "dns/0/srv.name.two.example.org", true)
+
+}
+
+func verifyPresence(t *testing.T, tgroups map[string][]*Target, name string, present bool) {
+	if _, ok := tgroups[name]; ok != present {
+		msg := ""
+		if !present {
+			msg = "not "
+		}
+		t.Fatalf("'%s' should %sbe present in TargetSet.tgroups: %s", name, msg, tgroups)
+	}
+
+}