Merge pull request #662 from prometheus/fabxc/sd_cfg

Cleanup, test, and document config.

config/config.go

@@ -29,8 +29,10 @@ import (
 	pb "github.com/prometheus/prometheus/config/generated"
 )
 
-var jobNameRE = regexp.MustCompile("^[a-zA-Z_][a-zA-Z0-9_-]*$")
-var labelNameRE = regexp.MustCompile("^[a-zA-Z_][a-zA-Z0-9_]*$")
+var (
+	jobNameRE   = regexp.MustCompile("^[a-zA-Z_][a-zA-Z0-9_-]*$")
+	labelNameRE = regexp.MustCompile("^[a-zA-Z_][a-zA-Z0-9_]*$")
+)
 
 // Config encapsulates the configuration of a Prometheus instance. It wraps the
 // raw configuration protocol buffer to be able to add custom methods to it.
@@ -232,15 +234,17 @@ func (c *DNSConfig) Validate() error {
 	return nil
 }
 
-// SDRefreshInterval gets the the SD refresh interval for the scrape config.
+// RefreshInterval gets the the refresh interval for DNS service discovery.
 func (c *DNSConfig) RefreshInterval() time.Duration {
 	return stringToDuration(c.GetRefreshInterval())
 }
 
+// RelabelConfig encapsulates the protobuf configuration object for relabeling.
 type RelabelConfig struct {
 	pb.RelabelConfig
 }
 
+// Validate checks the RelabelConfig for the validity of its fields.
 func (c *RelabelConfig) Validate() error {
 	if len(c.GetSourceLabel()) == 0 {
 		return errors.New("at least one source label is required")

config/config_test.go

@@ -34,8 +34,9 @@ var configTests = []struct {
 		inputFile: "empty.conf.input",
 	}, {
 		inputFile: "sd_targets.conf.input",
-	},
-	{
+	}, {
+		inputFile: "full.conf.input",
+	}, {
 		inputFile:   "invalid_proto_format.conf.input",
 		shouldFail:  true,
 		errContains: "unknown field name",

config/fixtures/full.conf.input

@@ -0,0 +1,89 @@
+global <
+  scrape_interval: "30s"
+  evaluation_interval: "30s"
+  labels: <
+    label: <
+      name: "monitor"
+      value: "test"
+    >
+    label: <
+      name: "more"
+      value: "test"
+    >
+  >
+  rule_file: "prometheus.rules"
+  rule_file: "prometheus.more.rules"
+>
+
+scrape_config: <
+  job_name: "prometheus"
+  scrape_interval: "15s"
+  metrics_path: "/metrics"
+  scheme: "http"
+
+  target_group: <
+    target: "localhost:9090"
+  >
+>
+
+scrape_config: <
+  job_name: "myjob"
+  scrape_interval: "15s"
+  metrics_path: "/metrics"
+  scheme: "http"
+
+  dns_config: <
+    name: "first.srv.name"
+    name: "second.srv.name"
+    refresh_interval: "1h"
+  >
+
+  dns_config: <
+    name: "first2.srv.name"
+    name: "second2.srv.name"
+    refresh_interval: "1m"
+  >
+
+  relabel_config: <
+    source_label: "l1"
+    source_label: "l2"
+    regex: "^foobar.*$"
+    target_label: "l3"
+    replacement: "static"
+  >
+  relabel_config: <
+    source_label: "l4"
+    regex: "^foobar.*$"
+    action: DROP
+  >
+  relabel_config: <
+    source_label: "l4"
+    regex: "^foobar.*$"
+    action: KEEP
+  >
+
+  target_group: <
+    target: "localhost:9090"
+    target: "localhost:9091"
+    labels: <
+      label: <
+        name: "tg1"
+        value: "tg1"
+      >
+    >
+  > 
+  target_group: <
+    target: "my.domain:9090"
+    target: "my.domain:9091"
+    labels: <
+      label: <
+        name: "tg2"
+        value: "tg2"
+      >
+      label: <
+        name: "tg2_1"
+        value: "tg2_1"
+      >
+    >
+  >
+>

config/fixtures/sd_targets.conf.input

@@ -2,5 +2,7 @@ scrape_config: <
   job_name: "testjob"
   dns_config: <
   	name: "sd_name"
+  	name: "sd_name2"
+  	refresh_interval: "15s"
   >
 >

config/load.go

@@ -22,10 +22,10 @@ import (
 )
 
 // LoadFromString returns a config parsed from the provided string.
-func LoadFromString(configStr string) (Config, error) {
+func LoadFromString(configStr string) (*Config, error) {
 	configProto := pb.PrometheusConfig{}
 	if err := proto.UnmarshalText(configStr, &configProto); err != nil {
-		return Config{}, err
+		return nil, err
 	}
 	if configProto.Global == nil {
 		configProto.Global = &pb.GlobalConfig{}
@@ -36,17 +36,17 @@ func LoadFromString(configStr string) (Config, error) {
 		}
 	}
 
-	config := Config{configProto}
+	config := &Config{configProto}
 	err := config.Validate()
 
 	return config, err
 }
 
 // LoadFromFile returns a config parsed from the file of the provided name.
-func LoadFromFile(fileName string) (Config, error) {
+func LoadFromFile(fileName string) (*Config, error) {
 	configStr, err := ioutil.ReadFile(fileName)
 	if err != nil {
-		return Config{}, err
+		return nil, err
 	}
 
 	return LoadFromString(string(configStr))

config/load_test.go

@@ -20,6 +20,6 @@ import (
 func TestLoadFromFile(t *testing.T) {
 	_, err := LoadFromFile("file-does-not-exist.conf")
 	if err == nil {
-		t.Error(err)
+		t.Error("Error expected on non-existing config file path but got none")
 	}
 }

retrieval/targetmanager.go

@@ -63,7 +63,7 @@ type TargetManager struct {
 }
 
 // NewTargetManager creates a new TargetManager based on the given config.
-func NewTargetManager(cfg config.Config, sampleAppender storage.SampleAppender) (*TargetManager, error) {
+func NewTargetManager(cfg *config.Config, sampleAppender storage.SampleAppender) (*TargetManager, error) {
 	tm := &TargetManager{
 		sampleAppender: sampleAppender,
 		targets:        make(map[string][]Target),
@@ -273,7 +273,7 @@ func (tm *TargetManager) Pools() map[string][]Target {
 
 // ApplyConfig resets the manager's target providers and job configurations as defined
 // by the new cfg. The state of targets that are valid in the new configuration remains unchanged.
-func (tm *TargetManager) ApplyConfig(cfg config.Config) error {
+func (tm *TargetManager) ApplyConfig(cfg *config.Config) error {
 	tm.stop(false)
 	// Even if updating the config failed, we want to continue rather than stop scraping anything.
 	defer tm.Run()
@@ -285,7 +285,7 @@ func (tm *TargetManager) ApplyConfig(cfg config.Config) error {
 	return nil
 }
 
-func (tm *TargetManager) applyConfig(cfg config.Config) error {
+func (tm *TargetManager) applyConfig(cfg *config.Config) error {
 	// Only apply changes if everything was successful.
 	providers := map[*config.ScrapeConfig][]TargetProvider{}
 

retrieval/targetmanager_test.go

@@ -262,7 +262,7 @@ func TestTargetManagerConfigUpdate(t *testing.T) {
 		},
 	}
 
-	targetManager, err := NewTargetManager(config.Config{}, nopAppender{})
+	targetManager, err := NewTargetManager(&config.Config{}, nopAppender{})
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -273,7 +273,7 @@ func TestTargetManagerConfigUpdate(t *testing.T) {
 		cfg := pb.PrometheusConfig{
 			ScrapeConfig: step.scrapeConfigs,
 		}
-		err := targetManager.ApplyConfig(config.Config{cfg})
+		err := targetManager.ApplyConfig(&config.Config{cfg})
 		if err != nil {
 			t.Fatal(err)
 		}

rules/manager/manager.go

@@ -74,7 +74,7 @@ func init() {
 // NewRuleManager.
 type RuleManager interface {
 	// Load and add rules from rule files specified in the configuration.
-	AddRulesFromConfig(config config.Config) error
+	AddRulesFromConfig(config *config.Config) error
 	// Start the rule manager's periodic rule evaluation.
 	Run()
 	// Stop the rule manager's rule evaluation cycles.
@@ -267,7 +267,7 @@ func (m *ruleManager) runIteration() {
 	wg.Wait()
 }
 
-func (m *ruleManager) AddRulesFromConfig(config config.Config) error {
+func (m *ruleManager) AddRulesFromConfig(config *config.Config) error {
 	for _, ruleFile := range config.Global.RuleFile {
 		newRules, err := rules.LoadRulesFromFile(ruleFile)
 		if err != nil {