Merge pull request #773 from prometheus/fabxc/simple-cfg

config: simplify default config handling.

config/config.go

@@ -45,19 +45,19 @@ func LoadFromFile(filename string) (*Config, error) {
 // The defaults applied before parsing the respective config sections.
 var (
 	// The default top-level configuration.
-	DefaultConfig = DefaultedConfig{
+	DefaultConfig = Config{
-		GlobalConfig: &GlobalConfig{DefaultGlobalConfig},
+		GlobalConfig: DefaultGlobalConfig,
 	}
 
 	// The default global configuration.
-	DefaultGlobalConfig = DefaultedGlobalConfig{
+	DefaultGlobalConfig = GlobalConfig{
 		ScrapeInterval:     Duration(1 * time.Minute),
 		ScrapeTimeout:      Duration(10 * time.Second),
 		EvaluationInterval: Duration(1 * time.Minute),
 	}
 
-	// Te default scrape configuration.
+	// The default scrape configuration.
-	DefaultScrapeConfig = DefaultedScrapeConfig{
+	DefaultScrapeConfig = ScrapeConfig{
 		// ScrapeTimeout and ScrapeInterval default to the
 		// configured globals.
 		MetricsPath: "/metrics",
@@ -65,23 +65,23 @@ var (
 	}
 
 	// The default Relabel configuration.
-	DefaultRelabelConfig = DefaultedRelabelConfig{
+	DefaultRelabelConfig = RelabelConfig{
 		Action:    RelabelReplace,
 		Separator: ";",
 	}
 
 	// The default DNS SD configuration.
-	DefaultDNSSDConfig = DefaultedDNSSDConfig{
+	DefaultDNSSDConfig = DNSSDConfig{
 		RefreshInterval: Duration(30 * time.Second),
 	}
 
 	// The default file SD configuration.
-	DefaultFileSDConfig = DefaultedFileSDConfig{
+	DefaultFileSDConfig = FileSDConfig{
 		RefreshInterval: Duration(30 * time.Second),
 	}
 
 	// The default Consul SD configuration.
-	DefaultConsulSDConfig = DefaultedConsulSDConfig{
+	DefaultConsulSDConfig = ConsulSDConfig{
 		TagSeparator: ",",
 		Scheme:       "http",
 	}
@@ -89,8 +89,9 @@ var (
 
 // Config is the top-level configuration for Prometheus's config files.
 type Config struct {
-	// DefaultedConfig contains the actual fields of Config.
+	GlobalConfig  GlobalConfig    `yaml:"global"`
-	DefaultedConfig `yaml:",inline"`
+	RuleFiles     []string        `yaml:"rule_files,omitempty"`
+	ScrapeConfigs []*ScrapeConfig `yaml:"scrape_configs,omitempty"`
 
 	// original is the input from which the config was parsed.
 	original string
@@ -109,8 +110,12 @@ func (c Config) String() string {
 
 // UnmarshalYAML implements the yaml.Unmarshaler interface.
 func (c *Config) UnmarshalYAML(unmarshal func(interface{}) error) error {
-	c.DefaultedConfig = DefaultConfig
+	*c = DefaultConfig
-	if err := unmarshal(&c.DefaultedConfig); err != nil {
+	// We want to set c to the defaults and then overwrite it with the input.
+	// To make unmarshal fill the plain data struct rather than calling UnmarshalYAML
+	// again, we have to hide it using a type indirection.
+	type plain Config
+	if err := unmarshal((*plain)(c)); err != nil {
 		return err
 	}
 	for _, rf := range c.RuleFiles {
@@ -136,31 +141,9 @@ func (c *Config) UnmarshalYAML(unmarshal func(interface{}) error) error {
 	return nil
 }
 
-// DefaultedConfig is a proxy type for Config.
-type DefaultedConfig struct {
-	GlobalConfig  *GlobalConfig   `yaml:"global"`
-	RuleFiles     []string        `yaml:"rule_files,omitempty"`
-	ScrapeConfigs []*ScrapeConfig `yaml:"scrape_configs,omitempty"`
-}
-
 // GlobalConfig configures values that are used across other configuration
 // objects.
 type GlobalConfig struct {
-	// DefaultedGlobalConfig contains the actual fields for GlobalConfig.
-	DefaultedGlobalConfig `yaml:",inline"`
-}
-
-// UnmarshalYAML implements the yaml.Unmarshaler interface.
-func (c *GlobalConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
-	c.DefaultedGlobalConfig = DefaultGlobalConfig
-	if err := unmarshal(&c.DefaultedGlobalConfig); err != nil {
-		return err
-	}
-	return nil
-}
-
-// DefaultedGlobalConfig is a proxy type for GlobalConfig.
-type DefaultedGlobalConfig struct {
 	// How frequently to scrape targets by default.
 	ScrapeInterval Duration `yaml:"scrape_interval,omitempty"`
 	// The default timeout when scraping targets.
@@ -172,27 +155,18 @@ type DefaultedGlobalConfig struct {
 	Labels clientmodel.LabelSet `yaml:"labels,omitempty"`
 }
 
-// ScrapeConfig configures a scraping unit for Prometheus.
-type ScrapeConfig struct {
-	// DefaultedScrapeConfig contains the actual fields for ScrapeConfig.
-	DefaultedScrapeConfig `yaml:",inline"`
-}
-
 // UnmarshalYAML implements the yaml.Unmarshaler interface.
-func (c *ScrapeConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
+func (c *GlobalConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
-	c.DefaultedScrapeConfig = DefaultScrapeConfig
+	*c = DefaultGlobalConfig
-	err := unmarshal(&c.DefaultedScrapeConfig)
+	type plain GlobalConfig
-	if err != nil {
+	if err := unmarshal((*plain)(c)); err != nil {
 		return err
 	}
-	if !patJobName.MatchString(c.JobName) {
-		return fmt.Errorf("%q is not a valid job name", c.JobName)
-	}
 	return nil
 }
 
-// DefaultedScrapeConfig is a proxy type for ScrapeConfig.
+// ScrapeConfig configures a scraping unit for Prometheus.
-type DefaultedScrapeConfig struct {
+type ScrapeConfig struct {
 	// The job name to which the job label is set by default.
 	JobName string `yaml:"job_name"`
 	// How frequently to scrape the targets of this scrape config.
@@ -218,6 +192,20 @@ type DefaultedScrapeConfig struct {
 	RelabelConfigs []*RelabelConfig `yaml:"relabel_configs,omitempty"`
 }
 
+// UnmarshalYAML implements the yaml.Unmarshaler interface.
+func (c *ScrapeConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
+	*c = DefaultScrapeConfig
+	type plain ScrapeConfig
+	err := unmarshal((*plain)(c))
+	if err != nil {
+		return err
+	}
+	if !patJobName.MatchString(c.JobName) {
+		return fmt.Errorf("%q is not a valid job name", c.JobName)
+	}
+	return nil
+}
+
 // BasicAuth contains basic HTTP authentication credentials.
 type BasicAuth struct {
 	Username string `yaml:"username"`
@@ -301,14 +289,15 @@ func (tg *TargetGroup) UnmarshalJSON(b []byte) error {
 
 // DNSSDConfig is the configuration for DNS based service discovery.
 type DNSSDConfig struct {
-	// DefaultedDNSSDConfig contains the actual fields for DNSSDConfig.
+	Names           []string `yaml:"names"`
-	DefaultedDNSSDConfig `yaml:",inline"`
+	RefreshInterval Duration `yaml:"refresh_interval,omitempty"`
 }
 
 // UnmarshalYAML implements the yaml.Unmarshaler interface.
 func (c *DNSSDConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
-	c.DefaultedDNSSDConfig = DefaultDNSSDConfig
+	*c = DefaultDNSSDConfig
-	err := unmarshal(&c.DefaultedDNSSDConfig)
+	type plain DNSSDConfig
+	err := unmarshal((*plain)(c))
 	if err != nil {
 		return err
 	}
@@ -318,22 +307,17 @@ func (c *DNSSDConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
 	return nil
 }
 
-// DefaultedDNSSDConfig is a proxy type for DNSSDConfig.
+// FileSDConfig is the configuration for file based discovery.
-type DefaultedDNSSDConfig struct {
+type FileSDConfig struct {
 	Names           []string `yaml:"names"`
 	RefreshInterval Duration `yaml:"refresh_interval,omitempty"`
 }
 
-// FileSDConfig is the configuration for file based discovery.
-type FileSDConfig struct {
-	// DefaultedFileSDConfig contains the actual fields for FileSDConfig.
-	DefaultedFileSDConfig `yaml:",inline"`
-}
-
 // UnmarshalYAML implements the yaml.Unmarshaler interface.
 func (c *FileSDConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
-	c.DefaultedFileSDConfig = DefaultFileSDConfig
+	*c = DefaultFileSDConfig
-	err := unmarshal(&c.DefaultedFileSDConfig)
+	type plain FileSDConfig
+	err := unmarshal((*plain)(c))
 	if err != nil {
 		return err
 	}
@@ -348,22 +332,24 @@ func (c *FileSDConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
 	return nil
 }
 
-// DefaultedFileSDConfig is a proxy type for FileSDConfig.
-type DefaultedFileSDConfig struct {
-	Names           []string `yaml:"names"`
-	RefreshInterval Duration `yaml:"refresh_interval,omitempty"`
-}
-
 // ConsulSDConfig is the configuration for Consul service discovery.
 type ConsulSDConfig struct {
-	// DefaultedConsulSDConfig contains the actual fields for ConsulSDConfig.
+	Server       string `yaml:"server"`
-	DefaultedConsulSDConfig `yaml:",inline"`
+	Token        string `yaml:"token"`
+	Datacenter   string `yaml:"datacenter"`
+	TagSeparator string `yaml:"tag_separator"`
+	Scheme       string `yaml:"scheme"`
+	Username     string `yaml:"username"`
+	Password     string `yaml:"password"`
+	// The list of services for which targets are discovered.
+	Services []string `yaml:"services"`
 }
 
 // UnmarshalYAML implements the yaml.Unmarshaler interface.
 func (c *ConsulSDConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
-	c.DefaultedConsulSDConfig = DefaultConsulSDConfig
+	*c = DefaultConsulSDConfig
-	err := unmarshal(&c.DefaultedConsulSDConfig)
+	type plain ConsulSDConfig
+	err := unmarshal((*plain)(c))
 	if err != nil {
 		return err
 	}
@@ -376,18 +362,6 @@ func (c *ConsulSDConfig) UnmarshalYAML(unmarshal func(interface{}) error) error
 	return nil
 }
 
-// DefaultedConsulSDConfig is a proxy type for ConsulSDConfig.
-type DefaultedConsulSDConfig struct {
-	Server       string   `yaml:"server"`
-	Token        string   `yaml:"token"`
-	Datacenter   string   `yaml:"datacenter"`
-	TagSeparator string   `yaml:"tag_separator"`
-	Scheme       string   `yaml:"scheme"`
-	Username     string   `yaml:"username"`
-	Password     string   `yaml:"password"`
-	Services     []string `yaml:"services"`
-}
-
 // RelabelAction is the action to be performed on relabeling.
 type RelabelAction string
 
@@ -416,18 +390,6 @@ func (a *RelabelAction) UnmarshalYAML(unmarshal func(interface{}) error) error {
 
 // RelabelConfig is the configuration for relabeling of target label sets.
 type RelabelConfig struct {
-	// DefaultedRelabelConfig contains the actual fields for RelabelConfig.
-	DefaultedRelabelConfig `yaml:",inline"`
-}
-
-// UnmarshalYAML implements the yaml.Unmarshaler interface.
-func (c *RelabelConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
-	c.DefaultedRelabelConfig = DefaultRelabelConfig
-	return unmarshal(&c.DefaultedRelabelConfig)
-}
-
-// DefaultedRelabelConfig is a proxy type for RelabelConfig.
-type DefaultedRelabelConfig struct {
 	// A list of labels from which values are taken and concatenated
 	// with the configured separator in order.
 	SourceLabels clientmodel.LabelNames `yaml:"source_labels,flow"`
@@ -443,6 +405,13 @@ type DefaultedRelabelConfig struct {
 	Action RelabelAction `yaml:"action,omitempty"`
 }
 
+// UnmarshalYAML implements the yaml.Unmarshaler interface.
+func (c *RelabelConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
+	*c = DefaultRelabelConfig
+	type plain RelabelConfig
+	return unmarshal((*plain)(c))
+}
+
 // Regexp encapsulates a regexp.Regexp and makes it YAML marshallable.
 type Regexp struct {
 	regexp.Regexp

config/config_test.go

@@ -14,8 +14,8 @@ import (
 	clientmodel "github.com/prometheus/client_golang/model"
 )
 
-var expectedConf = &Config{DefaultedConfig{
+var expectedConf = &Config{
-	GlobalConfig: &GlobalConfig{DefaultedGlobalConfig{
+	GlobalConfig: GlobalConfig{
 		ScrapeInterval:     Duration(15 * time.Second),
 		ScrapeTimeout:      DefaultGlobalConfig.ScrapeTimeout,
 		EvaluationInterval: Duration(30 * time.Second),
@@ -24,7 +24,7 @@ var expectedConf = &Config{DefaultedConfig{
 			"monitor": "codelab",
 			"foo":     "bar",
 		},
-	}},
+	},
 
 	RuleFiles: []string{
 		"first.rules",
@@ -33,7 +33,7 @@ var expectedConf = &Config{DefaultedConfig{
 	},
 
 	ScrapeConfigs: []*ScrapeConfig{
-		{DefaultedScrapeConfig{
+		{
 			JobName: "prometheus",
 
 			ScrapeInterval: Duration(15 * time.Second),
@@ -56,28 +56,28 @@ var expectedConf = &Config{DefaultedConfig{
 			},
 
 			FileSDConfigs: []*FileSDConfig{
-				{DefaultedFileSDConfig{
+				{
 					Names:           []string{"foo/*.slow.json", "foo/*.slow.yml", "single/file.yml"},
 					RefreshInterval: Duration(10 * time.Minute),
-				}},
+				},
-				{DefaultedFileSDConfig{
+				{
 					Names:           []string{"bar/*.yaml"},
 					RefreshInterval: Duration(30 * time.Second),
-				}},
+				},
 			},
 
 			RelabelConfigs: []*RelabelConfig{
-				{DefaultedRelabelConfig{
+				{
 					SourceLabels: clientmodel.LabelNames{"job", "__meta_dns_srv_name"},
 					TargetLabel:  "job",
 					Separator:    ";",
 					Regex:        &Regexp{*regexp.MustCompile("(.*)some-[regex]$")},
 					Replacement:  "foo-${1}",
 					Action:       RelabelReplace,
-				}},
 				},
-		}},
+			},
-		{DefaultedScrapeConfig{
+		},
+		{
 			JobName: "service-x",
 
 			ScrapeInterval: Duration(50 * time.Second),
@@ -91,34 +91,41 @@ var expectedConf = &Config{DefaultedConfig{
 			Scheme:      "https",
 
 			DNSSDConfigs: []*DNSSDConfig{
-				{DefaultedDNSSDConfig{
+				{
 					Names: []string{
 						"first.dns.address.domain.com",
 						"second.dns.address.domain.com",
 					},
 					RefreshInterval: Duration(15 * time.Second),
-				}},
+				},
-				{DefaultedDNSSDConfig{
+				{
 					Names: []string{
 						"first.dns.address.domain.com",
 					},
 					RefreshInterval: Duration(30 * time.Second),
-				}},
+				},
 			},
 
 			RelabelConfigs: []*RelabelConfig{
-				{DefaultedRelabelConfig{
+				{
 					SourceLabels: clientmodel.LabelNames{"job"},
 					Regex:        &Regexp{*regexp.MustCompile("(.*)some-[regex]$")},
 					Separator:    ";",
 					Action:       RelabelDrop,
-				}},
 				},
-		}},
 			},
-}, ""}
+		},
+	},
+	original: "",
+}
 
 func TestLoadConfig(t *testing.T) {
+	// Parse a valid file that sets a global scrape timeout. This tests whether parsing
+	// an overwritten default field in the global config permanently changes the default.
+	if _, err := LoadFromFile("testdata/global_timeout.good.yml"); err != nil {
+		t.Errorf("Error parsing %s: %s", "testdata/conf.good.yml", err)
+	}
+
 	c, err := LoadFromFile("testdata/conf.good.yml")
 	if err != nil {
 		t.Errorf("Error parsing %s: %s", "testdata/conf.good.yml", err)

config/testdata/global_timeout.good.yml

@@ -0,0 +1,2 @@
+global:
+  scrape_timeout: 1h

retrieval/relabel_test.go

@@ -13,7 +13,7 @@ import (
 func TestRelabel(t *testing.T) {
 	tests := []struct {
 		input   clientmodel.LabelSet
-		relabel []config.DefaultedRelabelConfig
+		relabel []*config.RelabelConfig
 		output  clientmodel.LabelSet
 	}{
 		{
@@ -22,7 +22,7 @@ func TestRelabel(t *testing.T) {
 				"b": "bar",
 				"c": "baz",
 			},
-			relabel: []config.DefaultedRelabelConfig{
+			relabel: []*config.RelabelConfig{
 				{
 					SourceLabels: clientmodel.LabelNames{"a"},
 					Regex:        &config.Regexp{*regexp.MustCompile("f(.*)")},
@@ -45,7 +45,7 @@ func TestRelabel(t *testing.T) {
 				"b": "bar",
 				"c": "baz",
 			},
-			relabel: []config.DefaultedRelabelConfig{
+			relabel: []*config.RelabelConfig{
 				{
 					SourceLabels: clientmodel.LabelNames{"a", "b"},
 					Regex:        &config.Regexp{*regexp.MustCompile("^f(.*);(.*)r$")},
@@ -74,7 +74,7 @@ func TestRelabel(t *testing.T) {
 			input: clientmodel.LabelSet{
 				"a": "foo",
 			},
-			relabel: []config.DefaultedRelabelConfig{
+			relabel: []*config.RelabelConfig{
 				{
 					SourceLabels: clientmodel.LabelNames{"a"},
 					Regex:        &config.Regexp{*regexp.MustCompile("o$")},
@@ -94,7 +94,7 @@ func TestRelabel(t *testing.T) {
 			input: clientmodel.LabelSet{
 				"a": "foo",
 			},
-			relabel: []config.DefaultedRelabelConfig{
+			relabel: []*config.RelabelConfig{
 				{
 					SourceLabels: clientmodel.LabelNames{"a"},
 					Regex:        &config.Regexp{*regexp.MustCompile("no-match")},
@@ -109,7 +109,7 @@ func TestRelabel(t *testing.T) {
 			input: clientmodel.LabelSet{
 				"a": "foo",
 			},
-			relabel: []config.DefaultedRelabelConfig{
+			relabel: []*config.RelabelConfig{
 				{
 					SourceLabels: clientmodel.LabelNames{"a"},
 					Regex:        &config.Regexp{*regexp.MustCompile("no-match")},
@@ -122,7 +122,7 @@ func TestRelabel(t *testing.T) {
 			input: clientmodel.LabelSet{
 				"a": "foo",
 			},
-			relabel: []config.DefaultedRelabelConfig{
+			relabel: []*config.RelabelConfig{
 				{
 					SourceLabels: clientmodel.LabelNames{"a"},
 					Regex:        &config.Regexp{*regexp.MustCompile("^f")},
@@ -138,7 +138,7 @@ func TestRelabel(t *testing.T) {
 			input: clientmodel.LabelSet{
 				"a": "boo",
 			},
-			relabel: []config.DefaultedRelabelConfig{
+			relabel: []*config.RelabelConfig{
 				{
 					SourceLabels: clientmodel.LabelNames{"a"},
 					Regex:        &config.Regexp{*regexp.MustCompile("^f")},
@@ -154,11 +154,7 @@ func TestRelabel(t *testing.T) {
 	}
 
 	for i, test := range tests {
-		var relabel []*config.RelabelConfig
+		res, err := Relabel(test.input, test.relabel...)
-		for _, rl := range test.relabel {
-			relabel = append(relabel, &config.RelabelConfig{rl})
-		}
-		res, err := Relabel(test.input, relabel...)
 		if err != nil {
 			t.Errorf("Test %d: error relabeling: %s", i+1, err)
 		}

retrieval/targetmanager_test.go

@@ -25,7 +25,7 @@ import (
 )
 
 func TestTargetManagerChan(t *testing.T) {
-	testJob1 := &config.ScrapeConfig{config.DefaultedScrapeConfig{
+	testJob1 := &config.ScrapeConfig{
 		JobName:        "test_job1",
 		ScrapeInterval: config.Duration(1 * time.Minute),
 		TargetGroups: []*config.TargetGroup{{
@@ -34,7 +34,7 @@ func TestTargetManagerChan(t *testing.T) {
 				{clientmodel.AddressLabel: "example.com:80"},
 			},
 		}},
-	}}
+	}
 	prov1 := &fakeTargetProvider{
 		sources: []string{"src1", "src2"},
 		update:  make(chan *config.TargetGroup),
@@ -154,7 +154,7 @@ func TestTargetManagerChan(t *testing.T) {
 }
 
 func TestTargetManagerConfigUpdate(t *testing.T) {
-	testJob1 := &config.ScrapeConfig{config.DefaultedScrapeConfig{
+	testJob1 := &config.ScrapeConfig{
 		JobName:        "test_job1",
 		ScrapeInterval: config.Duration(1 * time.Minute),
 		TargetGroups: []*config.TargetGroup{{
@@ -163,8 +163,8 @@ func TestTargetManagerConfigUpdate(t *testing.T) {
 				{clientmodel.AddressLabel: "example.com:80"},
 			},
 		}},
-	}}
+	}
-	testJob2 := &config.ScrapeConfig{config.DefaultedScrapeConfig{
+	testJob2 := &config.ScrapeConfig{
 		JobName:        "test_job2",
 		ScrapeInterval: config.Duration(1 * time.Minute),
 		TargetGroups: []*config.TargetGroup{
@@ -191,14 +191,14 @@ func TestTargetManagerConfigUpdate(t *testing.T) {
 			},
 		},
 		RelabelConfigs: []*config.RelabelConfig{
-			{config.DefaultedRelabelConfig{
+			{
 				SourceLabels: clientmodel.LabelNames{clientmodel.AddressLabel},
 				Regex:        &config.Regexp{*regexp.MustCompile(`^test\.(.*?):(.*)`)},
 				Replacement:  "foo.${1}:${2}",
 				TargetLabel:  clientmodel.AddressLabel,
 				Action:       config.RelabelReplace,
-			}},
+			},
-			{config.DefaultedRelabelConfig{
+			{
 				// Add a new label for example.* targets.
 				SourceLabels: clientmodel.LabelNames{clientmodel.AddressLabel, "boom", "foo"},
 				Regex:        &config.Regexp{*regexp.MustCompile("^example.*?-b([a-z-]+)r$")},
@@ -206,17 +206,17 @@ func TestTargetManagerConfigUpdate(t *testing.T) {
 				Replacement:  "$1",
 				Separator:    "-",
 				Action:       config.RelabelReplace,
-			}},
+			},
-			{config.DefaultedRelabelConfig{
+			{
 				// Drop an existing label.
 				SourceLabels: clientmodel.LabelNames{"boom"},
 				Regex:        &config.Regexp{*regexp.MustCompile(".*")},
 				TargetLabel:  "boom",
 				Replacement:  "",
 				Action:       config.RelabelReplace,
-			}},
 			},
-	}}
+		},
+	}
 
 	sequence := []struct {
 		scrapeConfigs []*config.ScrapeConfig
@@ -275,7 +275,8 @@ func TestTargetManagerConfigUpdate(t *testing.T) {
 			},
 		},
 	}
-	conf := &config.Config{DefaultedConfig: config.DefaultConfig}
+	conf := &config.Config{}
+	*conf = config.DefaultConfig
 
 	targetManager := NewTargetManager(nopAppender{})
 	targetManager.ApplyConfig(conf)