pkg/config: allow configuration to be read from json schema

pkg/config/config.go

@@ -9,9 +9,9 @@ type MetricsDiscoveryConfig struct {
 	// custom metrics API resources.  The rules are applied independently,
 	// and thus must be mutually exclusive.  Rules with the same SeriesQuery
 	// will make only a single API call.
-	Rules         []DiscoveryRule `yaml:"rules"`
-	ResourceRules *ResourceRules  `yaml:"resourceRules,omitempty"`
-	ExternalRules []DiscoveryRule `yaml:"externalRules,omitempty"`
+	Rules         []DiscoveryRule `json:"rules" yaml:"rules"`
+	ResourceRules *ResourceRules  `json:"resourceRules,omitempty" yaml:"resourceRules,omitempty"`
+	ExternalRules []DiscoveryRule `json:"externalRules,omitempty" yaml:"externalRules,omitempty"`
 }
 
 // DiscoveryRule describes a set of rules for transforming Prometheus metrics to/from
@@ -19,32 +19,32 @@ type MetricsDiscoveryConfig struct {
 type DiscoveryRule struct {
 	// SeriesQuery specifies which metrics this rule should consider via a Prometheus query
 	// series selector query.
-	SeriesQuery string `yaml:"seriesQuery"`
+	SeriesQuery string `json:"seriesQuery" yaml:"seriesQuery"`
 	// SeriesFilters specifies additional regular expressions to be applied on
 	// the series names returned from the query.  This is useful for constraints
 	// that can't be represented in the SeriesQuery (e.g. series matching `container_.+`
 	// not matching `container_.+_total`.  A filter will be automatically appended to
 	// match the form specified in Name.
-	SeriesFilters []RegexFilter `yaml:"seriesFilters"`
+	SeriesFilters []RegexFilter `json:"seriesFilters" yaml:"seriesFilters"`
 	// Resources specifies how associated Kubernetes resources should be discovered for
 	// the given metrics.
-	Resources ResourceMapping `yaml:"resources"`
+	Resources ResourceMapping `json:"resources" yaml:"resources"`
 	// Name specifies how the metric name should be transformed between custom metric
 	// API resources, and Prometheus metric names.
-	Name NameMapping `yaml:"name"`
+	Name NameMapping `json:"name" yaml:"name"`
 	// MetricsQuery specifies modifications to the metrics query, such as converting
 	// cumulative metrics to rate metrics.  It is a template where `.LabelMatchers` is
 	// a the comma-separated base label matchers and `.Series` is the series name, and
 	// `.GroupBy` is the comma-separated expected group-by label names. The delimeters
 	// are `<<` and `>>`.
-	MetricsQuery string `yaml:"metricsQuery,omitempty"`
+	MetricsQuery string `json:"metricsQuery,omitempty" yaml:"metricsQuery,omitempty"`
 }
 
 // RegexFilter is a filter that matches positively or negatively against a regex.
 // Only one field may be set at a time.
 type RegexFilter struct {
-	Is    string `yaml:"is,omitempty"`
-	IsNot string `yaml:"isNot,omitempty"`
+	Is    string `json:"is,omitempty" yaml:"is,omitempty"`
+	IsNot string `json:"isNot,omitempty" yaml:"isNot,omitempty"`
 }
 
 // ResourceMapping specifies how to map Kubernetes resources to Prometheus labels
@@ -54,16 +54,16 @@ type ResourceMapping struct {
 	// the `.Group` and `.Resource` fields.  The `.Group` field will have
 	// dots replaced with underscores, and the `.Resource` field will be
 	// singularized.  The delimiters are `<<` and `>>`.
-	Template string `yaml:"template,omitempty"`
+	Template string `json:"template,omitempty" yaml:"template,omitempty"`
 	// Overrides specifies exceptions to the above template, mapping label names
 	// to group-resources
-	Overrides map[string]GroupResource `yaml:"overrides,omitempty"`
+	Overrides map[string]GroupResource `json:"overrides,omitempty" yaml:"overrides,omitempty"`
 }
 
 // GroupResource represents a Kubernetes group-resource.
 type GroupResource struct {
-	Group    string `yaml:"group,omitempty"`
-	Resource string `yaml:"resource"`
+	Group    string `json:"group,omitempty" yaml:"group,omitempty"`
+	Resource string `json:"resource" yaml:"resource"`
 }
 
 // NameMapping specifies how to convert Prometheus metrics
@@ -72,38 +72,38 @@ type NameMapping struct {
 	// Matches is a regular expression that is used to match
 	// Prometheus series names.  It may be left blank, in which
 	// case it is equivalent to `.*`.
-	Matches string `yaml:"matches"`
+	Matches string `json:"matches" yaml:"matches"`
 	// As is the name used in the API.  Captures from Matches
 	// are available for use here.  If not specified, it defaults
 	// to $0 if no capture groups are present in Matches, or $1
 	// if only one is present, and will error if multiple are.
-	As string `yaml:"as"`
+	As string `json:"as" yaml:"as"`
 }
 
 // ResourceRules describe the rules for querying resource metrics
 // API results.  It's assumed that the same metrics can be used
 // to aggregate across different resources.
 type ResourceRules struct {
-	CPU    ResourceRule `yaml:"cpu"`
-	Memory ResourceRule `yaml:"memory"`
+	CPU    ResourceRule `json:"cpu" yaml:"cpu"`
+	Memory ResourceRule `json:"memory" yaml:"memory"`
 	// Window is the window size reported by the resource metrics API.  It should match the value used
 	// in your containerQuery and nodeQuery if you use a `rate` function.
-	Window pmodel.Duration `yaml:"window"`
+	Window pmodel.Duration `json:"window" yaml:"window"`
 }
 
 // ResourceRule describes how to query metrics for some particular
 // system resource metric.
 type ResourceRule struct {
 	// Container is the query used to fetch the metrics for containers.
-	ContainerQuery string `yaml:"containerQuery"`
+	ContainerQuery string `json:"containerQuery" yaml:"containerQuery"`
 	// NodeQuery is the query used to fetch the metrics for nodes
 	// (for instance, simply aggregating by node label is insufficient for
 	// cadvisor metrics -- you need to select the `/` container).
-	NodeQuery string `yaml:"nodeQuery"`
+	NodeQuery string `json:"nodeQuery" yaml:"nodeQuery"`
 	// Resources specifies how associated Kubernetes resources should be discovered for
 	// the given metrics.
-	Resources ResourceMapping `yaml:"resources"`
+	Resources ResourceMapping `json:"resources" yaml:"resources"`
 	// ContainerLabel indicates the name of the Prometheus label containing the container name
 	// (since "container" is not a resource, this can't go in the `resources` block, but is similar).
-	ContainerLabel string `yaml:"containerLabel"`
+	ContainerLabel string `json:"containerLabel" yaml:"containerLabel"`
 }