Merge pull request #164 from Nexucis/feature/change-prometheus-client

Update prometheus client implementation

Author: slrtbtfs

langserver/completion.go

@@ -20,6 +20,7 @@ import (
 	"sort"
 	"strconv"
 	"strings"
+	"time"
 
 	"github.com/pkg/errors"
 
@@ -94,7 +95,7 @@ func (s *server) Completion(ctx context.Context, params *protocol.CompletionPara
 }
 
 func (s *server) completeMetricName(ctx context.Context, completions *[]protocol.CompletionItem, location *cache.Location, metricName string) error {
-	allMetadata, err := s.prometheusClient.AllMetadata(ctx)
+	allMetadata, err := s.metadataService.AllMetricMetadata(ctx)
 	if err != nil {
 		return err
 	}
@@ -311,7 +312,7 @@ func (s *server) completeLabel(ctx context.Context, completions *[]protocol.Comp
 	if vs != nil {
 		metricName = vs.Name
 	}
-	allNames, err := s.prometheusClient.LabelNames(ctx, metricName)
+	allNames, err := s.metadataService.LabelNames(ctx, metricName, time.Now().Add(-100*time.Hour), time.Now())
 	if err != nil {
 		// nolint: errcheck
 		s.client.LogMessage(s.lifetime, &protocol.LogMessageParams{
@@ -327,14 +328,8 @@ func (s *server) completeLabel(ctx context.Context, completions *[]protocol.Comp
 	}
 
 	labelName := location.Node.(*promql.Item).Val
-	var prevMatched string
 OUTER:
 	for _, match := range getMatches(labelName, allNames) {
-		// Skip duplicates
-		if prevMatched == match.Str {
-			continue
-		}
-		prevMatched = match.Str
 		// Skip labels that already have matchers
 		if vs != nil {
 			for _, m := range vs.LabelMatchers {
@@ -360,7 +355,7 @@ OUTER:
 
 // nolint: funlen
 func (s *server) completeLabelValue(ctx context.Context, completions *[]protocol.CompletionItem, location *cache.Location, labelName string) error {
-	labelValues, err := s.prometheusClient.LabelValues(ctx, labelName)
+	labelValues, err := s.metadataService.LabelValues(ctx, labelName)
 	if err != nil {
 		// nolint: errcheck
 		s.client.LogMessage(s.lifetime, &protocol.LogMessageParams{

langserver/hover.go

@@ -138,7 +138,7 @@ func (s *server) nodeToDocMarkdown(ctx context.Context, location *cache.Location
 		}
 	}
 
-	promURL := s.prometheusClient.GetURL()
+	promURL := s.metadataService.GetURL()
 
 	if promURL != "" && !s.headless {
 		loc := *location
@@ -195,7 +195,7 @@ func (s *server) getMetricDocs(ctx context.Context, metric string) (string, erro
 	var ret strings.Builder
 	ret.WriteString(fmt.Sprintf("### %s\n\n", metric))
 
-	metadata, err := s.prometheusClient.Metadata(ctx, metric)
+	metadata, err := s.metadataService.MetricMetadata(ctx, metric)
 	if err != nil {
 		return "", err
 	}

langserver/server.go

@@ -56,7 +56,7 @@ type server struct {
 
 	config *Config
 
-	prometheusClient promClient.Client
+	metadataService promClient.MetadataService
 
 	lifetime context.Context
 	exit     func()
@@ -80,12 +80,12 @@ func (s Server) Run() error {
 // CreateHeadlessServer creates a locked down server instance for the REST API.
 //
 // "locked down" in this case means, that the instance cannot send or receive any JSONRPC communication. Logging messages that the instance tries to send over JSONRPC are redirected to stderr.
-func CreateHeadlessServer(ctx context.Context, prometheusClient promClient.Client, logger log.Logger) (HeadlessServer, error) {
+func CreateHeadlessServer(ctx context.Context, metadataService promClient.MetadataService, logger log.Logger) (HeadlessServer, error) {
 	s := &server{
-		client:           &headlessClient{logger: logger},
-		headless:         true,
-		config:           &Config{PrometheusURL: prometheusClient.GetURL()},
-		prometheusClient: prometheusClient,
+		client:          &headlessClient{logger: logger},
+		headless:        true,
+		config:          &Config{PrometheusURL: metadataService.GetURL()},
+		metadataService: metadataService,
 	}
 
 	s.lifetime, s.exit = context.WithCancel(ctx)
@@ -130,13 +130,13 @@ func ServerFromStream(ctx context.Context, stream jsonrpc2.Stream, config *Confi
 		})
 		panic(err)
 	}
-	s.prometheusClient = prometheusClient
+	s.metadataService = prometheusClient
 
 	return ctx, Server{s}
 }
 
 func (s *server) connectPrometheus(url string) error {
-	if err := s.prometheusClient.ChangeDataSource(url); err != nil {
+	if err := s.metadataService.ChangeDataSource(url); err != nil {
 		// nolint: errcheck
 		s.client.ShowMessage(s.lifetime, &protocol.ShowMessageParams{
 			Type:    protocol.Error,

prometheus/compatible.go

@@ -23,11 +23,11 @@ import (
 
 // compatibleHTTPClient must be used to contact a distant prometheus with a version >= v2.15.
 type compatibleHTTPClient struct {
-	Client
+	MetadataService
 	prometheusClient v1.API
 }
 
-func (c *compatibleHTTPClient) Metadata(ctx context.Context, metric string) (v1.Metadata, error) {
+func (c *compatibleHTTPClient) MetricMetadata(ctx context.Context, metric string) (v1.Metadata, error) {
 	metadata, err := c.prometheusClient.Metadata(ctx, metric, "1")
 	if err != nil {
 		return v1.Metadata{}, err
@@ -42,25 +42,30 @@ func (c *compatibleHTTPClient) Metadata(ctx context.Context, metric string) (v1.
 	}, nil
 }
 
-func (c *compatibleHTTPClient) AllMetadata(ctx context.Context) (map[string][]v1.Metadata, error) {
+func (c *compatibleHTTPClient) AllMetricMetadata(ctx context.Context) (map[string][]v1.Metadata, error) {
 	return c.prometheusClient.Metadata(ctx, "", "")
 }
 
-func (c *compatibleHTTPClient) LabelNames(ctx context.Context, name string) ([]string, error) {
+func (c *compatibleHTTPClient) LabelNames(ctx context.Context, name string, startTime time.Time, endTime time.Time) ([]string, error) {
 	if len(name) == 0 {
 		names, _, err := c.prometheusClient.LabelNames(ctx)
 		return names, err
 	}
-	labelNames, _, err := c.prometheusClient.Series(ctx, []string{name}, time.Now().Add(-100*time.Hour), time.Now())
+	labelNames, _, err := c.prometheusClient.Series(ctx, []string{name}, startTime, endTime)
 	if err != nil {
 		return nil, err
 	}
-	var result []string
+	// subResult is used as a set of label. Like that we are sure we don't have any duplication
+	subResult := make(map[string]bool)
 	for _, ln := range labelNames {
 		for l := range ln {
-			result = append(result, string(l))
+			subResult[string(l)] = true
 		}
 	}
+	result := make([]string, 0, len(subResult))
+	for l := range subResult {
+		result = append(result, l)
+	}
 	return result, nil
 }
 

prometheus/empty.go

@@ -15,25 +15,26 @@ package prometheus
 import (
 	"context"
 	"fmt"
+	"time"
 
 	v1 "github.com/prometheus/client_golang/api/prometheus/v1"
 	"github.com/prometheus/common/model"
 )
 
 // emptyHTTPClient must be used when no prometheus URL has been defined.
 type emptyHTTPClient struct {
-	Client
+	MetadataService
 }
 
-func (c *emptyHTTPClient) Metadata(_ context.Context, _ string) (v1.Metadata, error) {
+func (c *emptyHTTPClient) MetricMetadata(_ context.Context, _ string) (v1.Metadata, error) {
 	return v1.Metadata{}, nil
 }
 
-func (c *emptyHTTPClient) AllMetadata(_ context.Context) (map[string][]v1.Metadata, error) {
+func (c *emptyHTTPClient) AllMetricMetadata(_ context.Context) (map[string][]v1.Metadata, error) {
 	return make(map[string][]v1.Metadata), nil
 }
 
-func (c *emptyHTTPClient) LabelNames(_ context.Context, _ string) ([]string, error) {
+func (c *emptyHTTPClient) LabelNames(_ context.Context, _ string, _ time.Time, _ time.Time) ([]string, error) {
 	return []string{}, nil
 }
 

prometheus/client.go renamed to prometheus/metadata_service.go

@@ -84,15 +84,15 @@ type buildInfoData struct {
 	GoVersion string `json:"goVersion"`
 }
 
-// Client is a light prometheus client used by LSP to get data from a a prometheus Server.
-type Client interface {
-	// Metadata returns the first occurrence of metadata about metrics currently scraped by the metric name.
-	Metadata(ctx context.Context, metric string) (v1.Metadata, error)
-	// AllMetadata returns metadata about metrics currently scraped for all existing metrics.
-	AllMetadata(ctx context.Context) (map[string][]v1.Metadata, error)
+// MetadataService is a light prometheus client used by LSP to get metric or label information from prometheus Server.
+type MetadataService interface {
+	// MetricMetadata returns the first occurrence of metadata about metrics currently scraped by the metric name.
+	MetricMetadata(ctx context.Context, metric string) (v1.Metadata, error)
+	// AllMetricMetadata returns metadata about metrics currently scraped for all existing metrics.
+	AllMetricMetadata(ctx context.Context) (map[string][]v1.Metadata, error)
 	// LabelNames returns all the unique label names present in the block in sorted order.
 	// If a metric is provided, then it will return all unique label names linked to the metric during a predefined period of time
-	LabelNames(ctx context.Context, metricName string) ([]string, error)
+	LabelNames(ctx context.Context, metricName string, startTime time.Time, endTime time.Time) ([]string, error)
 	// LabelValues performs a query for the values of the given label.
 	LabelValues(ctx context.Context, label string) ([]model.LabelValue, error)
 	// ChangeDataSource is used if the prometheusURL is changing.
@@ -107,14 +107,14 @@ type Client interface {
 // You should use this instance directly and not the other one (compatibleHTTPClient and notCompatibleHTTPClient)
 // because it will manage which sub instance of the Client to use (like a factory).
 type httpClient struct {
-	Client
+	MetadataService
 	requestTimeout time.Duration
 	mutex          sync.RWMutex
-	subClient      Client
+	subClient      MetadataService
 	url            string
 }
 
-func NewClient(prometheusURL string) (Client, error) {
+func NewClient(prometheusURL string) (MetadataService, error) {
 	c := &httpClient{
 		requestTimeout: 30,
 	}
@@ -124,22 +124,22 @@ func NewClient(prometheusURL string) (Client, error) {
 	return c, nil
 }
 
-func (c *httpClient) Metadata(ctx context.Context, metric string) (v1.Metadata, error) {
+func (c *httpClient) MetricMetadata(ctx context.Context, metric string) (v1.Metadata, error) {
 	c.mutex.RLock()
 	defer c.mutex.RUnlock()
-	return c.subClient.Metadata(ctx, metric)
+	return c.subClient.MetricMetadata(ctx, metric)
 }
 
-func (c *httpClient) AllMetadata(ctx context.Context) (map[string][]v1.Metadata, error) {
+func (c *httpClient) AllMetricMetadata(ctx context.Context) (map[string][]v1.Metadata, error) {
 	c.mutex.RLock()
 	defer c.mutex.RUnlock()
-	return c.subClient.AllMetadata(ctx)
+	return c.subClient.AllMetricMetadata(ctx)
 }
 
-func (c *httpClient) LabelNames(ctx context.Context, name string) ([]string, error) {
+func (c *httpClient) LabelNames(ctx context.Context, name string, startTime time.Time, endTime time.Time) ([]string, error) {
 	c.mutex.RLock()
 	defer c.mutex.RUnlock()
-	return c.subClient.LabelNames(ctx, name)
+	return c.subClient.LabelNames(ctx, name, startTime, endTime)
 }
 
 func (c *httpClient) LabelValues(ctx context.Context, label string) ([]model.LabelValue, error) {

prometheus/not_compatible.go

@@ -23,11 +23,11 @@ import (
 
 // notCompatibleHTTPClient must be used to contact a distant prometheus with a version < v2.15.
 type notCompatibleHTTPClient struct {
-	Client
+	MetadataService
 	prometheusClient v1.API
 }
 
-func (c *notCompatibleHTTPClient) Metadata(ctx context.Context, metric string) (v1.Metadata, error) {
+func (c *notCompatibleHTTPClient) MetricMetadata(ctx context.Context, metric string) (v1.Metadata, error) {
 	metadata, err := c.prometheusClient.TargetsMetadata(ctx, "", metric, "1")
 	if err != nil {
 		return v1.Metadata{}, err
@@ -42,7 +42,7 @@ func (c *notCompatibleHTTPClient) Metadata(ctx context.Context, metric string) (
 	}, nil
 }
 
-func (c *notCompatibleHTTPClient) AllMetadata(ctx context.Context) (map[string][]v1.Metadata, error) {
+func (c *notCompatibleHTTPClient) AllMetricMetadata(ctx context.Context) (map[string][]v1.Metadata, error) {
 	metricNames, _, err := c.prometheusClient.LabelValues(ctx, "__name__")
 	if err != nil {
 		return nil, err
@@ -54,21 +54,26 @@ func (c *notCompatibleHTTPClient) AllMetadata(ctx context.Context) (map[string][
 	return allMetadata, nil
 }
 
-func (c *notCompatibleHTTPClient) LabelNames(ctx context.Context, name string) ([]string, error) {
+func (c *notCompatibleHTTPClient) LabelNames(ctx context.Context, name string, startTime time.Time, endTime time.Time) ([]string, error) {
 	if len(name) == 0 {
 		names, _, err := c.prometheusClient.LabelNames(ctx)
 		return names, err
 	}
-	labelNames, _, err := c.prometheusClient.Series(ctx, []string{name}, time.Now().Add(-100*time.Hour), time.Now())
+	labelNames, _, err := c.prometheusClient.Series(ctx, []string{name}, startTime, endTime)
 	if err != nil {
 		return nil, err
 	}
-	var result []string
+	// subResult is used as a set of label. Like that we are sure we don't have any duplication
+	subResult := make(map[string]bool)
 	for _, ln := range labelNames {
 		for l := range ln {
-			result = append(result, string(l))
+			subResult[string(l)] = true
 		}
 	}
+	result := make([]string, 0, len(subResult))
+	for l := range subResult {
+		result = append(result, l)
+	}
 	return result, nil
 }
 

rest/handler.go

@@ -35,16 +35,16 @@ import (
 //
 // Expects a prometheus Client as a second argument.
 // The provided Logger should be synchronized.
-func CreateHandler(ctx context.Context, prometheusClient promClient.Client, logger log.Logger) (http.Handler, error) {
-	return CreateInstHandler(ctx, prometheusClient, nil, logger)
+func CreateHandler(ctx context.Context, metadataService promClient.MetadataService, logger log.Logger) (http.Handler, error) {
+	return CreateInstHandler(ctx, metadataService, nil, logger)
 }
 
 // CreateInstHandler creates an instrumented http.Handler for the PromQL langserver REST API.
 //
 // Expects a prometheus Client as a second argument and a Registry as third argument.
 // The provided Logger should be synchronized.
-func CreateInstHandler(ctx context.Context, prometheusClient promClient.Client, r *prometheus.Registry, logger log.Logger) (http.Handler, error) {
-	lgs, err := langserver.CreateHeadlessServer(ctx, prometheusClient, logger)
+func CreateInstHandler(ctx context.Context, metadataService promClient.MetadataService, r *prometheus.Registry, logger log.Logger) (http.Handler, error) {
+	lgs, err := langserver.CreateHeadlessServer(ctx, metadataService, logger)
 	if err != nil {
 		return nil, err
 	}