add user metrics collection

pkg/sloop/server/internal/config/config.go

@@ -20,6 +20,7 @@ import (
 	"github.com/golang/glog"
 	"github.com/pkg/errors"
 
+	"github.com/salesforce/sloop/pkg/sloop/server/server_metrics"
 	"github.com/salesforce/sloop/pkg/sloop/webserver"
 )
 
@@ -29,9 +30,10 @@ type SloopConfig struct {
 	// These fields can only come from command line
 	ConfigFile string
 	// These fields can only come from file because they use complex types
-	LeftBarLinks   []webserver.LinkTemplate         `json:"leftBarLinks"`
-	ResourceLinks  []webserver.ResourceLinkTemplate `json:"resourceLinks"`
-	ExclusionRules map[string][]any                 `json:"exclusionRules"`
+	LeftBarLinks       []webserver.LinkTemplate           `json:"leftBarLinks"`
+	ResourceLinks      []webserver.ResourceLinkTemplate   `json:"resourceLinks"`
+	ExclusionRules     map[string][]any                   `json:"exclusionRules"`
+	UserMetricsHeaders []server_metrics.UserMetricsConfig `json:"userMetricsHeaders"`
 	// Normal fields that can come from file or cmd line
 	DisableKubeWatcher       bool          `json:"disableKubeWatch"`
 	KubeWatchResyncInterval  time.Duration `json:"kubeWatchResyncInterval"`
@@ -76,6 +78,7 @@ type SloopConfig struct {
 	BadgerVLogTruncate       bool          `json:"badgerVLogTruncate"`
 	EnableDeleteKeys         bool          `json:"enableDeleteKeys"`
 	EnableGranularMetrics    bool          `json:"enableGranularMetrics"`
+	EnableUserMetrics        bool          `json:"enableUserMetrics"`
 	PrivilegedAccess         bool          `json:"PrivilegedAccess"`
 	BadgerDetailLogEnabled   bool          `json:"badgerDetailLogEnabled"`
 }
@@ -124,6 +127,7 @@ func registerFlags(fs *flag.FlagSet, config *SloopConfig) {
 	fs.BoolVar(&config.BadgerSyncWrites, "badger-sync-writes", config.BadgerSyncWrites, "Sync Writes ensures writes are synced to disk if set to true")
 	fs.BoolVar(&config.EnableDeleteKeys, "enable-delete-keys", config.EnableDeleteKeys, "Use delete prefixes instead of dropPrefix for GC")
 	fs.BoolVar(&config.EnableGranularMetrics, "enable-granular-metrics", config.EnableGranularMetrics, "default:True , allows metrics of event kind to be granular with reason, type and name")
+	fs.BoolVar(&config.EnableUserMetrics, "enable-user-metrics", config.EnableUserMetrics, "Enable collection of user metrics from request headers")
 	fs.BoolVar(&config.PrivilegedAccess, "allow-privileged-access", config.PrivilegedAccess, "default:True , allows sloop to access kube root path")
 	fs.BoolVar(&config.BadgerVLogFileIOMapping, "badger-vlog-fileIO-mapping", config.BadgerVLogFileIOMapping, "Indicates which file loading mode should be used for the value log data, in memory constrained environments the value is recommended to be true")
 	fs.BoolVar(&config.BadgerVLogTruncate, "badger-vlog-truncate", config.BadgerVLogTruncate, "Truncate value log if badger db offset is different from badger db size")
@@ -176,6 +180,7 @@ func getDefaultConfig() *SloopConfig {
 		BadgerVLogTruncate:       true,
 		EnableDeleteKeys:         false,
 		EnableGranularMetrics:    false,
+		EnableUserMetrics:        false,
 		PrivilegedAccess:         true,
 		BadgerDetailLogEnabled:   false,
 		ExclusionRules:           map[string][]any{},

pkg/sloop/server/server.go

@@ -18,6 +18,7 @@ import (
 
 	"github.com/salesforce/sloop/pkg/sloop/ingress"
 	"github.com/salesforce/sloop/pkg/sloop/server/internal/config"
+	"github.com/salesforce/sloop/pkg/sloop/server/server_metrics"
 	"github.com/salesforce/sloop/pkg/sloop/store/typed"
 	"github.com/salesforce/sloop/pkg/sloop/store/untyped"
 
@@ -146,18 +147,24 @@ func RealMain() error {
 		displayContext = conf.DisplayContext
 	}
 
+	// Initialize user metrics if enabled
+	if conf.EnableUserMetrics {
+		server_metrics.InitUserMetrics(conf.UserMetricsHeaders)
+	}
+
 	webConfig := webserver.WebConfig{
-		BindAddress:      conf.BindAddress,
-		Port:             conf.Port,
-		WebFilesPath:     conf.WebFilesPath,
-		ConfigYaml:       conf.ToYaml(),
-		MaxLookback:      conf.MaxLookback,
-		DefaultNamespace: conf.DefaultNamespace,
-		DefaultLookback:  conf.DefaultLookback,
-		DefaultResources: conf.DefaultKind,
-		ResourceLinks:    conf.ResourceLinks,
-		LeftBarLinks:     conf.LeftBarLinks,
-		CurrentContext:   displayContext,
+		BindAddress:       conf.BindAddress,
+		Port:              conf.Port,
+		WebFilesPath:      conf.WebFilesPath,
+		ConfigYaml:        conf.ToYaml(),
+		MaxLookback:       conf.MaxLookback,
+		DefaultNamespace:  conf.DefaultNamespace,
+		DefaultLookback:   conf.DefaultLookback,
+		DefaultResources:  conf.DefaultKind,
+		ResourceLinks:     conf.ResourceLinks,
+		LeftBarLinks:      conf.LeftBarLinks,
+		CurrentContext:    displayContext,
+		EnableUserMetrics: conf.EnableUserMetrics,
 	}
 	err = webserver.Run(webConfig, tables)
 	if err != nil {

pkg/sloop/server/server_metrics/server_metrics.go

@@ -0,0 +1,181 @@
+/*
+ * Copyright (c) 2019, salesforce.com, inc.
+ * All rights reserved.
+ * SPDX-License-Identifier: BSD-3-Clause
+ * For full license text, see LICENSE.txt file in the repo root or https://opensource.org/licenses/BSD-3-Clause
+ */
+
+package server_metrics
+
+import (
+	"net/http"
+	"sort"
+	"sync"
+
+	"github.com/golang/glog"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+const (
+	// Metric names
+	MetricUserRequests = "user_requests"
+
+	// Built-in request context label keys (always included)
+	LabelHandler   = "handler"
+	LabelCluster   = "cluster"
+	LabelQuery     = "query"
+	LabelNamespace = "namespace"
+	LabelKind      = "kind"
+	LabelName      = "name"
+	LabelLookback  = "lookback"
+)
+
+// UserMetricsConfig defines a single header extraction rule for user metrics
+type UserMetricsConfig struct {
+	// Label is the Prometheus metric label name (e.g., "username", "email", "team")
+	Label string `json:"label"`
+	// Headers is a list of HTTP header names to check, in order of preference
+	// The first non-empty header value found will be used
+	Headers []string `json:"headers"`
+}
+
+var (
+	userRequestCounter    *prometheus.CounterVec
+	configuredLabels      []string
+	configuredHeaderRules []UserMetricsConfig
+	initOnce              sync.Once
+
+	// Built-in labels that are always included for request context
+	builtInLabels = []string{LabelHandler, LabelCluster, LabelQuery, LabelNamespace, LabelKind, LabelName, LabelLookback}
+)
+
+// GetDefaultUserMetricsConfig returns the default configuration for user metrics (username and user_agent)
+func GetDefaultUserMetricsConfig() []UserMetricsConfig {
+	return []UserMetricsConfig{
+		{
+			Label:   "username",
+			Headers: []string{"X-Username", "x-username"},
+		},
+		{
+			Label:   "user_agent",
+			Headers: []string{"User-Agent"},
+		},
+	}
+}
+
+// InitUserMetrics initializes the user metrics with the given configuration
+// This should be called once during application startup before serving requests
+// If config is nil or empty, default configuration will be used
+func InitUserMetrics(config []UserMetricsConfig) {
+	initOnce.Do(func() {
+		// Use default config if none provided
+		if len(config) == 0 {
+			config = GetDefaultUserMetricsConfig()
+			glog.Infof("No user metrics configuration provided, using defaults")
+		}
+
+		// Store the configuration
+		configuredHeaderRules = config
+
+		// Start with built-in labels for request context
+		labelSet := make(map[string]bool)
+		for _, label := range builtInLabels {
+			labelSet[label] = true
+		}
+
+		// Add header-based labels from configuration
+		for _, rule := range config {
+			if rule.Label != "" {
+				labelSet[rule.Label] = true
+			}
+		}
+
+		// Sort labels for consistent ordering
+		configuredLabels = make([]string, 0, len(labelSet))
+		for label := range labelSet {
+			configuredLabels = append(configuredLabels, label)
+		}
+		sort.Strings(configuredLabels)
+
+		// Create the counter with configured labels
+		userRequestCounter = prometheus.NewCounterVec(
+			prometheus.CounterOpts{
+				Name: MetricUserRequests,
+				Help: "Counter of requests broken out by user and request information.",
+			},
+			configuredLabels,
+		)
+
+		// Register with Prometheus
+		prometheus.MustRegister(userRequestCounter)
+
+		glog.Infof("User metrics initialized with labels: %v", configuredLabels)
+		glog.Infof("  Built-in request labels: %v", builtInLabels)
+		for _, rule := range config {
+			glog.Infof("  Header label '%s': headers=%v", rule.Label, rule.Headers)
+		}
+	})
+}
+
+// ============================================================================
+// Header Information Extraction Functions
+// ============================================================================
+
+// getHeaderWithFallback tries multiple header names and returns the first non-empty value
+func getHeaderWithFallback(headers *http.Header, headerNames []string) string {
+	for _, headerName := range headerNames {
+		if value := headers.Get(headerName); value != "" {
+			return value
+		}
+	}
+	return ""
+}
+
+// extractRequesterInfo extracts user information from request headers based on configuration
+func extractRequesterInfo(headers *http.Header) map[string]string {
+	requesterInfo := make(map[string]string)
+
+	for _, rule := range configuredHeaderRules {
+		if rule.Label != "" && len(rule.Headers) > 0 {
+			requesterInfo[rule.Label] = getHeaderWithFallback(headers, rule.Headers)
+		}
+	}
+
+	return requesterInfo
+}
+
+// mergeMaps merges two maps, with values from additionalTags taking precedence
+func mergeMaps(base, additional map[string]string) map[string]string {
+	result := make(map[string]string)
+
+	for k, v := range base {
+		result[k] = v
+	}
+
+	for k, v := range additional {
+		result[k] = v
+	}
+
+	return result
+}
+
+// PublishHeaderMetrics publishes header metrics to the metrics server
+func PublishHeaderMetrics(headers *http.Header, additionalTags map[string]string, enableUserMetrics bool) {
+	if !enableUserMetrics {
+		return
+	}
+
+	userInfo := extractRequesterInfo(headers)
+	allLabels := mergeMaps(userInfo, additionalTags)
+
+	// Build label values in the correct order
+	labelValues := make([]string, len(configuredLabels))
+	for i, label := range configuredLabels {
+		labelValues[i] = allLabels[label]
+	}
+
+	userRequestCounter.WithLabelValues(labelValues...).Inc()
+
+	// Log user request at V(2) verbosity level for debugging
+	glog.V(2).Infof("User request made with labels: %v", allLabels)
+}