From 28adb688a8b4628eb9a67921e419587af1696aba Mon Sep 17 00:00:00 2001
From: RRashmit <132996156+RRashmit@users.noreply.github.com>
Date: Fri, 20 Dec 2024 14:05:49 +0000
Subject: [PATCH] Updates NAP receivers when NAP directives are deleted (#940)

---
 internal/collector/otel_collector_plugin.go   | 45 ++++++++++++++++++-
 .../collector/otel_collector_plugin_test.go   | 16 +++++++
 internal/collector/otelcol.tmpl               |  4 +-
 internal/config/types.go                      |  7 ++-
 4 files changed, 69 insertions(+), 3 deletions(-)

diff --git a/internal/collector/otel_collector_plugin.go b/internal/collector/otel_collector_plugin.go
index 85daaa94d..07f425236 100644
--- a/internal/collector/otel_collector_plugin.go
+++ b/internal/collector/otel_collector_plugin.go
@@ -539,7 +539,50 @@ func (oc *Collector) updateTcplogReceivers(nginxConfigContext *model.NginxConfig
 		}
 	}
 
-	return newTcplogReceiverAdded
+	tcplogReceiverDeleted := oc.areNapReceiversDeleted(nginxConfigContext)
+
+	return newTcplogReceiverAdded || tcplogReceiverDeleted
+}
+
+func (oc *Collector) areNapReceiversDeleted(nginxConfigContext *model.NginxConfigContext) bool {
+	listenAddressesToBeDeleted := oc.getConfigDeletedNapReceivers(nginxConfigContext)
+	if len(listenAddressesToBeDeleted) != 0 {
+		oc.deleteNapReceivers(listenAddressesToBeDeleted)
+		return true
+	}
+
+	return false
+}
+
+func (oc *Collector) deleteNapReceivers(listenAddressesToBeDeleted map[string]bool) {
+	filteredReceivers := (oc.config.Collector.Receivers.TcplogReceivers)[:0]
+	for _, receiver := range oc.config.Collector.Receivers.TcplogReceivers {
+		if !listenAddressesToBeDeleted[receiver.ListenAddress] {
+			filteredReceivers = append(filteredReceivers, receiver)
+		}
+	}
+	oc.config.Collector.Receivers.TcplogReceivers = filteredReceivers
+}
+
+func (oc *Collector) getConfigDeletedNapReceivers(nginxConfigContext *model.NginxConfigContext) map[string]bool {
+	elements := make(map[string]bool)
+
+	for _, tcplogReceiver := range oc.config.Collector.Receivers.TcplogReceivers {
+		elements[tcplogReceiver.ListenAddress] = true
+	}
+
+	if nginxConfigContext.NAPSysLogServers != nil {
+		addressesToDelete := make(map[string]bool)
+		for _, napAddress := range nginxConfigContext.NAPSysLogServers {
+			if !elements[napAddress] {
+				addressesToDelete[napAddress] = true
+			}
+		}
+
+		return addressesToDelete
+	}
+
+	return elements
 }
 
 func (oc *Collector) doesTcplogReceiverAlreadyExist(listenAddress string) bool {
diff --git a/internal/collector/otel_collector_plugin_test.go b/internal/collector/otel_collector_plugin_test.go
index b948e7e06..48db96981 100644
--- a/internal/collector/otel_collector_plugin_test.go
+++ b/internal/collector/otel_collector_plugin_test.go
@@ -755,6 +755,22 @@ func TestCollector_updateTcplogReceivers(t *testing.T) {
 		assert.Equal(t, "localhost:151", conf.Collector.Receivers.TcplogReceivers[0].ListenAddress)
 		assert.Len(t, conf.Collector.Receivers.TcplogReceivers[0].Operators, 4)
 	})
+
+	t.Run("Test 3: TcplogReceiver deleted", func(tt *testing.T) {
+		tcplogReceiverDeleted := collector.updateTcplogReceivers(&model.NginxConfigContext{})
+		assert.True(t, tcplogReceiverDeleted)
+		assert.Empty(t, conf.Collector.Receivers.TcplogReceivers)
+	})
+
+	t.Run("Test 4: New tcplogReceiver added and deleted another", func(tt *testing.T) {
+		tcplogReceiverDeleted := collector.updateTcplogReceivers(&model.NginxConfigContext{NAPSysLogServers: []string{
+			"localhost:152",
+		}})
+		assert.True(t, tcplogReceiverDeleted)
+		assert.Len(t, conf.Collector.Receivers.TcplogReceivers, 1)
+		assert.Equal(t, "localhost:152", conf.Collector.Receivers.TcplogReceivers[0].ListenAddress)
+		assert.Len(t, conf.Collector.Receivers.TcplogReceivers[0].Operators, 4)
+	})
 }
 
 func createFakeCollector() *typesfakes.FakeCollectorInterface {
diff --git a/internal/collector/otelcol.tmpl b/internal/collector/otelcol.tmpl
index d92d2b18e..35c7f88ab 100644
--- a/internal/collector/otelcol.tmpl
+++ b/internal/collector/otelcol.tmpl
@@ -214,6 +214,7 @@ service:
     {{- end}}
   {{- end}}
   pipelines:
+    {{- if or (ne .Receivers.HostMetrics nil) (gt (len .Receivers.OtlpReceivers) 0) (gt (len .Receivers.NginxReceivers) 0) (gt (len .Receivers.NginxPlusReceivers) 0) }}
     metrics:
       receivers:
         {{- if ne .Receivers.HostMetrics nil }}
@@ -252,7 +253,8 @@ service:
         {{- if ne .Exporters.Debug nil }}
         - debug
         {{- end  }}
-    {{- if ne .Receivers.TcplogReceivers nil }}
+    {{- end }}    
+    {{- if gt (len .Receivers.TcplogReceivers) 0 }}
     logs:
       receivers:
         {{- range $index, $tcplogReceiver := .Receivers.TcplogReceivers }}
diff --git a/internal/config/types.go b/internal/config/types.go
index 377ccd88d..39fe78925 100644
--- a/internal/config/types.go
+++ b/internal/config/types.go
@@ -366,9 +366,14 @@ func (c *Config) AreReceiversConfigured() bool {
 	}
 
 	return c.Collector.Receivers.NginxPlusReceivers != nil ||
+		len(c.Collector.Receivers.NginxPlusReceivers) > 0 ||
 		c.Collector.Receivers.OtlpReceivers != nil ||
+		len(c.Collector.Receivers.OtlpReceivers) > 0 ||
 		c.Collector.Receivers.NginxReceivers != nil ||
-		c.Collector.Receivers.HostMetrics != nil
+		len(c.Collector.Receivers.NginxReceivers) > 0 ||
+		c.Collector.Receivers.HostMetrics != nil ||
+		c.Collector.Receivers.TcplogReceivers != nil ||
+		len(c.Collector.Receivers.TcplogReceivers) > 0
 }
 
 func isAllowedDir(dir string, allowedDirs []string) bool {