From 759d87b25da4bc3f955b9fa6aab61be67fa17985 Mon Sep 17 00:00:00 2001
From: Gustavo Caso <gustavo.caso@datadoghq.com>
Date: Thu, 23 Nov 2023 10:29:45 +0100
Subject: [PATCH] Move fetching apmStats from the CLI to the status package

---
 cmd/agent/subcommands/status/command.go | 34 --------------
 pkg/status/apm/apm.go                   | 59 +++++++++++++++++++++++++
 pkg/status/status.go                    |  2 +
 3 files changed, 61 insertions(+), 34 deletions(-)
 create mode 100644 pkg/status/apm/apm.go

diff --git a/cmd/agent/subcommands/status/command.go b/cmd/agent/subcommands/status/command.go
index 88b30ee873dc1..a86a5d61e0076 100644
--- a/cmd/agent/subcommands/status/command.go
+++ b/cmd/agent/subcommands/status/command.go
@@ -11,10 +11,8 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"net/http"
 	"net/url"
 	"os"
-	"time"
 
 	"go.uber.org/fx"
 
@@ -162,14 +160,6 @@ func requestStatus(config config.Component, cliParams *cliParams) error {
 	if err != nil {
 		return err
 	}
-	// attach trace-agent status, if obtainable
-	temp := make(map[string]interface{})
-	if err := json.Unmarshal(r, &temp); err == nil {
-		temp["apmStats"] = getAPMStatus(config)
-		if newr, err := json.Marshal(temp); err == nil {
-			r = newr
-		}
-	}
 
 	// The rendering is done in the client so that the agent has less work to do
 	if cliParams.prettyPrintJSON {
@@ -195,30 +185,6 @@ func requestStatus(config config.Component, cliParams *cliParams) error {
 	return nil
 }
 
-// getAPMStatus returns a set of key/value pairs summarizing the status of the trace-agent.
-// If the status can not be obtained for any reason, the returned map will contain an "error"
-// key with an explanation.
-func getAPMStatus(config config.Component) map[string]interface{} {
-	port := config.GetInt("apm_config.debug.port")
-	url := fmt.Sprintf("http://localhost:%d/debug/vars", port)
-	resp, err := (&http.Client{Timeout: 2 * time.Second}).Get(url)
-	if err != nil {
-		return map[string]interface{}{
-			"port":  port,
-			"error": err.Error(),
-		}
-	}
-	defer resp.Body.Close()
-	status := make(map[string]interface{})
-	if err := json.NewDecoder(resp.Body).Decode(&status); err != nil {
-		return map[string]interface{}{
-			"port":  port,
-			"error": err.Error(),
-		}
-	}
-	return status
-}
-
 func componentStatusCmd(log log.Component, config config.Component, cliParams *cliParams) error {
 	if len(cliParams.args) != 1 {
 		return fmt.Errorf("a component name must be specified")
diff --git a/pkg/status/apm/apm.go b/pkg/status/apm/apm.go
new file mode 100644
index 0000000000000..dce29195b5abf
--- /dev/null
+++ b/pkg/status/apm/apm.go
@@ -0,0 +1,59 @@
+// Unless explicitly stated otherwise all files in this repository are licensed
+// under the Apache License Version 2.0.
+// This product includes software developed at Datadog (https://www.datadoghq.com/).
+// Copyright 2016-present Datadog, Inc.
+
+// Package apm fetch information about the apm agent.
+// This will, in time, be migrated to the apm agent component.
+package apm
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"sync"
+
+	apiutil "github.com/DataDog/datadog-agent/pkg/api/util"
+	"github.com/DataDog/datadog-agent/pkg/config"
+)
+
+// httpClients should be reused instead of created as needed. They keep cached TCP connections
+// that may leak otherwise
+var (
+	httpClient     *http.Client
+	clientInitOnce sync.Once
+)
+
+func getHTTPClient() *http.Client {
+	clientInitOnce.Do(func() {
+		httpClient = apiutil.GetClient(false)
+	})
+
+	return httpClient
+}
+
+// GetAPMStatus returns a set of key/value pairs summarizing the status of the trace-agent.
+// If the status can not be obtained for any reason, the returned map will contain an "error"
+// key with an explanation.
+func GetAPMStatus() map[string]interface{} {
+	port := config.Datadog.GetInt("apm_config.debug.port")
+
+	client := getHTTPClient()
+	url := fmt.Sprintf("http://localhost:%d/debug/vars", port)
+	resp, err := apiutil.DoGet(client, url, apiutil.CloseConnection)
+	if err != nil {
+		return map[string]interface{}{
+			"port":  port,
+			"error": err.Error(),
+		}
+	}
+
+	status := make(map[string]interface{})
+	if err := json.Unmarshal(resp, &status); err != nil {
+		return map[string]interface{}{
+			"port":  port,
+			"error": err.Error(),
+		}
+	}
+	return status
+}
diff --git a/pkg/status/status.go b/pkg/status/status.go
index 21696dc0ac489..a3f86b0c6cabb 100644
--- a/pkg/status/status.go
+++ b/pkg/status/status.go
@@ -30,6 +30,7 @@ import (
 	"github.com/DataDog/datadog-agent/pkg/config/utils"
 	logsStatus "github.com/DataDog/datadog-agent/pkg/logs/status"
 	"github.com/DataDog/datadog-agent/pkg/snmp/traps"
+	"github.com/DataDog/datadog-agent/pkg/status/apm"
 	"github.com/DataDog/datadog-agent/pkg/status/collector"
 	"github.com/DataDog/datadog-agent/pkg/status/jmx"
 	"github.com/DataDog/datadog-agent/pkg/status/otlp"
@@ -82,6 +83,7 @@ func GetStatus(verbose bool, invAgent inventoryagent.Component) (map[string]inte
 	}
 
 	stats["processAgentStatus"] = GetProcessAgentStatus()
+	stats["apmStats"] = apm.GetAPMStatus()
 
 	if !config.Datadog.GetBool("no_proxy_nonexact_match") {
 		stats["TransportWarnings"] = httputils.GetNumberOfWarnings() > 0