From 7188912dcc42af1de3acd0e9490d0559aeb84380 Mon Sep 17 00:00:00 2001
From: Ralf Pannemans <ralf.pannemans@sap.com>
Date: Wed, 19 Apr 2023 11:08:03 +0200
Subject: [PATCH] Do not add debug options if already available in
 JAVA_TOOL_OPTIONS

Co-authored-by: Johannes Dillmann <j.dillmann@sap.com>
Co-authored-by: Ralf Pannemans <ralf.pannemans@sap.com>
---
 helper/debug_8.go      | 11 ++++++++++-
 helper/debug_8_test.go | 14 ++++++++++++++
 helper/debug_9.go      | 11 ++++++++++-
 helper/debug_9_test.go | 14 ++++++++++++++
 4 files changed, 48 insertions(+), 2 deletions(-)

diff --git a/helper/debug_8.go b/helper/debug_8.go
index 6f73a44..8d08244 100644
--- a/helper/debug_8.go
+++ b/helper/debug_8.go
@@ -18,6 +18,7 @@ package helper
 
 import (
 	"fmt"
+	"strings"
 
 	"github.com/paketo-buildpacks/libpak/bard"
 	"github.com/paketo-buildpacks/libpak/sherpa"
@@ -33,6 +34,14 @@ func (d Debug8) Execute() (map[string]string, error) {
 		return nil, nil
 	}
 
+	opts := sherpa.GetEnvWithDefault("JAVA_TOOL_OPTIONS", "")
+	debugAlreadyExists := strings.Contains(opts, "-agentlib:jdwp=")
+
+	if debugAlreadyExists {
+		d.Logger.Info("Java agent 'jdwp' already configured")
+		return nil, nil
+	}
+
 	port := sherpa.GetEnvWithDefault("BPL_DEBUG_PORT", "8000")
 
 	suspend := sherpa.ResolveBool("BPL_DEBUG_SUSPEND")
@@ -49,7 +58,7 @@ func (d Debug8) Execute() (map[string]string, error) {
 		s = "n"
 	}
 
-	opts := sherpa.AppendToEnvVar("JAVA_TOOL_OPTIONS", " ", fmt.Sprintf("-agentlib:jdwp=transport=dt_socket,server=y,address=%s,suspend=%s", port, s))
+	opts = sherpa.AppendToEnvVar("JAVA_TOOL_OPTIONS", " ", fmt.Sprintf("-agentlib:jdwp=transport=dt_socket,server=y,address=%s,suspend=%s", port, s))
 
 	return map[string]string{"JAVA_TOOL_OPTIONS": opts}, nil
 }
diff --git a/helper/debug_8_test.go b/helper/debug_8_test.go
index 27ebace..d5d7430 100644
--- a/helper/debug_8_test.go
+++ b/helper/debug_8_test.go
@@ -53,6 +53,20 @@ func testDebug8(t *testing.T, context spec.G, it spec.S) {
 			}))
 		})
 
+		context("jdwp agent already configured", func() {
+			it.Before(func() {
+				Expect(os.Setenv("JAVA_TOOL_OPTIONS", "-agentlib:jdwp=something")).To(Succeed())
+			})
+
+			it.After(func() {
+				Expect(os.Unsetenv("JAVA_TOOL_OPTIONS")).To(Succeed())
+			})
+
+			it("does not update JAVA_TOOL_OPTIONS", func() {
+				Expect(d.Execute()).To(BeEmpty())
+			})
+		})
+
 		context("$BPL_DEBUG_PORT", func() {
 			it.Before(func() {
 				Expect(os.Setenv("BPL_DEBUG_PORT", "8001")).To(Succeed())
diff --git a/helper/debug_9.go b/helper/debug_9.go
index 6ddffd8..7b1405d 100644
--- a/helper/debug_9.go
+++ b/helper/debug_9.go
@@ -18,6 +18,7 @@ package helper
 
 import (
 	"fmt"
+	"strings"
 
 	"github.com/paketo-buildpacks/libpak/sherpa"
 
@@ -34,6 +35,14 @@ func (d Debug9) Execute() (map[string]string, error) {
 		return nil, nil
 	}
 
+	opts := sherpa.GetEnvWithDefault("JAVA_TOOL_OPTIONS", "")
+	debugAlreadyExists := strings.Contains(opts, "-agentlib:jdwp=")
+
+	if debugAlreadyExists {
+		d.Logger.Info("Java agent 'jdwp' already configured")
+		return nil, nil
+	}
+
 	port := "*:" + sherpa.GetEnvWithDefault("BPL_DEBUG_PORT", "8000")
 
 	suspend := sherpa.ResolveBool("BPL_DEBUG_SUSPEND")
@@ -50,7 +59,7 @@ func (d Debug9) Execute() (map[string]string, error) {
 		s = "n"
 	}
 
-	opts := sherpa.AppendToEnvVar("JAVA_TOOL_OPTIONS", " ", fmt.Sprintf("-agentlib:jdwp=transport=dt_socket,server=y,address=%s,suspend=%s", port, s))
+	opts = sherpa.AppendToEnvVar("JAVA_TOOL_OPTIONS", " ", fmt.Sprintf("-agentlib:jdwp=transport=dt_socket,server=y,address=%s,suspend=%s", port, s))
 
 	return map[string]string{"JAVA_TOOL_OPTIONS": opts}, nil
 }
diff --git a/helper/debug_9_test.go b/helper/debug_9_test.go
index aed5658..08c52fa 100644
--- a/helper/debug_9_test.go
+++ b/helper/debug_9_test.go
@@ -52,6 +52,20 @@ func testDebug9(t *testing.T, context spec.G, it spec.S) {
 			}))
 		})
 
+		context("jdwp agent already configured", func() {
+			it.Before(func() {
+				Expect(os.Setenv("JAVA_TOOL_OPTIONS", "-agentlib:jdwp=something")).To(Succeed())
+			})
+
+			it.After(func() {
+				Expect(os.Unsetenv("JAVA_TOOL_OPTIONS")).To(Succeed())
+			})
+
+			it("does not update JAVA_TOOL_OPTIONS", func() {
+				Expect(d.Execute()).To(BeEmpty())
+			})
+		})
+
 		context("$BPL_DEBUG_PORT", func() {
 			it.Before(func() {
 				Expect(os.Setenv("BPL_DEBUG_PORT", "8001")).To(Succeed())