SONARIAC-2775 Fix Docker build on Java 21 (#111)

In Java 21 there is a change in JDK around starting new processes, the
PATH environment variable is not taken into account. This PR fix it.

Author: mstachniuk

gradle-modules/src/main/kotlin/org.sonarsource.cloud-native.go-binary-builder.gradle.kts

@@ -21,6 +21,7 @@ import org.sonarsource.cloudnative.gradle.GoBuild
 import org.sonarsource.cloudnative.gradle.allGoSourcesAndMakeScripts
 import org.sonarsource.cloudnative.gradle.callMake
 import org.sonarsource.cloudnative.gradle.crossCompileEnv
+import org.sonarsource.cloudnative.gradle.findExecutable
 import org.sonarsource.cloudnative.gradle.getArchitecture
 import org.sonarsource.cloudnative.gradle.getPlatform
 import org.sonarsource.cloudnative.gradle.goLangCiLintVersion
@@ -50,6 +51,8 @@ goBuildExtension.dockerCommands.convention(
 )
 
 if (isCi()) {
+    val goLangCiLintExecutable = findExecutable("golangci-lint")
+
     val cleanGoCode by tasks.registering(Exec::class) {
         description = "Clean all compiled version of the go code."
         group = "build"
@@ -92,7 +95,7 @@ if (isCi()) {
         outputs.cacheIf { true }
 
         commandLine(
-            "golangci-lint",
+            goLangCiLintExecutable,
             "run",
             // Don't limit the number of issues in the report
             "--max-issues-per-linter=0",

gradle-modules/src/main/kotlin/org.sonarsource.cloud-native.go-docker-environment.gradle.kts

@@ -20,10 +20,13 @@ import org.sonarsource.cloudnative.gradle.GO_LICENSES_OUTPUT_DIR
 import org.sonarsource.cloudnative.gradle.GoBuild
 import org.sonarsource.cloudnative.gradle.allGoSourcesAndMakeScripts
 import org.sonarsource.cloudnative.gradle.crossCompileEnv
+import org.sonarsource.cloudnative.gradle.findExecutable
 import org.sonarsource.cloudnative.gradle.goLangCiLintVersion
 import org.sonarsource.cloudnative.gradle.goVersion
 import org.sonarsource.cloudnative.gradle.isCi
 
+val dockerExecutable = findExecutable("docker")
+
 val goBuildExtension = extensions.findByType<GoBuild>() ?: extensions.create<GoBuild>("goBuild")
 
 val buildDockerImage by tasks.registering(Exec::class) {
@@ -49,7 +52,7 @@ val buildDockerImage by tasks.registering(Exec::class) {
     val noTrafficInspection = "false" == System.getProperty("trafficInspection")
 
     val arguments = buildList {
-        add("docker")
+        add(dockerExecutable)
         add("buildx")
         add("build")
         add("--file")
@@ -102,7 +105,7 @@ val dockerTasks = goBuildExtension.dockerCommands.map { tasksToCommands ->
 
             val workDir = goBuildExtension.dockerWorkDir.get()
             commandLine(
-                "docker",
+                dockerExecutable,
                 "run",
                 "--rm",
                 "--network=host",

gradle-modules/src/main/kotlin/org/sonarsource/cloudnative/gradle/BuildUtils.kt

@@ -31,6 +31,29 @@ import org.gradle.internal.os.OperatingSystem
 
 fun isCi() = System.getenv("CI")?.equals("true") == true
 
+/**
+ * Resolves the absolute path of an executable by searching the PATH environment variable.
+ * This works around a JDK 21 issue where process creation may not properly resolve executables from PATH.
+ * Falls back to the bare executable name if not found (letting the OS handle resolution).
+ */
+fun findExecutable(name: String): String {
+    val pathSeparator = File.pathSeparator
+    val executableExtensions = if (OperatingSystem.current().isWindows) listOf(".exe", ".cmd", ".bat", "") else listOf("")
+    val pathDirs = System.getenv("PATH")
+        ?.split(pathSeparator)
+        ?.filter { it.isNotBlank() }
+        ?: return name
+    for (dir in pathDirs) {
+        for (ext in executableExtensions) {
+            val candidate = File(dir, "$name$ext")
+            if (candidate.isFile && candidate.canExecute()) {
+                return candidate.absolutePath
+            }
+        }
+    }
+    return name
+}
+
 fun Project.signingCondition(): Boolean {
     val branch = System.getenv("GITHUB_REF_NAME") ?: System.getenv("CIRRUS_BRANCH") ?: ""
     return (branch == "master" || branch.matches("branch-.+".toRegex())) &&
@@ -100,7 +123,7 @@ fun checkJarEntriesPathUniqueness(file: File) {
 
 fun Project.commitHashProvider(ref: String = "HEAD") =
     providers.exec {
-        commandLine("git", "rev-parse", ref)
+        commandLine(findExecutable("git"), "rev-parse", ref)
     }.standardOutput.asText
 
 fun getPlatform(): String {