Find likely JDK locations and check configurations

src/start-proxy/environment.ts

@@ -1,6 +1,10 @@
+import * as fs from "fs";
+import * as os from "os";
+import * as path from "path";
+
 import { JavaEnvVars, KnownLanguage, Language } from "../languages";
 import { Logger } from "../logging";
-import { isDefined } from "../util";
+import { getErrorMessage, isDefined } from "../util";
 
 /**
  * Checks whether an environment variable named `name` is set and logs its value if set.
@@ -37,6 +41,76 @@ export function checkJavaEnvVars(logger: Logger) {
   }
 }
 
+/**
+ * Discovers paths to JDK directories based on JAVA_HOME and GHA-specific environement variables.
+ * @returns A set of JDK paths.
+ */
+export function discoverActionsJdks(): Set<string> {
+  const paths: Set<string> = new Set();
+
+  // Check whether JAVA_HOME is set.
+  const javaHome = process.env[JavaEnvVars.JAVA_HOME];
+  if (isDefined(javaHome)) {
+    paths.add(javaHome);
+  }
+
+  for (const [envVar, value] of Object.entries(process.env)) {
+    if (isDefined(value) && envVar.match(/^JAVA_HOME_\d+_/)) {
+      paths.add(value);
+    }
+  }
+
+  return paths;
+}
+
+/**
+ * Tries to inspect JDK configuration files for the specified JDK path which may contain proxy settings.
+ *
+ * @param logger The logger to use.
+ * @param jdkHome The JDK home directory.
+ */
+export function checkJdkSettings(logger: Logger, jdkHome: string) {
+  const filesToCheck = [
+    // JDK 9+
+    path.join("conf", "net.properties"),
+    // JDK 8 and below
+    path.join("lib", "net.properties"),
+  ];
+
+  // The JRE properties that may affect the proxy.
+  const properties = [
+    "http.proxyHost",
+    "http.proxyPort",
+    "https.proxyHost",
+    "https.proxyPort",
+    "http.nonProxyHosts",
+    "java.net.useSystemProxies",
+  ];
+
+  for (const fileToCheck of filesToCheck) {
+    const file = path.join(jdkHome, fileToCheck);
+
+    try {
+      if (fs.existsSync(file)) {
+        logger.debug(`Found '${file}'.`);
+
+        const lines = String(fs.readFileSync(file)).split(os.EOL);
+        for (const line of lines) {
+          for (const property of properties) {
+            if (line.startsWith(`${property}=`)) {
+              logger.info(`Found '${line}' in '${file}'.`);
+            }
+          }
+        }
+      } else {
+        logger.debug(`'${file}' does not exist.`);
+      }
+    } catch (err) {
+      logger.debug(`Failed to read '${file}': ${getErrorMessage(err)}`);
+    }
+  }
+}
+
 /** Enumerates environment variable names which may contain information about proxy settings. */
 export enum ProxyEnvVars {
   HTTP_PROXY = "HTTP_PROXY",
@@ -74,5 +148,10 @@ export function checkProxyEnvironment(
   // then we perform all checks.
   if (language === undefined || language === KnownLanguage.java) {
     checkJavaEnvVars(logger);
+
+    const jdks = discoverActionsJdks();
+    for (const jdk of jdks) {
+      checkJdkSettings(logger, jdk);
+    }
   }
 }