Run java to show computed settings

src/start-proxy-action.ts

@@ -82,7 +82,7 @@ async function run(startedAt: Date) {
     // which may affect the operation of our proxy.
     if (core.isDebug() || util.isInTestMode()) {
       try {
-        checkProxyEnvironment(logger, language);
+        await checkProxyEnvironment(logger, language);
       } catch (err) {
         logger.debug(
           `Unable to inspect runner environment: ${util.getErrorMessage(err)}`,

src/start-proxy/environment.test.ts

@@ -2,7 +2,10 @@ import * as fs from "fs";
 import * as os from "os";
 import path from "path";
 
+import * as toolrunner from "@actions/exec/lib/toolrunner";
+import * as io from "@actions/io";
 import test, { ExecutionContext } from "ava";
+import sinon from "sinon";
 
 import { JavaEnvVars, KnownLanguage } from "../languages";
 import {
@@ -25,6 +28,15 @@ import {
 
 setupTests(test);
 
+function stubToolrunner() {
+  sinon.stub(io, "which").throws(new Error("Java not installed"));
+  sinon.stub(toolrunner, "ToolRunner").returns({
+    exec: async () => {
+      return 0;
+    },
+  });
+}
+
 function assertEnvVarLogMessages(
   t: ExecutionContext<any>,
   envVars: string[],
@@ -166,30 +178,36 @@ test("checkProxyEnvVars - credentials are removed from URLs", (t) => {
   );
 });
 
-test("checkProxyEnvironment - includes base checks for all known languages", (t) => {
+test("checkProxyEnvironment - includes base checks for all known languages", async (t) => {
+  stubToolrunner();
+
   for (const language of Object.values(KnownLanguage)) {
     const messages: LoggedMessage[] = [];
     const logger = getRecordingLogger(messages);
 
-    checkProxyEnvironment(logger, language);
+    await checkProxyEnvironment(logger, language);
     assertEnvVarLogMessages(t, Object.keys(ProxyEnvVars), messages, false);
   }
 });
 
-test("checkProxyEnvironment - includes Java checks for Java", (t) => {
+test("checkProxyEnvironment - includes Java checks for Java", async (t) => {
   const messages: LoggedMessage[] = [];
   const logger = getRecordingLogger(messages);
 
-  checkProxyEnvironment(logger, KnownLanguage.java);
+  stubToolrunner();
+
+  await checkProxyEnvironment(logger, KnownLanguage.java);
   assertEnvVarLogMessages(t, Object.keys(ProxyEnvVars), messages, false);
   assertEnvVarLogMessages(t, JAVA_PROXY_ENV_VARS, messages, false);
 });
 
-test("checkProxyEnvironment - includes language-specific checks if the language is undefined", (t) => {
+test("checkProxyEnvironment - includes language-specific checks if the language is undefined", async (t) => {
   const messages: LoggedMessage[] = [];
   const logger = getRecordingLogger(messages);
 
-  checkProxyEnvironment(logger, undefined);
+  stubToolrunner();
+
+  await checkProxyEnvironment(logger, undefined);
   assertEnvVarLogMessages(t, Object.keys(ProxyEnvVars), messages, false);
   assertEnvVarLogMessages(t, JAVA_PROXY_ENV_VARS, messages, false);
 });

src/start-proxy/environment.ts

@@ -1,6 +1,9 @@
 import * as fs from "fs";
 import * as path from "path";
 
+import * as toolrunner from "@actions/exec/lib/toolrunner";
+import * as io from "@actions/io";
+
 import { JavaEnvVars, KnownLanguage, Language } from "../languages";
 import { Logger } from "../logging";
 import { getErrorMessage, isDefined } from "../util";
@@ -128,6 +131,36 @@ export function checkJdkSettings(logger: Logger, jdkHome: string) {
   }
 }
 
+/** Invokes `java` to get it to show us the active configuration. */
+async function showJavaSettings(logger: Logger): Promise<void> {
+  try {
+    const java = await io.which("java", true);
+
+    let output = "";
+    await new toolrunner.ToolRunner(
+      java,
+      ["-XshowSettings:all", "-XshowSettings:security:all", "-version"],
+      {
+        silent: true,
+        listeners: {
+          stdout: (data) => {
+            output += String(data);
+          },
+          stderr: (data) => {
+            output += String(data);
+          },
+        },
+      },
+    ).exec();
+
+    logger.startGroup("Java settings");
+    logger.info(output);
+    logger.endGroup();
+  } catch (err) {
+    logger.debug(`Failed to query java settings: ${getErrorMessage(err)}`);
+  }
+}
+
 /** Enumerates environment variable names which may contain information about proxy settings. */
 export enum ProxyEnvVars {
   HTTP_PROXY = "HTTP_PROXY",
@@ -154,10 +187,10 @@ export function checkProxyEnvVars(logger: Logger) {
  * @param logger The logger to use.
  * @param language The enabled language, if known.
  */
-export function checkProxyEnvironment(
+export async function checkProxyEnvironment(
   logger: Logger,
   language: Language | undefined,
-) {
+): Promise<void> {
   // Determine whether there is an existing proxy configured.
   checkProxyEnvVars(logger);
 
@@ -166,6 +199,8 @@ export function checkProxyEnvironment(
   if (language === undefined || language === KnownLanguage.java) {
     checkJavaEnvVars(logger);
 
+    await showJavaSettings(logger);
+
     const jdks = discoverActionsJdks();
     for (const jdk of jdks) {
       checkJdkSettings(logger, jdk);