allow env override to disable browser launch

wizard-server/src/main/java/org/cobbzilla/wizard/server/listener/BrowserLauncherListener.java

@@ -7,34 +7,40 @@ import org.cobbzilla.wizard.server.RestServerLifecycleListenerBase;
 import org.cobbzilla.wizard.server.config.RestServerConfiguration;
 
 import java.awt.*;
+import java.util.Map;
 
 import static java.awt.Desktop.isDesktopSupported;
+import static java.lang.Boolean.parseBoolean;
 import static org.cobbzilla.util.daemon.ZillaRuntime.die;
+import static org.cobbzilla.util.daemon.ZillaRuntime.empty;
 
 @Slf4j
 public class BrowserLauncherListener extends RestServerLifecycleListenerBase {
 
+    public static final String DEFAULT_DISABLE_BROWSER_LAUNCH_ENV_VAR = "DISABLE_BROWSER_AUTO_LAUNCH";
+
+    public String getDisableBrowserAutoLaunchEnvVarName() { return DEFAULT_DISABLE_BROWSER_LAUNCH_ENV_VAR; }
+
     @Override public void onStart(RestServer server) {
         final RestServerConfiguration config = server.getConfiguration();
         final String baseUri = config.getPublicUriBase();
-        final Thread appThread = new Thread(new Runnable() {
-            @Override public void run() {
-                final Desktop desktop = isDesktopSupported() ? Desktop.getDesktop() : null;
-                if (desktop != null && desktop.isSupported(Desktop.Action.BROWSE)) {
-                    try {
-                        desktop.browse(URIUtil.toUri(baseUri));
-                    } catch (Exception e) {
-                        final String msg = "onStart: error launching default browser with url '" + baseUri + "':  " + e;
-                        log.error(msg, e);
-                        die(msg, e);
-                    }
-                } else {
-                    // no browser. tell the user where the server is listening via log statement
-                    final String versionInfo = server.getConfiguration().hasVersion()
-                            ? "\nVersion: " + server.getConfiguration().getVersion()
-                            : "";
-                    log.info("\n\n"+server.getConfiguration().getServerName()+" Successfully Started"+versionInfo+"\n\nNot launching browser: System lacks a browser and/or desktop window manager.\n\nWeb UI is: "+baseUri+"\nAPI is: "+baseUri+"/api\nHit Control-C to stop the server\n");
+        final Thread appThread = new Thread(() -> {
+            final boolean allowLaunch = configAllowsBrowserLaunch(config);
+            final Desktop desktop = allowLaunch && isDesktopSupported() ? Desktop.getDesktop() : null;
+            if (desktop != null && desktop.isSupported(Desktop.Action.BROWSE)) {
+                try {
+                    desktop.browse(URIUtil.toUri(baseUri));
+                } catch (Exception e) {
+                    final String msg = "onStart: error launching default browser with url '" + baseUri + "':  " + e;
+                    log.error(msg, e);
+                    die(msg, e);
                 }
+            } else {
+                // no browser. tell the user where the server is listening via log statement
+                final String versionInfo = server.getConfiguration().hasVersion()
+                        ? "\nVersion: " + server.getConfiguration().getVersion()
+                        : "";
+                log.info("\n\n"+server.getConfiguration().getServerName()+" Successfully Started"+versionInfo+"\n\nNot launching browser: System lacks a browser and/or desktop window manager.\n\nWeb UI is: "+baseUri+"\nAPI is: "+baseUri+"/api\nHit Control-C to stop the server\n");
             }
         });
         appThread.setName(BrowserLauncherListener.class.getSimpleName());
@@ -43,4 +49,15 @@ public class BrowserLauncherListener extends RestServerLifecycleListenerBase {
 
         super.onStart(server);
     }
+
+    public boolean configAllowsBrowserLaunch(RestServerConfiguration config) {
+        final Map<String, String> env = config.getEnvironment();
+        final String varName = getDisableBrowserAutoLaunchEnvVarName();
+        if (empty(varName)) {
+            log.warn("configAllowsBrowserLaunch: getDisableBrowserAutoLaunchEnvVarName() returned empty, not disabling");
+            return true;
+        }
+        return !parseBoolean(env.get(varName));
+    }
+
 }