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Add Templating (GoogleCloudPlatform#792)
* Add Templating 1. App Engine Sockets (moved from GoogleArchive) 2. J8 GAE Info now uses ThymeLeaf templating 3. Flex GAE Info for combat (WL’d only) sample 4. J8 Metadata - Only uses the Metadata server * add to parent 1. add a few things to the parent pom.xml (both app engine & appengine-java8) 2. Fix some copyrights.
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‎appengine-java8/gaeinfo/pom.xml

+6
Original file line numberDiff line numberDiff line change
@@ -62,6 +62,12 @@ Copyright 2017 Google Inc.
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<version>2.8.1</version>
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</dependency>
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<dependency>
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<groupId>org.thymeleaf</groupId>
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<artifactId>thymeleaf</artifactId>
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<version>3.0.7.RELEASE</version>
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</dependency>
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</dependencies>
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<build>

‎appengine-java8/gaeinfo/src/main/java/com/example/appengine/standard/GaeInfoServlet.java

+90-99
Original file line numberDiff line numberDiff line change
@@ -21,22 +21,23 @@
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import com.google.gson.Gson;
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import com.google.gson.GsonBuilder;
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import com.google.gson.JsonParser;
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import okhttp3.OkHttpClient;
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import okhttp3.Request;
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import okhttp3.Response;
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import java.io.IOException;
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import java.io.PrintWriter;
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import java.util.Enumeration;
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import java.util.Map;
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import java.util.Properties;
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import java.util.TreeMap;
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import java.util.concurrent.TimeUnit;
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import javax.servlet.annotation.WebServlet;
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import javax.servlet.http.Cookie;
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import javax.servlet.http.HttpServlet;
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import javax.servlet.http.HttpServletRequest;
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import javax.servlet.http.HttpServletResponse;
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import okhttp3.OkHttpClient;
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import okhttp3.Request;
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import okhttp3.Response;
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import org.thymeleaf.TemplateEngine;
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import org.thymeleaf.context.WebContext;
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import org.thymeleaf.templateresolver.ServletContextTemplateResolver;
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// [START example]
@@ -46,7 +47,7 @@
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urlPatterns = "/gaeinfo")
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public class GaeInfoServlet extends HttpServlet {
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49-
final String[] v1 = {
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private final String[] metaPath = {
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"/computeMetadata/v1/project/numeric-project-id", // (pending)
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"/computeMetadata/v1/project/project-id",
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"/computeMetadata/v1/instance/zone",
@@ -57,44 +58,30 @@ public class GaeInfoServlet extends HttpServlet {
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// "/computeMetadata/v1/instance/service-accounts/default/token"
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};
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60-
final String[] v1Acct = {
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final String[] metaServiceAcct = {
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"/computeMetadata/v1/instance/service-accounts/{account}/aliases",
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"/computeMetadata/v1/instance/service-accounts/{account}/email",
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"/computeMetadata/v1/instance/service-accounts/{account}/scopes",
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// Tokens work - but are a security risk to display
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// "/computeMetadata/v1/instance/service-accounts/{account}/token"
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};
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68-
final String metadata = "http://metadata.google.internal";
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private final String metadata = "http://metadata.google.internal";
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private TemplateEngine templateEngine;
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70-
public final OkHttpClient ok = new OkHttpClient.Builder()
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// Use OkHttp from Square as it's quite easy to use for simple fetches.
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private final OkHttpClient ok = new OkHttpClient.Builder()
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.readTimeout(500, TimeUnit.MILLISECONDS) // Don't dawdle
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.writeTimeout(500, TimeUnit.MILLISECONDS)
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.build();
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75-
public Gson gson = new GsonBuilder()
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// Setup to pretty print returned json
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private final Gson gson = new GsonBuilder()
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.setPrettyPrinting()
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.create();
78-
public JsonParser jp = new JsonParser();
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StringBuilder table(String title, String c) {
81-
StringBuilder sb = new StringBuilder();
82-
sb.append("<h3>");
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sb.append(title);
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sb.append("</h3><table>");
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sb.append(c);
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sb.append("</table>");
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return sb;
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}
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String tr(String c) {
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return "<tr>" + c + "</tr>";
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}
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String td(String s) {
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return "<td>" + s + "</td>";
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}
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private final JsonParser jp = new JsonParser();
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// Fetch Metadata
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String fetchMetadata(String key) throws IOException {
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Request request = new Request.Builder()
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.url(metadata + key)
@@ -106,122 +93,126 @@ String fetchMetadata(String key) throws IOException {
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return response.body().string();
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}
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109-
String recursMetadata(String prefix) throws IOException {
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String fetchJsonMetadata(String prefix) throws IOException {
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Request request = new Request.Builder()
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.url(metadata + prefix + "?recursive=true")
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.url(metadata + prefix )
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.addHeader("Metadata-Flavor", "Google")
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.get()
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.build();
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Response response = ok.newCall(request).execute();
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105+
// Convert json to prety json
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return gson.toJson(jp.parse(response.body().string()));
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}
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121-
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@Override
123-
public void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
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resp.setContentType("text/html");
125-
PrintWriter p = resp.getWriter();
126-
StringBuilder sb = new StringBuilder(4096);
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public void init() {
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// Setup ThymeLeaf
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ServletContextTemplateResolver templateResolver =
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new ServletContextTemplateResolver(this.getServletContext());
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templateResolver.setPrefix("/WEB-INF/templates/");
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templateResolver.setSuffix(".html");
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templateResolver.setCacheTTLMs(Long.valueOf(1200000L)); // TTL=20m
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128-
p.print("<html><body>");
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// Cache is set to true by default. Set to false if you want templates to
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// be automatically updated when modified.
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templateResolver.setCacheable(true);
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123+
templateEngine = new TemplateEngine();
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templateEngine.setTemplateResolver(templateResolver);
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}
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127+
128+
@Override
129+
public void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
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String key ="";
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final AppIdentityService appIdentity = AppIdentityServiceFactory.getAppIdentityService();
132+
WebContext ctx = new WebContext(req, resp, getServletContext(), req.getLocale());
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132-
sb.append(table("AppIdentity",
133-
tr(td("ServiceAccountName") + td(appIdentity.getServiceAccountName()))
134-
+ tr(td("GCS Bucket") + td(appIdentity.getDefaultGcsBucketName()))
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));
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resp.setContentType("text/html");
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136+
ctx.setVariable("production", SystemProperty.environment.value().name());
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ctx.setVariable("ServiceAccountName", appIdentity.getServiceAccountName());
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ctx.setVariable("gcs", appIdentity.getDefaultGcsBucketName());
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137-
sb.append(table("SystemProperties",
138-
tr(td("appId") + td(SystemProperty.applicationId.get()))
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+ tr(td("appVer") + td(SystemProperty.applicationVersion.get()))
140-
+ tr(td("version") + td(SystemProperty.version.get()))
141-
+ tr(td("environment") + td(SystemProperty.environment.get()))
142-
));
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ctx.setVariable("appId", SystemProperty.applicationId.get());
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ctx.setVariable("appVer", SystemProperty.applicationVersion.get());
142+
ctx.setVariable("version", SystemProperty.version.get());
143+
ctx.setVariable("environment", SystemProperty.environment.get());
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144145
// Environment Atributes
145146
ApiProxy.Environment env = ApiProxy.getCurrentEnvironment();
146147
Map<String, Object> attr = env.getAttributes();
148+
TreeMap<String, String> m = new TreeMap<>();
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148-
StringBuilder c = new StringBuilder(1024);
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for (String key : attr.keySet()) {
150-
Object o = attr.get(key);
150+
for (String k : attr.keySet()) {
151+
Object o = attr.get(k);
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152153
if (o.getClass().getCanonicalName().equals("java.lang.String")) {
153-
c.append(tr(td(key) + td((String) o)));
154+
m.put(k, (String) o);
155+
} else if (o.getClass().getCanonicalName().equals("java.lang.Boolean")) {
156+
m.put(k, ((Boolean) o).toString());
154157
} else {
155-
c.append(tr(td(key) + td(o.getClass().getCanonicalName())));
158+
m.put(k, "a " + o.getClass().getCanonicalName());
156159
}
157160
}
158-
sb.append(table("Environment Attributes", c.toString()));
161+
ctx.setVariable("attribs", m);
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160-
c = new StringBuilder(1024);
163+
m = new TreeMap<>();
161164
for (Enumeration<String> e = req.getHeaderNames(); e.hasMoreElements(); ) {
162-
String key = e.nextElement();
163-
String val = req.getHeader(key);
164-
c.append(tr(td(key) + td(val)));
165+
key = e.nextElement();
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m.put(key, req.getHeader(key));
165167
}
166-
sb.append(table("Headers", c.toString()));
168+
ctx.setVariable("headers", m);
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168170
Cookie[] cookies = req.getCookies();
171+
m = new TreeMap<>();
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if (cookies != null && cookies.length != 0) {
170-
c = new StringBuilder();
171173
for (Cookie co : cookies) {
172-
c.append(tr(td(co.getName()) + td(co.getValue()) + td(co.getComment())
173-
+ td(co.getPath()) + td(Integer.toString(co.getMaxAge()))));
174+
m.put(co.getName(), co.getValue());
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}
175-
sb.append(table("Cookies", c.toString()));
176176
}
177+
ctx.setVariable("cookies", m);
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178179
Properties properties = System.getProperties();
179-
c = new StringBuilder(1024);
180+
m = new TreeMap<>();
180181
for (Enumeration e = properties.propertyNames(); e.hasMoreElements(); ) {
181-
String key = (String) e.nextElement();
182-
c.append(tr(td(key) + td((String) properties.get(key))));
182+
key = (String) e.nextElement();
183+
m.put(key, (String) properties.get(key));
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}
184-
sb.append(table("Java SystemProperties", c.toString()));
185+
ctx.setVariable("systemprops", m);
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186187
Map<String, String> envVar = System.getenv();
187-
c = new StringBuilder(1024);
188-
for (String key : envVar.keySet()) {
189-
c.append(tr(td(key) + td(envVar.get(key))));
190-
}
191-
sb.append(table("Envirionment Variables", c.toString()));
188+
m = new TreeMap<>(envVar);
189+
ctx.setVariable("envvar", m);
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191+
// The metadata server is only on a production system
193192
if (SystemProperty.environment.value() == SystemProperty.Environment.Value.Production) {
194-
c = new StringBuilder(1024);
195-
for (String key : v1) {
196-
String val = fetchMetadata(key);
197-
if (val != null) {
198-
c.append(tr(td(key) + td(val)));
199-
}
193+
194+
m = new TreeMap<>();
195+
for (String k : metaPath) {
196+
m.put(k, fetchMetadata(key));
200197
}
201-
sb.append(table("Metadata", c.toString()));
202-
203-
c = new StringBuilder(1024);
204-
for (String key : v1Acct) {
205-
key = key.replace("{account}", appIdentity.getServiceAccountName());
206-
String val = fetchMetadata(key);
207-
if (val != null) {
208-
c.append(tr(td(key) + td(val)));
209-
}
198+
ctx.setVariable("Metadata", m.descendingMap());
199+
200+
m = new TreeMap<>();
201+
for (String k : metaServiceAcct) {
202+
// substitute a service account for {account}
203+
k = k.replace("{account}", appIdentity.getServiceAccountName());
204+
m.put(k, fetchMetadata(k));
210205
}
211-
sb.append(table("ServiceAccount Metadata", c.toString()));
212-
213-
sb.append("<h3>Recursive service-accounts</h3><pre><code>"
214-
+ recursMetadata("/computeMetadata/v1/instance/service-accounts/")
215-
+ "</code></pre>");
216-
sb.append("<h3>Recursive all metadata</h3><pre><code>"
217-
+ recursMetadata("/")
218-
+ "</code></pre>");
219-
}
206+
ctx.setVariable("sam", m.descendingMap());
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221-
sb.append("</body></html>");
222-
p.append(sb);
223-
p.close();
208+
// Recursivly get all info about service accounts -- Note tokens are leftout by default.
209+
ctx.setVariable("rsa",
210+
fetchJsonMetadata("/computeMetadata/v1/instance/service-accounts/?recursive=true"));
211+
// Recursivly get all data on Metadata server.
212+
ctx.setVariable("ram", fetchJsonMetadata("/?recursive=true"));
213+
}
224214

215+
templateEngine.process("index", ctx, resp.getWriter());
225216
}
226217
}
227218
// [END example]

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