Google Cloud Storage API无法在App Engine上获取应用程序默认凭据，以查找Compute Engine错误

Question

I have custom code using the Google Cloud Storage API library in a Play (v2.5.12) application running on the Google App Engine, not the Compute Engine. The Cloud Storage API is enabled. I am trying to send a file (as a file stream) to a storage bucket in the Google Cloud Platform.

Here is the code:

public static String sendFileToBucket(InputStream fileStream, String fileName) throws IOException {
    Logger.info("GoogleStorage: sendFileToBucket: Starting...");

    Storage storage = StorageOptions.getDefaultInstance().getService();

    // Modify access list to allow all users with link to read file
    List<Acl> acls = new ArrayList<>();
    acls.add(Acl.of(Acl.User.ofAllUsers(), Acl.Role.READER));
    // the inputstream is closed by default, so we don't need to close it
    // here
    Blob blob = null;
    blob = storage.create(BlobInfo.newBuilder(BUCKET_NAME, fileName).setAcl(acls).build(),
            fileStream);

    return blob.getMediaLink();

}

The code I wrote is using this example:

https://cloud.google.com/appengine/docs/flexible/java/using-cloud-storage#application_code

I am running into an error when I attempt to set the Storage object:

Storage storage = StorageOptions.getDefaultInstance().getService();

Here is the full error:

 [warn] c.g.a.o.ComputeEngineCredentials - Failed to detect whether we are running on Google Compute Engine.
java.net.SocketException: Network is unreachable: connect
        at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method)
        at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:85)
        at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
        at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
        at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
        at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
        at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
        at java.net.Socket.connect(Socket.java:589)
        at sun.net.NetworkClient.doConnect(NetworkClient.java:175)
        at sun.net.www.http.HttpClient.openServer(HttpClient.java:432)
[warn] c.g.a.o.ComputeEngineCredentials - Failed to detect whether we are running on Google Compute Engine.
java.net.SocketException: Network is unreachable: connect
        at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method)
        at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:85)
        at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
        at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
        at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
        at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
        at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
        at java.net.Socket.connect(Socket.java:589)
        at sun.net.NetworkClient.doConnect(NetworkClient.java:175)
        at sun.net.www.http.HttpClient.openServer(HttpClient.java:432)
[warn] c.g.a.o.ComputeEngineCredentials - Failed to detect whether we are running on Google Compute Engine.
java.net.SocketException: Network is unreachable: connect
        at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method)
        at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:85)
        at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
        at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
        at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
        at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
        at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
        at java.net.Socket.connect(Socket.java:589)
        at sun.net.NetworkClient.doConnect(NetworkClient.java:175)
        at sun.net.www.http.HttpClient.openServer(HttpClient.java:432)
com.google.cloud.storage.StorageException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
        at com.google.cloud.storage.spi.v1.HttpStorageRpc.translate(HttpStorageRpc.java:220)
        at com.google.cloud.storage.spi.v1.HttpStorageRpc.create(HttpStorageRpc.java:291)
        at com.google.cloud.storage.StorageImpl.create(StorageImpl.java:148)
        at google.GoogleStorage.sendFileToBucket(GoogleStorage.java:80)
        at controllers.AdultPTPController.adultPTPUpdateFields(AdultPTPController.java:3878)
        at controllers.AdultPTPController.adultPTPUpdate(AdultPTPController.java:3544)
        at router.Routes$$anonfun$routes$1$$anonfun$applyOrElse$10$$anonfun$apply$10.apply(Routes.scala:2083)
        at router.Routes$$anonfun$routes$1$$anonfun$applyOrElse$10$$anonfun$apply$10.apply(Routes.scala:2083)
        at play.core.routing.HandlerInvokerFactory$$anon$4.resultCall(HandlerInvoker.scala:157)
        at play.core.routing.HandlerInvokerFactory$$anon$4.resultCall(HandlerInvoker.scala:156)
        at play.core.routing.HandlerInvokerFactory$JavaActionInvokerFactory$$anon$14$$anon$3$$anon$1.invocation(HandlerInvoker.scala:136)
        at play.core.j.JavaAction$$anon$1.call(JavaAction.scala:73)
        at play.http.HttpRequestHandler$1.call(HttpRequestHandler.java:54)
        at play.core.j.JavaAction$$anonfun$7.apply(JavaAction.scala:108)
        at play.core.j.JavaAction$$anonfun$7.apply(JavaAction.scala:108)
        at scala.concurrent.impl.Future$PromiseCompletingRunnable.liftedTree1$1(Future.scala:24)
        at scala.concurrent.impl.Future$PromiseCompletingRunnable.run(Future.scala:24)
        at play.core.j.HttpExecutionContext$$anon$2.run(HttpExecutionContext.scala:56)
        at play.api.libs.iteratee.Execution$trampoline$.execute(Execution.scala:70)
        at play.core.j.HttpExecutionContext.execute(HttpExecutionContext.scala:48)
        at scala.concurrent.impl.Future$.apply(Future.scala:31)
        at scala.concurrent.Future$.apply(Future.scala:492)
        at play.core.j.JavaAction.apply(JavaAction.scala:108)
        at play.api.mvc.Action$$anonfun$apply$2$$anonfun$apply$5$$anonfun$apply$6.apply(Action.scala:112)
        at play.api.mvc.Action$$anonfun$apply$2$$anonfun$apply$5$$anonfun$apply$6.apply(Action.scala:112)
        at play.utils.Threads$.withContextClassLoader(Threads.scala:21)
        at play.api.mvc.Action$$anonfun$apply$2$$anonfun$apply$5.apply(Action.scala:111)
        at play.api.mvc.Action$$anonfun$apply$2$$anonfun$apply$5.apply(Action.scala:110)
        at scala.Option.map(Option.scala:146)
        at play.api.mvc.Action$$anonfun$apply$2.apply(Action.scala:110)
        at play.api.mvc.Action$$anonfun$apply$2.apply(Action.scala:103)
        at scala.concurrent.Future$$anonfun$flatMap$1.apply(Future.scala:251)
        at scala.concurrent.Future$$anonfun$flatMap$1.apply(Future.scala:249)
        at scala.concurrent.impl.CallbackRunnable.run(Promise.scala:32)
        at akka.dispatch.BatchingExecutor$AbstractBatch.processBatch(BatchingExecutor.scala:55)
        at akka.dispatch.BatchingExecutor$BlockableBatch$$anonfun$run$1.apply$mcV$sp(BatchingExecutor.scala:91)
        at akka.dispatch.BatchingExecutor$BlockableBatch$$anonfun$run$1.apply(BatchingExecutor.scala:91)
        at akka.dispatch.BatchingExecutor$BlockableBatch$$anonfun$run$1.apply(BatchingExecutor.scala:91)
        at scala.concurrent.BlockContext$.withBlockContext(BlockContext.scala:72)
        at akka.dispatch.BatchingExecutor$BlockableBatch.run(BatchingExecutor.scala:90)
        at akka.dispatch.TaskInvocation.run(AbstractDispatcher.scala:39)
        at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(AbstractDispatcher.scala:415)
        at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
        at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
        at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
        at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)
Caused by: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
        at sun.security.ssl.Alerts.getSSLException(Alerts.java:192)
        at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1949)
        at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:302)
        at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:296)
        at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1509)
        at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:216)
        at sun.security.ssl.Handshaker.processLoop(Handshaker.java:979)
        at sun.security.ssl.Handshaker.process_record(Handshaker.java:914)
        at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1062)
        at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1375)
        at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1403)
        at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1387)
        at sun.net.www.protocol.https.HttpsClient.afterConnect(HttpsClient.java:559)
        at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:185)
        at sun.net.www.protocol.http.HttpURLConnection.getOutputStream0(HttpURLConnection.java:1283)
        at sun.net.www.protocol.http.HttpURLConnection.access$100(HttpURLConnection.java:90)
        at sun.net.www.protocol.http.HttpURLConnection$8.run(HttpURLConnection.java:1250)
        at sun.net.www.protocol.http.HttpURLConnection$8.run(HttpURLConnection.java:1248)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.security.AccessController.doPrivilegedWithCombiner(AccessController.java:782)
        at sun.net.www.protocol.http.HttpURLConnection.getOutputStream(HttpURLConnection.java:1247)
        at sun.net.www.protocol.https.HttpsURLConnectionImpl.getOutputStream(HttpsURLConnectionImpl.java:250)
        at com.google.api.client.http.javanet.NetHttpRequest.execute(NetHttpRequest.java:77)
        at com.google.api.client.http.HttpRequest.execute(HttpRequest.java:981)
        at com.google.api.client.googleapis.media.MediaHttpUploader.executeCurrentRequestWithoutGZip(MediaHttpUploader.java:545)
        at com.google.api.client.googleapis.media.MediaHttpUploader.executeCurrentRequest(MediaHttpUploader.java:562)
        at com.google.api.client.googleapis.media.MediaHttpUploader.directUpload(MediaHttpUploader.java:360)
        at com.google.api.client.googleapis.media.MediaHttpUploader.upload(MediaHttpUploader.java:334)
        at com.google.api.client.googleapis.services.AbstractGoogleClientRequest.executeUnparsed(AbstractGoogleClientRequest.java:428)
        at com.google.api.client.googleapis.services.AbstractGoogleClientRequest.executeUnparsed(AbstractGoogleClientRequest.java:352)
        at com.google.api.client.googleapis.services.AbstractGoogleClientRequest.execute(AbstractGoogleClientRequest.java:469)
        at com.google.cloud.storage.spi.v1.HttpStorageRpc.create(HttpStorageRpc.java:288)
        ... 44 more
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
        at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:387)
        at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:292)
        at sun.security.validator.Validator.validate(Validator.java:260)
        at sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:324)
        at sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:229)
        at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:124)
        at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1491)
        ... 71 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
        at sun.security.provider.certpath.SunCertPathBuilder.build(SunCertPathBuilder.java:141)
        at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:126)
        at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:280)
        at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:382)
        ... 77 more

That error confuses me since I am running the application on the Google App Engine, not the Compute Engine. I checked the Service Accounts, I only have the default App Engine account and a Service Account that I created for Google Drive Access.

I am using the Application Default Credentials as stated here:

https://cloud.google.com/docs/authentication/production

The default App Engine Service Account does not have a key, but would creating a key and then try this code example:

Storage storage = StorageOptions.newBuilder()
    .setCredentials(ServiceAccountCredentials.fromStream(new FileInputStream("/path/to/my/key.json")))
    .build()
    .getService();

from this page:

https://github.com/GoogleCloudPlatform/google-cloud-java/blob/master/README.md#authentication

fix my issue?

I found a few posts on this, but I cannot decipher how to implement in my code, so they aren't helping me:

Default credential for app engine project accessing google cloud storage?

Providing Credentials to Google Cloud Storage API

I appreciate the help.

------------------------- EDIT 3/23/2018 --------------------------------

After receiving the error:

java.io.IOException: The Application Default Credentials are not available. They are available if running in Google Compute Engine. Otherwise, the environment variable GOOGLE_APPLICATION_CREDENTIALS must be defined pointing to a file defining the credentials. See https://developers.google.com/accounts/docs/application-default-credentials for more information.

and following the link, it states on that page:

If your application runs on Compute Engine, Kubernetes Engine, the App Engine flexible environment, or Cloud Functions, you don't need to create your own service account.

but I am using the App Engine flex environment, which confuses me.

So, I went to the Google Cloud Project, selected IAM & Admin > Service Accounts and for the default App Engine service account, I created a key, downloaded, and changed my code to:

public static String sendFileToBucket(InputStream fileStream, String fileName) throws IOException {
    Logger.info("GoogleStorage: sendFileToBucket: Starting...");

    GoogleCredential credential = null;
    String credentialsFileName = "";
    Storage storage = null;

    Logger.info("GoogleStorage: authorize: Getting credentialsFileName path...");
    credentialsFileName = Configuration.root().getString("google.storage.credentials.file");
    Logger.info("GoogleStorage: authorize: credentialsFileName = " + credentialsFileName);

    Logger.info("GoogleStorage: authorize: Setting InputStream...");
    InputStream in = GoogleStorage.class.getClassLoader().getResourceAsStream(credentialsFileName);
    if (in == null) {
        Logger.info("GoogleStorage: authorize: InputStream is null");
    }
    Logger.info("GoogleStorage: authorize: InputStream set...");

    storage = StorageOptions.newBuilder()
            .setCredentials(ServiceAccountCredentials.fromStream(in))
            .build()
            .getService();

    // Modify access list to allow all users with link to read file
    List<Acl> acls = new ArrayList<>();
    acls.add(Acl.of(Acl.User.ofAllUsers(), Acl.Role.READER));
    // the inputstream is closed by default, so we don't need to close it
    // here
    Blob blob = null;
    blob = storage.create(BlobInfo.newBuilder(BUCKET_NAME, fileName).setAcl(acls).build(),
            fileStream);

    return blob.getMediaLink();

}

I do not receive the original error and it does build the Storage object. However, when it attempts to build the Blob object, I receive this error:

[warn] c.g.a.c.h.HttpTransport - exception thrown while executing request
javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
...
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

...
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
...
com.google.cloud.storage.StorageException: Error getting access token for service account:
...
Caused by: java.io.IOException: Error getting access token for service account:
...
Caused by: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
...
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
...
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
...

which I see:

com.google.cloud.storage.StorageException: Error getting access token for service account

So, I am guessing it is still something with the Service Account credentials.

Answer 1

What about trying to get application default credentials directly?

Could you please try the following approach:

GoogleCredentials applicationDefault = GoogleCredentials.getApplicationDefault();
if (applicationDefault.createScopedRequired()){
    applicationDefault = applicationDefault.createScoped(Collections.singleton("https://www.googleapis.com/auth/devstorage.full_control"));
}
final Storage storage = StorageOptions.newBuilder()
                                      .setCredentials(applicationDefault)
                                      .build()
                                      .getService();

Also, are you using AppEngine standard or flexible?

Answer 2

I had faced similar issues with Compute Engine. Then, I used a static path on the environment to store all the properties required. This is my variables class:

public class Variables(){

    public Variables(){
        if(!loaded)init();
    }

    final static Logger logger = Logger.getLogger(Variables.class); 
    static Properties prop = new Properties();
    static InputStream input = null;
    static boolean loaded = false;

    private static void init(){         
        try{
            logger.info("Loading properties for server . . . ");
            //Do not change this path
            input = new FileInputStream("/path-on-server/app-config.properties");
            prop.load(input);
            loaded = true;
        }catch(Exception ex){
            logger.error("Error while loading configuration file for server. . . ");
            logger.error(ex.getMessage());
        }           
        finally{
            try {
                input.close();
            } catch (IOException e) {               
                e.printStackTrace();
            }
        }
    }

    public static final String gcsClientId          =  getGCSClientId();    
    public static final String gcsClientEmail       =  getGCSClientEmail(); 
    public static final String gcsPrivateKey        =  getGCSPrivateKey();  
    public static final String gcsPrivateKeyId      =  getGCSPrivateKeyId();    
    public static final String gcsProjectId         =  getGCSProjectId();
    public static final String gcsBucketName        =  getGCSBucketName();

    private static String getGCSClientId(){     
        if(!loaded)init();
        return prop.getProperty("storageClientId");
    }

    private static String getGCSClientEmail(){      
        if(!loaded)init();
        return prop.getProperty("storageClientEmail");
    }

    private static String getGCSPrivateKeyId(){     
        if(!loaded)init();
        return prop.getProperty("storagePrivateKeyId");
    }

    private static String getGCSPrivateKey(){       
        if(!loaded)init();
        return prop.getProperty("storagePrivateKey");
    }

    private static String getGCSProjectId(){
        if(!loaded)init();
        return prop.getProperty("storageProjectId");
    }

    private static String getGCSBucketName(){
        if(!loaded)init();
        return prop.getProperty("storageBucketName");
    }
}

And then use the variables class in my Google Storage:

public class GoogleCloudStorage {

    Variables variables = new Variables();

    public GoogleCloudStorage() {       
        setDefaultStorageCredentials();
    }

    private static Storage storage = null;
    private static String bucketName = null;
    private static Credentials credentials = null;

    private void setDefaultStorageCredentials() {
        try {
            this.bucketName = variables.gcsBucketName;
            credentials = ServiceAccountCredentials.fromPkcs8(variables.gcsClientId, variables.gcsClientEmail,
                    variables.gcsPrivateKey, variables.gcsPrivateKeyId, null);          
            storage = StorageOptions.newBuilder()
                    .setCredentials(credentials)
                    .setProjectId(variables.gcsProjectId).build().getService();

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Hope this helps.