HSFS is defaulting to PyHive instead of Spark on EMR (#171)

Also remove downloading of the certificates in the connect method for
PySpark clients. Certificates should already be present when the
application is started.

java/src/main/java/com/logicalclocks/hsfs/HopsworksConnection.java

@@ -85,10 +85,9 @@ public HopsworksConnection(String host, int port, String project, Region region,
     this.apiKeyFilePath = apiKeyFilePath;
     this.apiKeyValue = apiKeyValue;
 
-    HopsworksClient hopsworksClient = HopsworksClient.setupHopsworksClient(host, port, region, secretStore,
+    HopsworksClient.setupHopsworksClient(host, port, region, secretStore,
         hostnameVerification, trustStorePath, this.apiKeyFilePath, this.apiKeyValue);
     projectObj = getProject();
-    hopsworksClient.downloadCredentials(projectObj, certPath);
   }
 
   /**

java/src/main/java/com/logicalclocks/hsfs/metadata/HopsworksClient.java

@@ -21,7 +21,6 @@
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.google.common.annotations.VisibleForTesting;
 import com.logicalclocks.hsfs.FeatureStoreException;
-import com.logicalclocks.hsfs.Project;
 import com.logicalclocks.hsfs.SecretStore;
 import lombok.AllArgsConstructor;
 import lombok.Getter;
@@ -155,8 +154,4 @@ public <T> T handleRequest(HttpRequest request, Class<T> cls) throws IOException
   public <T> T handleRequest(HttpRequest request) throws IOException, FeatureStoreException {
     return hopsworksHttpClient.handleRequest(request, null);
   }
-
-  public void downloadCredentials(Project project, String certPath) throws IOException, FeatureStoreException {
-    certPwd = hopsworksHttpClient.downloadCredentials(project, certPath);
-  }
 }

java/src/main/java/com/logicalclocks/hsfs/metadata/HopsworksExternalClient.java

@@ -18,10 +18,8 @@
 
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.logicalclocks.hsfs.FeatureStoreException;
-import com.logicalclocks.hsfs.Project;
 import com.logicalclocks.hsfs.SecretStore;
 import org.apache.commons.io.FileUtils;
-import org.apache.commons.net.util.Base64;
 import org.apache.http.HttpHeaders;
 import org.apache.http.HttpHost;
 import org.apache.http.HttpRequest;
@@ -243,17 +241,4 @@ public <T> T handleRequest(HttpRequest request, ResponseHandler<T> responseHandl
       return httpClient.execute(httpHost, request, authHandler);
     }
   }
-
-  @Override
-  public String downloadCredentials(Project project, String certPath) throws IOException, FeatureStoreException {
-    LOGGER.info("Fetching certificates for the project");
-    ProjectApi projectApi = new ProjectApi();
-    Credentials credentials = projectApi.downloadCredentials(project);
-
-    FileUtils.writeByteArrayToFile(Paths.get(certPath, "keyStore.jks").toFile(),
-        Base64.decodeBase64(credentials.getkStore()));
-    FileUtils.writeByteArrayToFile(Paths.get(certPath, "trustStore.jks").toFile(),
-        Base64.decodeBase64(credentials.gettStore()));
-    return credentials.getPassword();
-  }
 }

java/src/main/java/com/logicalclocks/hsfs/metadata/HopsworksHttpClient.java

@@ -17,7 +17,6 @@
 package com.logicalclocks.hsfs.metadata;
 
 import com.logicalclocks.hsfs.FeatureStoreException;
-import com.logicalclocks.hsfs.Project;
 import org.apache.http.HttpRequest;
 import org.apache.http.client.ResponseHandler;
 
@@ -26,6 +25,4 @@
 public interface HopsworksHttpClient {
   <T> T handleRequest(HttpRequest request, ResponseHandler<T> responseHandler)
       throws IOException, FeatureStoreException;
-
-  String downloadCredentials(Project project, String certPath) throws IOException, FeatureStoreException;
 }

java/src/main/java/com/logicalclocks/hsfs/metadata/HopsworksInternalClient.java

@@ -17,7 +17,6 @@
 package com.logicalclocks.hsfs.metadata;
 
 import com.logicalclocks.hsfs.FeatureStoreException;
-import com.logicalclocks.hsfs.Project;
 import jdk.nashorn.internal.runtime.regexp.joni.exception.InternalException;
 import org.apache.http.HttpHeaders;
 import org.apache.http.HttpHost;
@@ -157,10 +156,4 @@ public <T> T handleRequest(HttpRequest request, ResponseHandler<T> responseHandl
       return httpClient.execute(httpHost, request, authHandler);
     }
   }
-
-  @Override
-  public String downloadCredentials(Project project, String certPath) {
-    // In Hopsworks internal client credentials are already setup.
-    return null;
-  }
 }

java/src/main/java/com/logicalclocks/hsfs/metadata/ProjectApi.java

@@ -30,7 +30,6 @@ public class ProjectApi {
   private static final Logger LOGGER = LoggerFactory.getLogger(ProjectApi.class);
 
   private static final String PROJECT_INFO_PATH = "/project/getProjectInfo{/projectName}";
-  private static final String CREDENTIALS_PATH = "/project{/projectId}/credentials";
 
   public Project get(String name) throws IOException, FeatureStoreException {
     HopsworksClient hopsworksClient = HopsworksClient.getInstance();
@@ -40,13 +39,4 @@ public Project get(String name) throws IOException, FeatureStoreException {
     LOGGER.info("Sending metadata request: " + uri);
     return hopsworksClient.handleRequest(new HttpGet(uri), Project.class);
   }
-
-  public Credentials downloadCredentials(Project project) throws IOException, FeatureStoreException {
-    HopsworksClient hopsworksClient = HopsworksClient.getInstance();
-    String uri = UriTemplate.fromTemplate(HopsworksClient.API_PATH + CREDENTIALS_PATH)
-        .set("projectId", project.getProjectId())
-        .expand();
-    LOGGER.info("Sending metadata request: " + uri);
-    return hopsworksClient.handleRequest(new HttpGet(uri), Credentials.class);
-  }
 }

java/src/test/java/com/logicalclocks/hsfs/TestHopsworksExternalClient.java

@@ -16,7 +16,6 @@
 package com.logicalclocks.hsfs;
 
 import com.logicalclocks.hsfs.metadata.Credentials;
-import com.logicalclocks.hsfs.metadata.HopsworksClient;
 import com.logicalclocks.hsfs.metadata.HopsworksExternalClient;
 import io.specto.hoverfly.junit.core.SimulationSource;
 import io.specto.hoverfly.junit.dsl.HttpBodyConverter;
@@ -53,21 +52,6 @@ public class TestHopsworksExternalClient {
         .willReturn(success().body(HttpBodyConverter.json(credentials)))
     ));
 
-  // @Test
-  // public void testReadAPIKey() throws IOException, FeatureStoreException {
-  //   CloseableHttpClient httpClient = HttpClients.createSystem();
-  //   try {
-  //     HopsworksConnection hc = HopsworksConnection.builder().host("35.241.253.100").hostnameVerification(false)
-  //             .project("demo_featurestore_admin000")
-  //             .apiKeyValue("ovVQksgJezSckjyK.ftO2YywCI6gZp4btlvWRnSDjSgyAQgCTRAoQTTSXBxPRMo0Dq029eAf3HVq3I6JO").build();
-  //     System.out.println("Connected");
-  //     FeatureStore fs = hc.getFeatureStore();
-  //     Assert.assertTrue(fs != null);
-  //   } catch (Exception e) {
-  // 	// Do not assert an error as this unit test method needs an external cluster
-  //   }
-  // }
-
   @Test
   public void testReadAPIKeyFromFile() throws IOException, FeatureStoreException {
     Path apiFilePath = Paths.get(System.getProperty("java.io.tmpdir"), "test.api");
@@ -79,19 +63,4 @@ public void testReadAPIKeyFromFile() throws IOException, FeatureStoreException {
     String apiKey = hopsworksExternalClient.readApiKey(null, null, apiFilePath.toString());
     Assert.assertEquals("hello", apiKey);
   }
-
-  @Test
-  public void testDownloadCredential() throws Exception {
-    Project project = new Project(1);
-
-    CloseableHttpClient httpClient = HttpClients.createSystem();
-    HttpHost httpHost = new HttpHost("test");
-
-    HopsworksExternalClient hopsworksExternalClient = new HopsworksExternalClient(
-        httpClient, httpHost);
-
-    HopsworksClient.setInstance(new HopsworksClient(hopsworksExternalClient));
-    String password = hopsworksExternalClient.downloadCredentials(project, System.getProperty("java.io.tmpdir"));
-    Assert.assertEquals(certPwd, password);
-  }
 }

python/hsfs/client/external.py

@@ -53,8 +53,6 @@ def __init__(
         self._base_url = "https://" + self._host + ":" + str(self._port)
         self._project_name = project
         self._region_name = region_name or self.DEFAULT_REGION
-        self._cert_folder_base = cert_folder
-        self._cert_folder = os.path.join(cert_folder, host, project)
 
         if api_key_value is not None:
             api_key = api_key_value
@@ -69,35 +67,45 @@ def __init__(
         project_info = self._get_project_info(self._project_name)
         self._project_id = str(project_info["projectId"])
 
-        os.makedirs(self._cert_folder, exist_ok=True)
-        credentials = self._get_credentials(self._project_id)
-        self._write_b64_cert_to_bytes(
-            str(credentials["kStore"]),
-            path=os.path.join(self._cert_folder, "keyStore.jks"),
-        )
-        self._write_b64_cert_to_bytes(
-            str(credentials["tStore"]),
-            path=os.path.join(self._cert_folder, "trustStore.jks"),
-        )
-
-        self._cert_key = str(credentials["password"])
-        with open(os.path.join(self._cert_folder, "material_passwd"), "w") as f:
-            f.write(str(credentials["password"]))
+        if cert_folder:
+            # On external Spark clients (Databricks, Spark Cluster),
+            # certificates need to be provided before the Spark application starts.
+            self._cert_folder_base = cert_folder
+            self._cert_folder = os.path.join(cert_folder, host, project)
+
+            os.makedirs(self._cert_folder, exist_ok=True)
+            credentials = self._get_credentials(self._project_id)
+            self._write_b64_cert_to_bytes(
+                str(credentials["kStore"]),
+                path=os.path.join(self._cert_folder, "keyStore.jks"),
+            )
+            self._write_b64_cert_to_bytes(
+                str(credentials["tStore"]),
+                path=os.path.join(self._cert_folder, "trustStore.jks"),
+            )
+
+            self._cert_key = str(credentials["password"])
+            with open(os.path.join(self._cert_folder, "material_passwd"), "w") as f:
+                f.write(str(credentials["password"]))
 
     def _close(self):
         """Closes a client and deletes certificates."""
-        if not os.path.exists("/dbfs/"):
-            # Clean up only on AWS, on databricks certs are needed at startup time
-            self._cleanup_file(os.path.join(self._cert_folder, "keyStore.jks"))
-            self._cleanup_file(os.path.join(self._cert_folder, "trustStore.jks"))
-            self._cleanup_file(os.path.join(self._cert_folder, "material_passwd"))
+        if self._cert_folder_base is None:
+            # On external Spark clients (Databricks, Spark Cluster),
+            # certificates need to be provided before the Spark application starts.
+            return
+
+        # Clean up only on AWS
+        self._cleanup_file(os.path.join(self._cert_folder, "keyStore.jks"))
+        self._cleanup_file(os.path.join(self._cert_folder, "trustStore.jks"))
+        self._cleanup_file(os.path.join(self._cert_folder, "material_passwd"))
+
         try:
             # delete project level
             os.rmdir(self._cert_folder)
             # delete host level
             os.rmdir(os.path.dirname(self._cert_folder))
             # on AWS base dir will be empty, and can be deleted otherwise raises OSError
-            # on Databricks there will still be the scripts and clients therefore raises OSError
             os.rmdir(self._cert_folder_base)
         except OSError:
             pass

python/hsfs/connection.py

@@ -16,6 +16,8 @@
 
 
 import os
+import importlib.util
+
 from requests.exceptions import ConnectionError
 
 from hsfs.decorators import connected, not_connected
@@ -36,10 +38,10 @@ class Connection:
     store but also any feature store which has been shared with the project you connect
     to.
 
-    This class provides convenience classmethods accesible from the `hsfs`-module:
+    This class provides convenience classmethods accessible from the `hsfs`-module:
 
     !!! example "Connection factory"
-        For convenience, `hsfs` provides a factory method, accesible from the top level
+        For convenience, `hsfs` provides a factory method, accessible from the top level
         module, so you don't have to import the `Connection` class manually:
 
         ```python
@@ -89,7 +91,7 @@ class Connection:
         trust_store_path: Path on the file system containing the Hopsworks certificates,
             defaults to `None`.
         cert_folder: The directory to store retrieved HopsFS certificates, defaults to
-            `"hops"`.
+            `"hops"`. Only required when running without a Spark environment.
         api_key_file: Path to a file containing the API Key, if provided,
             `secrets_store` will be ignored, defaults to `None`.
         api_key_value: API Key as string, if provided, `secrets_store` will be ignored`,
@@ -167,8 +169,8 @@ def connect(self):
         self._connected = True
         try:
             if client.base.Client.REST_ENDPOINT not in os.environ:
-                if os.path.exists("/dbfs/"):
-                    # databricks
+                if importlib.util.find_spec("pyspark"):
+                    # databricks, emr, external spark clusters
                     client.init(
                         "external",
                         self._host,
@@ -177,13 +179,9 @@ def connect(self):
                         self._region_name,
                         self._secrets_store,
                         self._hostname_verification,
-                        os.path.join("/dbfs", self._trust_store_path)
-                        if self._trust_store_path is not None
-                        else None,
-                        os.path.join("/dbfs", self._cert_folder),
-                        os.path.join("/dbfs", self._api_key_file)
-                        if self._api_key_file is not None
-                        else None,
+                        self._trust_store_path,
+                        None,
+                        self._api_key_file,
                         self._api_key_value,
                     )
                     engine.init("spark")

python/hsfs/engine/spark.py

@@ -14,7 +14,7 @@
 #   limitations under the License.
 #
 
-import os
+import importlib.util
 
 import pandas as pd
 import numpy as np
@@ -45,7 +45,7 @@ def __init__(self):
         self._spark_session.conf.set("hive.exec.dynamic.partition.mode", "nonstrict")
         self._spark_session.conf.set("spark.sql.hive.convertMetastoreParquet", "false")
 
-        if not os.path.exists("/dbfs/"):
+        if importlib.util.find_spec("pydoop"):
             # If we are on Databricks don't setup Pydoop as it's not available and cannot be easily installed.
             self._setup_pydoop()