Connecting your visualization software to Hadoop on Google Cloud

Initializing your environment

1. In the Google Cloud console, activate Cloud Shell.

   Activate Cloud Shell

2. In Cloud Shell, set environment variables with your project ID, and the region and zones of the Dataproc clusters:

   export PROJECT_ID=$(gcloud info --format='value(config.project)')
   export REGION=us-central1
   export ZONE=us-central1-b
   

   You can choose any region and zone, but keep them consistent as you follow this tutorial.

Setting up a service account

1. In Cloud Shell, create a service account.

   gcloud iam service-accounts create cluster-service-account \
     --description="The service account for the cluster to be authenticated as." \
     --display-name="Cluster service account"
   

   The cluster uses this account to access Google Cloud resources.

2. Add the following roles to the service account:

   • Dataproc Worker: to create and manage Dataproc clusters.
   • Cloud SQL Editor: for Ranger to connect to its database using Cloud SQL Proxy.

   • Cloud KMS CryptoKey Decrypter: to decrypt the passwords encrypted with Cloud KMS.

     bash -c 'array=( dataproc.worker cloudsql.editor cloudkms.cryptoKeyDecrypter )
     for i in "${array[@]}"
     do
       gcloud projects add-iam-policy-binding ${PROJECT_ID} \
         --member "serviceAccount:cluster-service-account@${PROJECT_ID}.iam.gserviceaccount.com" \
         --role roles/$i
     done'
     

Creating the backend cluster

In this section, you create the backend cluster where Ranger is located. You also create the Ranger database to store the policy rules, and a sample table in Hive to apply the Ranger policies.

Create the Ranger database instance

1. Create a MySQL instance to store the Apache Ranger policies:

   export CLOUD_SQL_NAME=cloudsql-mysql
   gcloud sql instances create ${CLOUD_SQL_NAME} \
       --tier=db-n1-standard-1 --region=${REGION}
   

   This command creates an instance called cloudsql-mysql with the machine type db-n1-standard-1 located in the region specified by the ${REGION} variable. For more information, see the Cloud SQL documentation.

2. Set the instance password for the user root connecting from any host. You can use the example password for demonstrative purposes, or create your own. If you create your own password, use a minimum of eight characters, including at least one letter and one number.

   gcloud sql users set-password root \
     --host=% --instance ${CLOUD_SQL_NAME} --password mysql-root-password-99
   

Encrypt the passwords

In this section, you create a cryptographic key to encrypt the passwords for Ranger and MySQL. To prevent exfiltration, you store the cryptographic key in Cloud KMS. For security purposes, you can't view, extract, or export the key bits.

You use the cryptographic key to encrypt the passwords and write them into files. You upload these files into a Cloud Storage bucket so that they are accessible to the service account that is acting on behalf of the clusters. The service account can decrypt these files because it has the cloudkms.cryptoKeyDecrypter role and access to the files and the cryptographic key. Even if a file is exfiltrated, the file can't be decrypted without the role and the key.

As an extra security measure, you create separate password files for each service. This action minimizes the potential impacted area if a password is exfiltrated.

For more information about key management, see the Cloud KMS documentation.

1. In Cloud Shell, create a Cloud KMS key ring to hold your keys:

   gcloud kms keyrings create my-keyring --location global
   

2. To encrypt your passwords, create a Cloud KMS cryptographic key:

   gcloud kms keys create my-key \
     --location global \
     --keyring my-keyring \
     --purpose encryption
   

3. Encrypt your Ranger admin user password using the key. You can use the example password or create your own. Your password must be a minimum of eight characters, including at least one letter and one number.

   echo "ranger-admin-password-99" | \
   gcloud kms encrypt \
     --location=global \
     --keyring=my-keyring \
     --key=my-key \
     --plaintext-file=- \
     --ciphertext-file=ranger-admin-password.encrypted
   

4. Encrypt your Ranger database admin user password with the key:

   echo "ranger-db-admin-password-99" | \
   gcloud kms encrypt \
     --location=global \
     --keyring=my-keyring \
     --key=my-key \
     --plaintext-file=- \
     --ciphertext-file=ranger-db-admin-password.encrypted
   

5. Encrypt your MySQL root password with the key:

   echo "mysql-root-password-99" | \
   gcloud kms encrypt \
     --location=global \
     --keyring=my-keyring \
     --key=my-key \
     --plaintext-file=- \
     --ciphertext-file=mysql-root-password.encrypted
   

6. Create a Cloud Storage bucket to store encrypted password files:

   gcloud storage buckets create gs://${PROJECT_ID}-ranger --location=${REGION}
   

7. Upload the encrypted password files to the Cloud Storage bucket:

   gcloud storage cp *.encrypted gs://${PROJECT_ID}-ranger
   

Create the cluster

In this section, you create a backend cluster with Ranger support. For more information about the Ranger optional component in Dataproc, see the Dataproc Ranger Component documentation page.

1. In Cloud Shell, create a Cloud Storage bucket to store the Apache Solr audit logs:

   gcloud storage buckets create gs://${PROJECT_ID}-solr --location=${REGION}
   

2. Export all the variables required in order to create the cluster:

   export BACKEND_CLUSTER=backend-cluster
   
   export PROJECT_ID=$(gcloud info --format='value(config.project)')
   export REGION=us-central1
   export ZONE=us-central1-b
   export CLOUD_SQL_NAME=cloudsql-mysql
   
   export RANGER_KMS_KEY_URI=\
   projects/${PROJECT_ID}/locations/global/keyRings/my-keyring/cryptoKeys/my-key
   
   export RANGER_ADMIN_PWD_URI=\
   gs://${PROJECT_ID}-ranger/ranger-admin-password.encrypted
   
   export RANGER_DB_ADMIN_PWD_URI=\
   gs://${PROJECT_ID}-ranger/ranger-db-admin-password.encrypted
   
   export MYSQL_ROOT_PWD_URI=\
   gs://${PROJECT_ID}-ranger/mysql-root-password.encrypted
   

   For convenience, some of the variables that you set before are repeated in this command so you can modify them as you require.

   The new variables contain:

   • The name of the backend cluster.
   • The URI of the cryptographic key so that the service account can decrypt the passwords.
   • The URI of the files containing the encrypted passwords.

   If you used a different key ring or key, or different filenames, use the corresponding values in your command.

3. Create the backend Dataproc cluster:

   gcloud beta dataproc clusters create ${BACKEND_CLUSTER} \
     --optional-components=SOLR,RANGER \
     --region ${REGION} \
     --zone ${ZONE} \
     --enable-component-gateway \
     --scopes=default,sql-admin \
     --service-account=cluster-service-account@${PROJECT_ID}.iam.gserviceaccount.com \
     --properties="\
   dataproc:ranger.kms.key.uri=${RANGER_KMS_KEY_URI},\
   dataproc:ranger.admin.password.uri=${RANGER_ADMIN_PWD_URI},\
   dataproc:ranger.db.admin.password.uri=${RANGER_DB_ADMIN_PWD_URI},\
   dataproc:ranger.cloud-sql.instance.connection.name=${PROJECT_ID}:${REGION}:${CLOUD_SQL_NAME},\
   dataproc:ranger.cloud-sql.root.password.uri=${MYSQL_ROOT_PWD_URI},\
   dataproc:solr.gcs.path=gs://${PROJECT_ID}-solr,\
   hive:hive.server2.thrift.http.port=10000,\
   hive:hive.server2.thrift.http.path=cliservice,\
   hive:hive.server2.transport.mode=http"
   

   This command has the following properties:

   • The final three lines in the command are the Hive properties to configure HiveServer2 in HTTP mode, so that Apache Knox can call Apache Hive through HTTP.
   • The other parameters in the command operate as follows:
     • The --optional-components=SOLR,RANGER parameter enables Apache Ranger and its Solr dependency.
     • The --enable-component-gateway parameter enables the Dataproc Component Gateway to make the Ranger and other Hadoop user interfaces available directly from the cluster page in Google Cloud console. When you set this parameter, there is no need for SSH tunneling to the backend master node.
     • The --scopes=default,sql-admin parameter authorizes Apache Ranger to access its Cloud SQL database.

If you need to create an external Hive metastore that persists beyond the lifetime of any cluster and can be used across multiple clusters, see Using Apache Hive on Dataproc. To run the procedure, you must run the table creation examples directly on Beeline. While the gcloud dataproc jobs submit hive commands use Hive binary transport, these commands aren't compatible with HiveServer2 when it's configured in HTTP mode.

Create a sample Hive table

1. In Cloud Shell, create a Cloud Storage bucket to store a sample Apache Parquet file:

   gcloud buckets create gs://${PROJECT_ID}-hive --location=${REGION}
   

2. Copy a publicly available sample Parquet file into your bucket:

   gcloud storage cp gs://hive-solution/part-00000.parquet \
     gs://${PROJECT_ID}-hive/dataset/transactions/part-00000.parquet
   

3. Connect to the master node of the backend cluster you created in the previous section using SSH:

   gcloud compute ssh --zone ${ZONE} ${BACKEND_CLUSTER}-m
   

   The name of your cluster master node is the name of the cluster followed by -m. The HA cluster master node names have an extra suffix.

   If it's your first time connecting to your master node from Cloud Shell, you are prompted to generate SSH keys.

4. In the terminal you opened with SSH, connect to the local HiveServer2 using Apache Beeline, which is pre-installed on the master node:

   beeline -u "jdbc:hive2://localhost:10000/;transportMode=http;httpPath=cliservice admin admin-password"\
     --hivevar PROJECT_ID=$(gcloud info --format='value(config.project)')
   

   This command starts the Beeline command-line tool and passes the name of your Google Cloud project in an environment variable.

   Hive isn't performing any user authentication, but to perform most tasks it requires a user identity. The admin user here is a default user that's configured in Hive. The identity provider that you configure with Apache Knox later in this tutorial handles user authentication for any requests that come from BI tools.

5. In the Beeline prompt, create a table using the Parquet file you previously copied to your Hive bucket:

   CREATE EXTERNAL TABLE transactions
     (SubmissionDate DATE, TransactionAmount DOUBLE, TransactionType STRING)
     STORED AS PARQUET
     LOCATION 'gs://${PROJECT_ID}-hive/dataset/transactions';
   

6. Verify that the table was created correctly:

   SELECT *
     FROM transactions
     LIMIT 10;
   
   SELECT TransactionType, AVG(TransactionAmount) AS AverageAmount
     FROM transactions
     WHERE SubmissionDate = '2017-12-22'
     GROUP BY TransactionType;
   

   The results of the two queries appear in the Beeline prompt.

7. Exit the Beeline command-line tool:

   !quit
   

8. Copy the internal DNS name of the backend master:

   hostname -A | tr -d '[:space:]'; echo
   

   You use this name in the next section as backend-master-internal-dns-name to configure the Apache Knox topology. You also use the name to configure a service in Ranger.

9. Exit the terminal on the node:

   exit
   

Creating the proxy cluster

In this section, you create the proxy cluster that has the Apache Knox initialization action.

Create a topology

1. In Cloud Shell, clone the Dataproc initialization-actions GitHub repository:

   git clone https://github.com/GoogleCloudDataproc/initialization-actions.git
   

2. Create a topology for the backend cluster:

   export KNOX_INIT_FOLDER=`pwd`/initialization-actions/knox
   cd ${KNOX_INIT_FOLDER}/topologies/
   mv example-hive-nonpii.xml hive-us-transactions.xml
   

   Apache Knox uses the name of the file as the URL path for the topology. In this step, you change the name to represent a topology called hive-us-transactions. You can then access the fictitious transaction data that you loaded into Hive in Create a sample Hive table

3. Edit the topology file:

   vi hive-us-transactions.xml
   

   To see how backend services are configured, see the topology descriptor file. This file defines a topology that points to one or more backend services. Two services are configured with sample values: WebHDFS and HIVE. The file also defines the authentication provider for the services in this topology and the authorization ACLs.

4. Add the data analyst sample LDAP user identity sara.

   <param>
      <name>hive.acl</name>
      <value>admin,sara;*;*</value>
   </param>
   

   Adding the sample identity lets the user access the Hive backend service through Apache Knox.

5. Change the HIVE URL to point to the backend cluster Hive service. You can find the HIVE service definition at the bottom of the file, under WebHDFS.

   <service>
     <role>HIVE</role>
     <url>http://<backend-master-internal-dns-name>:10000/cliservice</url>
   </service>
   

6. Replace the <backend-master-internal-dns-name> placeholder with the internal DNS name of the backend cluster that you acquired in Create a sample Hive table.

7. Save the file and close the editor.

To create additional topologies, repeat the steps in this section. Create one independent XML descriptor for each topology.

In Create the proxy cluster you copy these files into a Cloud Storage bucket. To create new topologies, or change them after you create the proxy cluster, modify the files, and upload them again to the bucket. The Apache Knox initialization action creates a cron job that regularly copies changes from the bucket to the proxy cluster.

Configure the SSL/TLS certificate

A client uses an SSL/TLS certificate when it communicates with Apache Knox. The initialization action can generate a self-signed certificate, or you can provide your CA-signed certificate.

1. In Cloud Shell, edit the Apache Knox general configuration file:

   vi ${KNOX_INIT_FOLDER}/knox-config.yaml
   

2. Replace HOSTNAME with the external DNS name of your proxy master node as the value for the certificate_hostname attribute. For this tutorial, use localhost.

   certificate_hostname: localhost
   

   Later in this tutorial, you create an SSH tunnel and the proxy cluster for the localhost value.

   The Apache Knox general configuration file also contains the master_key that encrypts the certificates BI tools use to communicate with the proxy cluster. By default, this key is the word secret.

3. If you are providing your own certificate, change the following two properties:

   generate_cert: false
   custom_cert_name: <filename-of-your-custom-certificate>
   

4. Save the file and close the editor.

   If you are providing your own certificate, you can specify it in the property custom_cert_name.

Create the proxy cluster

1. In Cloud Shell, create a Cloud Storage bucket:

   gcloud storage buckets create gs://${PROJECT_ID}-knox --location=${REGION}
   

   This bucket provides the configurations you created in the previous section to the Apache Knox initialization action.

2. Copy all the files from the Apache Knox initialization action folder to the bucket:

   gcloud storage cp ${KNOX_INIT_FOLDER}/* gs://${PROJECT_ID}-knox --recursive
   

3. Export all the variables required in order to create the cluster:

   export PROXY_CLUSTER=proxy-cluster
   export PROJECT_ID=$(gcloud info --format='value(config.project)')
   export REGION=us-central1
   export ZONE=us-central1-b
   

   In this step, some of the variables that you set before are repeated so that you can make modifications as required.

4. Create the proxy cluster:

   gcloud dataproc clusters create ${PROXY_CLUSTER} \
     --region ${REGION} \
     --zone ${ZONE} \
     --service-account=cluster-service-account@${PROJECT_ID}.iam.gserviceaccount.com \
     --initialization-actions gs://goog-dataproc-initialization-actions-${REGION}/knox/knox.sh \
     --metadata knox-gw-config=gs://${PROJECT_ID}-knox
   

Verify the connection through proxy

1. After the proxy cluster is created, use SSH to connect to its master node from Cloud Shell:

   gcloud compute ssh --zone ${ZONE} ${PROXY_CLUSTER}-m
   

2. From the terminal of the proxy cluster's master node, run the following query:

   beeline -u "jdbc:hive2://localhost:8443/;\
   ssl=true;sslTrustStore=/usr/lib/knox/data/security/keystores/gateway-client.jks;trustStorePassword=secret;\
   transportMode=http;httpPath=gateway/hive-us-transactions/hive"\
     -e "SELECT SubmissionDate, TransactionType FROM transactions LIMIT 10;"\
     -n admin -p admin-password
   

This command has the following properties:

• The beeline command uses localhost instead of the DNS internal name because the certificate that you generated when you configured Apache Knox specifies localhost as the host name. If you are using your own DNS name or certificate, use the corresponding host name.
• The port is 8443, which corresponds to the Apache Knox default SSL port.
• The line that begins ssl=true enables SSL and provides the path and password for the SSL Trust Store to be used by client applications such as Beeline.
• The transportMode line indicates that the request should be sent over HTTP and provides the path for the HiveServer2 service. The path is composed of the keyword gateway, the topology name that you defined in a previous section, and the service name configured in the same topology, in this case hive.
• The -e parameter provides the query to run on Hive. If you omit this parameter, you open an interactive session in the Beeline command-line tool.
• The -n parameter provides a user identity and password. In this step, you are using the default Hive admin user. In the next sections, you create an analyst user identity and set up credentials and authorization policies for this user.

Add a user to the authentication store

By default, Apache Knox includes an authentication provider that is based on Apache Shiro. This authentication provider is configured with BASIC authentication against an ApacheDS LDAP store. In this section, you add a sample data analyst user identity sara to the authentication store.

1. From the terminal in the proxy's master node, install the LDAP utilities:

   sudo apt-get install ldap-utils
   

2. Create an LDAP Data Interchange Format (LDIF) file for the new user sara:

   export USER_ID=sara
   
   printf '%s\n'\
     "# entry for user ${USER_ID}"\
     "dn: uid=${USER_ID},ou=people,dc=hadoop,dc=apache,dc=org"\
     "objectclass:top"\
     "objectclass:person"\
     "objectclass:organizationalPerson"\
     "objectclass:inetOrgPerson"\
     "cn: ${USER_ID}"\
     "sn: ${USER_ID}"\
     "uid: ${USER_ID}"\
     "userPassword:${USER_ID}-password"\
   > new-user.ldif
   

3. Add the user ID to the LDAP directory:

   ldapadd -f new-user.ldif \
     -D 'uid=admin,ou=people,dc=hadoop,dc=apache,dc=org' \
     -w 'admin-password' \
     -H ldap://localhost:33389
   

   The -D parameter specifies the distinguished name (DN) to bind when the user that is represented byldapadd accesses the directory. The DN must be a user identity that is already in the directory, in this case the user admin.

4. Verify that the new user is in the authentication store:

   ldapsearch -b "uid=${USER_ID},ou=people,dc=hadoop,dc=apache,dc=org" \
     -D 'uid=admin,ou=people,dc=hadoop,dc=apache,dc=org' \
     -w 'admin-password' \
     -H ldap://localhost:33389
   

   The user details appear in your terminal.

5. Copy and save the internal DNS name of the proxy master node:

   hostname -A | tr -d '[:space:]'; echo
   

   You use this name in the next section as <proxy-master-internal-dns-name> to configure the LDAP synchronization.

6. Exit the terminal on the node:

   exit
   

Setting up authorization

In this section, you configure identity synchronization between the LDAP service and Ranger.

Sync user identities into Ranger

To ensure that Ranger policies apply to the same user identities as Apache Knox, you configure the Ranger UserSync daemon to sync the identities from the same directory.

In this example, you connect to the local LDAP directory that is available by default with Apache Knox. However, in a production environment, we recommend that you set up an external identity directory. For more information, see the Apache Knox User's Guide and the Google Cloud Cloud Identity, Managed Active Directory, and Federated AD documentation.

1. Using SSH, connect to the master node of the backend cluster that you created:

   export BACKEND_CLUSTER=backend-cluster
   gcloud compute ssh --zone ${ZONE} ${BACKEND_CLUSTER}-m
   

2. In the terminal, edit the UserSync configuration file:

   sudo vi /etc/ranger/usersync/conf/ranger-ugsync-site.xml
   

3. Set the values of the following LDAP properties. Make sure that you modify the user properties and not the group properties, which have similar names.

   <property>
     <name>ranger.usersync.sync.source</name>
     <value>ldap</value>
   </property>
   
   <property>
     <name>ranger.usersync.ldap.url</name>
     <value>ldap://<proxy-master-internal-dns-name>:33389</value>
   </property>
   
   <property>
     <name>ranger.usersync.ldap.binddn</name>
     <value>uid=admin,ou=people,dc=hadoop,dc=apache,dc=org</value>
   </property>
   
   <property>
     <name>ranger.usersync.ldap.ldapbindpassword</name>
     <value>admin-password</value>
   </property>
   
   <property>
     <name>ranger.usersync.ldap.user.searchbase</name>
     <value>dc=hadoop,dc=apache,dc=org</value>
   </property>
   
   <property>
     <name>ranger.usersync.source.impl.class</name>
     <value>org.apache.ranger.ldapusersync.process.LdapUserGroupBuilder</value>
   </property>
   

   Replace the <proxy-master-internal-dns-name> placeholder with the internal DNS name of the proxy server, which you retrieved in the last section.

   These properties are a subset of a full LDAP configuration that syncs both users and groups. For more information, see How to integrate Ranger with LDAP.

4. Save the file and close the editor.

5. Restart the ranger-usersync daemon:

   sudo service ranger-usersync restart
   

6. Run the following command:

   grep sara /var/log/ranger-usersync/*
   

   If the identities are synched, you see at least one log line for the user sara.

Creating Ranger policies

In this section, you configure a new Hive service in Ranger. You also set up and test a Ranger policy to limit the access to the Hive data for a specific identity.

Configure the Ranger service

1. From the terminal of the master node, edit the Ranger Hive configuration:

   sudo vi /etc/hive/conf/ranger-hive-security.xml
   

2. Edit the <value> property of the ranger.plugin.hive.service.name property:

   <property>
      <name>ranger.plugin.hive.service.name</name>
      <value>ranger-hive-service-01</value>
      <description>
        Name of the Ranger service containing policies for this YARN instance
      </description>
   </property>
   

3. Save the file and close the editor.

4. Restart the HiveServer2 Admin service:

   sudo service hive-server2 restart
   

   You are ready to create Ranger policies.

Set up the service in the Ranger Admin console

1. In the Google Cloud console, go to the Dataproc page.

2. Click your backend cluster name, and then click Web Interfaces.

   Because you created your cluster with Component Gateway, you see a list of the Hadoop components that are installed in your cluster.

3. Click the Ranger link to open the Ranger console.

4. Log in to Ranger with the user admin and your Ranger admin password. The Ranger console shows the Service Manager page with a list of services.

5. Click the plus sign in the HIVE group to create a new Hive service.

   

6. In the form, set the following values:

   • Service name: ranger-hive-service-01. You previously defined this name in the ranger-hive-security.xml configuration file.
   • Username: admin
   • Password: admin-password
   • jdbc.driverClassName: keep the default name asorg.apache.hive.jdbc.HiveDriver
   • jdbc.url: jdbc:hive2:<backend-master-internal-dns-name>:10000/;transportMode=http;httpPath=cliservice
   • Replace the <backend-master-internal-dns-name> placeholder with the name you retrieved in a previous section.

7. Click Add.

   Each Ranger plugin installation supports a single Hive service. An easy way to configure additional Hive services is to start up additional backend clusters. Each cluster has its own Ranger plugin. These clusters can share the same Ranger DB, so that you have a unified view of all the services whenever you access the Ranger Admin console from any of those clusters.

Set up a Ranger policy with limited permissions

The policy allows the sample analyst LDAP user sara access to specific columns of the Hive table.

1. On the Service Manager window, click the name of the service you created.

   The Ranger Admin console shows the Policies window.

2. Click Add New Policy.

   With this policy, you give sara the permission to see only the columns submissionDate and transactionType from table transactions.

3. In the form, set the following values:

   • Policy name: any name, for example allow-tx-columns
   • Database: default
   • Table: transactions
   • Hive column: submissionDate, transactionType
   • Allow conditions:
     • Select user: sara
     • Permissions: select

4. At the bottom of the screen, click Add.

Test the policy with Beeline

1. In the master node terminal, start the Beeline command-line tool with the user sara.

   beeline -u "jdbc:hive2://localhost:10000/;transportMode=http;httpPath=cliservice sara user-password"
   

   Although the Beeline command-line tool doesn't enforce the password, you must provide a password to run the preceding command.

2. Run the following query to verify that Ranger blocks it.

    SELECT *
      FROM transactions
      LIMIT 10;
   

   The query includes the column transactionAmount, which sara doesn't have permission to select.

   A Permission denied error displays.

3. Verify that Ranger allows the following query:

   SELECT submissionDate, transactionType
     FROM transactions
     LIMIT 10;
   

4. Exit the Beeline command-line tool:

   !quit
   

5. Exit the terminal:

   exit
   

6. In the Ranger console, click the Audit tab. Both denied and allowed events display. You can filter the events by the service name you previously defined, for example, ranger-hive-service-01.

   

Connecting from a BI tool

The final step in this tutorial is to query the Hive data from Tableau Desktop.

Create a firewall rule

1. Copy and save your public IP address.

2. In Cloud Shell, create a firewall rule that opens TCP port 8443 for ingress from your workstation:

   gcloud compute firewall-rules create allow-knox\
     --project=${PROJECT_ID} --direction=INGRESS --priority=1000 \
     --network=default --action=ALLOW --rules=tcp:8443 \
     --target-tags=knox-gateway \
     --source-ranges=<your-public-ip>/32
   

   Replace the <your-public-ip> placeholder with your public IP address.

3. Apply the network tag from the firewall rule to the proxy cluster's master node:

   gcloud compute instances add-tags ${PROXY_CLUSTER}-m --zone=${ZONE} \
     --tags=knox-gateway
   

Create an SSH tunnel

This procedure is only necessary if you're using a self-signed certificate valid for localhost. If you are using your own certificate or your proxy master node has its own external DNS name, you can skip to Connect to Hive.

1. In Cloud Shell, generate the command to create the tunnel:

   echo "gcloud compute ssh ${PROXY_CLUSTER}-m \
     --project ${PROJECT_ID} \
     --zone ${ZONE} \
     -- -L 8443:localhost:8443"
   

2. Run gcloud init to authenticate your user account and grant access permissions.

3. Open a terminal in your workstation.

4. Create an SSH tunnel to forward port 8443. Copy the command generated in the first step and paste it into the workstation terminal, and then run the command.

5. Leave the terminal open so that the tunnel remains active.

Connect to Hive

1. On your workstation, install the Hive ODBC driver.
2. Open Tableau Desktop, or restart it if it was open.
3. On the home page under Connect / To a Server, select More.
4. Search for and then select Cloudera Hadoop.

5. Using the sample data analyst LDAP user sara as the user identity, fill out the fields as follows:

   • Server: If you created a tunnel, use localhost. If you didn't create a tunnel, use the external DNS name of your proxy master node.
   • Port: 8443
   • Type: HiveServer2
   • Authentication: Username and Password
   • Username: sara
   • Password: sara-password
   • HTTP Path: gateway/hive-us-transactions/hive
   • Require SSL: yes

6. Click Sign In.

   

Query Hive data

1. On the Data Source screen, click Select Schema and search for default.

2. Double-click the default schema name.

   The Table panel loads.

3. In the Table panel, double-click New Custom SQL.

   The Edit Custom SQL window opens.

4. Enter the following query, which selects the date and transaction type from the transactions table:

   SELECT `submissiondate`,
          `transactiontype`
   FROM `default`.`transactions`
   

5. Click OK.

   The metadata for the query is retrieved from Hive.

6. Click Update Now.

   Tableau retrieves the data from Hive because sara is authorized to read these two columns from the transactions table.

   

7. To try to select all columns from the transactions table, in the Table panel, double-click New Custom SQL again. The Edit Custom SQL window opens.

8. Enter the following query:

   SELECT *
   FROM `default`.`transactions`
   

9. Click OK. The following error message displays:

   Permission denied: user [sara] does not have [SELECT] privilege on [default/transactions/*].

   Because sara doesn't have authorization from Ranger to read the transactionAmount column, this message is expected. This example shows how you can limit what data Tableau users can access.

   To see all the columns, repeat the steps using the user admin.

10. Close Tableau and your terminal window.