Troubleshooting Ambari SSL and LDAPS Setup

This section provides comprehensive troubleshooting steps for setting up SSL and LDAPS with Ambari, specifically focusing on truststore configuration, SSL connections, and LDAP integration. It will help you ensure proper configuration for secure communications with Ambari and LDAP.

Verify the Truststore Configuration for Ambari UI or LDAPS

Ambari requires a truststore for both SSL/TLS connections to the Ambari UI and secure LDAPS connections to the LDAP server. The truststore holds certificates needed to establish trust.

1. Check Truststore Location in ambari.properties:
   1. Verify that the Ambari truststore is correctly configured by checking the ambari.properties file.

cat /etc/ambari-server/conf/ambari.properties | grep truststore

2. Look for the following properties:
   1. ssl.trustStore.path: This property specifies the location of the truststore.
   2. ssl.trustStore.password: The password to access the truststore.
   3. ssl.trustStore.type: The truststore type (e.g., JKS or PKCS12).

Example output:

ssl.trustStore.path=/etc/ambari-server/conf/ambari_truststore.jks

ssl.trustStore.password=changeme

ssl.trustStore.type=jks

3. Ensure the path and type are correct and accessible.
4. Check Permissions. Verify that the Ambari service user has read access to the truststore file.

ls -l /etc/ambari-server/conf/ambari_truststore.jks

If permissions are incorrect, modify them accordingly:

chmod 640 /etc/ambari-server/conf/ambari_truststore.jks

chown ambari:ambari /etc/ambari-server/conf/ambari_truststore.jks

Import the LDAP Server Certificates into the Ambari Truststore

To establish an LDAPS connection between Ambari and the LDAP server, the LDAP server’s certificate (or its CA certificate) must be imported into Ambari’s truststore.

1. Obtain the LDAP Server's Certificate: You can either request the certificate from the LDAP administrator or extract it yourself. To extract the LDAP server certificate:

openssl s_client -connect <ldap-server-host>:636 -showcerts

2. Save the server’s certificate to a file (e.g., ldap_cert.pem).
3. Import the Certificate into Ambari's Truststore: Use the keytool command to import the LDAP server certificate into Ambari’s truststore.
   1. -alias ldapcert: A unique alias to identify the certificate in the truststore.
   2. -keystore /path/to/truststore.jks: Path to Ambari’s truststore.
   3. -file /path/to/ldap_cert.pem: Path to the LDAP certificate file.

keytool -import -alias ldapcert -keystore /path/to/truststore.jks -file /path/to/ldap_cert.pem

After importing, verify that the certificate is present in the truststore:

keytool -list -keystore /path/to/truststore.jks

4. Restart Ambari Server: After importing the certificate, restart the Ambari Server to apply the changes.

ambari-server restart

Validate the LDAPS Connection

Once the LDAP server certificate has been added to the truststore, you need to validate the LDAPS connection between Ambari and LDAP.

Test LDAP Connection: Test the connection to the LDAP server using the ambari-server setup-ldap command.

ambari-server setup-ldap

1. Follow the prompts to input LDAP server details (hostname, port, bind DN, password, etc.). Ensure that LDAPS (port 636) is specified and the correct truststore is configured.
2. Check the ambari.properties for LDAP Configuration: Ensure the LDAP properties in ambari.properties are correct.

cat /etc/ambari-server/conf/ambari.properties | grep ldap

3. Look for the following properties:
   1. authentication.ldap.primaryUrl: LDAP server URL (with ldaps:// for LDAPS).
   2. authentication.ldap.useSSL=true: Ensure SSL is enabled for secure LDAP communication.

Example:

authentication.ldap.primaryUrl=ldaps://ldap.example.com:636

authentication.ldap.useSSL=true

4. Check the Ambari logs (/var/log/ambari-server/ambari-server.log) for detailed information about LDAP connection errors.

Common Issues and Fixes

1. Certificate Expiration: If the LDAP server’s certificate has expired, the LDAPS connections fail. Ensure the LDAP server’s certificate is renewed and re-imported into Ambari’s truststore.
2. Invalid Truststore Path or Permissions: If the truststore path is incorrect or permissions are wrong, Ambari cannot load the truststore, leading to SSL or LDAPS connection failures. Ensure the truststore is accessible by Ambari.
3. Hostname Mismatch: If the LDAP certificate’s Common Name (CN) does not match the LDAP server’s hostname, Ambari may reject the connection. Ensure the certificate is issued with the correct hostname or update your DNS configuration.
4. Truststore Password Errors: Ensure the truststore password is correctly set in ambari.properties. An incorrect password prevents Ambari from accessing the truststore.

Test the Ambari UI SSL Setup

If you're setting up SSL for the Ambari UI, ensure that the Ambari Server is correctly configured to serve HTTPS.

1. Check Ambari UI Certificate:

   • If Ambari’s UI is served over SSL, use a browser to visit the UI (e.g., https://<ambari-server>:8443) and inspect the certificate.
   • Verify the certificate details (validity, issuer, etc.) using the browser’s developer tools.

2. Validate the SSL Connection Using curl : You can also validate the SSL connection to the Ambari UI using curl:

curl -v -k https://<ambari-server>:8443

Ensure that there are no SSL errors (e.g., certificate mismatch, untrusted certificates, etc.).