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Chapter 4. Installing an IdM server: With integrated DNS, with an external CA as the root CA

Installing a new Identity Management (IdM) server with integrated DNS has the following advantages:

  • You can automate much of the maintenance and DNS record management using native IdM tools. For example, DNS SRV records are automatically created during the setup, and later on are automatically updated.
  • You can configure global forwarders during the installation of the IdM server for a stable external internet connection. Global forwarders are also useful for trusts with Active Directory.
  • You can set up a DNS reverse zone to prevent emails from your domain to be considered spam by email servers outside of the IdM domain.

Installing IdM with integrated DNS has certain limitations:

This chapter describes how you can install a new IdM server with an external certificate authority (CA) as the root CA.

4.1. Interactive installation

During the interactive installation using the ipa-server-install utility, you are asked to supply basic configuration of the system, for example the realm, the administrator’s password and the Directory Manager’s password.

The ipa-server-install installation script creates a log file at /var/log/ipaserver-install.log. If the installation fails, the log can help you identify the problem.

Follow this procedure to install a server:

  • With integrated DNS
  • With an external certificate authority (CA) as the root CA

Prerequisites

  • You have determined the type of the external CA to specify with the --external-ca-type option. See the ipa-server-install(1) man page for details.
  • If you are using a Microsoft Certificate Services certificate authority (MS CS CA) as your external CA: you have determined the certificate profile or template to specify with the --external-ca-profile option. By default, the SubCA template is used.

    For more information about the --external-ca-type and --external-ca-profile options, see Options used when installing an IdM CA with an external CA as the root CA.

Procedure

  1. Run the ipa-server-install utility with the --external-ca option.

    # ipa-server-install --external-ca
    • If you are using the Microsoft Certificate Services (MS CS) CA, also use the --external-ca-type option and, optionally, the --external-ca-profile option:

      [root@server ~]# ipa-server-install --external-ca --external-ca-type=ms-cs --external-ca-profile=<oid>/<name>/default
    • If you are not using MS CS to generate the signing certificate for your IdM CA, no other option may be necessary:

      # ipa-server-install --external-ca
  2. The script prompts to configure an integrated DNS service. Enter yes or no. In this procedure, we are installing a server with integrated DNS.

    Do you want to configure integrated DNS (BIND)? [no]: yes
    Note

    If you want to install a server without integrated DNS, the installation script will not prompt you for DNS configuration as described in the steps below. See Chapter 6, Installing an IdM server: Without integrated DNS, with an integrated CA as the root CA for details on the steps for installing a server without DNS.

  3. The script prompts for several required settings and offers recommended default values in brackets.

    • To accept a default value, press Enter.
    • To provide a custom value, enter the required value.

      Server host name [server.idm.example.com]:
      Please confirm the domain name [idm.example.com]:
      Please provide a realm name [IDM.EXAMPLE.COM]:
      Warning

      Plan these names carefully. You will not be able to change them after the installation is complete.

  4. Enter the passwords for the Directory Server superuser (cn=Directory Manager) and for the Identity Management (IdM) administration system user account (admin).

    Directory Manager password:
    IPA admin password:
  5. The script prompts for per-server DNS forwarders.

    Do you want to configure DNS forwarders? [yes]:
    • To configure per-server DNS forwarders, enter yes, and then follow the instructions on the command line. The installation process will add the forwarder IP addresses to the IdM LDAP.

      • For the forwarding policy default settings, see the --forward-policy description in the ipa-dns-install(1) man page.
    • If you do not want to use DNS forwarding, enter no.

      With no DNS forwarders, hosts in your IdM domain will not be able to resolve names from other, internal, DNS domains in your infrastructure. The hosts will only be left with public DNS servers to resolve their DNS queries.

  6. The script prompts to check if any DNS reverse (PTR) records for the IP addresses associated with the server need to be configured.

    Do you want to search for missing reverse zones? [yes]:

    If you run the search and missing reverse zones are discovered, the script asks you whether to create the reverse zones along with the PTR records.

    Do you want to create reverse zone for IP 192.0.2.1 [yes]:
    Please specify the reverse zone name [2.0.192.in-addr.arpa.]:
    Using reverse zone(s) 2.0.192.in-addr.arpa.
    Note

    Using IdM to manage reverse zones is optional. You can use an external DNS service for this purpose instead.

  7. Enter yes to confirm the server configuration.

    Continue to configure the system with these values? [no]: yes
  8. During the configuration of the Certificate System instance, the utility prints the location of the certificate signing request (CSR): /root/ipa.csr:

    ...
    
    Configuring certificate server (pki-tomcatd): Estimated time 3 minutes 30 seconds
      [1/8]: creating certificate server user
      [2/8]: configuring certificate server instance
    The next step is to get /root/ipa.csr signed by your CA and re-run /sbin/ipa-server-install as:
    /sbin/ipa-server-install --external-cert-file=/path/to/signed_certificate --external-cert-file=/path/to/external_ca_certificate

    When this happens:

    1. Submit the CSR located in /root/ipa.csr to the external CA. The process differs depending on the service to be used as the external CA.
    2. Retrieve the issued certificate and the CA certificate chain for the issuing CA in a base 64-encoded blob (either a PEM file or a Base_64 certificate from a Windows CA). Again, the process differs for every certificate service. Usually, a download link on a web page or in the notification email allows the administrator to download all the required certificates.

      Important

      Be sure to get the full certificate chain for the CA, not just the CA certificate.

    3. Run ipa-server-install again, this time specifying the locations and names of the newly-issued CA certificate and the CA chain files. For example:

      # ipa-server-install --external-cert-file=/tmp/servercert20170601.pem --external-cert-file=/tmp/cacert.pem
  9. The installation script now configures the server. Wait for the operation to complete.
  10. After the installation script completes, update your DNS records in the following way:

    1. Add DNS delegation from the parent domain to the IdM DNS domain. For example, if the IdM DNS domain is idm.example.com, add a name server (NS) record to the example.com parent domain.

      Important

      Repeat this step each time after an IdM DNS server is installed.

    2. Add an _ntp._udp service (SRV) record for your time server to your IdM DNS. The presence of the SRV record for the time server of the newly-installed IdM server in IdM DNS ensures that future replica and client installations are automatically configured to synchronize with the time server used by this primary IdM server.
Note

The ipa-server-install --external-ca command can sometimes fail with the following error:

ipa         : CRITICAL failed to configure ca instance Command '/usr/sbin/pkispawn -s CA -f /tmp/configuration_file' returned non-zero exit status 1
Configuration of CA failed

This failure occurs when the *_proxy environmental variables are set. For a solution of the problem, see Troubleshooting: External CA installation fails.

4.2. Troubleshooting: External CA installation fails

The ipa-server-install --external-ca command fails with the following error:

ipa         : CRITICAL failed to configure ca instance Command '/usr/sbin/pkispawn -s CA -f /tmp/configuration_file' returned non-zero exit status 1
Configuration of CA failed

The env|grep proxy command displays variables such as the following:

# env|grep proxy
http_proxy=http://example.com:8080
ftp_proxy=http://example.com:8080
https_proxy=http://example.com:8080

What this means:

The *_proxy environmental variables are preventing the server from being installed.

To fix the problem:

  1. Use the following shell script to unset the *_proxy environmental variables:

    # for i in ftp http https; do unset ${i}_proxy; done
  2. Run the pkidestroy utility to remove the unsuccessful certificate authority (CA) subsystem installation:

    # pkidestroy -s CA -i pki-tomcat; rm -rf /var/log/pki/pki-tomcat /etc/sysconfig/pki-tomcat /etc/sysconfig/pki/tomcat/pki-tomcat /var/lib/pki/pki-tomcat /etc/pki/pki-tomcat /root/ipa.csr
  3. Remove the failed Identity Management (IdM) server installation:

    # ipa-server-install --uninstall
  4. Retry running ipa-server-install --external-ca.