4.2. Initial SIMP Server Configuration

4.2.1. Introduction to the SIMP Utility

The simp command provides a CLI intended to make the configuration of the SIMP server straightforward and repeatable. In these instructions, we will be using the config and bootstrap options of the simp command

For a list of the commands simp provides, type simp help. Type simp <Command> --help for more information on a specific command.

  • simp config sets up configuration required to bootstrap the SIMP server with Puppet. It asks questions, generates configuration files, and applies preliminary server configuration based on the answers. It records the options chosen in a file, /root/.simp/simp_conf.yaml and generates a log file under /root/.simp/.
  • simp bootstrap uses several targeted Puppet runs to configure the rest of the system and generates a log file under /root/.simp/.

For more details about initial configuration provided by simp config see Advanced Configuration.

4.2.2. Configuring the SIMP Server


Puppet has problems when hostnames contain capital letters (SERVER-1809) — do not use them!

  1. Log on as a user that can gain root access and sudo to root.
    • If you installed from the ISO
      • Log in as simp.
      • Run sudo su - root.
    • If you installed from RPM
      • Create a local user that can escalate to root and use it to access the root account.
  2. Run simp config and configure the system as prompted.
    • These settings will be used to set up files appropriate for bootstrapping the system.
      • For each setting:
        • Press Enter to keep the recommended value or enter your desired value.


If you see a message about ‘simp bootstrap’ being ‘locked’, follow the steps in Prevent Lockout from the SIMP Server during RPM Installation:

  1. Run simp bootstrap.

    If your SIMP server is on a virtual machine, or slow system, the default timeout for the Puppet server to start (5 minutes) may be too short. You will want to extend this time by using the -w option.

    For example, to extend the timeout to 10 minutes:

    $ simp bootstrap -w 10


    If the bootstrap progress bars of each Puppet run are of equal length, a problem has probably occurred due to an error in SIMP configuration. Refer to the previous step and make sure that all configuration options are correct.

    You can debug issues by either looking at the log files in /root/.simp or by running puppet agent -t --masterport=8150.

  2. Run reboot to restart your system and apply the necessary kernel configuration items.

After rebooting, SIMP-managed security settings have been applied and the SIMP server is ready for site-specific configuration.

To su to root from the simp user, you must now use sudo su - root.

4.2.3. Next Steps

The following are links to other information in the user guide that are answers to questions sometimes asked at this time:

4.2.4. Prevent Lockout from the SIMP Server during RPM Installation

By default, SIMP:

  • Disables remote logins for all users.
  • Disables root logins at the console.

If either of the following scenarios applies, you must enable sudo and ssh access for a local user. If you do not do this, you may lose access to your system.

Scenario 1:

Console access is available, but not allowed. Only the root user (and no other user account) is available.

  • This generally occurs when SIMP is installed from RPM and the user accepts simp config’s default value for useradd:securetty (an empty array).
Scenario 2:

Console access is not available, and the administrative user’s ssh access has not yet been enabled permanently via Puppet.

  • This generally occurs when SIMP is installed from RPM on cloud systems.

In either of these scenarios, simp config will issue the following warning and write a lock file to prevent simp bootstrap from running:

'simp bootstrap' has been locked due to potential login lockout.
* See /root/.simp/simp_bootstrap_start_lock for details

The remainder of this document provides instructions on ensuring that a local user has the appropriate level of system access.

After you address all issues identified in /root/.simp/simp_bootstrap_start_lock (see Resolve Other Issues in the Bootstrap Lock File), you should remove the file and continue with the bootstrap process. Ensuring Local User Access

  • If you already have an unprivileged account:

    • Replace userx with your current non-root username throughout the example code.
  • If you do NOT already have an unprivileged account:

    • Create a local user account, using useradd.
      • This example assumes the local user is named userx.
      • Be sure to set the user’s password if the user is logging in with a password!
  1. Run sudo su - root
  2. Run cd /etc/puppetlabs/code/environments/production/data/hosts
  3. Add the following to <puppetserver fqdn>.yaml
# Add sudo user rules
  # Any unique name
    # The users to which to apply this sudo rule
      - userx
    # The commands that the user is allowed to run
      - ALL
    # Whether or not the user must use a password
    passwd: false
# Add a PAM remote access rule
  # The user to add
    # Allow access from everywhere
      - ALL If Your Local User Uses an SSH Public Key

If the local user has an SSH public key available, copy the authorized_keys file for that user to the SIMP-managed location for authorized keys /etc/ssh/local_keys:

mkdir -p /etc/ssh/local_keys
chmod 755 /etc/ssh/local_keys
cp ~userx/.ssh/authorized_keys /etc/ssh/local_keys/userx
chmod 644 /etc/ssh/local_keys/userx Resolve Other Issues in the Bootstrap Lock File

If any other issues are identified in /root/.simp/simp_bootstrap_start_lock, you must address them before removing the file.

  • Currently, the only other issue simp config will identify is a possible misconfiguration of YUM repositories. simp config will lock out bootstrap if it cannot find a few of the key packages needed for bootstrapping. Fix your yum repository configuration and then verify the fix using the verification instructions in the lock message. Resume Bootstrap Operation and Verify User Access



  1. Remove the lock file and bootstrap the system

    • rm /root/.simp/simp_bootstrap_start_lock
    • simp bootstrap
    • puppet agent -t

    The following items are not failures and can be ignored. All other errors or warnings should be addressed prior to proceeding:

    • Reboot notifications.
    • Warning/errors related to modules that manage services you have not completely set up, such as named.
    • svckill warnings regarding services found that would be killed if svckill::mode was set to enforcing.
  2. Verify user accesss

    • Using a NEW SSH SESSION OR TERMINAL (do NOT close your working session)
      • Log in as userx
      • sudo su - root


If your new user cannot ssh into the server and sudo to root

  • DO NOT reboot the server until you resolve the problem!
  • DO NOT log out of your primary work terminal unti you resolve the problem! Finalization

Reboot your system to enact the kernel-level enforcement changes:

  • reboot

Re-verify system access:

  • Log back in as userx
  • sudo su - root

4.2.5. Advanced Configuration

The goal of simp config is to allow the user to quickly configure the SIMP server with minimal user input/operations. To that end simp config sets installation variables based on information gathered from the user, existing system settings, and SIMP security requirements. It then applies the smallest subset of these system settings that is required to bootstrap the system with Puppet. Both the installation variables and their application via simp config are described in subsections that follow. Installation Variables

This section describes the installation variables set by simp config. Although the table that follows lists all possible installation variables, the user will not be prompted for all of them, nor will all of them appear in the configuration files generated by simp config. Some of these variables will be automatically set based on other installation variables, system settings, or SIMP security requirements. Others will be omitted because either they are unnecessary for a particular site configuration, or their defaults are appropriate. Also, please note that variables beginning with cli:: are only used internally by simp config, itself. The cli:: variables are written to simp_conf.yaml, but not persisted to any Puppet hiera data files.


  • Not all the settings listed below may be able to be preset in a configuration file input to simp config, via either -a <Config File> or -A <Config File>. Some settings for which you would not be prompted if you ran simp config interactively may be automatically determined by simp config.
  • Passwords for which only hashed values are stored in the YAML output of simp config must be input as hashed values in an input configuration file.
  • simp config behaves differently (asks different questions, automatically determines different settings) depending on the SIMP installation type. This is because it can safely assume certain server setup has been done, only if SIMP has been installed from the SIMP-provided ISO. For example, consider a simp local user. When SIMP is installed from ISO, simp config can safely assume that this user is the backup user installed by the ISO to prevent server lockout. As such, su and ssh privileges for the simp user should be allowed. For non-ISO installs, however, it would not be prudent for simp config to grant just any simp user both su and ssh privileges.
  • simp config detects that SIMP has been installed from a SIMP-provided ISO by the presence of /etc/yum.repos.d/simp_filesystem.repo.


There are two simp config options that are particularly useful:

  • --dry-run will run through all of the prompts without applying any changes to the system. This is useful to:
    • become familiar with the variables set by simp config without applying them
    • generate a configuration file to use as a template for subsequent simp config runs
  • -a <Config File> will load and apply a previously-generated configuration (aka the ‘answers’ file) in lieu of prompting for settings.
    • This is useful to run on systems that will be rebuilt often.
    • Please note, however: if you edit the answers file, only configuration settings for which you would be prompted by simp config can be modified in that file—any changes made to settings that simp config automatically determines will be ignored.

If you want to understand what variables apply to your setup, run simp config --dry-run and examine the generated simp_conf.yaml file. That file will contain both the settings and their documentation.

Variable Description
cli::is_simp_ldap_server Whether the SIMP server will also be a SIMP-provided LDAP server
cli::network::dhcp Whether to use DHCP for the network; dhcp to enable DHCP, static otherwise
cli::network::gateway Default gateway
cli::network::hostname FQDN of server
cli::network::interface Network interface to use
cli::network::ipaddress IP address of server
cli::network::netmask Netmask of the system
cli::network::set_up_nic Whether to set up the network interface; true or false
cli::set_grub_password Whether to set a GRUB password on the server; true or false
cli::simp::scenario SIMP scenario; simp = full SIMP system, simp_lite = SIMP system with some security features disabled for clients, poss = SIMP system with all security features disabled for clients
cli::use_internet_simp_yum_repos Whether to configure SIMP nodes to use internet SIMP and SIMP dependency YUM repositories
grub::password GRUB password hash
puppetdb::master::config::puppetdb_port Port used by the puppet database
puppetdb::master::config::puppetdb_server DNS name or IP of puppet database server
simp_openldap::server::conf::rootpw LDAP Root password hash
simp_options::dns::search Search domain for DNS
simp_options::dns::servers List of DNS servers for the managed hosts
simp_options::fips Enable FIPS-140-2 compliance; true or false; value automatically set to detected system FIPS status
simp_options::ldap Whether to use LDAP; true or false
simp_options::ldap::base_dn LDAP Server Base Distinguished Name
simp_options::ldap::bind_dn LDAP Bind Distinguished Name
simp_options::ldap::bind_hash LDAP Bind password hash
simp_options::ldap::bind_pw LDAP Bind password
simp_options::ldap::master LDAP master URI
simp_options::ldap::sync_dn LDAP Sync Distinguished Name
simp_options::ldap::sync_hash LDAP Sync password hash
simp_options::ldap::sync_pw LDAP Sync password
simp_options::ldap::uri List of LDAP server URIs
simp_options::ntpd::servers NTP servers
simp_options::puppet::ca FQDN of Puppet Certificate Authority (CA)
simp_options::puppet::ca_port Port Puppet CA will listen on
simp_options::puppet::server FQDN of the puppet server
simp_options::sssd Whether to use SSSD
simp_options::syslog::failover_log_servers IP addresses of failover log servers
simp_options::syslog::log_servers IP addresses of primary log servers
simp_options::trusted_nets Subnet used for clients managed by the puppet server
simp::runlevel Default system run level; 1-5
simp::server::allow_simp_user Whether to allow local ‘simp’ user su and ssh privileges
simp::yum::repo::local_os_updates::enable_repo Whether to enable the SIMP-managed, OS Update YUM repository that the SIMP ISO installs on the SIMP server
simp::yum::repo::local_os_updates::servers YUM server(s) for SIMP-managed, OS Update packages
simp::yum::repo::local_simp::enable_repo Whether to enable the SIMP-managed, SIMP and SIMP dependency YUM repository that the SIMP ISO installs on the SIMP server.
simp::yum::repo::local_simp::servers YUM server(s) for SIMP-managed, SIMP and SIMP dependency packages
sssd::domains List of SSSD domains
svckill::mode Strategy svckill should use when it encounters undeclared services; enforcing = shutdown and disable all services not listed in your manifests or the exclusion file warning = only report what undeclared services should be shut down and disabled, without actually making the changes to the system
useradd::securetty A list of TTYs for which the root user can login simp config Actions

In addition to creating the three configuration, YAML files, simp config performs a limited set of actions in order to prepare the system for bootstrapping. Although the table that follows lists all possible simp config actions, not all of these actions will apply for all site configurations.

Category Actions Performed
Certificates If no certificates for the host are found in /var/simp/environments/production/site_files/pki_files/files/keydist, simp config will use SIMP’s FakeCA to generate interim host certificates. These certificates, which are independent of the certificates managed by Puppet, are required by SIMP and should be replaced by certificates from an official Certificate Authority, as soon as is practical.
GRUB When the user selects to set the GRUB password simp config will set the password in the appropriate grub configuration file, /etc/grub.conf or /etc/grub2.cfg. After initial configuration, the GRUB password can be managed with the simp-simp_grub module. See Managing GRUB Users for more information.

When the SIMP server is also a SIMP-provided LDAP server, simp config

  • Adds simp::server::ldap to the SIMP server host YAML file, which allows the SIMP server to act as a LDAP server
  • Adds the hash of the user-supplied LDAP root password to the SIMP server host YAML file as simp_openldap::server::conf::rootpw to the SIMP
Lockout Prevention

When the SIMP server is installed from ISO, the install creates a local simp user that the SIMP server configure to have both su and ssh privileges. (This user is provider to prevent server lockout, as, per security policy, SIMP by default disables logins via ssh for all users, including root.) So, when SIMP is not installed from ISO, simp config does the following:

  • Warns the operator of this problem
  • Writes a lock file containing details on how to rectify the problem. This lock file prevents simp bootstrap from running until the user manually fixes the problem.
  • Turns off the SIMP server configuration that allows su and ssh privileges for an inapplicable simp user.
  • When the user selects to configure the network interface, simp config uses Puppet to set the network interface parameters in system networking files and to bring up the interface.
  • simp config sets the hostname.
  • Creates a new production SIMP Omni-Environment unless --force-config is specified.
  • Backs up any existing ‘production’ environment prior to creating a new one.
  • Creates/updates /etc/puppetlabs/puppet/autosign.conf.
  • Updates the following Puppet settings: digest_algorithm, keylength, server, ca_server, ca_port, and trusted_server_facts.
  • Updates /etc/hosts to ensure a puppet server entry exists.
SIMP Hiera & Site Manifest
  • Sets the $simp_scenario variable in the site.pp of the ‘production’ environment to the user-selected scenario.
  • If a host YAML file for the SIMP server does not already exist in /etc/puppetlabs/.../production/data/hosts simp config will create one from a SIMP template.
  • Updates the SIMP server host YAML file with appropriate PuppetDB settings.
  • Creates YAML file containing global data relevant to both the SIMP server and SIMP clients in the ‘production’, environment, .../production/data/simp_config_settings.yaml
  • When the SIMP filesystem YUM repo from an ISO install exists (/etc/yum.repos.d/simp_filesystem.repo), simp config
    • Configures SIMP server to act as a YUM server for the on-server repo, by adding the simp::server::yum class to the SIMP server host YAML file.
    • Configures SIMP clients to use the SIMP server’s YUM repos by adding simp::yum::repo::local_os_updates and simp::yum::repo::local_simp classes to simp_config_settings.yaml.
    • Disables the use of the simp::yum::repo::local* repos in the SIMP server’s host YAML file, as it is already configured to use the more efficient, filesystem repo.
    • Updates the appropriate OS YUM Updates repository, contained at /var/www/yum/OSTYPE/MAJORRELEASE/ARCH.
    • Disables any default CentOS repos.
  • When the SIMP filesystem YUM repo does not exist, but the user wants to use internet repos simp config
    • Enables internet SIMP server repos in the SIMP server host YAML file by adding the simp::yum::repo::internet_simp_server class.
    • Enables internet SIMP dependency repos for both SIMP clients and in the SIMP server by adding the simp::yum::repo::internet_simp_dependencies class to simp_config_settings.yaml.
  • When the SIMP filesystem YUM repo does not exist and the user does not want to use internet repos, simp config
    • Checks the configuration of the SIMP server’s YUM repos via repoquery. If this check fails, writes a lock to prevent simp bootstrap from running until the user manually fixes the issue.
    • Reminds the user to (manually) set up YUM repos for SIMP clients. simp config Output

At the end of simp config, when you answer yes to Ready to apply?, simp config generates three files:

  1. /root/.simp/simp_conf.yaml:
    File containing all your simp config settings; can include additional settings related to ones you entered and other settings required for SIMP.
  2. /etc/puppetlabs/code/environments/production/data/simp_config_settings.yaml:
    File containing global Hiera data relevant to SIMP clients and the SIMP server.
  3. /etc/puppetlabs/code/environments/production/data/hosts/<server_fqdn>.yaml:
    The SIMP server’s host-specific Hiera configuration.

If you terminate simp config before applying the configuration, it will generate a file /root/.simp/.simp_conf.yaml. This interim file (aka the safety-save file), contains the answers up until the point you terminated simp config.