Prerequisites

The following prerequisites apply to every installation of the Chef server.

Platforms

The following table lists the Foundational platforms for the Chef server:

Untested Platforms

The following platforms are not tested by Chef Software:

• Any Linux or UNIX distribution that is not listed as a Foundational platform.
• Microsoft Windows
• 32-bit architectures

Capacity Planning

Read the guidance around capacity planning for information about how to choose the right toplogy for the Chef server.

Software Requirements

Before installing the Chef server, ensure that each machine has the following installed and configured properly:

• Hostnames — Ensure that all systems have properly configured hostnames. The hostname for the Chef server must be a FQDN, including the domain suffix, and must be resolvable. See Hostnames, FQDNs for more information
• FQDNs — Ensure that all systems have a resolvable FQDN
• NTP — Ensure that every server is connected to NTP; the Chef server is sensitive to clock drift
• Mail Relay — The Chef server uses email to send notifications for various events; a local mail transfer agent should be installed and available to the Chef server
• cron — Periodic maintenance tasks are performed using cron
• git — git must be installed so that various internal services can confirm revisions
• libfreetype and libpng — These libraries are required
• Apache Qpid — This daemon must be disabled on CentOS and Red Hat systems
• Required users — If the environment in which the Chef server will run has restrictions on the creation of local user and group accounts, ensure that the correct users and groups exist before reconfiguring
• Firewalls and ports — If host-based firewalls (iptables, ufw, etc.) are being used, ensure that ports 80 and 443 are open. These ports are used by the nginx service
• Hostname — The hostname for the Chef server must be a FQDN, including the domain suffix, and must be resolvable. See Hostnames, FQDNs for more information

In addition:

• Browser — Firefox, Google Chrome, Safari, or Internet Explorer (versions 9 or better)
• chef-client communication with the Chef server Every node that will be configured by the chef-client and every workstation that will upload data to the Chef server must be able to communicate with the Chef server

UIDs and GIDs

The installation process for the Chef server requires the use of at least two user and group identifiers (UIDs and GIDs). These are used to create the opscode and opscode-pgsql users and their default groups.

$ grep -E '(UID|GID)' /etc/login.defs

UID_MIN             500
UID_MAX           60000
GID_MIN             500
GID_MAX           60000

SELinux

On CentOS and Red Hat Enterprise Linux systems, SELinux is enabled in enforcing mode by default. The Chef server does not have a profile available to run under SELinux. In order for the Chef server to run, SELinux must be disabled or set to Permissive mode.

To determine if SELinux is installed, run the following command:

$ getenforce

If a response other than "Disabled" or "Permissive" is returned, SELinux must be disabled.

To set SELinux to Permissive mode, run:

$ setenforce Permissive

and then check the status:

$ getenforce

AppArmor

On Ubuntu systems, AppArmor is enabled in enforcing mode by default. Chef products do not have a profile available to run under AppArmor. In order for the Chef products to run, AppArmor must set to Complaining mode or disabled.

To determine if AppArmor is installed, run the following command:

$ sudo apparmor_status

To install AppArmor, run the following command:

$ sudo apt-get install apparmor-utils —yes

If a response other than "0 processes are in enforce mode" or "0 profiles are in enforce mode." is returned, AppArmor must be set to Complaining mode or disabled.

To set AppArmor to Complaining mode, run:

$ sudo aa-complain /etc/apparmor.d/*

Or to disable AppArmor entirely, run:

$ sudo invoke-rc.d apparmor kill
$ sudo update-rc.d -f apparmor remove

and then check the status:

$ sudo apparmor_status

Apache Qpid

On CentOS and Red Hat Enterprise Linux systems, the Apache Qpid daemon is installed by default. The Chef server uses RabbitMQ for messaging. Because both Apache Qpid and RabbitMQ share the same protocol, Apache Qpid must be disabled.

To determine if Apache Qpid is installed, run the following command:

$ rpm -qa | grep qpid

If Apache Qpid is installed, a response similar to the following is displayed:

$ qpid-cpp-server-0.12-6.el6.x86_64

To disable Apache Qpid run:

$ service qpidd stop

and then:

$ chkconfig --del qpidd

cron

Periodic maintenance tasks are performed on the Chef server servers via cron and the /etc/cron.d directory. With certain CentOS 6 configurations, an additional step is required to install crontab:

$ yum install crontabs

Enterprise Linux Updates

The Chef server requires an x86_64 compatible systems architecture. When the Chef server is installed on Red Hat Enterprise Linux or CentOS, run yum update prior to installing the Chef server. This will ensure those platforms are fully compatible with this requirement.

Hostnames

The hostname for the Chef server may be specified using a FQDN or an IP address. This hostname must be resolvable. For example, a Chef server running in a production environment with a resolvable FQDN hostname can be added the DNS system. But when deploying Chef server into a testing environment, adding the hostname to the /etc/hosts file is enough to ensure that hostname is resolvable.

• FQDN Hostnames When the hostname for the Chef server is a FQDN be sure to include the domain suffix. For example, something like mychefserver.example.com (and not something like mychefserver).

• IP Address Hostnames When the Chef server is run in IPv6 mode, a hostname specified using an IP address must also be bracketed ([ ]) or the Chef server will not be able to recognize it as an IPv6 address. For example:

  bookshelf['url'] "https://[2001:db8:85a3:8d3:1319:8a2e:370:7348]"

The api_fqdn setting can be added to the private-chef.rb file (it is not there by default). When added, its value should be equal to the FQDN or IP address for the service URI used by the Chef server. Then configure the same value for the bookshelf['vip'] setting prior to installing the Chef server. For example: api_fqdn "chef.example.com" or api_fqdn 123.45.67.890.

Configure Hostnames

Use the following sections to verify the hostnames that is used by the Chef server.

To verify if a hostname is a FQDN

To verify if a hostname is a FQDN, run the following command:

$ hostname

If the hostname is a FQDN, it will return something like:

$ mychefserver.example.com

If the hostname is not a FQDN, it must be configured so that it is one.

To verify the FQDN is all lowercase

To verify if the alphabetic parts of a FQDN are all lowercase, run the following command:

$ hostname -f | grep -E '^([[:digit:]]|[[:lower:]]|\.|-|_)+$' && echo yes

If the hostname is all lowercase, it will return something like:

mychefserver.example.com
yes

If the hostname’s alphabetic parts are not all lowercase, it must be configured so that they are.

To verify a hostname is resolvable

To verify is a hostname is resolvable, run the following command:

$ hostname -f

If the hostname is resolvable, it will return something like:

$ mychefserver.example.com

To change a hostname

In some cases, the hostname for the Chef server needs to be updated. The process for updating a hostname varies, depending on the platform on which the Chef server will run. Refer to the manual for the platform or contact a local systems administrator for specific guidance for a specific platform. The following example shows how a hostname can be changed when running Red Hat or CentOS:

$ sudo hostname 'mychefserver.example.com'

and then:

$ echo "mychefserver.example.com" | sudo tee /etc/hostname

To add a hostname to /etc/hosts

If a hostname is not resolvable, refer to a local systems administrator for specific guidance on how to add the hostname to the DNS system. If the Chef server is being into a testing environment, just add the hostname to /etc/hosts. The following example shows how a hostname can be added to /etc/hosts when running Red Hat or CentOS:

$ echo -e "127.0.0.2 `hostname` `hostname -s`" | sudo tee -a /etc/hosts

Chef Analytics

The hostname for the Chef Analytics server may be specified using a FQDN or an IP address. This hostname must be resolvable. For example, a Chef Analytics server that is running in a production environment with a resolvable FQDN hostname can be added in the DNS system. But when deploying Chef Analytics into a testing environment, adding the hostname to the /etc/hosts file is enough to ensure that hostname is resolvable.

• FQDN Hostnames When the hostname for the Chef Analytics server is a FQDN be sure to include the domain suffix. For example, something like myanalyticsserver.example.com (and not something like myanalyticsserver).

The analytics_fqdn setting must be added to the opscode-analytics.rb file (it is not there by default). Its value should be equal to the FQDN or IP address for the service URI used by the Chef Analytics server. For example: analytics_fqdn "chef-analytics.example.com" or analytics_fqdn 123.45.67.890.

Mail Relay

The Chef server server uses email to send notifications for various events:

• Password resets
• User invitations
• Failover notifications
• Failed job notifications

Configure a local mail transfer agent on the Chef server using the steps appropriate for the platform on which the Chef server is running.

NTP

The Chef server requires that the systems on which it is running be connected to Network Time Protocol (NTP), as the Chef server is particularly sensitive to clock drift. For Red Hat and CentOS 6:

$ yum install ntp

or:

$ chkconfig ntpd on

or:

$ service ntpd start

For Ubuntu:

$ apt-get install ntp

chef-client

The Chef server server requires that every node that is under management by Chef also have an accurate clock that is synchronized very closely with the clock on the Chef server. If the clocks are not synchronized closely, the authentication process may fail when the clocks are out-of-sync by more than 15 minutes. A failure will trigger a 401 Unauthorized response similar to:

[Tue, 01 Nov 2011 16:55:23 -0700] INFO: *** Chef 11.X.X ***
[Tue, 01 Nov 2011 16:55:23 -0700] INFO: Client key /etc/chef/client.pem is not present - registering
[Tue, 01 Nov 2011 16:55:24 -0700] INFO: HTTP Request Returned 401 Unauthorized:
    Failed to authenticate as ORGANIZATION-validator. Synchronize the clock on your host.
[Tue, 01 Nov 2011 16:55:24 -0700] FATAL: Stacktrace dumped to /var/chef/cache/chef-stacktrace.out
[Tue, 01 Nov 2011 16:55:24 -0700] FATAL: Net::HTTPServerException: 401 "Unauthorized"

In this situation, re-synchronize the system clocks with the Network Time Protocol (NTP) server, and then re-run the chef-client.

Required Accounts

By default, accounts required by the Chef server are created during setup. If your environment has restrictions on the creation of local user and group accounts that will prevent these accounts from being created automatically during setup, you will need to create these accounts.

Group Accounts

The following group accounts are required:

User Accounts

The following user accounts are required: