Chef Infra Server Prerequisites

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The following is a detailed discussion of the prerequisites for every installation of the Chef Infra Server. See Install Chef Infra Server for installation instructions.

Platforms

The following table lists the commercially-supported platforms and versions for the Chef Infra 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 topology for the Chef Infra Server.

Hardware Requirements

All machines in a Chef Infra Server deployment have the following hardware requirements. Disk space for standalone and backend servers should scale up with the number of nodes that the servers are managing. A good rule to follow is to allocate 2 MB for each node. The disk values listed below should be a good default value that you will want to modify later if/when your node count grows. Fast, redundant storage (SSD/RAID-based solution either on-prem or in a cloud environment) is preferred.

All Deployments

• 64-bit CPU architecture
• CPU support for SSE4.2 extensions (Xeons starting in 2007 and Opterons in 2012)

Standalone Deployments

• 4 total cores (physical or virtual)
• 8 GB of RAM or more
• 5 GB of free disk space in /opt
• 10 GB of free disk space in /var

For a high availability deployment:

General Requirements

• Three backend servers; as many frontend servers as required
• 1 x GigE NIC interface (if on premises)

Frontend Requirements

• 4 cores (physical or virtual)
• 4GB RAM
• 20 GB of free disk space (SSD if on premises, Premium Storage in Microsoft Azure, EBS-Optimized GP2 in AWS)

Backend Requirements

• 2 cores (physical or virtual)
• 8GB RAM
• 50 GB/backend server (SSD if on premises, Premium Storage in Microsoft Azure, EBS-Optimized GP2 in AWS)

Software Requirements

Before installing the Chef Infra 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 Infra Server must be a FQDN, have fewer than 64 characters including the domain suffix, be lowercase, and 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 Infra Server is sensitive to clock drift
• Mail Relay — The Chef Infra 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
• Apache Qpid — This daemon must be disabled on CentOS and Red Hat systems
• Required users — If the environment in which the Chef Infra 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.

In addition:

• Browser — Firefox, Google Chrome, Safari, or Internet Explorer (versions 9 or better)
• Chef Infra Client communication with the Chef Infra Server The Chef Infra Server must be able to communicate with every node that will be configured by Chef Infra Client and every workstation that will upload data to the Chef Infra

UIDs and GIDs

The installation process for the Chef Infra 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

Firewalls

iptables

To allow access to your Chef Infra Server on ports 80 and 443 via the iptables firewall, issue the following command with root privileges:

iptables -A INPUT -p tcp -m multiport --destination-ports 80,443 -j ACCEPT

Note that you will need to make use of a tool such as iptables-persistent to restore your iptables rules upon reboot.

FirewallD

On RHEL and CentOS versions 7 and above, the FirewallD firewall is enabled by default. Issue the following command with root privileges to open ports 80 and 443:

firewall-cmd --permanent --zone public --add-service http && firewall-cmd --permanent --zone public --add-service https && firewall-cmd --reload

UFW

While UFW is installed on Ubuntu, it is not enabled by default. However, if you wish to use a UFW-based firewall on your Chef Infra Server, issue the following command with root privileges to open ports 80 and 443:

ufw allow proto tcp from any to any port 80,443

Security Modules

SELinux

On CentOS and Red Hat Enterprise Linux systems, SELinux is enabled in enforcing mode by default. The Chef Infra Server does not have a profile available to run under SELinux. In order for the Chef Infra 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.

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

IP Addresses

Unless you intend to operate the Chef Infra Server in IPv6 mode, you should disable ipv6 in the system’s /etc/hosts file by commenting out or removing all references to IPv6 addresses like “::1” or “fe80:db8:85a3:8d3:1319:8a2e:370:7348”.

Without these changes, a Chef Infra Server install intended to run in ipv4 mode will mistakenly only start the postgres service on the ipv6 loopback address of “::1” rather than the ipv4 loopback address of 127.0.0.1. This will make further progress through an initial reconfiguration impossible.

Hostnames

The hostname for the Chef Infra Server may be specified using a FQDN or an IP address. This hostname must be resolvable, be 64 characters or less, and be lowercase. For example, a Chef Infra Server running in a production environment with a resolvable FQDN hostname can be added the DNS system. But when deploying Chef Infra 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 Infra 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 Infra Server is run in IPv6 mode, a hostname specified using an IP address must also be bracketed ([ ]) or the Chef Infra 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 Infra Server. Then configure the same value for the bookshelf['vip'] setting prior to installing the Chef Infra 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 Infra 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 Infra Server needs to be updated. The process for updating a hostname varies, depending on the platform on which the Chef Infra 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 Infra 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

Mail Relay

The Chef Infra 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 Infra Server using the steps appropriate for the platform on which the Chef Infra Server is running.

NTP

The Chef Infra Server requires that the systems on which it is running be connected to Network Time Protocol (NTP), as the Chef Infra 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 Infra Client

The Chef Infra 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 Infra 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::HTTPClientException: 401 "Unauthorized"

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

Required Accounts

By default, accounts required by the Chef Infra 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: