Tiered Installation

[edit on GitHub]

This topic describes how to set up the Chef Infra Server with a single back end and multiple load-balanced frontend servers.

Prerequisites

Before installing the Chef Infra Server software, perform the following steps:

• The backend server must be accessible from each frontend server. A virtual IP address is created and managed by the Chef Infra Server, but will also need to be added to the DNS so that all machines in the tiered configuration may access it.
• Persistent data on the backend Chef Infra Server is primarily composed of cookbook files and directories. Separate disks should be dedicated entirely to storing this data prior to installing the Chef Infra Server.
• Load-balancing should be used with frontend servers, along with a DNS entry for the virtual IP address used for load balancing. This virtual IP address is added to the chef-server.rb file as the api_fqdn.
• All required ports must be open. See the Firewalls section (below) for the list of ports. All connections to and from the Chef Infra Server are accomplished via TCP. Refer to the operating system’s manual or your systems administrators for instructions on how to configure to ports, if necessary.
• The hostname for the Chef Infra Server must be an FQDN, including the domain suffix, and must be resolvable by the backend and frontend servers. See Hostnames, FQDNs for more information.
• chef-server-ctl reconfigure will not bind the backend_vip to the backend server. The easiest thing to do is just define backend_vip as the already configured main IP address of the backend system. If you need to use an additional address, it will need to be configured and bound on the system before chef-server-ctl reconfigure is run.

Basic Hardware Requirements

For a tiered deployment, your backend server should support the following hardware requirements:

• 64-bit architecture
• 8 total cores (physical or virtual)
• 16GB RAM
• Fast, redundant storage (SSD/RAID-based solution)
  • 50 GB/backend server (SSD if on premises, Premium Storage in Microsoft Azure, EBS-Optimized GP2 in AWS)
• 1 GigE NIC interface
• A back-end server; all other systems will be front-end servers.

Disk Configuration

Persistent data on the backend server of the Chef Infra Server is primarily composed of cookbook files and directories. Separate disks should be dedicated entirely to storing this data prior to installing the Chef Infra Server. These disks should be part of a SSD or hardware RAID-based solution that ensure redundancy and high IOPS. This configuration guide assumes that:

• ~50GB of raw, unpartitioned disk space is available. Disk space should scale up with the number of nodes that the backend server is managing. A good rule to follow is to allocate 2 MB per node.
• The disk space presents as a single device. For example: /dev/sdb.
• The storage is added to a volume group named opscode and is presented to the Chef Infra Server by mounting on /var/opt/opscode before a reconfiguration

The following commands properly set up disk configuration on the backend server:

pvcreate /dev/sdb

and:

vgcreate opscode /dev/sdb

and:

lvcreate -l 80%VG -n tiered opscode

Mount Storage Device

To build and mount the storage device on the backend server, do the following:

1. Create the file system. For example, an ext4 type named tiered:

   mkfs.ext4 /dev/opscode/tiered
   

   then:

   mkdir -p /var/opt/opscode
   

   and then:

   mount /dev/opscode/tiered /var/opt/opscode
   

Backend

Use the following steps to set up the backend Chef Infra Server:

1. Download the packages from https://downloads.chef.io/chef-server/. For Red Hat and CentOS 6:

   rpm -Uvh /tmp/chef-server-core-<version>.rpm
   

   For Ubuntu:

   dpkg -i /tmp/chef-server-core-<version>.deb
   

   After a few minutes, the Chef Infra Server will be installed.

2. Create a file named chef-server.rb that is located in the /etc/opscode/ directory. See the chef-server.rb section below for an example of the settings and values that are required.

chef-server.rb

The chef-server.rb file that is located in the /etc/opscode/ directory describes the topology of the tiered configuration. On the backend server, create a file named chef-server.rb and save it in the /etc/opscode/ directory.

Add the following settings to the chef-server.rb file:

1. Define the topology type:

   topology "tier"
   

2. Define the backend server:

   server "FQDN",
     :ipaddress => "IP_ADDRESS",
     :role => "backend",
     :bootstrap => true
   

   Replace FQDN with the FQDN of the server and IP_ADDRESS with the IP address of the server. The role is a backend server is "backend".

3. Define the backend virtual IP address:

   backend_vip "FQDN",
     :ipaddress => "IP_ADDRESS",
     :device => "eth0"
   

   Replace FQDN with the FQDN of the server. Replace IP_ADDRESS with the virtual IP address of the server. The :device parameter should be the ethernet interface to which the virtual IP address will bind. This is typically the public interface of the server. In a typical tiered install, the config here could also be just the main FQDN and IP address that are already configured for the backend. Running chef-server-ctl reconfigure will not bind the backend_vip address to an interface, this must be done on startup of the machine.

4. Define each frontend server:

   server "FQDN",
     :ipaddress => "IP_ADDRESS",
     :role => "frontend"
   

   Replace FQDN with the FQDN of the frontend server. Replace IP_ADDRESS with the IP address of the frontend server. Set :role to "frontend".

   Add separate entry in the chef-server.rb file for each frontend server.

5. Define the API FQDN:

   api_fqdn "FQDN"
   

   Replace FQDN with the FQDN of the load balanced virtual IP address, which should be equal to the FQDN for the service URI that is used by the Chef Infra Server.

6. Reconfigure the Chef Infra Server and the Chef management console (standalone and frontend group members of a High Availabilty installation):

chef-server-ctl reconfigure

Frontend

For each frontend server, use the following steps to set up the Chef Infra Server:

1. Install the Chef Infra Server package. For Red Hat and CentOS 6:

   rpm -Uvh /tmp/chef-server-core-<version>.rpm
   

   For Ubuntu:

   dpkg -i /tmp/chef-server-core-<version>.deb
   

   After a few minutes, the Chef Infra Server will be installed.

2. Create the /etc/opscode/ directory, and then copy the entire contents of the /etc/opscode directory from the primary backend server, including all certificates and the chef-server.rb file.

3. Reconfigure the Chef Infra Server and the Chef management console (standalone and frontend group members of a High Availabilty installation):

chef-server-ctl reconfigure

4. Start the Chef Infra Server:

   chef-server-ctl start
   

On a single frontend server, create an administrator and an organization:

1. Run the following command to create an administrator:

sudo chef-server-ctl user-create USER_NAME FIRST_NAME LAST_NAME EMAIL 'PASSWORD' --filename FILE_NAME

An RSA private key is generated automatically. This is the user’s private key and should be saved to a safe location. The --filename option will save the RSA private key to the specified absolute path.

For example:

sudo chef-server-ctl user-create janedoe Jane Doe janed@example.com 'abc123' --filename /path/to/janedoe.pem

2. Run the following command to create an organization:

sudo chef-server-ctl org-create short_name 'full_organization_name' --association_user user_name --filename ORGANIZATION-validator.pem

For example:

sudo chef-server-ctl org-create 4thcoffee 'Fourth Coffee, Inc.' --association_user janedoe --filename /path/to/4thcoffee-validator.pem

The name must begin with a lower-case letter or digit, may only contain lower-case letters, digits, hyphens, and underscores, and must be between 1 and 255 characters. For example: 4thcoffee.

The full name must begin with a non-white space character and must be between 1 and 1023 characters. For example: 'Fourth Coffee, Inc.'.

The --association_user option will associate the user_name with the admins security group on the Chef Infra Server.

An RSA private key is generated automatically. This is the chef-validator key and should be saved to a safe location. The --filename option will save the RSA private key to the specified absolute path.

Enable Features

Enable additional features of the Chef Infra Server! The packages may be downloaded directly as part of the installation process or they may be first downloaded to a local directory, and then installed.

Use Downloads

The install subcommand downloads packages from https://packages.chef.io/ by default. For systems that are not behind a firewall (and have connectivity to https://packages.chef.io/), the Chef management console package can be installed as described below:

Chef Manage

Use Chef management console to manage data bags, attributes, run-lists, roles, environments, and cookbooks from a web user interface.

On each front end server in the Chef Infra Server configuration, run:

chef-server-ctl install chef-manage

then:

chef-server-ctl reconfigure

and then:

chef-manage-ctl reconfigure

To accept the Chef MLSA:

sudo chef-manage-ctl reconfigure --accept-license

This updates the Chef Infra Server and creates the /etc/opscode-manage/secrets.rb file. When running the Chef management console 1.11 (or higher), copy the secrets.rb file in the /etc/opscode-manage directory on one of the frontend servers to the same directory on each of the other frontend servers, and then rerun chef-manage-ctl reconfigure so the copied /etc/opscode-manage/secrets.rb file gets used correctly.

Use Local Packages

Use the install subcommand with the --path option to install the Chef Manage (chef-manage) add-on for Chef Infra Server.

sudo chef-server-ctl install PACKAGE_NAME --path /path/to/package/directory

For example:

sudo chef-server-ctl install chef-manage --path /root/packages

The chef-server-ctl command will install the first chef-manage package found in the /root/packages directory.

Reference

The following sections show an example chef-server.rb file and a list of the ports that are required by the Chef Infra Server.

chef-server.rb

A completed chef-server.rb configuration file for a four server tiered Chef Infra Server configuration, consisting of:

Looks like this:

topology "tier"

server "be1.example.com",
  :ipaddress => "192.0.2.0",
  :role => "backend",
  :bootstrap => true

backend_vip "be.example.com",
  :ipaddress => "192.168.4.7",
  :device => "eth0"

server "fe1.example.com",
  :ipaddress => "192.168.4.2",
  :role => "frontend"

server "fe2.example.com",
  :ipaddress => "192.168.4.3",
  :role => "frontend"

server "fe3.example.com",
  :ipaddress => "192.168.4.4",
  :role => "frontend"

api_fqdn "chef.example.com"

Firewalls

All of the ports used by the Chef Infra Server are TCP ports. Refer to the operating system’s manual or site systems administrators for instructions on how to enable changes to ports, if necessary.

All services must be listening on the appropriate ports. Most monitoring systems provide a means of testing whether a given port is accepting connections and service-specific tools may also be available. In addition, the generic system tool Telnet can also be used to initiate the connection:

telnet HOST_NAME PORT

A single loopback interface should be configured using the 127.0.0.1 address. This ensures that all of the services are available to the Chef Infra Server, in the event that the Chef Infra Server attempts to contact itself from within a front or back end machine. All ports should be accessible through the loopback interface of their respective hosts.

Backend

For back-end servers in a tiered Chef Infra Server installation, ensure that ports marked as external (marked as yes in the External column) are open and accessible via any firewalls that are in use:

Frontend

For front-end servers, ensure that ports marked as external (marked as yes in the External column) are open and accessible via any firewalls that are in use: