Chef Replication (DEPRECATED)¶

Warning

This topic is deprecated as of the 12.9 release of the Chef server.

Note

This topic is meant to support existing customers using Chef replication. The capabilities of Chef replication can be reproduced using the features of Chef Automate workflow and we encourage customers to adopt Chef Automate going forward.

Chef replication provides a way to asynchronously distribute cookbook, environment, role, and data bag data from a single, primary Chef server to one (or more) replicas of that Chef server.

Note

Chef replication requires Chef server version 12.

Note

This feature is included as part of the Chef Automate license agreement and is available via subscription.

Scenarios¶

Replication is configured on a per-organization and also a per-replica basis. Each organization must be configured to synchronize with each replica instance. Each organization may be configured to synchronize with all, some, or none of the available replica instances.

For example, a single primary Chef server and a single replica:

and for example, a single primary Chef server and multiple replicas:

_images/chef_server_replication_many.png

Chef replication should not be used for:

Disaster recovery or backup/restore processes. The replication process is read-only and cannot be changed to read-write
Synchronizing a replica instance with another replica instance
Node re-registration. A node may be associated only with a single Chef server

How Replication Works¶

A daemon named ec-syncd runs on each of the replica instances of the Chef server and periodically polls the primary Chef server via the updated_since endpoint in the Chef server API. The ec-syncd daemon requests a list of objects that have been updated since the last successful synchronization time. If there are updates, the ec-syncd daemon then pulls down the updated data from the primary Chef server to the replica.

_images/chef_server_replication_sequence.png

Configure Chef Replication¶

To configure replication of Chef server data, first install Chef replication, then configure the primary Chef server, then configure the replica Chef server, and then start the synchronization process.

To install Chef replication, run the following on all servers in the Chef server configuration. For dpkg:
```
$ dpkg -i chef-sync-<version>.deb
```
For RPM Package Manager:
```
$ rpm -Uvh chef-sync-<version>.rpm
```
On the primary Chef server, create the chef-sync.rb file in the /etc/chef-sync/ directory, and then add the following setting:
```
role :master
```
On the primary Chef server, run the following command:
```
$ chef-sync-ctl reconfigure
```
On the primary Chef server, run the following command:
```
$ chef-server-ctl reconfigure
```
On the primary Chef server, run the following command:
```
$ chef-sync-ctl prepare-org SOURCE_ORG_NAME
```
For each replica Chef server, move the /etc/chef-sync/ec_sync_user.pem file from the primary Chef server to the /etc/chef-sync directory on the replica. (This file is created automatically on the primary Chef server.)
For each replica Chef server, create the chef-sync.rb file in the /etc/chef-sync/ directory, and then add the following setting:
```
role :replica
master "https://FQDN_OF_MASTER"
```
and then define the source and destination organizations:
```
organizations [
                {
                  :destination => "DEST_ORG_NAME",
                  :source => "SOURCE_ORG_NAME"
                }
              ]
```
where DEST_ORG_NAME is an organization on the replica Chef server and SOURCE_ORG_NAME is an organization on the primary Chef server. Both of these organizations must already exist.
For each replica Chef server, run the following command:
```
$ chef-sync-ctl reconfigure
```
For each replica Chef server, run the following command:
```
$ chef-sync-ctl prepare-org DEST_ORG_NAME
```
For each replica Chef server, run the following command:
```
$ chef-server-ctl reconfigure
```

chef-sync-ctl (executable)¶

chef-sync-ctl is the command line tool for Chef replication, which allows asynchronous replication of cookbook content across Chef server organizations. This is done from a single, primary Chef server organization to one (or more) replicas of that Chef server.

manager-log¶

Use to show the log file for the synchronization manager. This subcommand should only be run for replica organizations.