(PE-40372) Add optional replica host to migration plan

This commit extends the migration plan to support and utilise an
optional new replica host parameter. Code has also been added to purge
old nodes from the newly restored infrastructure.

Author: petergmurphy

REFERENCE.md

@@ -2322,6 +2322,8 @@ The following parameters are available in the `peadm::migrate` plan:
 
 * [`old_primary_host`](#-peadm--migrate--old_primary_host)
 * [`new_primary_host`](#-peadm--migrate--new_primary_host)
+* [`upgrade_version`](#-peadm--migrate--upgrade_version)
+* [`replica_host`](#-peadm--migrate--replica_host)
 
 ##### <a name="-peadm--migrate--old_primary_host"></a>`old_primary_host`
 
@@ -2335,6 +2337,22 @@ Data type: `Peadm::SingleTargetSpec`
 
 The new server that will become the PE primary server
 
+##### <a name="-peadm--migrate--upgrade_version"></a>`upgrade_version`
+
+Data type: `Optional[String]`
+
+Optional version to upgrade to after migration is complete
+
+Default value: `undef`
+
+##### <a name="-peadm--migrate--replica_host"></a>`replica_host`
+
+Data type: `Optional[SingleTargetSpec]`
+
+
+
+Default value: `undef`
+
 ### <a name="peadm--modify_certificate"></a>`peadm::modify_certificate`
 
 Certificates can be modified by adding extensions, removing extensions, or

plans/migrate.pp

@@ -11,25 +11,28 @@
   Peadm::SingleTargetSpec $old_primary_host,
   Peadm::SingleTargetSpec $new_primary_host,
   Optional[String] $upgrade_version = undef,
+  Optional[Peadm::SingleTargetSpec] $replica_host = undef,
 ) {
   peadm::assert_supported_bolt_version()
 
   $backup_file = run_plan('peadm::backup', $old_primary_host, {
       backup_type => 'migration',
   })
 
-  download_file($backup_file['path'], 'backup', $old_primary_host)
+  $download_results = download_file($backup_file['path'], 'backup', $old_primary_host)
+  $download_path = $download_results[0]['path']
 
   $backup_filename = basename($backup_file['path'])
   $remote_backup_path = "/tmp/${backup_filename}"
-  $current_dir = system::env('PWD')
 
-  upload_file("${current_dir}/downloads/backup/${old_primary_host}/${backup_filename}", $remote_backup_path, $new_primary_host)
+  upload_file($download_path, $remote_backup_path, $new_primary_host)
 
   $old_primary_target = get_targets($old_primary_host)[0]
   $old_primary_password = peadm::get_pe_conf($old_primary_target)['console_admin_password']
   $old_pe_conf = run_task('peadm::get_peadm_config', $old_primary_target).first.value
 
+  out::message("old_pe_conf:${old_pe_conf}.")
+
   run_plan('peadm::install', {
       primary_host                => $new_primary_host,
       console_password            => $old_primary_password,
@@ -44,11 +47,76 @@
       input_file => $remote_backup_path,
   })
 
-  if $upgrade_version {
+  # Use the old PE configuration to determine which nodes to purge
+  $old_primary_host_value = $old_pe_conf['params']['primary_host']
+  $replica_host_value = $old_pe_conf['params']['replica_host']
+  $primary_postgresql_host_value = $old_pe_conf['params']['primary_postgresql_host']
+  $replica_postgresql_host_value = $old_pe_conf['params']['replica_postgresql_host']
+  $compilers_value = $old_pe_conf['params']['compilers']
+  $legacy_compilers_value = $old_pe_conf['params']['legacy_compilers']
+
+  $old_primary_host_string = !empty($old_primary_host_value) ? {
+    true    => $old_primary_host_value,
+    default => ''
+  }
+
+  $replica_host_string = !empty($replica_host_value) ? {
+    true    => $replica_host_value,
+    default => ''
+  }
+
+  $primary_postgresql_host_string = !empty($primary_postgresql_host_value) ? {
+    true    => $primary_postgresql_host_value,
+    default => ''
+  }
+
+  $replica_postgresql_host_string = !empty($replica_postgresql_host_value) ? {
+    true    => $replica_postgresql_host_value,
+    default => ''
+  }
+
+  $compilers_string = !empty($compilers_value) ? {
+    true    => $compilers_value.filter |$node| { !empty($node) }.join(','),
+    default => ''
+  }
+
+  $legacy_compilers_string = !empty($legacy_compilers_value) ? {
+    true    => $legacy_compilers_value.filter |$node| { !empty($node) }.join(','),
+    default => ''
+  }
+
+  $purge_components = [
+    $replica_host_string,
+    $primary_postgresql_host_string,
+    $replica_postgresql_host_string,
+    $compilers_string,
+    $legacy_compilers_string,
+    $old_primary_host_string,
+  ].filter |$component| { !empty($component) }
+
+  if !empty($purge_components) {
+    out::message('Purging nodes from old configuration individually')
+    $purge_components.each |$component| {
+      out::message("Purging component: ${component}")
+      run_command("/opt/puppetlabs/bin/puppet node purge ${component}", $new_primary_host)
+    }
+  } else {
+    out::message('No nodes to purge from old configuration')
+  }
+
+  if $replica_host {
+    run_plan('peadm::add_replica', {
+        primary_host => $new_primary_host,
+        replica_host => $replica_host,
+    })
+  }
+
+  if $upgrade_version and $upgrade_version != '' and !empty($upgrade_version) {
     run_plan('peadm::upgrade', {
         primary_host                => $new_primary_host,
         version                     => $upgrade_version,
-        download_mode              => 'direct',
+        download_mode               => 'direct',
+        replica_host                => $replica_host,
     })
   }
 }