Introduction
This article explains how to configure different replica counts for various regions when using Packer with Azure Resource Manager (ARM). It covers how to set up replication counts both globally and for specific regions directly within your Packer configuration.
Problem
If you’re using multiple regions with the Packer ARM provider and want to specify different replica counts for each region, you might run into issues. For example, you might want to set 5 replicas for regionA, 2 for regionB, and 3 for regionC, but the existing methods may not support this level of detail.
Cause
The previous method allowed defining a global shared_image_gallery_replica_count and specifying regions within the shared_image_gallery_destination block. This approach looks like this:
shared_image_gallery_replica_count = 2
shared_image_gallery_destination {
image_name = "arm-linux-specialized-sig"
gallery_name = "packergallery"
image_version = "1.0.0"
resource_group = var.resource_group_name
specialized = true
replication_regions = [“regionA”, “regionB”, “regionC”]
}
In this approach, you define a single global count (shared_image_gallery_replica_count) that applies to all the regions listed in replication_regions. This method doesn’t allow for different replica counts for different regions.
Solutions
To set specific replica counts for each region, you can use the newer target_region block in your Packer configuration. This method lets you specify different replica counts for each region individually:
shared_image_gallery_destination {
image_name = "arm-linux-specialized-sig"
gallery_name = "packergallery"
image_version = "1.0.0"
resource_group = var.resource_group_name
specialized = true
target_region {
name = "South Central US"
replicas = 5
}
target_region {
name = "West US"
replicas = 2
}
target_region {
name = "East US"
replicas = 3
}
}
With this updated approach, you can set a different number of replicas for each region, giving you more flexibility in how your images are replicated.
References