copr-be: start builders in random availability zones

Aarch64 hosts are not in all zones, so specify subnets per-architecture.

inventory/group_vars/copr_all_instances_aws

@@ -0,0 +1,17 @@
+# Your requested instance type (a1.xlarge) is not supported in your requested Availability Zone (us-east-1a).
+# Your requested instance type (a1.xlarge) is not supported in your requested Availability Zone (us-east-1d).
+# Your requested instance type (a1.xlarge) is not supported in your requested Availability Zone (us-east-1f).
+
+aws_arch_subnets:
+  x86_64:
+    - subnet-0995f6a466849f4c3
+    - subnet-08cadf5a14b530ac4
+    - subnet-07b0b3168a353e3ee
+    - subnet-09c74a3e6420a206b
+    - subnet-01d4e967ab5e78005
+    - subnet-05437ac82d63b6ef5
+
+  aarch64:
+    - subnet-0995f6a466849f4c3
+    - subnet-08cadf5a14b530ac4
+    - subnet-07b0b3168a353e3ee

inventory/inventory

@@ -907,6 +907,10 @@ copr_back_dev_aws
 copr_dist_git_dev_aws
 copr_keygen_dev_aws
 
+[copr_all_instances_aws:children]
+copr_aws
+copr_dev_aws
+
 # [copr_hypervisors_aarch64]
 # virthost-aarch64-os01.fedorainfracloud.org
 # virthost-aarch64-os02.fedorainfracloud.org

roles/copr/backend/files/provision/spinup_aws_task.yml

@@ -1,5 +1,9 @@
 - debug: msg="vm_name={{ vm_name }}"
 
+- name: random subnet to overcome datacenter failures
+  set_fact: subnet_id={{ item }}
+  with_random_choice: "{{ aws_arch_subnets[arch] }}"
+
 - name: Launch instance
   ec2:
     key_name: "{{ keypair }}"
@@ -9,7 +13,7 @@
     wait: true
     region: "{{ aws_region }}"
     # both x86_64 and aarch64 arches can be allocated in us-east-1c
-    vpc_subnet_id: subnet-0995f6a466849f4c3
+    vpc_subnet_id: "{{ subnet_id }}"
     assign_public_ip: yes
     instance_tags:
       FedoraGroup: copr