Neaten up SSH handling

Explicitly use the specified private key where possible. Also, use a
struct for the user, address and private key.

3 files changed, 10 insertions, 14 deletions

diff --git a/app/models/backends/terraform_aws.rb b/app/models/backends/terraform_aws.rb
index d0655ee..2bf68a3 100644
--- a/app/models/backends/terraform_aws.rb
+++ b/app/models/backends/terraform_aws.rb
@@ -64,6 +64,14 @@ class Backends::TerraformAws < ApplicationRecord
     }
   end
 
+  def build_remote_host
+    RemoteHost.new(
+      'ubuntu',
+      backend_latest_terraform_state.output_value('guix_daemon_public_dns'),
+      ssh_private_key
+    )
+  end
+
   def terraform_state_id
     "backend/terraform_aws/#{id}"
   end
diff --git a/app/models/backends/terraform_aws/backend_methods.rb b/app/models/backends/terraform_aws/backend_methods.rb
index 7489325..f069d77 100644
--- a/app/models/backends/terraform_aws/backend_methods.rb
+++ b/app/models/backends/terraform_aws/backend_methods.rb
@@ -20,12 +20,8 @@
 
 module Backends::TerraformAws::BackendMethods
   def create_data_snapshot
-    remote_host = backend_latest_terraform_state.output_value(
-      'guix_daemon_public_dns'
-    )
-
     GovukGuix::CreateDataSnapshotJob.enqueue(
-      run_remotely_on_host: "ubuntu@#{remote_host}",
+      run_remotely_on_host: build_remote_host,
       backend_type: self.class.name,
       backend_id: id
     )
diff --git a/app/models/backends/terraform_aws/mini_environment_methods.rb b/app/models/backends/terraform_aws/mini_environment_methods.rb
index 1885af7..350df2a 100644
--- a/app/models/backends/terraform_aws/mini_environment_methods.rb
+++ b/app/models/backends/terraform_aws/mini_environment_methods.rb
@@ -22,14 +22,6 @@ module Backends::TerraformAws::MiniEnvironmentMethods
   def build(mini_environment)
     slug = mini_environment.name.parameterize
 
-    remote_build_host =
-      mini_environment
-        .backend
-        .backend_latest_terraform_state
-        .output_value(
-          'guix_daemon_public_dns'
-        )
-
     GovukGuix::BuildMiniEnvironment.build(
       mini_environment.id,
       services: mini_environment.services.map(&:build_argument_string),
@@ -50,7 +42,7 @@ module Backends::TerraformAws::MiniEnvironmentMethods
           '/var/log/govuk-mini-environment-admin=/var/log'
         ]
       },
-      run_remotely_on_host: "ubuntu@#{remote_build_host}"
+      run_remotely_on_host: mini_environment.backend.build_remote_host
     )
   end