Add support for ARM64 runners

* Support Graviton (a1) and Graviton2 (*6g*)

Author: bdruth

main.tf

@@ -62,6 +62,8 @@ module "runners" {
 
   instance_type = var.instance_type
 
+  ami_filter = substr(var.instance_type,0,2) == "a1" || substr(var.instance_type,1,2) == "6g" ? {name = ["amzn2-ami-hvm-2*-arm64-gp2"]} : {name = ["amzn2-ami-hvm-2.*-x86_64-ebs"]}
+
   sqs_build_queue                 = aws_sqs_queue.queued_builds
   github_app                      = var.github_app
   enable_organization_runners     = var.enable_organization_runners
@@ -92,9 +94,12 @@ module "runner_binaries" {
 
   distribution_bucket_name = "${var.environment}-dist-${random_string.random.result}"
 
+  runner_architecture = substr(var.instance_type,0,2) == "a1" || substr(var.instance_type,1,2) == "6g" ? "arm64" : "x64"
+
   lambda_zip     = var.runner_binaries_syncer_lambda_zip
   lambda_timeout = var.runner_binaries_syncer_lambda_timeout
 
+
   role_path                 = var.role_path
   role_permissions_boundary = var.role_permissions_boundary
 }

modules/runner-binaries-syncer/lambdas/runner-binaries-syncer/src/syncer/handler.ts

@@ -31,13 +31,13 @@ interface ReleaseAsset {
   downloadUrl: string;
 }
 
-async function getLinuxReleaseAsset(): Promise<ReleaseAsset | undefined> {
+async function getLinuxReleaseAsset(runnerArch = 'x64'): Promise<ReleaseAsset | undefined> {
   const githubClient = new Octokit();
   const assets = await githubClient.repos.getLatestRelease({
     owner: 'actions',
     repo: 'runner',
   });
-  const linuxAssets = assets.data.assets?.filter((a) => a.name?.includes('actions-runner-linux-x64-'));
+  const linuxAssets = assets.data.assets?.filter((a) => a.name?.includes(`actions-runner-linux-${runnerArch}-`));
 
   return linuxAssets?.length === 1
     ? { name: linuxAssets[0].name, downloadUrl: linuxAssets[0].browser_download_url }
@@ -73,6 +73,8 @@ async function uploadToS3(s3: S3, cacheObject: CacheObject, actionRunnerReleaseA
 export const handle = async (): Promise<void> => {
   const s3 = new AWS.S3();
 
+  const runnerArch = process.env.GITHUB_RUNNER_ARCHITECTURE || 'x64'
+
   const cacheObject: CacheObject = {
     bucket: process.env.S3_BUCKET_NAME as string,
     key: process.env.S3_OBJECT_KEY as string,
@@ -81,7 +83,7 @@ export const handle = async (): Promise<void> => {
     throw Error('Please check all mandatory variables are set.');
   }
 
-  const actionRunnerReleaseAsset = await getLinuxReleaseAsset();
+  const actionRunnerReleaseAsset = await getLinuxReleaseAsset(runnerArch);
   if (actionRunnerReleaseAsset === undefined) {
     throw Error('Cannot find GitHub release asset.');
   }

modules/runner-binaries-syncer/runner-binaries-syncer.tf

@@ -16,6 +16,7 @@ resource "aws_lambda_function" "syncer" {
     variables = {
       S3_BUCKET_NAME = aws_s3_bucket.action_dist.id
       S3_OBJECT_KEY  = local.action_runner_distribution_object_key
+      GITHUB_RUNNER_ARCHITECTURE = var.runner_architecture
     }
   }
 

modules/runner-binaries-syncer/variables.tf

@@ -48,3 +48,9 @@ variable "role_path" {
   type        = string
   default     = null
 }
+
+variable "runner_architecture" {
+  description = "The platform architecture for the runner instance (x64, arm64), defaults to 'x64'"
+  type        = string
+  default     = "x64"
+}

modules/runners/templates/user-data.sh

@@ -20,6 +20,56 @@ aws s3 cp ${s3_location_runner_distribution} actions-runner.tar.gz
 tar xzf ./actions-runner.tar.gz
 rm -rf actions-runner.tar.gz
 
+# Patch for ARM64 (no ICU install by default)
+yum install -y patch
+patch -p1 <<ICU_PATCH
+diff -Naur a/bin/Runner.Listener.runtimeconfig.json b/bin/Runner.Listener.runtimeconfig.json
+--- a/bin/Runner.Listener.runtimeconfig.json	2020-07-01 02:21:09.000000000 +0000
++++ b/bin/Runner.Listener.runtimeconfig.json	2020-07-28 00:02:38.748868613 +0000
+@@ -8,7 +8,8 @@
+       }
+     ],
+     "configProperties": {
+-      "System.Runtime.TieredCompilation.QuickJit": true
++      "System.Runtime.TieredCompilation.QuickJit": true,
++      "System.Globalization.Invariant": true
+     }
+   }
+-}
+\ No newline at end of file
++}
+diff -Naur a/bin/Runner.PluginHost.runtimeconfig.json b/bin/Runner.PluginHost.runtimeconfig.json
+--- a/bin/Runner.PluginHost.runtimeconfig.json	2020-07-01 02:21:22.000000000 +0000
++++ b/bin/Runner.PluginHost.runtimeconfig.json	2020-07-28 00:02:59.358680003 +0000
+@@ -8,7 +8,8 @@
+       }
+     ],
+     "configProperties": {
+-      "System.Runtime.TieredCompilation.QuickJit": true
++      "System.Runtime.TieredCompilation.QuickJit": true,
++      "System.Globalization.Invariant": true
+     }
+   }
+-}
+\ No newline at end of file
++}
+diff -Naur a/bin/Runner.Worker.runtimeconfig.json b/bin/Runner.Worker.runtimeconfig.json
+--- a/bin/Runner.Worker.runtimeconfig.json	2020-07-01 02:21:16.000000000 +0000
++++ b/bin/Runner.Worker.runtimeconfig.json	2020-07-28 00:02:19.159028531 +0000
+@@ -8,7 +8,8 @@
+       }
+     ],
+     "configProperties": {
+-      "System.Runtime.TieredCompilation.QuickJit": true
++      "System.Runtime.TieredCompilation.QuickJit": true,
++      "System.Globalization.Invariant": true
+     }
+   }
+-}
+\ No newline at end of file
++}
+ICU_PATCH
+
 INSTANCE_ID=$(wget -q -O - http://169.254.169.254/latest/meta-data/instance-id)
 REGION=$(curl -s 169.254.169.254/latest/dynamic/instance-identity/document | jq -r .region)