Provide a default for linux to allow providing a custom limit on linux containers

action.yml

@@ -109,13 +109,14 @@ inputs:
   dockerCpuLimit:
     required: false
     default: ''
-    description: 'Number of CPU cores to assign the Windows docker container. Defaults to all available cores.'
+    description: 'Number of CPU cores to assign the docker container. Defaults to all available cores on all platforms.'
   dockerMemoryLimit:
     required: false
     default: ''
     description:
-      'Amount of memory to assign the Windows docker container. Defaults to 75% of total system memory rounded down to
+      'Amount of memory to assign the docker container. Defaults to 95% of total system memory rounded down to the
-      the nearest gigabyte.'
+      nearest megabyte on Linux and 80% on Windows. On unrecognized platforms, defaults to 75% of total system memory.
+      To manually specify a value, use the format <number><unit>, where unit is either m or g. ie: 512m = 512 megabytes'
   allowDirtyBuild:
     required: false
     default: ''

src/model/docker.ts

@@ -48,6 +48,8 @@ class Docker {
       sshPublicKeysDirectoryPath,
       gitPrivateToken,
       dockerWorkspacePath,
+      dockerCpuLimit,
+      dockerMemoryLimit,
     } = parameters;
 
     const githubHome = path.join(runnerTempPath, '_github_home');
@@ -72,6 +74,8 @@ class Docker {
             --volume "${actionFolder}/platforms/ubuntu/steps:/steps:z" \
             --volume "${actionFolder}/platforms/ubuntu/entrypoint.sh:/entrypoint.sh:z" \
             --volume "${actionFolder}/unity-config:/usr/share/unity3d/config/:z" \
+            --cpus=${dockerCpuLimit} \
+            --memory=${dockerMemoryLimit} \
             ${sshAgent ? `--volume ${sshAgent}:/ssh-agent` : ''} \
             ${
               sshAgent && !sshPublicKeysDirectoryPath

src/model/input.ts

@@ -232,9 +232,24 @@ class Input {
   }
 
   static get dockerMemoryLimit(): string {
-    const bytesInGigabyte = 1024 * 1024 * 1024;
+    const bytesInMegabyte = 1024 * 1024;
 
-    return Input.getInput('dockerMemoryLimit') || `${Math.floor((os.totalmem() / bytesInGigabyte) * 0.75)}G`;
+    let memoryMultiplier;
+    switch (os.platform()) {
+      case 'linux':
+        memoryMultiplier = 0.95;
+        break;
+      case 'win32':
+        memoryMultiplier = 0.8;
+        break;
+      default:
+        memoryMultiplier = 0.75;
+        break;
+    }
+
+    return (
+      Input.getInput('dockerMemoryLimit') || `${Math.floor((os.totalmem() / bytesInMegabyte) * memoryMultiplier)}m`
+    );
   }
 
   public static ToEnvVarFormat(input: string) {