Revert "Vminitd: Remove special cased /run mount (#233)" (#253)

This reverts commit 5f7dcd2a16. Rosetta is
setup at /run because the guest rootfs is ro, and unfortunately this
happens prior to LinuxContainer getting to mount any of this. I'm not
super happy about this, but we can figure something out later.

Additionally this adds a rosetta flag to cctl so we can quickly
spotcheck things like this again.

Sources/Containerization/Agent/Vminitd.swift

@@ -56,8 +56,6 @@ extension Vminitd: VirtualMachineAgent {
         try await setenv(key: "PATH", value: Self.defaultPath)
 
         let mounts: [ContainerizationOCI.Mount] = [
-            // NOTE: /proc is always done implicitly by the guest agent.
-            .init(type: "tmpfs", source: "tmpfs", destination: "/run"),
             .init(type: "sysfs", source: "sysfs", destination: "/sys"),
             .init(type: "tmpfs", source: "tmpfs", destination: "/tmp"),
             .init(type: "devpts", source: "devpts", destination: "/dev/pts", options: ["gid=5", "mode=620", "ptmxmode=666"]),

Sources/cctl/RunCommand.swift

@@ -43,6 +43,9 @@ extension Application {
         @Option(name: .customLong("fs-size"), help: "The size to create the block filesystem as")
         var fsSizeInMB: UInt64 = 2048
 
+        @Flag(name: .customLong("rosetta"), help: "Enable rosetta x64 emulation")
+        var rosetta = false
+
         @Option(name: .customLong("mount"), help: "Directory to share into the container (Example: /foo:/bar)")
         var mounts: [String] = []
 
@@ -92,6 +95,7 @@ extension Application {
                 config.process.setTerminalIO(terminal: current)
                 config.process.arguments = arguments
                 config.process.workingDirectory = cwd
+                config.rosetta = rosetta
 
                 for mount in self.mounts {
                     let paths = mount.split(separator: ":")

vminitd/Sources/vminitd/Application.swift

@@ -99,7 +99,10 @@ struct Application {
             log.error("failed to mount /proc")
             exit(1)
         }
-
+        guard Musl.mount("tmpfs", "/run", "tmpfs", 0, "") == 0 else {
+            log.error("failed to mount /run")
+            exit(1)
+        }
         try Binfmt.mount()
 
         log.logLevel = .debug