Create RequestScheme type to handle registry interactions (#6)

Its a bit weird to have to pass `--http` when pulling / pushing images
if we are trying to do so from a local registry

This PR adds a `RequestScheme` enum type which tries to detect if the
connection to the registry should be over http or https. This auto
detection is the default behavior and can be overridden by passing the
`--scheme http/https` flag to the `run` ,`pull`, `push` `login` and
`registry default` command

The auto detection works by looking at the hostname / IP. HTTP is used
in the following cases
 - If the hostname starts with `localhost` or  is `127.x.x.x`
 - if the host looks like an IP from the private address space
 - If the host ends with the current default dns domain name

Also in this PR:
- Removing some used CLI flag groups and TODOs
- Better error messages when registry credentials are not found for a
host

Signed-off-by: Aditya Ramani <a_ramani@apple.com>

Sources/ContainerClient/Utility.swift

@@ -68,9 +68,11 @@ public struct Utility {
         process: Flags.Process,
         management: Flags.Management,
         resource: Flags.Resource,
+        registry: Flags.Registry,
         progressUpdate: @escaping ProgressUpdateHandler
     ) async throws -> (ContainerConfiguration, Kernel) {
         let requestedPlatform = Parser.platform(os: management.os, arch: management.arch)
+        let scheme = try RequestScheme(registry.scheme)
 
         await progressUpdate([
             .setDescription("Fetching image"),
@@ -81,6 +83,7 @@ public struct Utility {
         let img = try await ClientImage.fetch(
             reference: image,
             platform: requestedPlatform,
+            scheme: scheme,
             progressUpdate: ProgressTaskCoordinator.handler(for: fetchTask, from: progressUpdate)
         )
 
@@ -95,14 +98,11 @@ public struct Utility {
             progressUpdate: ProgressTaskCoordinator.handler(for: unpackTask, from: progressUpdate))
 
         await progressUpdate([
-            .setDescription("Fetching kernel image"),
-            .setItemsName("blobs"),
+            .setDescription("Fetching kernel"),
+            .setItemsName("binary"),
         ])
 
-        let fetchKernelTask = await taskManager.startTask()
-        let kernel = try await self.getKernel(
-            management: management,
-            progressUpdate: ProgressTaskCoordinator.handler(for: fetchKernelTask, from: progressUpdate))
+        let kernel = try await self.getKernel(management: management)
 
         // Pull and unpack the initial filesystem
         await progressUpdate([
@@ -111,7 +111,7 @@ public struct Utility {
         ])
         let fetchInitTask = await taskManager.startTask()
         let initImage = try await ClientImage.fetch(
-            reference: ClientImage.initImageRef, platform: .current,
+            reference: ClientImage.initImageRef, platform: .current, scheme: scheme,
             progressUpdate: ProgressTaskCoordinator.handler(for: fetchInitTask, from: progressUpdate))
 
         await progressUpdate([
@@ -185,18 +185,10 @@ public struct Utility {
         return (config, kernel)
     }
 
-    private static func getKernel(management: Flags.Management, progressUpdate: @escaping ProgressUpdateHandler) async throws -> Kernel {
+    private static func getKernel(management: Flags.Management) async throws -> Kernel {
         // For the image itself we'll take the user input and try with it as we can do userspace
         // emulation for x86, but for the kernel we need it to match the hosts architecture.
-        let s: SystemPlatform
-        switch Platform.current.architecture {
-        case "arm64":
-            s = .linuxArm
-        case "amd64":
-            s = .linuxAmd
-        default:
-            throw ContainerizationError.init(.unsupported, message: "platform architecture \(Platform.current.architecture)")
-        }
+        let s: SystemPlatform = .current
         if let userKernel = management.kernel {
             guard FileManager.default.fileExists(atPath: userKernel) else {
                 throw ContainerizationError(.notFound, message: "Kernel file not found at path \(userKernel)")