tart clone: make pruning limit configurable (#1126)

* tart clone: make pruning limit configurable

* Fixed compilation

Author: fkorotkov

Sources/tart/Commands/Clone.swift

@@ -31,6 +31,9 @@ struct Clone: AsyncParsableCommand {
   @Flag(help: .hidden)
   var deduplicate: Bool = false
 
+  @Option(help: ArgumentHelp("limit automatic pruning to n gigabytes", valueName: "n"))
+  var pruneLimit: UInt = 100
+
   func validate() throws {
     if newName.contains("/") {
       throw ValidationError("<new-name> should be a local name")
@@ -77,7 +80,7 @@ struct Clone: AsyncParsableCommand {
       // So, once we clone the VM let's try to claim the rest of space for the VM to run without errors.
       let unallocatedBytes = try sourceVM.sizeBytes() - sourceVM.allocatedSizeBytes()
       // Avoid reclaiming an excessive amount of disk space.
-      let reclaimBytes = min(unallocatedBytes, 100 * 1024 * 1024 * 1024)
+      let reclaimBytes = min(unallocatedBytes, Int(pruneLimit) * 1024 * 1024 * 1024)
       if reclaimBytes > 0 {
         try Prune.reclaimIfNeeded(UInt64(reclaimBytes), sourceVM)
       }

docs/faq.md

@@ -166,6 +166,8 @@ Tart does have an analogue of Anka Controller for managing VMs across a cluster
 
 In case there's not enough space to fit the newly pulled or cloned VM image, Tart will remove the least recently accessed VMs from OCI cache and `.ipsw` files from IPSW cache until enough free space is available.
 
+The `tart clone` command limits this automatic pruning to 100 GB by default to avoid removing too many cached items. You can change this limit with the `--prune-limit` option (in gigabytes).
+
 To disable this functionality, set the `TART_NO_AUTO_PRUNE` environment variable either globally:
 
 ```shell