Support for copying from other named image layers

ninjarobot · Jul 29, 2021 · 5981f0a · 5981f0a
1 parent 26410ef
commit 5981f0a
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Showing 2 changed files with 24 additions and 2 deletions.
diff --git a/src/Dockerfile.fs b/src/Dockerfile.fs
@@ -21,6 +21,10 @@ module Dockerfile =
     type BuildStage = 
         | Name of string
         | Index of int
+        member this.AsString =
+            match this with
+            | Name n -> n
+            | Index i -> string i
 
     type Signal =
         | Sigquit
@@ -133,19 +137,32 @@ module Dockerfile =
                 |> sprintf "ADD %s"
             else
                 sprintf "ADD %s %s" (sources |> String.concat " ") dest
-        | Copy (SingleSource (source), dest, from) ->
+        | Copy (SingleSource (source), dest, None) ->
             if source |> stringContainsWhitepace || dest |> stringContainsWhitepace then
                 [source; dest] |> stringsToQuotedArray
                 |> sprintf "COPY %s"
             else
                 sprintf "COPY %s %s" source dest
-        | Copy (MultipleSources (sources), dest, from) ->
+        | Copy (SingleSource (source), dest, Some (from)) ->
+            if source |> stringContainsWhitepace || dest |> stringContainsWhitepace then
+                [source; dest] |> stringsToQuotedArray
+                |> sprintf "COPY --from=%s %s" from.AsString
+            else
+                sprintf "COPY --from=%s %s %s" from.AsString source dest
+        | Copy (MultipleSources (sources), dest, None) ->
             if sources |> List.exists(stringContainsWhitepace) || dest |> stringContainsWhitepace then
                 sources@[dest] |> stringsToQuotedArray
                 |> sprintf "COPY %s"
             else
                 sources@[dest] |> String.concat " "
                 |> sprintf "COPY %s"
+        | Copy (MultipleSources (sources), dest, Some(from)) ->
+            if sources |> List.exists(stringContainsWhitepace) || dest |> stringContainsWhitepace then
+                sources@[dest] |> stringsToQuotedArray
+                |> sprintf "COPY --from=%s %s" from.AsString
+            else
+                sources@[dest] |> String.concat " "
+                |> sprintf "COPY --from=%s %s" from.AsString
         | Entrypoint (Exec (executable, args)) -> 
             sprintf "ENTRYPOINT %s" (executable::args |> stringsToQuotedArray)
         | Entrypoint (ShellCommand (command)) ->

diff --git a/tests/DockerfileTests.fs b/tests/DockerfileTests.fs
@@ -165,6 +165,11 @@ let ``COPY multiple sources with whitespace`` () =
     let instruction = Copy (MultipleSources (["path to/source"; "some/other source"]), "/dest/in/image", None) |> printInstruction
     Assert.Equal ("""COPY ["path to/source", "some/other source", "/dest/in/image"]""", instruction)
 
+[<Fact>]
+let ``COPY from named layer`` () =
+    let instruction = Copy (SingleSource ("path/to/source"), "/dest/in/image", Some (BuildStage.Name "builder")) |> printInstruction
+    Assert.Equal ("COPY --from=builder path/to/source /dest/in/image", instruction)
+
 [<Fact>]
 let ``ENTRYPOINT exec no args`` () =
     let instruction = Entrypoint (Exec ("/bin/bash", [])) |> printInstruction