Don't fail copy to emptydir

When a COPY command was being targeted at an empty new directory, the copy would fail. It could be "worked around" by putting a dummy file into the directory. Addresses: containers#2964 Signed-off-by: TomSweeneyRedHat <[email protected]>
rhatdan · Feb 11, 2021 · f379c5c · f379c5c
1 parent 0bc5bfd
commit f379c5c
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diff --git a/add.go b/add.go
@@ -303,6 +303,13 @@ func (b *Builder) Add(destination string, extract bool, options AddAndCopyOption
 		renameTarget = filepath.Base(extractDirectory)
 		extractDirectory = filepath.Dir(extractDirectory)
 	}
+
+	// if the destination is a directory that doesn't yet exist, let's copy it.
+	newDestDirFound := false
+	if (len(destStats) == 1 || len(destStats[0].Globbed) == 0) && destMustBeDirectory && !destCanBeFile {
+		newDestDirFound = true
+	}
+
 	if len(destStats) == 1 && len(destStats[0].Globbed) == 1 && destStats[0].Results[destStats[0].Globbed[0]].IsRegular {
 		if destMustBeDirectory {
 			return errors.Errorf("destination %v already exists but is not a directory", destination)
@@ -393,6 +400,12 @@ func (b *Builder) Add(destination string, extract bool, options AddAndCopyOption
 
 		// Iterate through every item that matched the glob.
 		itemsCopied := 0
+
+		// if the destination is a directory that doesn't yet exist, let's copy it.
+		if newDestDirFound {
+			itemsCopied++
+		}
+
 		for _, glob := range localSourceStat.Globbed {
 			rel, err := filepath.Rel(contextDir, glob)
 			if err != nil {

diff --git a/tests/bud.bats b/tests/bud.bats
@@ -2552,3 +2552,25 @@ _EOF
   run_buildah manifest inspect testlist
   expect_output --substring $digest
 }
+
+@test "bud test empty newdir" {
+  _prefetch alpine
+  mytmpdir=${TESTDIR}/my-dir
+  mkdir -p ${mytmpdir}
+cat > $mytmpdir/Containerfile << _EOF
+FROM alpine as galaxy
+
+RUN mkdir -p /usr/share/ansible/roles /usr/share/ansible/collections
+RUN echo "bar"
+RUN echo "foo" > /usr/share/ansible/collections/file.txt
+
+FROM galaxy
+
+RUN mkdir -p /usr/share/ansible/roles /usr/share/ansible/collections
+COPY --from=galaxy /usr/share/ansible/roles /usr/share/ansible/roles
+COPY --from=galaxy /usr/share/ansible/collections /usr/share/ansible/collections
+_EOF
+
+  run_buildah bud --layers --signature-policy ${TESTSDIR}/policy.json -t testbud $mytmpdir                                                   
+  expect_output --substring "COPY --from=galaxy /usr/share/ansible/collections /usr/share/ansible/collections"
+}