From e12293463e40b431da94a600c7a6d0255c03a54d Mon Sep 17 00:00:00 2001
From: Nicolas De Loof <nicolas.deloof@gmail.com>
Date: Mon, 22 Jul 2024 11:02:57 +0200
Subject: [PATCH] resolveRelativePaths can run with non-canonical model

Signed-off-by: Nicolas De Loof <nicolas.deloof@gmail.com>
---
 loader/extends.go                         |  2 +-
 loader/extends_test.go                    | 17 +++++++++++++
 loader/testdata/extends/interpolated.yaml |  5 ++++
 paths/resolve.go                          | 30 ++++++++++++++---------
 4 files changed, 41 insertions(+), 13 deletions(-)
 create mode 100644 loader/testdata/extends/interpolated.yaml

diff --git a/loader/extends.go b/loader/extends.go
index 21730f10..b2990453 100644
--- a/loader/extends.go
+++ b/loader/extends.go
@@ -190,7 +190,7 @@ func getExtendsBaseFromFile(
 			)
 		}
 
-		// Attempt to make a canonical model so ResolveRelativePaths can operate on source:target short syntaxes
+		// Attempt to make a canonical model so ResolveRelativePaths can operate on source:target short syntax
 		source, err = transform.Canonical(source, true)
 		if err != nil {
 			return nil, nil, err
diff --git a/loader/extends_test.go b/loader/extends_test.go
index 3990b3de..8f25f35d 100644
--- a/loader/extends_test.go
+++ b/loader/extends_test.go
@@ -484,3 +484,20 @@ services:
 	assert.NilError(t, err)
 	assert.Check(t, p.Services["test"].Command == nil)
 }
+
+func TestExtendsWithInterpolation(t *testing.T) {
+	yaml := `
+name: test-extends-with-interpolation
+services:
+  test:
+    extends: { file: testdata/extends/interpolated.yaml, service: foo }
+`
+	p, err := Load(types.ConfigDetails{
+		ConfigFiles: []types.ConfigFile{{
+			Content:  []byte(yaml),
+			Filename: "-",
+		}},
+	})
+	assert.NilError(t, err)
+	assert.Check(t, p.Services["test"].Volumes[0].Source == "/dev/null")
+}
diff --git a/loader/testdata/extends/interpolated.yaml b/loader/testdata/extends/interpolated.yaml
new file mode 100644
index 00000000..17d0ac5a
--- /dev/null
+++ b/loader/testdata/extends/interpolated.yaml
@@ -0,0 +1,5 @@
+services:
+  foo:
+    image: bash
+    volumes:
+      - ${SOURCE:-/dev/null}:/tmp/foo:ro
\ No newline at end of file
diff --git a/paths/resolve.go b/paths/resolve.go
index 3bb97f8c..303f39e2 100644
--- a/paths/resolve.go
+++ b/paths/resolve.go
@@ -116,24 +116,30 @@ func (r *relativePathsResolver) absPath(value any) (any, error) {
 		}
 		return v, nil
 	}
+
 	return nil, fmt.Errorf("unexpected type %T", value)
 }
 
 func (r *relativePathsResolver) absVolumeMount(a any) (any, error) {
-	vol := a.(map[string]any)
-	if vol["type"] != types.VolumeTypeBind {
+	switch vol := a.(type) {
+	case map[string]any:
+		if vol["type"] != types.VolumeTypeBind {
+			return vol, nil
+		}
+		src, ok := vol["source"]
+		if !ok {
+			return nil, errors.New(`invalid mount config for type "bind": field Source must not be empty`)
+		}
+		abs, err := r.maybeUnixPath(src.(string))
+		if err != nil {
+			return nil, err
+		}
+		vol["source"] = abs
 		return vol, nil
+	default:
+		// not using canonical format, skip
+		return a, nil
 	}
-	src, ok := vol["source"]
-	if !ok {
-		return nil, errors.New(`invalid mount config for type "bind": field Source must not be empty`)
-	}
-	abs, err := r.maybeUnixPath(src.(string))
-	if err != nil {
-		return nil, err
-	}
-	vol["source"] = abs
-	return vol, nil
 }
 
 func (r *relativePathsResolver) volumeDriverOpts(a any) (any, error) {