Retrieve checksum from subfolder/filename (#239)

checksum.go

@@ -274,6 +274,13 @@ func (c *Client) ChecksumFromFile(ctx context.Context, checksumURL, checksummedP
 				return checksum, nil
 			}
 		}
+		// The checksum filename can contain a sub folder to differ versions.
+		// e.g. ./netboot/mini.iso and ./hwe-netboot/mini.iso
+		// In this case we remove root folder characters to compare with the checksummed path
+		fn := strings.TrimLeft(checksum.Filename, "./")
+		if strings.Contains(checksummedPath, fn) {
+			return checksum, nil
+		}
 	}
 	return nil, fmt.Errorf("no checksum found in: %s", checksumURL)
 }

checksum_test.go

@@ -0,0 +1,23 @@
+package getter
+
+import (
+	"context"
+	"testing"
+)
+
+func TestClient_ChecksumFromFileWithSubFolder(t *testing.T) {
+	httpChecksums := httpTestModule("checksum-file")
+	defer httpChecksums.Close()
+	ctx := context.TODO()
+	isoURL := "http://hashicorp.com/ubuntu/dists/bionic-updates/main/installer-amd64/current/images/netboot/mini.iso"
+
+	client := Client{}
+	file, err := client.ChecksumFromFile(ctx, httpChecksums.URL+"/sha256-subfolder.sum", isoURL)
+
+	if err != nil {
+		t.Fatalf("bad: should not have error: %s", err.Error())
+	}
+	if file.Filename != "./netboot/mini.iso" {
+		t.Fatalf("bad: expecting filename ./netboot/mini.iso but was: %s", file.Filename)
+	}
+}

testdata/checksum-file/sha256-subfolder.sum

@@ -0,0 +1,2 @@
+a264b6b009dfaa16286fdfd046a156a43587333b  ./hwe-netboot/mini.iso
+27c39bac2cf4640c00cacfc8982b0ba39e7b7f96  ./netboot/mini.iso