From c2b38544f0c356342f05a3f20b244cb915dc0209 Mon Sep 17 00:00:00 2001
From: Michael Vogt <michael.vogt@gmail.com>
Date: Mon, 25 Nov 2024 13:09:24 +0100
Subject: [PATCH] blueprint: make `minsize` required for `disk.Customizations`

This commit enforces the use of "minsize" for disk customizations.
Without this the `disk` code will create zero sized partitions when
`minsize` is omited which then later yields a strange error from
osbuild:
```
Building manifest-qcow2-raw-vmdk-vhd-gce.json
<stdin> has errors:

.pipelines[1].stages[2].options.volumes[0].size:
  '0B' does not match '[1-9][0-9]*[bBsSkKmMgGtTpPeE]?'

2024/11/25 09:35:42 error: cannot run osbuild: running osbuild failed: exit status 2
```

We could also attempt to fix this by making guesses about minsize
(which is what the existing filesystem customizations do). But that
seems less appropriate here as this is about finer control and an
arbitrary size of e.g. `1 GiB` seems unexpected. Another alternative
would be to infere from the parent container size and split equally.
But we can always do this later and relax the rules (and even add
things like `minsize: 50%` which would imply the parent container).
---
 pkg/blueprint/disk_customizations.go      | 42 +++++++++++++----------
 pkg/blueprint/disk_customizations_test.go | 31 +++--------------
 2 files changed, 28 insertions(+), 45 deletions(-)

diff --git a/pkg/blueprint/disk_customizations.go b/pkg/blueprint/disk_customizations.go
index 331d33b859..e2655acef5 100644
--- a/pkg/blueprint/disk_customizations.go
+++ b/pkg/blueprint/disk_customizations.go
@@ -113,13 +113,15 @@ func (lv *LVCustomization) UnmarshalJSON(data []byte) error {
 	lv.Name = lvAnySize.Name
 	lv.FilesystemTypedCustomization = lvAnySize.FilesystemTypedCustomization
 
-	if lvAnySize.MinSize != nil {
-		size, err := decodeSize(lvAnySize.MinSize)
-		if err != nil {
-			return err
-		}
-		lv.MinSize = size
+	if lvAnySize.MinSize == nil {
+		return fmt.Errorf("minsize is required")
+	}
+	size, err := decodeSize(lvAnySize.MinSize)
+	if err != nil {
+		return err
 	}
+	lv.MinSize = size
+
 	return nil
 }
 
@@ -177,14 +179,16 @@ func (v *PartitionCustomization) UnmarshalJSON(data []byte) error {
 
 	v.Type = partType
 
-	if typeSniffer.MinSize != nil {
-		minsize, err := decodeSize(typeSniffer.MinSize)
-		if err != nil {
-			return fmt.Errorf("%s error decoding minsize for partition: %w", errPrefix, err)
-		}
-		v.MinSize = minsize
+	if typeSniffer.MinSize == nil {
+		return fmt.Errorf("minsize is required")
 	}
 
+	minsize, err := decodeSize(typeSniffer.MinSize)
+	if err != nil {
+		return fmt.Errorf("%s error decoding minsize for partition: %w", errPrefix, err)
+	}
+	v.MinSize = minsize
+
 	return nil
 }
 
@@ -301,13 +305,15 @@ func (v *PartitionCustomization) UnmarshalTOML(data any) error {
 
 	v.Type = partType
 
-	if minsizeField, ok := d["minsize"]; ok {
-		minsize, err := decodeSize(minsizeField)
-		if err != nil {
-			return fmt.Errorf("%s error decoding minsize for partition: %w", errPrefix, err)
-		}
-		v.MinSize = minsize
+	minsizeField, ok := d["minsize"]
+	if !ok {
+		return fmt.Errorf("minsize is required")
+	}
+	minsize, err := decodeSize(minsizeField)
+	if err != nil {
+		return fmt.Errorf("%s error decoding minsize for partition: %w", errPrefix, err)
 	}
+	v.MinSize = minsize
 
 	return nil
 }
diff --git a/pkg/blueprint/disk_customizations_test.go b/pkg/blueprint/disk_customizations_test.go
index 7a22d8b779..9c3259b5dc 100644
--- a/pkg/blueprint/disk_customizations_test.go
+++ b/pkg/blueprint/disk_customizations_test.go
@@ -1035,16 +1035,8 @@ func TestPartitionCustomizationUnmarshalJSON(t *testing.T) {
 
 	testCases := map[string]testCase{
 		"nothing": {
-			input: "{}",
-			expected: &blueprint.PartitionCustomization{
-				Type:    "plain",
-				MinSize: 0,
-				FilesystemTypedCustomization: blueprint.FilesystemTypedCustomization{
-					Mountpoint: "",
-					Label:      "",
-					FSType:     "",
-				},
-			},
+			input:    "{}",
+			errorMsg: "minsize is required",
 		},
 		"plain": {
 			input: `{
@@ -1346,16 +1338,8 @@ func TestPartitionCustomizationUnmarshalTOML(t *testing.T) {
 
 	testCases := map[string]testCase{
 		"nothing": {
-			input: "",
-			expected: &blueprint.PartitionCustomization{
-				Type:    "plain",
-				MinSize: 0,
-				FilesystemTypedCustomization: blueprint.FilesystemTypedCustomization{
-					Mountpoint: "",
-					Label:      "",
-					FSType:     "",
-				},
-			},
+			input:    "",
+			errorMsg: "toml: line 0: minsize is required",
 		},
 		"plain": {
 			input: `type = "plain"
@@ -1647,13 +1631,6 @@ func TestDiskCustomizationUnmarshalJSON(t *testing.T) {
 	}
 
 	testCases := map[string]testCase{
-		"nothing": {
-			inputJSON: "{}",
-			inputTOML: "",
-			expected: &blueprint.DiskCustomization{
-				MinSize: 0,
-			},
-		},
 		"minsize/int": {
 			inputJSON: `{
 				"minsize": 1234