From 37b3207792c6a27f0e23554c4aa7331b9a208820 Mon Sep 17 00:00:00 2001
From: Mateusz Gozdek <mateusz@kinvolk.io>
Date: Fri, 24 May 2019 00:40:21 +0200
Subject: [PATCH] pkg: improve support for systemd >= 240 and native btrfs
 parititions

Systemd prior to version 240 was creating /var/lib/machines.raw as btrfs
volume for storing machined disks. However, this functionality is now
remove and now it stores it as regular files. More details here:
https://github.com/systemd/systemd/blob/401faa3533280b05fee972e0c64885caf4b31e4c/units/var-lib-machines.mount#L10

Additionally, it someone already have /var/lib/machines baked by btrfs,
machined won't create machines.raw, which will also cause setting up
cluster to fail.

This patch adds check, if machineImage exists and it not, it fallbacks
to just checking disk space available for /var/lib/machines.

Refs #339 #293

Signed-off-by: Mateusz Gozdek <mateusz@kinvolk.io>
---
 pkg/bootstrap/node.go  | 32 +++++++++++++++++++++++++++-----
 pkg/cluster/cluster.go | 20 +++++++++++++++++---
 2 files changed, 44 insertions(+), 8 deletions(-)

diff --git a/pkg/bootstrap/node.go b/pkg/bootstrap/node.go
index 890e9740..0f90b3ab 100644
--- a/pkg/bootstrap/node.go
+++ b/pkg/bootstrap/node.go
@@ -62,19 +62,30 @@ func GetPoolSize(baseImageName string, nodes int) (int64, error) {
 	var extraSizeRatio float64 = 0.5
 	var err error
 
-	baseImageAbspath := path.Join(machinesDir, baseImageName+".raw")
-
-	if poolSize, err = getAllocatedFileSize(machinesImage); err != nil {
+	// Select correct path to check disk space. On older systemd versions
+	// machinesImage is used.
+	p := machinesDir
+	poolExists, err := CheckPoolExists()
+	if err != nil {
 		return 0, err
+	} else if poolExists {
+		p = machinesImage
+
+		if poolSize, err = getAllocatedFileSize(machinesImage); err != nil {
+			return 0, err
+		}
+
+		extraSize = int64(float64(poolSize) * extraSizeRatio)
 	}
-	extraSize = int64(float64(poolSize) * extraSizeRatio)
+
+	baseImageAbspath := path.Join(machinesDir, baseImageName+".raw")
 
 	if biSize, err = getAllocatedFileSize(baseImageAbspath); err != nil {
 		return 0, err
 	}
 	extraSize += int64(float64(biSize)*extraSizeRatio) * int64(nodes)
 
-	varDir, _ := path.Split(machinesImage)
+	varDir, _ := path.Split(p)
 	freeVolSpace, err := getVolFreeSpace(varDir)
 	if err != nil {
 		return 0, err
@@ -95,6 +106,17 @@ func GetPoolSize(baseImageName string, nodes int) (int64, error) {
 	return poolSize, nil
 }
 
+func CheckPoolExists() (bool, error) {
+	if _, err := os.Stat(machinesImage); err != nil {
+		if os.IsNotExist(err) {
+			return false, nil
+		} else {
+			return false, err
+		}
+	}
+	return true, nil
+}
+
 func setPoolLimit(poolSize int64) error {
 	var cmdPath string
 	var err error
diff --git a/pkg/cluster/cluster.go b/pkg/cluster/cluster.go
index aa6dd607..d91dea54 100644
--- a/pkg/cluster/cluster.go
+++ b/pkg/cluster/cluster.go
@@ -368,15 +368,29 @@ func (c *Cluster) Start(numberNodes int, cniPluginDir, cniPlugin, flatcarChannel
 		return err
 	}
 
-	poolSize, err := bootstrap.GetPoolSize(bootstrap.BaseImageName, numberNodes)
+	poolExists, err := bootstrap.CheckPoolExists()
 	if err != nil {
 		return err
 	}
-	log.Printf("new poolSize to be : %d\n", poolSize)
-	if err := bootstrap.EnlargeStoragePool(poolSize); err != nil {
+
+	// TODO This shouldn't be hardcoded, but I don't know where to put it yet
+	imageName := "flatcar"
+	if poolExists {
+		imageName = bootstrap.BaseImageName
+	}
+
+	poolSize, err := bootstrap.GetPoolSize(imageName, numberNodes)
+	if err != nil {
 		return err
 	}
 
+	if poolExists {
+		log.Printf("new poolSize to be : %d\n", poolSize)
+		if err := bootstrap.EnlargeStoragePool(poolSize); err != nil {
+			return err
+		}
+	}
+
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()