Add {{.Temp}} variable to host templates

Allows writing the temp mount as

mounts:
- location: "{{.Temp}}/lima"
  mountPoint: /tmp/lima

Note that on macOS this would use $TMPDIR and not /tmp, so would be a change
in behaviour. It would not affect existing instances though.

Signed-off-by: Jan Dubois <[email protected]>

pkg/limayaml/defaults.go

@@ -703,7 +703,7 @@ func FillDefault(y, d, o *LimaYAML, filePath string, warn bool) {
 	location := make(map[string]int)
 	for _, mount := range slices.Concat(d.Mounts, y.Mounts, o.Mounts) {
 		if out, err := executeHostTemplate(mount.Location, instDir, y.Param); err == nil {
-			mount.Location = out.String()
+			mount.Location = filepath.Clean(out.String())
 		} else {
 			logrus.WithError(err).Warnf("Couldn't process mount location %q as a template", mount.Location)
 		}
@@ -927,6 +927,7 @@ func executeHostTemplate(format, instDir string, param map[string]string) (bytes
 			"User":  currentUser.Username,
 			"Home":  userHomeDir,
 			"Param": param,
+			"Temp":  os.TempDir(),
 
 			"Instance": filepath.Base(instDir), // DEPRECATED, use `{{.Name}}`
 			"LimaHome": limaHome,               // DEPRECATED, use `{{.Dir}}` instead of `{{.LimaHome}}/{{.Instance}}`

pkg/limayaml/defaults_test.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"net"
 	"os"
+	"path"
 	"path/filepath"
 	"runtime"
 	"slices"
@@ -146,8 +147,8 @@ func TestFillDefault(t *testing.T) {
 			},
 		},
 		Mounts: []Mount{
-			{Location: "/tmp"},
-			{Location: "{{.Dir}}/{{.Param.ONE}}", MountPoint: ptr.Of("/mnt/{{.Param.ONE}}")},
+			{Location: filepath.Clean(os.TempDir())},
+			{Location: filepath.Clean("{{.Dir}}/{{.Param.ONE}}"), MountPoint: ptr.Of("/mnt/{{.Param.ONE}}")},
 		},
 		MountType: ptr.Of(NINEP),
 		Provision: []Provision{
@@ -231,8 +232,8 @@ func TestFillDefault(t *testing.T) {
 	expect.Mounts[0].NineP.Cache = ptr.Of(Default9pCacheForRO)
 	expect.Mounts[0].Virtiofs.QueueSize = nil
 	// Only missing Mounts field is Writable, and the default value is also the null value: false
-	expect.Mounts[1].Location = fmt.Sprintf("%s/%s", instDir, y.Param["ONE"])
-	expect.Mounts[1].MountPoint = ptr.Of(fmt.Sprintf("/mnt/%s", y.Param["ONE"]))
+	expect.Mounts[1].Location = filepath.Join(instDir, y.Param["ONE"])
+	expect.Mounts[1].MountPoint = ptr.Of(path.Join("/mnt", y.Param["ONE"]))
 	expect.Mounts[1].Writable = ptr.Of(false)
 	expect.Mounts[1].SSHFS.Cache = ptr.Of(true)
 	expect.Mounts[1].SSHFS.FollowSymlinks = ptr.Of(false)
@@ -385,7 +386,7 @@ func TestFillDefault(t *testing.T) {
 
 		Mounts: []Mount{
 			{
-				Location: "/var/log",
+				Location: filepath.Clean("/var/log"),
 				Writable: ptr.Of(false),
 			},
 		},
@@ -593,7 +594,7 @@ func TestFillDefault(t *testing.T) {
 
 		Mounts: []Mount{
 			{
-				Location: "/var/log",
+				Location: filepath.Clean("/var/log"),
 				Writable: ptr.Of(true),
 				SSHFS: SSHFS{
 					Cache:          ptr.Of(false),

templates/default.yaml

@@ -99,7 +99,8 @@ mounts:
     # See https://www.kernel.org/doc/Documentation/filesystems/9p.txt
     # 🟢 Builtin default: "fscache" for non-writable mounts, "mmap" for writable mounts
     cache: null
-- location: "/tmp/lima"
+- location: "{{.Temp}}/lima"
+  mountPoint: /tmp/lima
   # 🟢 Builtin default: false
   # 🔵 This file: true (only for "/tmp/lima")
   writable: true