tests: add yet another workaround attempt

overlord/configstate/configcore/netplan.go

@@ -33,6 +33,7 @@ package configcore
 import (
 	"encoding/json"
 	"fmt"
+	"io/ioutil"
 	"path/filepath"
 	"sort"
 	"strings"
@@ -165,10 +166,14 @@ func handleNetplanConfiguration(tr config.Conf, opts *fsOnlyContext) error {
 	// that got unset.
 	//
 	// XXX: The osutil.FileExists() is needed until LP:1946957 gets fixed
-	var configs []string
-	if osutil.FileExists(filepath.Join(dirs.GlobalRootDir, "/etc/netplan/90-snapd-conf.yaml")) {
-		configs = []string{"network=null"}
+	originHint := "90-snapd-conf"
+	netplanCfgPath := filepath.Join(dirs.GlobalRootDir, fmt.Sprintf("/etc/netplan/%s.yaml", originHint))
+	if !osutil.FileExists(netplanCfgPath) {
+		if err := ioutil.WriteFile(netplanCfgPath, nil, 0644); err != nil {
+			return err
+		}
 	}
+	configs := []string{"network=null"}
 	// and then pass the full new config in
 	for key := range cfg {
 		// We pass the new config back to netplan as json, the reason
@@ -185,7 +190,6 @@ func handleNetplanConfiguration(tr config.Conf, opts *fsOnlyContext) error {
 	for _, jsonNetplanConfig := range configs {
 		logger.Debugf("calling netplan.Set: %v", jsonNetplanConfig)
 
-		originHint := "90-snapd-conf"
 		var wasSet bool
 		if err := netplanCfgSnapshot.Call("io.netplan.Netplan.Config.Set", 0, jsonNetplanConfig, originHint).Store(&wasSet); err != nil {
 			return fmt.Errorf("cannot Set() config: %v", err)

overlord/configstate/configcore/netplan_test.go

@@ -98,7 +98,7 @@ func (s *netplanSuite) SetUpTest(c *C) {
 	restore = release.MockOnClassic(false)
 	s.AddCleanup(restore)
 
-	err = os.MkdirAll(filepath.Join(dirs.GlobalRootDir, "/etc/"), 0755)
+	err = os.MkdirAll(filepath.Join(dirs.GlobalRootDir, "/etc/netplan"), 0755)
 	c.Assert(err, IsNil)
 }
 
@@ -239,40 +239,7 @@ func (s *netplanSuite) TestNetplanConnectivityCheck(c *C) {
 	}
 }
 
-func (s *netplanSuite) TestNetplanWriteConfigHappyNoPrevConfig(c *C) {
-	// export the V2 api, things work with that
-	s.backend.ExportApiV2()
-
-	// and everything is fine
-	s.fakestore.status = map[string]bool{"host1": true}
-	s.backend.ConfigApiTryRet = true
-	s.backend.ConfigApiApplyRet = true
-
-	s.state.Lock()
-	tr := config.NewTransaction(s.state)
-	s.state.Unlock()
-	tr.Set("core", "system.network.netplan.network.ethernets.eth0.dhcp4", true)
-	tr.Set("core", "system.network.netplan.network.wifi.wlan0.dhcp4", true)
-
-	err := configcore.Run(coreDev, tr)
-	c.Assert(err, IsNil)
-
-	c.Check(s.backend.ConfigApiSetCalls, DeepEquals, []string{
-		`network={"ethernets":{"eth0":{"dhcp4":true}},"renderer":"NetworkManager","version":2,"wifi":{"wlan0":{"dhcp4":true}}}/90-snapd-conf`,
-	})
-	c.Check(s.backend.ConfigApiTryCalls, Equals, 1)
-	c.Check(s.backend.ConfigApiApplyCalls, Equals, 1)
-}
-
 func (s *netplanSuite) TestNetplanWriteConfigHappy(c *C) {
-	// see https://bugs.launchpad.net/netplan/+bug/1946957 why needed
-	// XXX: once the above bug is fixed we can delete this test
-	mockNetplanFile := filepath.Join(dirs.GlobalRootDir, "/etc/netplan/90-snapd-conf.yaml")
-	err := os.MkdirAll(filepath.Dir(mockNetplanFile), 0755)
-	c.Assert(err, IsNil)
-	err = ioutil.WriteFile(mockNetplanFile, nil, 0644)
-	c.Assert(err, IsNil)
-
 	// export the V2 api, things work with that
 	s.backend.ExportApiV2()
 
@@ -287,14 +254,15 @@ func (s *netplanSuite) TestNetplanWriteConfigHappy(c *C) {
 	tr.Set("core", "system.network.netplan.network.ethernets.eth0.dhcp4", true)
 	tr.Set("core", "system.network.netplan.network.wifi.wlan0.dhcp4", true)
 
-	err = configcore.Run(coreDev, tr)
+	err := configcore.Run(coreDev, tr)
 	c.Assert(err, IsNil)
 
 	c.Check(s.backend.ConfigApiSetCalls, DeepEquals, []string{
 		`network=null/90-snapd-conf`,
 		`network={"ethernets":{"eth0":{"dhcp4":true}},"renderer":"NetworkManager","version":2,"wifi":{"wlan0":{"dhcp4":true}}}/90-snapd-conf`,
 	})
 	c.Check(s.backend.ConfigApiTryCalls, Equals, 1)
+	c.Check(s.backend.ConfigApiApplyCalls, Equals, 1)
 }
 
 func (s *netplanSuite) TestNetplanWriteConfigNoNetworkAfterTry(c *C) {

tests/core/netplan-cfg/task.yaml

@@ -44,4 +44,5 @@ execute: |
 
     echo "Unset the whole subtree works"
     snap unset system system.network.netplan.network.bridges.br54
+    snap get -d system system.network.netplan | NOMATCH br54
     ip link | NOMATCH br54