Merge ~morphis/snappy-hwe-snaps/+git/network-manager:move-dhcp-leases into ~snappy-hwe-team/snappy-hwe-snaps/+git/network-manager:master

[Simon Fels]

Add transitioning of DHCP lease files from SNAP_DATA to /run

The current implementation stores DHCP lease files inside /run which means they are lost after rebooting the system. This can lead to problems with losing a previously assigned IP address if the lease is still valid. We can't just simply move the leases back to SNAP_DATA as probert/console-conf needs to read them from /run. To satisfy this requirement until probert/console-conf are fixed we're syncing the lease files from SNAP_DATA to /run whenever they change.

This is based on top of https://code.launchpad.net/~morphis/snappy-hwe-snaps/+git/network-manager/+merge/309743

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diff --git a/bin/dhcp-lease-mover b/bin/dhcp-lease-mover
new file mode 100755
index 0000000..c54aeb0
--- /dev/null
+++ b/bin/dhcp-lease-mover
@@ -0,0 +1,26 @@
+#!/bin/sh
+set -x
+
+lease_path=$SNAP_DATA/state/dhcp
+public_lease_path=/run/NetworkManager/dhcp/
+
+if [ ! -e $public_lease_path ] ; then
+    mkdir -p $public_lease_path
+fi
+
+if [ ! -e $lease_path ] ; then
+    mkdir -p $lease_path
+fi
+
+# Copy all leases when we start to make sure we're in sync
+rm -f $public_lease_path/*
+cp $lease_path/* $public_lease_path
+
+# Now we wait until a lease changes, gets added or removed and when
+# that happened we simply just move all leases files into the public
+# location.
+while $SNAP/usr/bin/inotifywait -e create,modify,delete,move $lease_path ; do
+    sleep 1
+    rm -f $public_lease_path/*
+    cp $lease_path/* $public_lease_path
+done
diff --git a/bin/networkmanager b/bin/networkmanager
index 7c003d5..f72fa93 100755
--- a/bin/networkmanager
+++ b/bin/networkmanager
@@ -1,6 +1,5 @@
 #!/bin/sh
-set -e
-set -x
+set -ex
 
 # Create all necessary directories we need at runtime
 mkdir -p $SNAP_DATA/conf/system-connections
@@ -25,6 +24,7 @@ mkdir -p $SNAP_DATA/conf.d
 # State dir where network-manager stores several things like the
 # secret key used for IPv6
 mkdir -p $SNAP_DATA/state
+mkdir -p $SNAP_DATA/state/dhcp
 
 # If netplan is not configured to render by default to NetworkManager
 # configuration files we disable management of any ethernet device
@@ -60,6 +60,13 @@ else
     fi
 fi
 
+# HACK: Until we've fixed probert to look in $SNAP_DATA/state/dhcp or
+# somewhere else for our lease files we use inotifywatch to monitor
+# our lease files and copy all over when something has changed. This
+# background process gets stopped when our systemd service unit gets
+# stopped.
+$SNAP/bin/dhcp-lease-mover &
+
 export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:$SNAP/usr/lib/NetworkManager"
 
 $SNAP/usr/sbin/NetworkManager \
diff --git a/snapcraft.yaml b/snapcraft.yaml
index 37dfc66..2e9044f 100644
--- a/snapcraft.yaml
+++ b/snapcraft.yaml
@@ -32,9 +32,25 @@ parts:
     plugin: copy
     files:
       bin/networkmanager: bin/networkmanager
+      bin/dhcp-lease-mover: bin/dhcp-lease-mover
       conf/NetworkManager.conf: etc/NetworkManager/NetworkManager.conf
       data/copyright: usr/share/doc/network-manager/copyright
 
+  inotify-tools:
+    plugin: nil
+    stage-packages:
+      - libinotifytools0
+      - inotify-tools
+    filesets:
+      wanted:
+        - usr/share/doc/inotify-tools/copyright
+        - usr/bin/inotifywait
+        - usr/share/doc/libinotifytools0/copyright
+        - usr/lib/libinotifytools.so.0.4.1
+        - usr/lib/libinotifytools.so.0
+    snap:
+      - $wanted
+
   networkmanager:
     plugin: autotools
 
diff --git a/tests/main/dhcp-leases-are-moved/task.yaml b/tests/main/dhcp-leases-are-moved/task.yaml
new file mode 100644
index 0000000..fff2d6a
--- /dev/null
+++ b/tests/main/dhcp-leases-are-moved/task.yaml
@@ -0,0 +1,32 @@
+summary: Verify that the DHCP leases are moved to the correct location
+
+execute: |
+    . $TESTSLIB/utilities.sh
+    case "$SPREAD_REBOOT" in
+        0)
+            switch_netplan_to_network_manager
+            REBOOT
+            ;;
+        1)
+            # Now we have network-manager also with ethernet support
+            test -e /run/NetworkManager/dhcp
+            test -e /var/snap/network-manager/current/state/dhcp
+
+            num_leases=`ls -1 /var/snap/network-manager/current/state/dhcp | wc -l`
+            num_public_leases=`ls -1 /run/NetworkManager/dhcp | wc -l`
+            test $num_leases -eq $num_public_leases
+
+            # Create a new lease file and ensure it gets copied over
+            test ! -e /run/NetworkManager/dhcp/temp.lease
+            touch /var/snap/network-manager/current/state/dhcp/temp.lease
+            sleep 2
+            test -e /run/NetworkManager/dhcp/temp.lease
+            # Ensure that the lease is also removed from /run again when it
+            # gets removed from SNAP_DATA
+            rm /var/snap/network-manager/current/state/dhcp/temp.lease
+            sleep 2
+            test ! -e /var/snap/network-manager/current/state/dhcp/temp.lease
+            ;;
+        *)
+            ;;
+    esac