eth-eni-setup init script (#87)

* eth-eni-setup init script

before networking starts up, makes sure eth interfaces match attached ENIs

also fixes a permissions problem with eth-eni-hotplug mdev config

* fix aarch64 build

profiles/arch/aarch64-1

@@ -3,7 +3,7 @@
 
 arch                = "aarch64"
 build_arch          = "arm64"
-build_instance_type = "a1.medium"
+build_instance_type = "t4g.nano"
 apk_tools           = "https://github.com/alpinelinux/apk-tools/releases/download/v2.10.3/apk-tools-2.10.3-aarch64-linux.tar.gz"
 apk_tools_sha256    = "58a07e547c83c3a30eb0a0bd73db57d6bbaf92cc093df7a1d9805631f7d349e3"
 alpine_keys         = "http://dl-cdn.alpinelinux.org/alpine/v3.12/main/aarch64/alpine-keys-2.2-r0.apk"

profiles/base/1

@@ -76,6 +76,7 @@ svcs {
   }
   default {
     chronyd             = true
+    eth-eni-setup       = true
     networking          = true
     sshd                = true
     tiny-ec2-bootstrap  = true

profiles/base/2

@@ -75,6 +75,7 @@ svcs {
   }
   default {
     chronyd             = true
+    eth-eni-setup       = true
     networking          = true
     sshd                = true
     tiny-ec2-bootstrap  = true

scripts/setup-ami

@@ -221,7 +221,7 @@ install_grub_efi() {
 
     # install default grub config
     install -o root -g root -Dm644 -t "$TARGET/etc/default" \
-        "$SETUP/etc/grub.default" grub
+        "$SETUP/etc/grub"
 
     # generate/install new config
     chroot "$TARGET" grub-mkconfig -o /boot/grub/grub.cfg
@@ -253,6 +253,10 @@ setup_networking() {
         ln -sf /usr/share/udhcpc/eth-eni-hook \
             "$TARGET/etc/udhcpc/$i"
     done
+
+    # install ENI interface setup init script
+    install -o root -g root -Dm755 -t "$TARGET/etc/init.d" \
+        "$SETUP/eth-eni-setup"
 }
 
 enable_services() {

scripts/setup-ami.d/etc/mdev-ec2.conf

@@ -1,5 +1,5 @@
 # additional ENIs
-eth[1-9]	root:root 0666 */lib/mdev/eth-eni-hotplug
+eth[1-9]	root:root 0644 */lib/mdev/eth-eni-hotplug
 
 # EBS NVMe links
 nvme[0-9]+n[0-9]+.*	root:root 0660 */lib/mdev/nvme-ebs-links

scripts/setup-ami.d/eth-eni-setup

@@ -0,0 +1,36 @@
+#!/sbin/openrc-run
+
+description="Sets up interfaces for attached Elastic Network Interfaces"
+
+IFACE_CFG=/etc/network/interfaces
+
+depend() {
+	before net
+	need sysfs
+}
+
+eni_eths() {
+	local iface
+	for iface in /sys/class/net/eth*; do
+		echo "${iface##*/}"
+	done
+}
+
+start() {
+	local iface
+
+	ebegin "Setting up interfaces for attached ENIs"
+
+	cat "$IFACE_CFG.d/lo" > "$IFACE_CFG.new"
+
+	for iface in $(eni_eths); do
+		[ -f "$IFACE_CFG.d/$iface" ] ||
+			sed -e "s/%%/$iface/g" "$IFACE_CFG.d/DEFAULT" > "$IFACE_CFG.d/$iface"
+		cat "$IFACE_CFG.d/$iface" >> "$IFACE_CFG.new"
+		einfo "$iface configured"
+	done
+
+	mv "$IFACE_CFG.new" "$IFACE_CFG"
+
+	eend "$?"
+}