From ee5d485deb99aceec3f946343d519eab04fe114e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timoth=C3=A9e=20Floure?= <timothee.floure@posteo.net>
Date: Thu, 23 Jan 2020 14:58:27 +0100
Subject: [PATCH] Add support for interfaces, safety checks, fix shellcheck
 errors

---
 README.md    |  1 +
 uncloud-init | 68 +++++++++++++++++++++++++++++++++++++++-------------
 2 files changed, 53 insertions(+), 16 deletions(-)

diff --git a/README.md b/README.md
index 8a7f285..df45517 100644
--- a/README.md
+++ b/README.md
@@ -5,3 +5,4 @@ This tool takes care of initializing and maintaining virtual machines in
 
   * Growing root partition/filesystem when the underlying disk is expanded.
   * Fetch and deploy SSH keys.
+  * UP networks interfaces.
diff --git a/uncloud-init b/uncloud-init
index 0654060..d58374c 100755
--- a/uncloud-init
+++ b/uncloud-init
@@ -3,9 +3,19 @@
 # Initialize an uncloud VM. This script depends on:
 # curl grep getent (i.e. glibc) curl,dirname (i.e. coreutils)
 
+# TODO: complete other tasks even if one fail.
+# TODO: do not up ALL network interfaces.
+# TODO: write configuration instead of manually setting interfaces up?
+
+if [ "$(whoami)" != 'root' ]; then
+	echo "This script must be run as root." >&2
+	exit 1
+fi
+
 ###
 # TODO: handle command-line parameters.
 
+ENABLE_NETWORKING=1
 DEPLOY_SSH_AUTHORIZED_KEYS=1
 OVERRIDE_EXISTING_SSH_AUTHORIZED_KEYS=0
 GROW_ROOT_PARTITION=0
@@ -14,8 +24,14 @@ SSH_USER=root
 SSH_DAEMON_CONFIG=/etc/ssh/sshd_config
 UNCLOUD_METADATA_SERVER=https://key.wf
 
+if [ ! $ENABLE_NETWORKING ] && [ $DEPLOY_SSH_AUTHORIZED_KEYS ]; then
+	echo "SSH key deployment requires networking, please review uncloud-init \
+		configuration." >&2
+	exit 1
+fi
+
 ###
-# SSH key deployment logic.
+# Internal logic.
 
 deploy_ssh_authorized_keys () {
 	# Ensure SSHD configuration can be found.
@@ -31,46 +47,66 @@ deploy_ssh_authorized_keys () {
 		fi
 	fi
 
-	# Get home directory of SSH_USER.
+	# Get home directory of SSH_USER. User might not exist or have a home
+	# directory.
 	homedir=$(getent passwd "$SSH_USER" | cut -d: -f6)
-	if [ $? != 0 ]; then
-		echo "Could not resolve user $SSH_USER." >&2
+	if [ "$homedir" = "" ]; then
+		echo "Could not resolve home directory of user $SSH_USER." >&2
 		exit 1
 	fi
 
 	# Fetch and deploy SSH keys from metadata server.
 	authorized_keys_file="$homedir/.ssh/authorized_keys"
-	mkdir -p $(dirname "$authorized_keys_file")
+	mkdir -p "$(dirname "$authorized_keys_file")"
 	if [ -f "$authorized_keys_file" ] \
-		&& if [ ! $OVERRIDE_EXISTING_SSH_AUTHORIZED_KEYS ];
+		&& [ ! $OVERRIDE_EXISTING_SSH_AUTHORIZED_KEYS ]; then
 			echo "Aborting SSH key deployement to not override existing $authorized_keys_file."
 			echo "You can change this behavior with the OVERRIDE_EXISTING_SSH_AUTHORIZED_KEYS flag."
 			return
 	fi
 
-	curl "$METDATA_SERVER/fnux" --output $authorized_keys_file
+	curl "$UNCLOUD_METADATA_SERVER/fnux" --output "$authorized_keys_file"
 }
 
-###
-# Partition/filesystem growth logic.
-
 grow_root_partition () {
-	# TODO
+	growpart_script='uncloud-init-growpart'
+	if [ -x "$(command -v "$growpart_script")" ]; then
+		# TODO: this command seems quite fragile...
+		# sh growpart -q /dev/vda 3 > /dev/null;
+		true # no-op
+	else
+		echo "Could not find or execute $growpart_script." >&2
+		exit 1
+	fi
+}
+
+up_network_interfaces () {
+	interfaces=$(ip -o link | cut -d: -f2 | grep -v '^ lo')
+	for i in $interfaces; do
+		ip link set dev "$i" up
+	done
 }
 
 ###
 # Entrypoint.
 
-if [ $DEPLOY_SSH_AUTHORIZED_KEYS ]; then
-	routine='SSH authorized_keys deployment routine'
+if [ $ENABLE_NETWORKING ]; then
+	routine='up main network interface'
 	echo "--- RUNNING $routine..."
-	deploy_ssh_authorized_keys()
+	up_network_interfaces
 	echo "--- DONE with $routine."
 fi
 
-if [ $GROW_ROOT_PARTITION ]: then
+if [ $DEPLOY_SSH_AUTHORIZED_KEYS ]; then
 	routine='SSH authorized_keys deployment routine'
 	echo "--- RUNNING $routine..."
-	grow_root_partition()
+	deploy_ssh_authorized_keys
+	echo "--- DONE with $routine."
+fi
+
+if [ $GROW_ROOT_PARTITION ]; then
+	routine='growing root partition and filesystem'
+	echo "--- RUNNING $routine..."
+	grow_root_partition
 	echo "--- DONE with $routine."
 fi