From b5af450a8e5e183a3f110929b38343fca0d75039 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jake=20Buchholz=20G=C3=B6kt=C3=BCrk?= <tomalok@gmail.com>
Date: Sun, 2 Jan 2022 15:09:21 -0800
Subject: [PATCH] move logic from init scripts to /lib/tiny-cloud/*

---
 README.md                   | 40 ++++++++++++++--------------
 etc/conf.d/tiny-cloud       | 18 ++++++++++---
 etc/init.d/tiny-cloud       | 42 ++++++------------------------
 etc/init.d/tiny-cloud-early | 26 ++++---------------
 etc/init.d/tiny-cloud-final | 30 +++++++--------------
 lib/tiny-cloud/aws/imds     |  2 +-
 lib/tiny-cloud/azure/imds   |  2 +-
 lib/tiny-cloud/gcp/imds     |  2 +-
 lib/tiny-cloud/imds         | 52 +++++++++++++++++++++----------------
 lib/tiny-cloud/init-common  | 15 +++++++++++
 lib/tiny-cloud/init-early   | 28 ++++++++++++++++++++
 lib/tiny-cloud/init-final   | 30 +++++++++++++++++++++
 lib/tiny-cloud/init-main    | 37 ++++++++++++++++++++++++++
 lib/tiny-cloud/oci/imds     |  2 +-
 14 files changed, 201 insertions(+), 125 deletions(-)
 create mode 100644 lib/tiny-cloud/init-common
 create mode 100644 lib/tiny-cloud/init-early
 create mode 100644 lib/tiny-cloud/init-final
 create mode 100644 lib/tiny-cloud/init-main

diff --git a/README.md b/README.md
index e2beca0..085482a 100644
--- a/README.md
+++ b/README.md
@@ -22,8 +22,8 @@ instance:
 * set the instance's hostname from instance metadata
 * install SSH keys from instance metadata to the cloud user account's
   `authorized_keys` file (the user must already exist)
-* save the instance user-data to a file and if it's a script, execute it at the
-  end of the **default** runlevel 
+* save the instance user-data to a file, and if it's a script, execute it at
+  the end of the **default** runlevel
 
 Optional features, which may not be universally necessary:
 * manage symlinks from NVMe block devices to `/dev/xvd` and `/dev/sd` devices
@@ -68,26 +68,26 @@ rc-update add tiny-cloud-final default
 
 ## Configuration
 
-Tiny Cloud looks expects configuration to be found at
-[`/etc/conf.d/tiny-cloud`](etc/conf.d/tiny-cloud), which documents all
-tuneable parameters (and their defaults).
+By default, Tiny Cloud expects configuration at `/etc/conf.d/tiny-cloud`,
+although the location can be overridden by setting the `TINY_CLOUD_CONF`
+environment variable.  The stock [`etc/conf.d/tiny-cloud`](
+etc/conf.d/tiny-cloud) file contains details of all tuneable settings.
 
-However, because Tiny Cloud does not do auto-detection, you ***must*** set a
-value for `CLOUD` indicating which cloud provider which will be used when
-instantiating the image.  Current valid values are `aws`, `azure`, `gcp`, and
-`oci`.
+*Because Tiny Cloud does not currently do auto-detection, you **MUST** set a
+configuration value for `CLOUD` indicating which cloud provider will be used.
+Current valid values are `aws`, `azure`, `gcp`, and `oci`.*
 
 ## Operation
 
 The first time an instance boots -- either freshly instantiated from an image,
-or after installation on an existing instance -- Tiny Cloud sets up the
+or after installation on a pre-existing instance -- Tiny Cloud sets up the
 instance in three phases...
 
 ### Early Phase
 
 The `tiny-cloud-early` init script does not depend on the cloud provider's
-Instance MetaData Service (IMDS), and does therefore does not have a dependency
-on networking.  During this "early" phase, the root filesystem is expanded, and
+Instance MetaData Service (IMDS), and therefore does not have a dependency on
+networking.  During this "early" phase, the root filesystem is expanded, and
 any necessary `mdev` rules for device hotplug are set up.
 
 ### Main Phase
@@ -99,16 +99,18 @@ data, and sets up instance's hostname and the cloud user's SSH keys before
 ### Final Phase
 
 `tiny-cloud-final` should be the very last init script to run in the
-**default** runlevel, and saves the instance's user data to
-`/var/lib/cloud/user-data`.
+**default** runlevel.  By default, it saves the instance's user data to
+`/var/lib/cloud/user-data`, which is overrideable via the `TINY_CLOUD_VAR`
+andr `CLOUD_USERDATA` config settings.
 
-If the user data is a script that starts with `#!` (aka "[shebang](
-https://en.wikipedia.org/wiki/Shebang_(Unix))"), it will be executed; its
-output (combined STDOUT and STDERR) is saved to `/var/log/cloud/user-data.log`
-and the exit code can be found in `/var/log/cloud/user-data.exit`.
+If the user data is a script starting with `#!/`, it will be executed; its
+output (combined STDOUT and STDERR) and exit code are saved to
+`/var/log/user-data.log` and `/var/log/user-data.exit`, respectively -- unless
+overriden with `TINY_CLOUD_LOGS` and `CLOUD_USERDATA` config settings.
 
 If all went well, the very last thing `tiny-cloud-final` does is touch
-`/var/lib/cloud/.bootstrap-complete` into existence.
+a `.bootstrap-complete` file into existence in `/var/lib/cloud` or another
+directory specified by the `TINY_CLOUD_VAR` config setting.
 
 ### Further Reboots
 
diff --git a/etc/conf.d/tiny-cloud b/etc/conf.d/tiny-cloud
index 74b3f26..0739192 100644
--- a/etc/conf.d/tiny-cloud
+++ b/etc/conf.d/tiny-cloud
@@ -1,4 +1,4 @@
-# tiny-cloud configuration
+# Tiny Cloud configuration
 
 # REQUIRED: The instance's cloud provider (valid: aws, azure, gcp, oci)
 CLOUD=
@@ -6,5 +6,17 @@ CLOUD=
 # User account where instance SSH keys are installed
 #CLOUD_USER=alpine
 
-# Number of seconds an AWS IMDS token is valid
-#IMDS_TOKEN_TTL=5
\ No newline at end of file
+# Filename of userdata file (in TINY_CLOUD_VAR directory)
+#CLOUD_USERDATA=user-data
+
+# IMDS token validity, in seconds (AWS only)
+#IMDS_TOKEN_TTL=5
+
+# Location of libraries
+#TINY_CLOUD_LIBS=/lib/tiny-cloud
+
+# Location of var directory
+#TINY_CLOUD_VAR=/var/lib/cloud
+
+# Location of log directory
+#TINY_CLOUD_LOGS=/var/log
diff --git a/etc/init.d/tiny-cloud b/etc/init.d/tiny-cloud
index 736aff6..acbcc3d 100644
--- a/etc/init.d/tiny-cloud
+++ b/etc/init.d/tiny-cloud
@@ -8,44 +8,18 @@ depend() {
 	before sshd
 }
 
-_update_hostname() {
-	local fqdn=$(imds_hostname)
-	local host="${fqdn%%\.*}"
-	echo "$host" > /etc/hostname
-	hostname -F /etc/hostname
-	echo -e "127.0.1.1\t$fqdn $host" >> /etc/hosts
-}
-
-_set_ssh_keys() {
-	local user="$1"
-	local pwent=$(getent passwd "$user")
-	local group=$(echo "$pwent" | cut -d: -f4)
-	local ssh_dir="$(echo "$pwent" | cut -d: -f6)/.ssh"
-	local keys_file="$ssh_dir/authorized_keys"
-
-	if [ ! -d "$ssh_dir" ]; then
-		mkdir -p "$ssh_dir"
-		chmod 700 "$ssh_dir"
-	fi
-
-	touch "$keys_file"
-	chmod 600 "$keys_file"
-	chown -R "$user:$group" "$ssh_dir"
-	imds_ssh_keys > "$keys_file"
-}
-
 start() {
-	[ -f "/var/lib/cloud/.bootstrap-complete" ] && return 0
-	[ -d "/var/lib/cloud" ] || mkdir -p /var/lib/cloud
+	source /lib/tiny-cloud/init-main
 
-	source /var/lib/tiny-cloud/imds
-	CLOUD_USER="${CLOUD_USER:-alpine}"
+	# TODO: background tiny-cloud network watcher?
 
-	ebegin "Setting Instance Hostname"; _update_hostname; eend $?
+	is_bootstrapped && return 0
 
-	ebegin "Installing SSH Keys for $CLOUD_USER User"
-	_set_ssh_keys "$CLOUD_USER"
+	ebegin "Setting Instance Hostname"
+	set_hostname
 	eend $?
 
-	# TODO: background tiny-cloud-network watcher?
+	ebegin "Installing SSH Keys for $CLOUD_USER User"
+	set_ssh_keys "$CLOUD_USER"
+	eend $?
 }
\ No newline at end of file
diff --git a/etc/init.d/tiny-cloud-early b/etc/init.d/tiny-cloud-early
index 184177a..59249f2 100644
--- a/etc/init.d/tiny-cloud-early
+++ b/etc/init.d/tiny-cloud-early
@@ -7,30 +7,14 @@ depend() {
 	before mdev
 }
 
-_expand_root_partition() {
-	local mountpoint=$(busybox mountpoint -n / | cut -d' ' -f1)
-	local volume=$(echo "$mountpoint" |
-		sed -Ee "s/(nvme\d+n\d|(xv|s)d[a-z])p?\d?$/\1/"
-	)
-
-	if [ "$mountpoint" != "$volume" ]; then
-		partition=$(echo "$volume" | sed -Ee "s/.*(\d+)$/\2/")
-		einfo "Expanding root partition to volume size..."
-		echo ", +" | sfdisk -q --no-reread -N "$partition" "$volume"
-		einfo "Updating kernel with new partition table..."
-		partx -u "$volume"
-	fi
-	einfo "Resizing root filesystem..."
-	resize2fs "$mountpoint"
-}
-
 start() {
-	[ -f "/var/lib/cloud/.bootstrap-complete" ] && return 0
-	[ -d "/var/lib/cloud" ] || mkdir -p /var/lib/cloud
+	source /lib/tiny-cloud/init-early
 
-	source /etc/conf.d/tiny-cloud	# or use auto-sourced tiny-cloud-early?
+	is_bootstrapped && return 0
 
-	ebegin "Expanding Root Partition"; _expand_root_partition; eend $?
+	ebegin "Expanding Root Volume/Partition"
+	expand_root
+	eend $?
 
 	# TODO: _setup mdev things, if applicable
 }
\ No newline at end of file
diff --git a/etc/init.d/tiny-cloud-final b/etc/init.d/tiny-cloud-final
index 9c9a64e..0a6291e 100644
--- a/etc/init.d/tiny-cloud-final
+++ b/etc/init.d/tiny-cloud-final
@@ -8,30 +8,18 @@ depend() {
 	provide cloud-final
 }
 
-_save_userdata() {
-	imds_userdata > "$USERDATA"
-}
-
-_run_userdata() {
-	local log="/var/log/user-data.log"
-	local exit="/var/log/user-data.exit"
-
-	chmod +x "$USERDATA"
-	{ "$USERDATA" 2>& 1; echo $? > "$exit"; } | tee "$log"
-
-	return $(cat "$exit")
-}
-
 start() {
-	[ -f "/var/lib/cloud/.bootstrap-complete" ] && return 0
-	[ -d "/var/lib/cloud" ] || mkdir -p /var/lib/cloud
+	source /lib/tiny-cloud/init-final
 
-	source /lib/tiny-cloud/imds
+	is_bootstrapped && return 0
 
-	USERDATA="/var/lib/cloud/user-data"
+	ebegin "Saving Instance UserData"
+	save_userdata
+	eend $?
 
-	ebegin "Saving Instance UserData"; _save_userdata; eend $?
-	if head -n1 "$USERDATA" | grep -q '^#!/'; then
-		ebegin "Executing UserData Script"; _run_userdata; eend $?
+	if is_userdata_script; then
+		ebegin "Executing UserData Script"
+		run_userdata
+		eend $?
 	fi
 }
\ No newline at end of file
diff --git a/lib/tiny-cloud/aws/imds b/lib/tiny-cloud/aws/imds
index 06b8b91..3e474e8 100644
--- a/lib/tiny-cloud/aws/imds
+++ b/lib/tiny-cloud/aws/imds
@@ -1,4 +1,4 @@
-# AWS Instance MetaData Service related variables and functions
+# AWS Instance MetaData Service variables and functions
 # vim:set ft=sh noet ts=4:
 
 IMDS_HEADER="X-aws-ec2-metadata-token"
diff --git a/lib/tiny-cloud/azure/imds b/lib/tiny-cloud/azure/imds
index 7e63a32..08a34fb 100644
--- a/lib/tiny-cloud/azure/imds
+++ b/lib/tiny-cloud/azure/imds
@@ -1,4 +1,4 @@
-# Azure metadata-related variables and functions
+# Azure Instance MetaData Service variables and functions
 # vim:set ft=sh noet ts=4:
 
 IMDS_HEADER="Metadata"
diff --git a/lib/tiny-cloud/gcp/imds b/lib/tiny-cloud/gcp/imds
index ea70b3f..0770337 100644
--- a/lib/tiny-cloud/gcp/imds
+++ b/lib/tiny-cloud/gcp/imds
@@ -1,4 +1,4 @@
-# Google Cloud metadata-related variables and functions
+# Google Cloud Instance MetaData Service variables and functions
 # vim:set ft=sh noet ts=4:
 
 IMDS_HEADER="Metadata-Flavor"
diff --git a/lib/tiny-cloud/imds b/lib/tiny-cloud/imds
index f8b43b7..03708c1 100644
--- a/lib/tiny-cloud/imds
+++ b/lib/tiny-cloud/imds
@@ -1,32 +1,33 @@
-# tiny-cloud Instance MetaData Service related functions and variables
+# Tiny Cloud - Instance MetaData Service functions and variables
 # vim:set ft=sh ts=4 noet:
 
-CONF_DIR="/etc/conf.d"
-LIB_DIR="/lib/tiny-cloud"
+### configuration
 
-### load configuration
-
-[ -f "$CONF_DIR"/tiny-cloud ] && source "$CONF_DIR"/tiny-cloud
-
-### configuration defaults
-
-CLOUD="${CLOUD:-unknown}"
-CLOUD_LOGIN="${CLOUD_LOGIN:-alpine}"
-if [ ! -d "$LIB_DIR/$CLOUD" ]; then
-	echo "ERROR: Unknown Cloud '$CLOUD'" >&2
-	exit 1
+if [ -z "$TINY_CLOUD_LIBS" ]; then
+    TINY_CLOUD_CONF=${TINY_CLOUD_CONF:-/etc/conf.d/tiny-cloud}
+    [ -f "$TINY_CLOUD_CONF" ] && source "$TINY_CLOUD_CONF"
+    TINY_CLOUD_LIBS=${TINY_CLOUD_LIBS:-/lib/tiny-cloud}
 fi
 
-IMDS_HEADER=
-IMDS_QUERY=
-IMDS_URL=
+# defaults
+CLOUD="${CLOUD:-unknown}"
 
-IMDS_HOSTNAME=
-IMDS_SSH_KEYS=
-IMDS_USERDATA=
+# these are always cloud-specific
 
-### default/common functions
+unset \
+	IMDS_HEADER	\
+	IMDS_QUERY \
+	IMDS_URL \
+	IMDS_HOSTNAME \
+	IMDS_SSH_KEYS \
+	IMDS_USERDATA
 
+unset -f \
+	_imds_token \
+	_imds_header \
+	2>/dev/null	|| true
+
+# without error reporting or ending newline enforcement
 _imds() {
 	wget --quiet --header "$(_imds_header)" --output-document - \
 		"$IMDS_URL/$1/$IMDS_QUERY"
@@ -55,6 +56,11 @@ imds_ssh_keys() {
 	imds "$IMDS_SSH_KEYS"
 }
 
-# cloud-specific things (potentially overriding the above)
+### load cloud-specific things
 
-[ -f "$LIB_DIR/$CLOUD/metadata" ] && source "$LIB_DIR/$CLOUD"/imds
+if [ ! -d "$TINY_CLOUD_LIBS/$CLOUD" ]; then
+	echo "ERROR: Unknown Cloud '$CLOUD'" >&2
+	exit 1
+fi
+
+source "$TINY_CLOUD_LIBS/$CLOUD/imds"
diff --git a/lib/tiny-cloud/init-common b/lib/tiny-cloud/init-common
new file mode 100644
index 0000000..31529ed
--- /dev/null
+++ b/lib/tiny-cloud/init-common
@@ -0,0 +1,15 @@
+# Tiny Cloud - Common Initialization
+# vim:set ft=sh ts=4 noet:
+
+# set defaults
+CLOUD_USER=${CLOUD_USER:-alpine}
+CLOUD_USERDATA=${CLOUD_USERDATA:-user-data}
+TINY_CLOUD_LOGS=${TINY_CLOUD_LOGS:-/var/log}
+TINY_CLOUD_VAR=${TINY_CLOUD_VAR:-/var/lib/cloud}
+
+# ensure existence of output directories
+[ ! -d "$TINY_CLOUD_VAR" ] && mkdir -p "$TINY_CLOUD_VAR"
+[ ! -d "$TINY_CLOUD_LOGS" ] && mkdir -p "$TINY_CLOUD_LOGS"
+
+# is initial bootstrap already done?
+is_bootstrapped() { [ -f "$TINY_CLOUD_VAR"/.bootstrap-complete ]; }
\ No newline at end of file
diff --git a/lib/tiny-cloud/init-early b/lib/tiny-cloud/init-early
new file mode 100644
index 0000000..68c8bd9
--- /dev/null
+++ b/lib/tiny-cloud/init-early
@@ -0,0 +1,28 @@
+# Tiny Cloud - Early Phase Functions
+# vim:set ft=sh ts=4 noet:
+
+if [ -z "$TINY_CLOUD_LIBS" ]; then
+    TINY_CLOUD_CONF=${TINY_CLOUD_CONF:-/etc/conf.d/tiny-cloud}
+    [ -f "$TINY_CLOUD_CONF" ] && source "$TINY_CLOUD_CONF"
+    TINY_CLOUD_LIBS=${TINY_CLOUD_LIBS:-/lib/tiny-cloud}
+fi
+
+source "$TINY_CLOUD_LIBS"/init-common
+
+expand_root() {
+    # explicitly use busybox, in case util-linux is also installed
+	local mountpoint=$(busybox mountpoint -n / | cut -d' ' -f1)
+	local volume=$(echo "$mountpoint" |
+		sed -Ee "s/(nvme\d+n\d|(xv|s)d[a-z])p?\d?$/\1/"
+	)
+
+	if [ "$mountpoint" != "$volume" ]; then
+		partition=$(echo "$volume" | sed -Ee "s/.*(\d+)$/\2/")
+		einfo "Expanding root partition to volume size..."
+		echo ", +" | sfdisk -q --no-reread -N "$partition" "$volume"
+		einfo "Updating kernel with new partition table..."
+		partx -u "$volume"
+	fi
+	einfo "Resizing root filesystem..."
+	resize2fs "$mountpoint"
+}
\ No newline at end of file
diff --git a/lib/tiny-cloud/init-final b/lib/tiny-cloud/init-final
new file mode 100644
index 0000000..107d949
--- /dev/null
+++ b/lib/tiny-cloud/init-final
@@ -0,0 +1,30 @@
+# Tiny Cloud - Final Phase Functions
+# vim:set ft=sh ts=4 noet:
+
+if [ -z "$TINY_CLOUD_LIBS" ]; then
+    TINY_CLOUD_CONF=${TINY_CLOUD_CONF:-/etc/conf.d/tiny-cloud}
+    [ -f "$TINY_CLOUD_CONF" ] && source "$TINY_CLOUD_CONF"
+    TINY_CLOUD_LIBS=${TINY_CLOUD_LIBS:-/lib/tiny-cloud}
+fi
+
+source "$TINY_CLOUD_LIBS"/init-common
+source "$TINY_CLOUD_LIBS"/imds
+
+save_userdata() {
+	imds_userdata > "$USERDATA"
+}
+
+is_userdata_script() {
+    head -n1 "$TINY_CLOUD_VAR/$CLOUD_USERSDATA" | grep -q '%#!/'
+}
+
+run_userdata() {
+	local log="$TINY_CLOUD_LOGS/$CLOUD_USERDATA.log"
+	local exit="$TINY_CLOUD_LOGS/$CLOUD_USERDATA.exit"
+    local userdata="$TINY_CLOUD_VAR/$CLOUD_USERDATA"
+
+	chmod +x "$userdata"
+	{ "$userdata" 2>& 1; echo $? > "$exit"; } | tee "$log"
+
+	return $(cat "$exit")
+}
\ No newline at end of file
diff --git a/lib/tiny-cloud/init-main b/lib/tiny-cloud/init-main
new file mode 100644
index 0000000..9ff1ebe
--- /dev/null
+++ b/lib/tiny-cloud/init-main
@@ -0,0 +1,37 @@
+# Tiny Cloud - Main Phase Functions
+# vim:set ft=sh ts=4 noet:
+
+if [ -z "$TINY_CLOUD_LIBS" ]; then
+    TINY_CLOUD_CONF=${TINY_CLOUD_CONF:-/etc/conf.d/tiny-cloud}
+    [ -f "$TINY_CLOUD_CONF" ] && source "$TINY_CLOUD_CONF"
+    TINY_CLOUD_LIBS=${TINY_CLOUD_LIBS:-/lib/tiny-cloud}
+fi
+
+source "$TINY_CLOUD_LIBS"/init-common
+source "$TINY_CLOUD_LIBS"/imds
+
+set_hostname() {
+	local fqdn=$(imds_hostname)
+	local host="${fqdn%%\.*}"
+	echo "$host" > /etc/hostname
+	hostname -F /etc/hostname
+	echo -e "127.0.1.1\t$fqdn $host" >> /etc/hosts
+}
+
+set_ssh_keys() {
+	local user="$CLOUD_USER"
+	local pwent=$(getent passwd "$user")
+	local group=$(echo "$pwent" | cut -d: -f4)
+	local ssh_dir="$(echo "$pwent" | cut -d: -f6)/.ssh"
+	local keys_file="$ssh_dir/authorized_keys"
+
+	if [ ! -d "$ssh_dir" ]; then
+		mkdir -p "$ssh_dir"
+		chmod 700 "$ssh_dir"
+	fi
+
+	touch "$keys_file"
+	chmod 600 "$keys_file"
+	chown -R "$user:$group" "$ssh_dir"
+	imds_ssh_keys > "$keys_file"
+}
\ No newline at end of file
diff --git a/lib/tiny-cloud/oci/imds b/lib/tiny-cloud/oci/imds
index 264b634..1589aac 100644
--- a/lib/tiny-cloud/oci/imds
+++ b/lib/tiny-cloud/oci/imds
@@ -1,4 +1,4 @@
-# OCI metadata-related variables and functions
+# OCI Instance MetaData Service variables and functions
 # vim:set ft=sh noet ts=4:
 
 IMDS_HEADER="Authorization"