WIP: New bash update script

[poll-busily]

Overview

Hi all. We have a couple of pages in the wiki about updating Cloudlog. There's the Linux installation page which gives a sample update script and there's a separate page which is more for manual updates as far as I can see.

I've been working on a comprehensive bash script for managing updates in a more flexible way and I thought I'd better open a discussion before going too far with the coding. There are a few questions in my mind and I'd like to see what you all think. First of all though, the aims:

• Keep it minimal and tight a la Unix philosophy. Let Cron handle scheduling.
• Make it easier for admins to configure the way updates are applied
  • Allow setting the Git remote that's used
  • Allow setting the user/group applied by chown
  • Allow choosing between pulling the tip of master or the latest tag (on the master branch)
• Make it easier to maintain
  • Single list for subdirectories requiring ownership to be re-applied
  • Flags used to control behaviour
  • Includes some error handling, debug output
  • Documented in code

Open Questions

• Since creating an update script is part of the installation instructions, should we add this script to the repo itself so that it's already there and ready to go?
• If yes to the above, is there an appropriate directory I should put it in?
• Is there a plan to continue tagged releases? If so then the script could default to using the latest tag as a sort of "stable channel".
• Any other input / things you'd like to see here?

Draft Script

My working draft of this script is below, included here along with some sample output.

Source

#!/bin/bash
# Cloudlog update script
#
# Pulls changes from Git remote and re-sets appropriate directory ownership.
# Can be run manually or on a schedule using Cron.
#
# Please check the DIR_OWNERSHIP variable carefully to make sure it is
# appropriately set for your system!

# The user and group that own the CLOUDLOG_SUBDIR directories. Passed to 'chown' as-is.
DIR_OWNERSHIP="root:www-data"
# The list of directories that need to have ownership restored after a git pull
declare -a CLOUDLOG_SUBDIRS=("application/config" "assets/qslcard" "backup" "updates" "uploads")
# The name of the Git remote to fetch/pull from
GIT_ORIGIN="origin"
# If true, pull from the HEAD of the configured origin, otherwise the latest tag
BLEEDING_EDGE="true"
# If true, restore directory onwership on CLOUDLOG_SUBDIRS after a git pull
RESTORE_OWNERSHIP="true"

check_working_dir() {
	# Quick sanity check to make sure that pwd looks like a Cloudlog install
	if [[ ! -d "$(pwd)/application" ]]
	then
		echo "$(pwd) doesn't look like a Cloudlog install directory! Stopping here."
		exit 1
	fi
}

fast_forward_to_tag() {
	# Find the latest tag on the current branch
	# See https://git-scm.com/docs/git-describe for details on retrieving tags
	LATEST_TAG=$(git describe --tags --abbrev=0)
	echo "Fast-forwarding to latest tag: $LATEST_TAG..."
	if git pull $GIT_ORIGIN $LATEST_TAG ; then
		echo "Fast-forward finished successfully."
	else
		echo "Fast-forward failed; stopping here."
		exit 2
	fi
}

fast_forward_to_head() {
	echo "Fast-forwarding to HEAD (bleeding-edge)..."
	if git pull $GIT_ORIGIN ; then
		echo "Fast-forward finished successfully".
	else
		echo "Fast-forward failed; stopping here."
		exit 3
	fi
}

restore_ownership() {
	for dir in "${CLOUDLOG_SUBDIRS[@]}"; do
		echo "Setting ownership as $DIR_OWNERSHIP on $dir"
		chown -R $DIR_OWNERSHIP $(pwd)/$dir
	done
}


echo "Cloudlog update started"
echo "-----------------------"
echo "Using $(pwd) as working directory"

check_working_dir

# Fetch the latest changes from the master branch
echo "Fetching changes from origin..."
if git fetch $GIT_ORIGIN --tags ; then
	echo "Fetched latest changes successfully"
else
	echo "Fetch failed; stopping here."
	exit 4
fi

if [ "$BLEEDING_EDGE" = true ]; then
	fast_forward_to_head
else
	fast_forward_to_tag
fi

if [ "$RESTORE_OWNERSHIP" = true ]; then
	restore_ownership
fi

echo "Cloudlog update finished"

Sample Output

root@cloudlog-vm:/var/www/html# ./update_cloudlog.sh 
Cloudlog update started
-----------------------
Using /var/www/html as working directory
Fetching changes from origin...
Fetched latest changes successfully
Fast-forwarding to HEAD (bleeding-edge)...
Updating 0b84d4c0..bccfa676
Fast-forward
 .gitignore                                    |  1 +
 application/controllers/Lotw.php              | 22 ++++++++++++++++------
 application/controllers/Qso.php               |  1 +
 application/models/LotwCert.php               |  4 +++-
 application/views/interface_assets/footer.php |  5 +++++
 application/views/lotw_views/upload_cert.php  | 13 +++++++++++++
 assets/js/sections/contesting.js              | 36 ++++++++++++++++++++++++++++++++++++
 7 files changed, 75 insertions(+), 7 deletions(-)
Fast-forward finished successfully.
Setting ownership as root:www-data on application/config
Setting ownership as root:www-data on assets/qslcard
Setting ownership as root:www-data on backup
Setting ownership as root:www-data on updates
Setting ownership as root:www-data on uploads
Cloudlog update finished