Script to build an electron based app in lxd

build_electron_snap.sh

#!/bin/bash
# Override that with the tag
#   build-snap v1.16.2 # build specific tag
# Override with latest
#   build-snap master # build git master
# Override with most recent release
#   build-snap release # build latest stable release

# Set these variables
# Lower case name as it would appear in the store
SNAPNAME="mockman"
# Specify to master branch
GITURL=https://github.com/LanceGin/Mockman.git
# Correctly cased for the git project
APPNAME="Mockman"
# List of commands used to prepare the lxd container
PREP_COMMANDS="#!/bin/bash
echo '*** Installing core to get us latest snapd'
snap install core
echo '*** Installing node'
snap install --color=never --unicode=never node  --classic --channel=10/stable
echo '*** Installing snapcraft'
snap install --color=never --unicode=never snapcraft --classic
echo '*** apt update'
apt update -y -qqq
echo '*** apt install build tools'
export DEBIAN_FRONTEND=noninteractive
apt install -y -qq -o Dpkg::Use-Pty=0 python build-essential > /dev/null
"
# List of commands used to ninja in snap support 
PATCH_COMMANDS="#!/bin/bash
cd $APPNAME
sed -i -e 's/AppImage/snap/g' package.json
"
# Where does the snap file end up
OUTPUT_DIR="./build"
# List of commands used to build the application
BUILD_COMMANDS="#!/bin/bash
# Set dumb terminal to work around issue where snapcraft does progress indicators
export TERM=dumb
# Build the application
cd $APPNAME
# May need to install electron-builder if it's not already a devDependency
# npm install --save-dev electron-builder
# Here we build the application. Replace this with whatever commands
# are needed to build the app. Typically some node or yarn incantations
npm install
npm run build
# Once build we discover the name of the snap and put it in a file
# because lxc doesn't support wildcards and we don't know the name
# of the file ahead of time
find $OUTPUT_DIR -name '*.snap' > ~/snapfilename
"

# We begin
TMPDIR=$(mktemp -d)
DATESTAMP="$(date +%Y%m%d)-$(date +%H%M%S)"
CONTAINER=$SNAPNAME-$DATESTAMP
PREPSCRIPT=$APPNAME-prep.sh
PATCHSCRIPT=$APPNAME-patch.sh
BUILDSCRIPT=$APPNAME-build.sh
WAITFORSNAPD=5


display_container () {
    echo "Container: $CONTAINER"
} 

## Get the source
CWD=$(pwd)
## Clone the repo
echo "*** Cloning: " $GITURL
git clone -q $GITURL $TMPDIR/$APPNAME
cd $TMPDIR/$APPNAME
git fetch -q
last_committed_tag="$(git describe --tags --abbrev=0)"
if [ "$1" = "master" ]; then
  echo "*** Using master branch"
elif [ "$1" = "release" ]; then
  echo "*** Checking out ${last_committed_tag}"
  git checkout -q "${last_committed_tag}"
elif [ "$1" != "" ]; then
  echo "*** Using $1 tagged release"
  git checkout -q "$i"
fi

echo "*** Building: " $(git describe --tags)
cd $CWD

## Launch container
echo "*** Launch lxc container"
lxc launch -q ubuntu:16.04 $CONTAINER
if [ $? -ne 0 ];
then
    echo "Failed to launch container"
    exit 1
fi

## Push source into container
lxc file push -q -r $TMPDIR/$APPNAME $CONTAINER/root/
if [ $? -ne 0 ];
then
    echo "Failed to push source to container"
    exit 1
fi

## Build prep script
echo "$PREP_COMMANDS" >> $TMPDIR/$PREPSCRIPT

## Make script executable
chmod +x $TMPDIR/$PREPSCRIPT

## Push script to container
lxc file push -q $TMPDIR/$PREPSCRIPT $CONTAINER/root/
if [ $? -ne 0 ];
then
    echo "Failed to push to container"
    exit 1
fi

## Sleep because we're too quick to use snapd, so the prep will fail
sleep $WAITFORSNAPD

## Run prep script
echo "*** Run prep script in container"
/snap/bin/lxc exec -q $CONTAINER -- /root/$PREPSCRIPT
if [ $? -ne 0 ];
then
    echo "Failed to run prep script"
    exit 1
fi

## Build patch script
echo "$PATCH_COMMANDS" >> $TMPDIR/$PATCHSCRIPT

## Make script executable
chmod +x $TMPDIR/$PATCHSCRIPT

## Push script to container
lxc file push -q $TMPDIR/$PATCHSCRIPT $CONTAINER/root/
if [ $? -ne 0 ];
then
    echo "Failed to push patch script to container"
    exit 1
fi

## Run patch script
echo "*** Run patch script in container"
/snap/bin/lxc exec -q $CONTAINER -- /root/$PATCHSCRIPT
if [ $? -ne 0 ];
then
    echo "Failed to run patch script"
    exit 1
fi

## Create the script used inside the container to build the application
echo "*** Construct the build script"
echo "$BUILD_COMMANDS" >> $TMPDIR/$BUILDSCRIPT

## Make build script executable
chmod +x $TMPDIR/$BUILDSCRIPT

## Show the build script
echo "*** Here's the build script we'll run"
cat $TMPDIR/$BUILDSCRIPT

## Push script to container
echo "*** Push build script to container"
lxc file push -q $TMPDIR/$BUILDSCRIPT $CONTAINER/root/
if [ $? -ne 0 ];
then
    echo "Failed to push to container"
    display_container
    exit 1
fi

## Run build script
echo "*** Run build script in container"
/snap/bin/lxc exec -q $CONTAINER -- /root/$BUILDSCRIPT $APPNAME
if [ $? -ne 0 ];
then
    echo "Failed to run build script"
    display_container
    exit 1
fi

echo "*** Pull snap from container"
lxc file pull -q $CONTAINER/root/snapfilename $TMPDIR/snapfilename
if [ $? -ne 0 ];
then
    echo "Failed to get snapfilename"
    display_container
    exit 1
fi
FILENAME=$(cat $TMPDIR/snapfilename)
lxc file pull -q $CONTAINER/root/$APPNAME/$FILENAME .
if [ $? -ne 0 ];
then
    echo "Failed to get snap"
    display_container
    exit 1
fi

echo "*** Shutdown container"
lxc stop -q $CONTAINER
if [ $? -ne 0 ];
then
    echo "Failed to stop container"
    display_container
    exit 1
fi

echo "*** Delete temp folder"
rm -rf $TMPDIR
if [ $? -ne 0 ];
then
    echo "Failed to remove $TMPDIR"
    display_container
    exit 1
fi

echo "*** Destroy container"
lxc delete -q $CONTAINER
if [ $? -ne 0 ];
then
    echo "Failed to delete container"
    display_container
    exit 1
fi

echo "*** Snap built"
echo $(basename $FILENAME)