semaphore-assets-cache.sh

#----------------------------------------------
## add this snippet to ./config/application.rb
#----------------------------------------------
if ENV["SEMAPHORE_CACHE_DIR"]
  config.assets.configure do |env|
    env.cache = ActiveSupport::Cache::FileStore.new("#{ENV["SEMAPHORE_CACHE_DIR"]}/assets-cache")
  end
end

#---------------------------------------
## add to the setup
## bash ./scripts/restore-asset-cache.sh
#---------------------------------------

#!/usr/bin/env bash
set -eo pipefail

assets_cache_archive="$SEMAPHORE_CACHE_DIR/assets-cache.tar.gz"

if [ -e $assets_cache_archive ]; then
  echo "Restoring assets cache..."
  tar -xf $assets_cache_archive -C $SEMAPHORE_CACHE_DIR
  echo "Assets cache restored."
fi

#--------------------------------
## put in an after job
## bash ./scripts/cache-assets.sh
#--------------------------------

#!/usr/bin/env bash

assets_dir="assets-cache"
assets_path="$SEMAPHORE_CACHE_DIR/$assets_dir"
assets_archive="$SEMAPHORE_CACHE_DIR/${assets_dir}.tar.gz"

if [ -d $assets_path ]; then
  echo "Removing old archive..."
  rm -f $assets_archive

  echo "Creating new archive ..."
  tar -czf $assets_archive -C $SEMAPHORE_CACHE_DIR $assets_dir

  echo "Removing uncompressed assets..."
  rm -rf $assets_path

  echo "Done."
else
  echo "No asset cache found. Skipping compressing."
fi

There is a typo in the application.rb change:

if ENV["SEMAPHORE_CACHE_DIR"]
  config.assets.configure do |env|
    env.cache = ActiveSupport::Cache::FileStore.new("#{ENV["SEMAPHORE_CACHE_DIR"]}/assets-cache")
  end # WAS MISSING
end

Fixed. Thanks a lot!