Refresh demo/staging data in Heroku (cf. http://covidence.engineering/automatically-refresh-staging-db/)

heroku.sh

#!/usr/bin/env bash

set -ex

# Pass in Heroku API token
token=$1

# We run this script in a stateless Docker image, so to make the script a bit
# cleaner, we just write out the credentials to a file that the Heroku Toolbelt
# knows to read.
if ! grep -lq api.heroku.com ~/.netrc 2>/dev/null; then
  echo "machine api.heroku.com" > ~/.netrc
  echo "  login dev+heroku@covidence.org" >> ~/.netrc
  echo "  password $token" >> ~/.netrc

  chmod 0600 ~/.netrc
fi

# Helper function for calling Heroku API
function hapi {
  curl \
    --fail \
    --silent \
    --netrc \
    --header 'Accept: application/vnd.heroku+json; version=3' \
    https://api.heroku.com$*
}

# Routine to wait for DB to be caught up, then promote it and de-provision the
# old instance.
function promote {
  app=$1

  heroku pg:wait --wait-interval 10 -a $app
  heroku pg:unfollow -a $app --confirm $app $app::NEW_DATABASE || true
  heroku addons:attach -a $app $app::DATABASE --as OLD_DATABASE
  heroku pg:promote -a $app NEW_DATABASE
  heroku addons:detach -a $app NEW_DATABASE
  heroku addons:destroy -a $app --confirm $app OLD_DATABASE
  heroku run:detached -a $app rails runner 'Ops::Staging::Search.massacre!'
}

# Routine to create a new DB with a deterministic name so that we can more
# easily promote it later.
#
# There is also some logic here to recover from a build which got interrupted
# mid-way so that we don't accumulate orphaned DBs that we have to pay for.
function create {
  app=$1
  plan=$2

  shift 2

  existing=$(hapi /addons/$app::DATABASE | jq -Mr .name)
  new=$(hapi /addons/$app::NEW_DATABASE | jq -Mr .name || true)

  if [ -z "$new" ]; then
    heroku addons:create \
      -a $app heroku-postgresql:$plan \
      --as NEW_DATABASE \
      $*
  else
    if [ "$new" == "$existing" ]; then
      heroku addons:detach -a $app NEW_DATABASE
      create $app $plan
    else
      true # already got a new one in waiting
    fi
  fi
}

# Takes a snapshot and copies it. This takes longer, breaks the destination
# DB until it has completed, so is only used for demo to demo-staging, which
# use Hobby DBs which cannot be followed/forked.
#
# One benefit of this which might be worth applying to staging/dev is that the
# destination data sizes (tables+indexes) are much smaller, which suits the
# smaller instance sizes used there.
function copy {
  src=$1
  dst=$2

  heroku pg:copy $src::DATABASE NEW_DATABASE \
    --wait-interval 10 \
    --app $dst \
    --confirm $dst
}

# Create new DBs and trigger loading of data
create covidence-dev     premium-0 --fork covidence-production::DATABASE --fast
create covidence-staging premium-2 --fork covidence-production::DATABASE --fast
create covidence-demo-staging hobby-basic
copy covidence-demo covidence-demo-staging

# Promote DBs (these steps block until each DB to be ready for promotion)
promote covidence-dev
promote covidence-staging
promote covidence-demo-staging