dougal-software/sbin/upgrade_database.py

#!/usr/bin/python3

import sys
import os
# Because Python 🙄
bin_path = os.path.abspath(os.path.join(os.path.dirname(__file__), "../bin"))
sys.path.insert(1, bin_path)
import configuration

print(
"""
\u001b[31;4mYou are about to upgrade the database to the latest schema in /etc/db/schema-template.sql.\u001b[0m

\u001b[33mThis will cause all existing surveys to be wiped out and re-created.
Data which is captured by the database itself, e.g., event data will be exported
and re-imported. The rest should be brought back in at the next bin/runner.sh
run.

\u001b[0m

If this is what you want to do, press ENTER, else press Ctrl+C to cancel.
""")

input()

#
# If we got here it's because the user has asked us to proceed
#

locals().update(configuration.vars())

if os.path.exists(LOCKFILE):
	print(f"Dougal's runner is currently active. Retry in a few moments or remove {LOCKFILE} if you think it's stale")
	exit(1)

# Let's stop runner.sh from messing with our upgrade
with open(LOCKFILE, "w") as fd:
	fd.write(str(os.getpid()))

#
# Define some variables that we will need later on
#

dbname=os.environ["PGDATABASE"] if "PGDATABASE" in os.environ else "dougal"
dbuser=os.environ["PGUSER"] if "PGUSER" in os.environ else "postgres"
dbtemplate=os.path.abspath(os.path.join(bin_path, "..", "etc", "db", "database-template.sql"))

system_exports = os.path.join(bin_path, "system_exports.py")
system_dump = os.path.join(bin_path, "system_dump.py")
system_load = os.path.join(bin_path, "system_load.py")
create_survey = os.path.join(bin_path, "create_survey.sh")
runner = "RUNNER_NOEXPORT=true RUNNER_IMPORT=true " + os.path.join(bin_path, "runner.sh")

#
# Export data
#

# The usual exports
print(system_exports)
os.system(system_exports)

# And the exports from “mixed” data
print(system_dump)
os.system(system_dump)

#
# Do database stuff – this is where we start breaking things
#

# Everyone gets kicked out
print(f"Terminate all sessions in {dbname}")
cmd = f"psql -U {dbuser} -d {dbname} -c 'SELECT pg_terminate_backend(pid) FROM pg_stat_activity WHERE datname = current_database() AND pid <> pg_backend_pid();'"
print(cmd)
res = os.system(cmd)

# The database gets dropped
cmd = f"psql -U {dbuser} -d template1 -c 'DROP DATABASE {dbname};'"
print(cmd)
res = os.system(cmd)
if res != 0:
	print("Cannot proceed. Upgrade aborted.")
	exit(res)

# The new database gets created
cmd = f"psql -U {dbuser} -d template1 <{dbtemplate}"
print(cmd)
os.system(cmd)

#for survey in configuration.surveys():
	#schema = survey["schema"]
	#cmd = f"psql dougal -c 'DROP schema {schema} CASCADE;'"
	#print(cmd)

# The surveys get re-created
for survey in configuration.surveys(include_archived=True):
	id = survey["id"].lower()
	name = survey["name"]
	epsg = survey["epsg"]
	schema = survey["schema"]

	cmd = f"SCHEMA_NAME={schema} {create_survey} \"{id}\" \"{name}\" {epsg}"
	print(cmd)
	os.system(cmd)

#
# Here is where we re-import the data
#

os.remove(LOCKFILE) # Let runner.sh run again
# Import the bulk of the data
print(runner)
os.system(runner)
# Import the data that lives only in the database
print(system_load)
os.system(system_load)


print("Done")