Class: KamalBackup::Databases::Postgres

Inherits:
Base
  • Object
show all
Defined in:
lib/kamal_backup/databases/postgres.rb

Constant Summary collapse

SOURCE_ENV_KEYS = 
%w[
  PGHOST
  PGPORT
  PGUSER
  PGPASSWORD
  PGDATABASE
  PGSSLMODE
  PGSSLROOTCERT
  PGSSLCERT
  PGSSLKEY
  PGCONNECT_TIMEOUT
  PGSERVICE
  PGPASSFILE
].freeze

Instance Attribute Summary

Attributes inherited from Base

#config, #redactor

Instance Method Summary collapse

Methods inherited from Base

#backup, #backup_tags, build, #database_filename, #initialize

Constructor Details

This class inherits a constructor from KamalBackup::Databases::Base

Instance Method Details

#adapter_name ⇒ Object 



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# File 'lib/kamal_backup/databases/postgres.rb', line 24

def adapter_name
  'postgres'
end

#current_restore_command ⇒ Object 



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# File 'lib/kamal_backup/databases/postgres.rb', line 68

def current_restore_command
  connection = current_connection
  database = connection.fetch('PGDATABASE')

  argv = [postgres_binary('pg_restore', connection)] +
         %w[--clean --if-exists --no-owner --no-privileges --exit-on-error --dbname]
  argv << database
  CommandSpec.new(argv: argv, env: connection)
end

#current_target_identifier ⇒ Object 



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# File 'lib/kamal_backup/databases/postgres.rb', line 87

def current_target_identifier
  value('DATABASE_URL') || value('PGDATABASE')
end

#dump_command ⇒ Object 



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# File 'lib/kamal_backup/databases/postgres.rb', line 32

def dump_command
  connection = current_connection
  argv = [postgres_binary('pg_dump', connection)] + %w[--format=custom --no-owner --no-privileges]
  CommandSpec.new(argv: argv, env: connection)
end

#dump_extension ⇒ Object 



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# File 'lib/kamal_backup/databases/postgres.rb', line 28

def dump_extension
  'pgdump'
end

#restore_to_current(restic, snapshot, filename) ⇒ Object

Replace the target's user schemas before restoring.

pg_restore --clean emits DROP TABLE for each object in the dump, but PostgreSQL refuses to drop a table another table still references, and the dump's ordering cannot account for constraints that only exist in the target. Restoring over a schema Rails already created — which is every restore onto a freshly deployed host, since Kamal runs db:prepare on boot — leaves the drops failing, the CREATEs failing as "already exists", the COPYs never running, and the foreign keys rejected because the tables they point at are still empty.

Dropping every non-system schema first sidesteps the ordering problem entirely and removes target-only custom schemas as well as public. Current and scratch restores both promise that the target represents the selected snapshot, so both paths reset their target schema.



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# File 'lib/kamal_backup/databases/postgres.rb', line 53

def restore_to_current(restic, snapshot, filename)
  reset_schema(current_connection)
  result = super
  ensure_restore_reported_no_errors(result)
  result
end

#restore_to_scratch(restic, snapshot, filename, target:) ⇒ Object 



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# File 'lib/kamal_backup/databases/postgres.rb', line 60

def restore_to_scratch(restic, snapshot, filename, target:)
  validate_scratch_restore_target(target)
  reset_schema(current_connection.merge('PGDATABASE' => target))
  result = restic.pipe_dump_to_command(snapshot, filename, scratch_restore_command(target))
  ensure_restore_reported_no_errors(result)
  result
end

#scratch_restore_command(target) ⇒ Object 



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# File 'lib/kamal_backup/databases/postgres.rb', line 78

def scratch_restore_command(target)
  connection = current_connection.merge('PGDATABASE' => target)

  argv = [postgres_binary('pg_restore', connection)] +
         %w[--clean --if-exists --no-owner --no-privileges --exit-on-error --dbname]
  argv << target
  CommandSpec.new(argv: argv, env: connection)
end

#scratch_target_identifier(target) ⇒ Object 



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# File 'lib/kamal_backup/databases/postgres.rb', line 91

def scratch_target_identifier(target)
  [current_connection['PGHOST'], target].compact.join('/')
end