Script to pull down the latest database restore spec from backup for use with the WAL-E backup-fetch command.

fetch_restore_spec.py

#!/usr/bin/env python
import sys
import os
import json
from collections import namedtuple

from wal_e.storage.base import StorageLayout

ENV_MAP = {
    'WABS_ACCESS_KEY': 'access_key',
    'AWS_SECRET_ACCESS_KEY': 'access_key',
    'WABS_ACCOUNT_NAME': 'account_name',
    'AWS_ACCESS_KEY_ID': 'account_name',
    'WALE_WABS_PREFIX': 'prefix',
    'WALE_S3_PREFIX': 'prefix'
}

env = namedtuple('env', ['account', 'access_key', 'prefix'])


def load_env(env_path):
    fnames = os.listdir(env_path)
    for fname in fnames:
        if os.path.isfile(os.path.join(env_path, fname)) and fname in ENV_MAP:
            with open(os.path.join(env_path, fname), 'r') as fs:
                val = fs.read().strip('\n').strip()
                setattr(env, ENV_MAP[fname], val)
    return env


def main():
    if len(sys.argv) != 2:
        print "Usage: ./retrieve_spec.py <wal-e env path>"
        sys.exit(1)
    env_path = sys.argv[1]
    env = load_env(env_path)
    layout = StorageLayout(env.prefix)
    if layout.is_s3:
        from wal_e.blobstore import s3
        from wal_e.operator.s3_operator import S3Backup
        creds = s3.Credentials(env.account_name, env.access_key, None)
        backup_ctx = S3Backup(layout, creds, None)
    elif layout.is_wabs:
        from wal_e.blobstore import wabs
        from wal_e.operator.wabs_operator import WABSBackup
        creds = wabs.Credentials(env.account_name, env.access_key)
        backup_ctx = WABSBackup(layout, creds, None)
    else:
        print "Unknown blob store..."
        sys.exit(1)

    backup = list(backup_ctx._backup_list(False).find_all('LATEST'))[0]
    backup.load_detail(backup_ctx.new_connection())
    spec = backup.spec
    if 'base_prefix' in spec:
        del spec['base_prefix']
    with open('spec.json', 'w') as fs:
        json.dump(spec, fs)
    print "Recovery spec written to ./spec.json"
    print "You can now retrieve the latest full backup for the target"
    print "database by running:"
    print "   /usr/bin/envdir <path to wal-e env dir> /usr/local/bin/wal-e backup-fetch \\"
    print "    --restore-spec spec.json <path to PostgreSQL env dir> LATEST"

if __name__ == '__main__':
    main()