undelete.py

#!/usr/bin/env python3
import couchconnection
import json
import sys

(db, conn) = couchconnection.arsnova_connection(
    "/etc/arsnova/arsnova.properties")

db_url = "/" + db

# Iterate command line arguments (excluding the script file name).
# Each argument is assumed to be an ID that should be undeleted.
for arg in sys.argv[1:]:
    # TODO: Validate _id format
    url = db_url + "/" + arg
    res = conn.get(url)
    doc = json.loads(res.read().decode('utf-8'))
    # only consider deleted documents
    if "error" in doc and doc["reason"] == "deleted":
        # retrieve document meta info
        url = url + "?revs=true&open_revs=all"
        res = conn.get(url)
        body = res.read().decode('utf-8')
        # remove non-json data, then create object
        clean_body = body[body.find("{"):body.rfind("}")+1]
        doc = json.loads(clean_body)
        # first id is the deleted document, second id (index=1) is the document before it was deleted
        rev_number = doc["_revisions"]["start"] - 1
        rev_hash = doc["_revisions"]["ids"][1]
        last_rev = str(rev_number) + "-" + rev_hash

        url = db_url + "/" + arg + "?rev=" + last_rev
        res = conn.get(url)
        restored_doc = json.loads(res.read().decode('utf-8'))
        if not "error" in restored_doc:
            # successfully restored the document, now push it back to the db
            rev_number = doc["_revisions"]["start"]
            rev_hash = doc["_revisions"]["ids"][0]
            last_rev = str(rev_number) + "-" + rev_hash
            restored_doc["_rev"] = last_rev

            url = db_url + "/" + arg + "?rev=" + last_rev
            res = conn.json_put(url, json.dumps(restored_doc))
            print(res.read())