From 44cec12c285c1cefc73c258b6de47b0bb970ceb6 Mon Sep 17 00:00:00 2001
From: Jean-Paul Calderone <exarkun@twistedmatrix.com>
Date: Sat, 19 Feb 2022 16:27:47 -0500
Subject: [PATCH] start on a Tahoe-LAFS downloader
This test is bogus, though, because the Tahoe-LAFS web API test double
misbehaves for directory entry requests.
---
src/_zkapauthorizer/recover.py | 51 +++++++++++++++++++++++
src/_zkapauthorizer/tests/test_recover.py | 46 +++++++++++++++++++-
2 files changed, 95 insertions(+), 2 deletions(-)
diff --git a/src/_zkapauthorizer/recover.py b/src/_zkapauthorizer/recover.py
index e5b1580..8b570ba 100644
--- a/src/_zkapauthorizer/recover.py
+++ b/src/_zkapauthorizer/recover.py
@@ -19,7 +19,19 @@ from io import BytesIO
from sqlite3 import Cursor
from typing import BinaryIO, Callable, Dict, Iterator, Optional
+from allmydata.node import _Config
from attrs import define
+from hyperlink import DecodedURL
+from treq.client import HTTPClient
+from twisted.python.filepath import FilePath
+
+from .tahoe import download
+
+
+class SnapshotMissing(Exception):
+ """
+ No snapshot was not found in the replica directory.
+ """
class AlreadyRecovering(Exception):
@@ -183,3 +195,42 @@ def recover(statements: Iterator[str], cursor) -> None:
"""
for sql in statements:
cursor.execute(sql)
+
+
+async def tahoe_lafs_downloader(
+ treq: HTTPClient,
+ node_config: _Config,
+ recovery_cap: str,
+ set_state: SetState,
+) -> Awaitable: # Awaitable[FilePath]
+ """
+ Download replica data from the given replica directory capability into the
+ node's private directory.
+ """
+ api_root = DecodedURL.from_text(
+ FilePath(node_config.get_config_path("node.url")).getContent().decode("ascii")
+ )
+ snapshot_path = FilePath(node_config.get_private_path("snapshot.sql"))
+
+ set_state(RecoveryState(stage=RecoveryStages.downloading))
+ await download(treq, snapshot_path, api_root, recovery_cap, ["snapshot.sql"])
+ return snapshot_path
+
+
+def get_tahoe_lafs_downloader(
+ httpclient: HTTPClient, node_config: _Config
+) -> Callable[[str], Downloader]:
+ """
+ Bind some parameters to ``tahoe_lafs_downloader`` in a convenient way.
+
+ :return: A callable that accepts a Tahoe-LAFS capability string and
+ returns a downloader for that capability.
+ """
+
+ def get_downloader(cap_str):
+ def downloader(set_state):
+ return tahoe_lafs_downloader(httpclient, node_config, cap_str, set_state)
+
+ return downloader
+
+ return get_downloader
diff --git a/src/_zkapauthorizer/tests/test_recover.py b/src/_zkapauthorizer/tests/test_recover.py
index a92dad8..e68aea2 100644
--- a/src/_zkapauthorizer/tests/test_recover.py
+++ b/src/_zkapauthorizer/tests/test_recover.py
@@ -5,7 +5,9 @@ Tests for ``_zkapauthorizer.recover``, the replication recovery system.
from sqlite3 import Connection, connect
from typing import Dict, Iterator
-from hypothesis import assume, note, settings
+from allmydata.testing.web import create_fake_tahoe_root, create_tahoe_treq_client
+from fixtures import TempDir
+from hypothesis import assume, given, note, settings
from hypothesis.stateful import (
RuleBasedStateMachine,
invariant,
@@ -24,18 +26,27 @@ from testtools.matchers import (
)
from testtools.twistedsupport import failed, succeeded
from twisted.internet.defer import Deferred
+from twisted.python.filepath import FilePath
from ..recover import (
AlreadyRecovering,
RecoveryStages,
StatefulRecoverer,
+ get_tahoe_lafs_downloader,
make_canned_downloader,
make_fail_downloader,
noop_downloader,
recover,
)
from .sql import Table, create_table
-from .strategies import deletes, inserts, sql_identifiers, tables, updates
+from .strategies import (
+ deletes,
+ inserts,
+ sql_identifiers,
+ tables,
+ tahoe_configs,
+ updates,
+)
def snapshot(connection: Connection) -> Iterator[str]:
@@ -261,3 +272,34 @@ class StatefulRecovererTests(TestCase):
),
),
)
+
+
+class TahoeLAFSDownloaderTests(TestCase):
+ """
+ Tests for ``get_tahoe_lafs_downloader`` and ``tahoe_lafs_downloader``.
+ """
+
+ @given(tahoe_configs())
+ def test_get_downloader(self, get_config):
+ """
+ ``get_tahoe_lafs_downloader`` returns a downloader factory that can be
+ used to download objects using a Tahoe-LAFS client.
+ """
+ tempdir = self.useFixture(TempDir())
+ nodedir = FilePath(tempdir.join("node"))
+ config = get_config(nodedir.path, "tub.port")
+ # The downloader wants to figure out the node's api root.
+ nodedir.child("private").makedirs()
+ nodedir.child("node.url").setContent(b"http://localhost/")
+ root = create_fake_tahoe_root()
+ cap_str = root.add_data(b"URI:DIR2-RO:", b"snapshot data").decode("ascii")
+ httpclient = create_tahoe_treq_client(root)
+ get_downloader = get_tahoe_lafs_downloader(httpclient, config)
+ download = get_downloader(cap_str)
+
+ self.assertThat(
+ Deferred.fromCoroutine(download(lambda state: None)),
+ succeeded(
+ AfterPreprocessing(lambda fp: fp.getContent(), Equals(b"snapshot data"))
+ ),
+ )
--
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