DAVx5 backups fail with rclone and apache2

[khimaros]

rclone: the server crashes during backup, usually around 30% of the way through rclone/rclone#6695 -- it makes more progress than any of the other methods but cannot complete a backup.

apache2 mod_dav_fs: has two failure modes:

• 301 Moved Permanently redirects are not handled correctly by DAVx5. apache2 returns 301 redirect response to PROPFIND directory requests if the requests is missing a trailing slash. SeedVault/DAVx5 sends PROPFIND /.SeedVaultAndroidBackup and apache2 returns a 301 redirect to /.SeedVaultAndroidBackup/ -- this problem can be worked around with BrowserMatch "^DAVx5/" redirect-carefully in the apache2 config. see also: follow 301 redirects bitfireAT/davx5-ose#253
• SeedVault/DAVx5 attempts to MKCOL /.SeedVaultAndroidBackup multiple times, even when the PROPFIND /.SeedVaultAndroidBackup returns a 207. subsequent MKCOL requests return a 405 Method Not Allowed response which causes the backup to abort. see also: [WebDAV] avoid MKCOL on directory that already exists bitfireAT/davx5-ose#254

radicale: i believe is "working as intended" -- it supports CardDAV and CalDAV but not plain WebDAV.

[khimaros]

here's a bit more detail from apache2 logs:

[14/Jan/2023:01:05:34 +0000] "MKCOL /blobs/.SeedVaultAndroidBackup HTTP/2.0" 201 239 "-" "DAVx5/4.2.6-ose (2022/12/12; dav4jvm; okhttp/4.10.0) Android/13" 152 0.021 0.020 . -
[14/Jan/2023:01:05:34 +0000]  "PROPFIND /blobs/.SeedVaultAndroidBackup HTTP/2.0" 207 815 "-" "DAVx5/4.2.6-ose (2022/12/12; dav4jvm; okhttp/4.10.0) Android/13" 526 0.018 0.020 . -
[14/Jan/2023:01:05:34 +0000] "PUT /blobs/.SeedVaultAndroidBackup/.nomedia HTTP/2.0" 201 246 "-" "DAVx5/4.2.6-ose (2022/12/12; dav4jvm; okhttp/4.10.0) Android/13" 162 0.044 0.040 . -
[14/Jan/2023:01:05:34 +0000] "PROPFIND /blobs/.SeedVaultAndroidBackup HTTP/2.0" 207 1403 "-" "DAVx5/4.2.6-ose (2022/12/12; dav4jvm; okhttp/4.10.0) Android/13" 526 0.046 0.048 . -
[14/Jan/2023:01:05:34 +0000] "MKCOL /blobs/.SeedVaultAndroidBackup/1673656571251 HTTP/2.0" 201 253 "-" "DAVx5/4.2.6-ose (2022/12/12; dav4jvm; okhttp/4.10.0) Android/13" 162 0.051 0.048 . -
[14/Jan/2023:01:05:35 +0000] "PROPFIND /blobs/.SeedVaultAndroidBackup/1673656571251 HTTP/2.0" 207 829 "-" "DAVx5/4.2.6-ose (2022/12/12; dav4jvm; okhttp/4.10.0) Android/13" 536 0.018 0.016 . -
[14/Jan/2023:01:05:35 +0000] "MKCOL /blobs/.SeedVaultAndroidBackup HTTP/2.0" 405 222 "-" "DAVx5/4.2.6-ose (2022/12/12; dav4jvm; okhttp/4.10.0) Android/13" 152 0.047 0.044 . -
<backup aborts>

[khimaros]

i have a theory as to why this might be happening.

seedvault/storage/lib/src/main/java/org/calyxos/backup/storage/plugin/saf/DocumentFileExt.kt

Line 47 in c856048

if (directory.name != name) {

may not be matching due to the redirect issue mentioned above:

$ curl --basic -u <name> -H 'Depth: 1' -X PROPFIND 'https://<host>/.SeedVaultAndroidBackup'
<?xml version="1.0" encoding="utf-8"?>
<D:multistatus xmlns:D="DAV:">
<D:response xmlns:lp1="DAV:" xmlns:lp2="http://apache.org/dav/props/">
<D:href>/.SeedVaultAndroidBackup/</D:href>

in other words, solving the trailing slash problem may solve both problems.

[khimaros]

hmm, the above only seems to be used for the .sv directories, so maybe not relevant here. this seems more relevant:

seedvault/app/src/main/java/com/stevesoltys/seedvault/plugins/saf/DocumentsStorage.kt

Line 69 in c856048

parent.createOrGetDirectory(context, DIRECTORY_ROOT).apply {

the solution may be as simple as appending a directory separator to DocumentFile.createOrGetDirectory() and DocumentFile.createOrGetFile() here:

seedvault/app/src/main/java/com/stevesoltys/seedvault/plugins/saf/DocumentsStorage.kt

Line 147 in c856048

/**

it may also be possible to fix this by modifying DocumentFile.findFileBlocking(), but the name matching in the two other functions may still get in the way:

seedvault/app/src/main/java/com/stevesoltys/seedvault/plugins/saf/DocumentsStorage.kt

Line 147 in c856048

/**

[grote]

Related to #500

[grote]

@khimaros did you try our new built-in WebDav functionality? Please re-open if it presents the same issues.

[khimaros]

the DAVx5 method now seems to work with apache2 mod_webdav_fs