Posts about nextcloud

Using fdupes to cleanup my file server

The overall problem:

Like many of us, I am guilty of copying files haphazardly, promising myself that I'll organize them later. This has built up to a significant problem over the years, particularly with old smartphone backups. I had a bad habit of dumping photo folder backups onto my server, with each dump containing even more dumps of old photos, resulting in multiple levels of duplication. Using the command-line tool called fdupes I've only just managed to get some of it under control.

fdupes is a command-line application designed to find and identify duplicate files within a directory or a set of directories. It employs various techniques to compare file contents and determine duplicates, enabling efficient cleanup and reclamation of storage space.

To streamline the review process and make sure I know what's about to happen before deleting any files, I created a simple bash wrapper script. This script acts as a nice safety belt, preventing accidental fat finger deletions.

Avoiding the rm -rf Pitfall:

As many of us have learned the hard way, the rm -rf command can have disastrous consequences if misused (goodbye email server with 2000 emails). A simple typo or a wrong path can result in irreversible data loss. To mitigate this risk, the bash wrapper script avoids using rm -rf altogether. Instead, it leverages the safer alternative of moving duplicate files to a temporary trash directory for review and then subsequent manual deletion.



find_files() {
  fdupes -rn "$*" > ${file}
  echo "Duplicate files have listed in ${file}"

remove_files() {
  echo "Reading from ${file}"
  echo ""
  read -p "Type yes to continue" choice
  case "$choice" in
    yes )
      mkdir -p "${TRASH}"
      while IFS= read -r line; do
        mv "${line}" "${TRASH}"
      done < ${file}
      echo "Duplicate files have been moved to ${TRASH}"
      exit ;;
    * )
      echo "Exiting"
      exit ;;

while getopts "rf:" option; do
  case "${option}" in
      remove=true  ;;
      file="${OPTARG:-dupes.txt}"  ;;
shift $((OPTIND - 1))

case "$remove" in
  true )
  false )
    find_files $*

Understanding the Script:

The script utilizes the fdupes command-line tool to identify duplicate files within a given directory or set of directories. Here's how it works:

Finding Duplicate Files:
  • The find_files function invokes the fdupes command with the -rn flags, instructing it to recursively search for duplicates and list the results in a specified file.
  • If no file name is provided as an argument, the script will use the default file name dupes.txt to store the duplicate file list.
  • After the duplicates are found, the script informs us that the duplicate files have been listed in the dupes.txt file.
Removing Duplicate Files:
  • The remove_files function allows us to decide whether to remove the duplicates. Make sure to review the dupes.txt file before running.
  • If no file name is provided as an argument, the script will still refer to the default dupes.txt file to read the duplicate file list.
  • After printing the file listing the duplicates, the script prompts us to confirm our decision by typing "yes."
  • If confirmed, the script creates a temporary trash directory and proceeds to move the duplicate files to it.
  • Finally, it provides a message confirming that the duplicate files have been successfully moved to the trash directory.

Using the Script:

To utilize the script effectively, follow these steps:

  • Copy the script into a text editor and save it as
  • Open a terminal and navigate to the directory containing the script.
  • Make the script executable by running the command: chmod +x
Execute the script with appropriate options:
  • To find duplicate files: ./ <directory>
  • To remove duplicate files: ./ -r

Note: If you don't specify a file name using the -f argument, it will default to using the dupes.txt file for listing duplicate files.

Eking out some Nextcloud performance

Tweeking my linux server

Nextcloud is notorious in the selfhosted community of being difficult for some people to achieve a decent level of performance. After enabling the basic caching with both APCu and Redis there are several options to trim some fat. Once all the easy stuff is taken care of the hidden bottlenecks is where I am focusing my efforts. So far I have had some success by switching to UNIX sockets in my dockerised Nextcloud deployment.

Generally I've found:

  • Shipping file logging off to syslog made a noticeable visual difference over logging to the nextcloud.log file.
  • Using postgresql has been often touted as a decent option for easy performance gains.
  • Using the preview generator app alongside using Imaginary makes images less of an issue for general browsing.

But what else can you do after that? Trying to find bottlenecks in your setup. Be it spinning rust vs SSD vs M.2 drives there are usually some form of low hanging fruit you can find that is causing issues. A big potential issue is of course your abstraction layer, in my case docker. Docker adds some minor overheads to any service, a trade off for simplifying deployment and replication, one of these overheads is the networking stack. My understanding is that Docker's networking when not in host mode acts as a NAT, even when one container is talking to another. One method of bypass networking overhead between local services is the use of unix sockets.

In researching how to achieve this I found @jonbaldie's post on How to Connect to Redis with Unix Sockets in Docker. A few modifications and I was ready to test and verify that this made a difference.


These are the modifications done to my docker-compose file. Note that I have made a few modifications to avoid the need to set the folders and sockets permissions as 777. This is mainly handled by modifying the container user group id to the www-data group from the Nextcloud app container.

version: '2'

    #Temporary busybox container to set correct permissions to shared socket folder
      image: busybox
      command: sh -c "chown -R 33:33 /tmp/docker/ && chmod -R 770 /tmp/docker/"
        - /tmp/docker/

      container_name: nextcloud_db
      image: postgres:14-alpine
      restart: always
        - ./volumes/postgresql:/var/lib/postgresql/data
        - /etc/localtime:/etc/localtime:ro
        - /etc/timezone:/etc/timezone:ro
        - db.env
      # Unix socket modifications
      # Run as a member of the www-data GID 33 group but keep postgres uid as 70
      user: "70:33"
      # Add the /tmp/docker/ socket folder to postgres
      command: postgres -c unix_socket_directories='/var/run/postgresql/,/tmp/docker/'
        - tmp
      # Add shared volume from Temporary busybox container
        - tmp

      container_name: nextcloud_redis
      image: redis:alpine
      restart: always
        - /etc/localtime:/etc/localtime:ro
        - /etc/timezone:/etc/timezone:ro
      # Unix socket modifications
        - ./volumes/redis.conf:/etc/redis.conf
      # Run redis with custom config
      command: redis-server /etc/redis.conf
      # Run as a member of the www-data GID 33 group but keep redis uid as 999
      user: "999:33"
        - tmp
      # Add shared volume from Temporary busybox container
        - tmp

      container_name: nextcloud_app
      image: nextcloud:apache
      restart: always
        - ./volumes/nextcloud:/var/www/html
        - ./volumes/php.ini:/usr/local/etc/php/conf.d/zzz-custom.ini
        - /etc/localtime:/etc/localtime:ro
        - /etc/timezone:/etc/timezone:ro
        - db
        - redis
      # Unix socket modifications
      # Add shared volume from Temporary busybox container
        - tmp

This is the redis.conf file that tells it to only listen to the unix socket, and what permissions to use on said socket. Note I have a password enabled here, this is not really need it if not exposed publicly but I've used it just for best practice.

# 0 = do not listen on a port
port 0

# listen on localhost only

# create a unix domain socket to listen on
unixsocket /tmp/docker/redis.sock

# set permissions for the socket
unixsocketperm 770

requirepass [password]

Finally the Nextcloud config I updated to reflect the connection changes

'dbtype' => 'pgsql',
'dbhost' => '/tmp/docker/',
'dbname' => 'nextcloud',
'dbuser' => 'nextcloud',
'dbpassword' => '{password}',

'memcache.local' => '\\OC\\Memcache\\APCu',
'memcache.distributed' => '\\OC\\Memcache\\Redis',
'memcache.locking' => '\\OC\\Memcache\\Redis',
'redis' =>
array (
  'host' => '/tmp/docker/redis.sock',
  'port' => 0,
  'dbindex' => 0,
  'password' => '{password}',
  'timeout' => 1.5,

Verifying the changes made a difference.

There is not much point in doing this without verification, otherwise we are all just participating in a cargo cult seeking performance enlightenment. With that in mind I set out to do some very basic benchmarks to ensure the performance gain I felt when navigating my Nextcloud install was in fact happening.

I did all my testing inside my Nextcloud container to better simulate a real-world result. I modified the redis.conf temporarily to allow both socket connections and TCP IP connections, then I had to install the redis-tools and postgresql-contrib packages to get the tools required.

# 0 = do not listen on a port
# port 0
port 6379

# listen on localhost only
# bind
sudo docker exec -it nextcloud_app bash

apt update && apt install redis-tools && apt install postgresql-contrib

I then performed the same tests as @jonbaldie's using the commands time redis-benchmark -a [password] -h redis -p 6379 and time redis-benchmark -a [password] -s /tmp/docker/redis.sock

REDIS TCP (s) UNIX (s) % Diff
Real 242.8 165.5 32%
User 63.4 60.9 4%
Sys 132.1 70.6 47%
Total 438.4 297.1 32%

As you can see on my system I saw a staggering 32% difference compared to @jonbaldie's 13%. Clearly the Redis socket is a very worthwhile modification.

Using some of what I learned from reading this article I now wanted to test my Postgres database using it's benchmarking tool pgbench. I did a quick database backup just in case, but it shouldn't harm the Nextcloud db as it's only adding the tables pgbench_accounts, pgbench_branches, pgbench_tellers and pgbench_history to perform the tests.

First test the testing tables initialisation

pgbench -h db -i -p 5432 -U nextcloud -d nextcloud


done in 1.85 s (drop tables 0.00 s, create tables 0.13 s, client-side generate 0.60 s, vacuum 0.60 s, primary keys 0.51 s)

Then I Ran 3 tests using the command pgbench -h db -c 10 -p 5432 -U nextcloud -d nextcloud simulating 10 clients.

Postgres TCP 1 2 3 Average
latency average 265.887 333.644 280.873 293.468
tps (including connections establishing) 37.60993 29.972067 35.603308 34.3951016666667
tps (excluding connections establishing) 38.089613 30.24576 35.997626 34.7776663333333

Clean up inbeteween tests

psql -h /tmp/docker/ -i -U nextcloud -d nextcloud

DROP TABLE pgbench_accounts, pgbench_branches, pgbench_tellers, pgbench_history;

First test the testing tables initialisation

pgbench -h /tmp/docker/ -i -U nextcloud -d nextcloud


done in 1.42 s (drop tables 0.00 s, create tables 0.11 s, client-side generate 0.68 s, vacuum 0.25 s, primary keys 0.38 s).

Then I Ran 3 tests using the command pgbench -h /tmp/docker/ -c 10 -U nextcloud -d nextcloud simulating 10 clients.

Postgres UNIX 1 2 3 Average
latency average 291.566 290.129 222.446 268.047
tps (including connections establishing) 34.297528 34.467479 44.954712 37.906573
tps (excluding connections establishing) 34.397523 34.570084 45.137941 38.0351826666667

My results show a much more modest performance difference with the database. But it's still an unambiguous improvement so well worth the minor amount of effort.

% Diff
latency average 9.00%
tps (including connections establishing) 10.00%
tps (excluding connections establishing) 9.00%
testing tables initialisation 23.00%

Finding, testing and minimising bottlenecks is possibly the most difficult task for any selfhosting admin. I hope you found this of use in your own bottleneck hunting journey.

Node-red - Phonetrack HomeAssistant Bridge

Node-RED is a flow-based programming tool, originally developed by IBM’s Emerging Technology Services team and now a part of the JS Foundation.

I threw together a quick way to bridge GPS data from the android app GPS Logger between HomeAssistant and the Nextcloud APP Phonetrack.

Note: Returns the highest http response code thrown by either service, this can result in the GPS logger submitting multiple times if there is any issues with either Nextcloud or HomeAssistant

Extra Nodes used



In HomeAssistant follow the instructions found here to obtain the GPS Logger web hook url and add this to the config node

In Nextcloud after creating a tacking session click the link icon and fetch the link labled GpsLogger GET and POST link : and add this to the config node

Edit the http auth Node with your desired credentials.

GPS Logger

Go to Logging details -> Log to custom URL -> URL and add your Node-Red url: https://example.tld/node-red/gps_logger?latitude=%LAT&longitude=%LON&device=[Your_Device_Name_Here]&accuracy=%ACC&battery=%BATT&speed=%SPD&direction=%DIR&altitude=%ALT&provider=%PROV&activity=%ACT&timestamp=%TIMESTAMP - Note: edit the url and the [Your_Device_Name_Here]

Go to Logging details -> Log to custom URL -> Basic Authentication add the username and password you set in the http auth node

[{"id":"f5b2b1b.1f8895","type":"http in","z":"4a1f60d7.aaf398","name":"GPS Logger endpoint","url":"/gps_logger","method":"post","upload":false,"swaggerDoc":"","x":180,"y":180,"wires":[["d18bbbaf.bd8138"]]},{"id":"c8badb69.d6dc78","type":"debug","z":"4a1f60d7.aaf398","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","x":1210,"y":240,"wires":[]},{"id":"2b58f523.f2713a","type":"http request","z":"4a1f60d7.aaf398","name":"Home Assistant","method":"POST","ret":"txt","paytoqs":false,"url":"","tls":"","proxy":"","authType":"","x":660,"y":260,"wires":[["b894f1e0.b35c28"]]},{"id":"7b5c470a.a86d7","type":"change","z":"4a1f60d7.aaf398","name":"Build HomeAssistant Query","rules":[{"t":"set","p":"headers","pt":"msg","to":"{}","tot":"json"},{"t":"set","p":"headers.content-type","pt":"msg","to":"application/x-www-form-urlencoded","tot":"str"},{"t":"set","p":"url","pt":"msg","to":"homeassistant","tot":"flow"},{"t":"set","p":"payload","pt":"msg","to":"\"latitude=\" & req.query.latitude & \"&longitude=\" & req.query.longitude & \"&device=\" & req.query.device & \"&accuracy=\" & req.query.accuracy & \"&battery=\" & req.query.battery & \"&speed=\" & req.query.speed & \"&direction=\" & req.query.direction & \"&altitude=\" & req.query.altitude & \"&provider=\" & req.query.provider  & \"&activity=\" & req.query.activity","tot":"jsonata"}],"action":"","property":"","from":"","to":"","reg":false,"x":440,"y":260,"wires":[["2b58f523.f2713a"]]},{"id":"ee593f24.f06ca8","type":"change","z":"4a1f60d7.aaf398","name":"Set Phonetrack URL","rules":[{"t":"set","p":"url","pt":"msg","to":"$flowContext(\"phonetrack\") & req.query.device & \"?lat=\" & req.query.latitude & \"&lon=\" & req.query.longitude & \"&acc=\" & req.query.accuracy & \"&speed=\" & req.query.speed & \"&bearing=\" & req.query.direction & \"&timestamp=\" & req.query.timestamp & \"&battery=\" & req.query.battery","tot":"jsonata"}],"action":"","property":"","from":"","to":"","reg":false,"x":420,"y":220,"wires":[["f9487911.1c6ed8"]]},{"id":"f9487911.1c6ed8","type":"http request","z":"4a1f60d7.aaf398","name":"PhoneTrack","method":"POST","ret":"txt","paytoqs":false,"url":"","tls":"","proxy":"","authType":"","x":650,"y":220,"wires":[["b894f1e0.b35c28"]]},{"id":"1b9f05f9.a0fb4a","type":"http response","z":"4a1f60d7.aaf398","name":"","statusCode":"","headers":{},"x":1210,"y":280,"wires":[]},{"id":"d9a79cbe.4e6668","type":"config","z":"4a1f60d7.aaf398","name":"URLS","properties":[{"p":"phonetrack","pt":"flow","to":"https://example.tld/apps/phonetrack/log/gpslogger/__phonetrackid__/","tot":"str"},{"p":"homeassistant","pt":"flow","to":"https://home.example.tld/api/webhook/__webhookkey__","tot":"str"}],"active":true,"x":150,"y":140,"wires":[]},{"id":"b894f1e0.b35c28","type":"join","z":"4a1f60d7.aaf398","name":"","mode":"custom","build":"array","property":"statusCode","propertyType":"msg","key":"url","joiner":"\\n","joinerType":"str","accumulate":false,"timeout":"","count":"2","reduceRight":false,"reduceExp":"","reduceInit":"","reduceInitType":"","reduceFixup":"","x":850,"y":240,"wires":[["fc27dbec.975ca8"]]},{"id":"fc27dbec.975ca8","type":"change","z":"4a1f60d7.aaf398","name":"","rules":[{"t":"set","p":"statusCode","pt":"msg","to":"$max(statusCode.$number())","tot":"jsonata"},{"t":"set","p":"payload","pt":"msg","to":"","tot":"str"}],"action":"","property":"","from":"","to":"","reg":false,"x":1000,"y":240,"wires":[["35d1687f.3e79d"]]},{"id":"51a8ee1e.cb9c38","type":"comment","z":"4a1f60d7.aaf398","name":"Set URLS for HomeAssistant and PhoneTrack","info":"","x":250,"y":100,"wires":[]},{"id":"35d1687f.3e79d","type":"switch","z":"4a1f60d7.aaf398","name":"","property":"statusCode","propertyType":"msg","rules":[{"t":"gt","v":"200","vt":"str"},{"t":"else"}],"checkall":"true","repair":false,"outputs":2,"x":1030,"y":280,"wires":[["c8badb69.d6dc78","1b9f05f9.a0fb4a"],["1b9f05f9.a0fb4a"]]},{"id":"d18bbbaf.bd8138","type":"node-red-contrib-httpauth","z":"4a1f60d7.aaf398","name":"","file":"","cred":"","authType":"Basic","realm":"","username":"","password":"","hashed":false,"x":220,"y":220,"wires":[["ee593f24.f06ca8","7b5c470a.a86d7"]]}]

Nextcry and Nextcloud security

About a month ago there was an urgent security notice from the Nexcloud devs regarding a flaw in Nginx php-fpm and the associated Nextcloud config. Unfortunately we are now seeing it being exploited in the wild.

The Nextcloud devs have confirmed that it doesn't appear to be an issue with Nextcloud itself and that patching and updating is highly advised.

This brings to mind some extra security measures I do for Nextcloud on top of my standard server checklist

Have extra security advice? Let me know in the comments down below!

Customizing the Nextcloud Mail App

Nextcloud is a suite of client-server software for creating and using file hosting services

As the mail app developers don’t want to add a horizontal reading pane to the app I have been using the custom css app 5 in order to do so, I also wrote a quick user script to automatically expand all my folders as that isn't an option in the mail app.

Jump to the Auto Expand script

Horizontal reading pane in mail app

Note: Tested in Firefox and Nextcloud 15


  1. Know what you are doing.
  2. Install the custom css app.
  3. Navigate to Admin -> Theming.
  4. Paste contents of this CSS file into the custom CSS text area 6.
  5. Save.

Currently I have:

  • The basic Horizontal layout
  • Added a resize to the message list so you can drag it up and down for simpler management of mail
  • Added a yellow highlight to The images have been blocked to protect your privacy notification
  • Added the color #ebebeb as the message header background to better separate panes
  • Added a thick border color #ebebeb to the top of the reply field to better separate it from the current message
  • Shrunk the load more messages scroll down area
  • Realigned the empty messages background
  • Changed subfolder background color from gradient to solid
  • Added indicator line to subfolder Parent
  • Added indicator line and Bold text to open Parent Folder

Auto Expand mail folders using GreaseMonkey


  1. The Latest Firefox
  2. Greasemonkey 4.3 or greater

Open the Greasemonkey dashboard and click the + sign to add a new script.

Past the following code, changing the yourdomain.tld to your domain:

// ==UserScript==
// @name     Nextcloud Mail Expand folders
// @namespace   https://yourdomain.tld/
// @include     https://yourdomain.tld/apps/mail/*
// @require
// @require
// @version  1
// @grant    NEXTCLOUDMAIL
// ==/UserScript==

/* Paste Here */

this.$ = this.jQuery = jQuery.noConflict(true);

console.log('[ NMEF ] - Waiting');
waitForKeyElements (".navigation-account", expandALL, true);

function expandALL() {
  console.log('[ NMEF ] - Expand ALL Folders');
  console.log('[ NMEF ] - Expand individual Folders');
    $('.with-counter.collapsible > button').trigger('hover').trigger("click");
    $('.with-counter.collapsible.ui-droppable > button').trigger('hover').trigger("click");

Note: this loads the remote content jquery and waitForKeyElements.js, if you wish to have them bound locally open the // @require links and past the contents at the / Paste Here / line. Then just delete the lines:

// @require
// @require