Error 403: Write access to namespace 'history' is forbidden

[FatalBulletHit]

I would like to restore my old print history after I recently created a clean installation of MainsailOS as my previous installation was corrupted (couldn't setup hardware PWM).

Because I already did some prints on the new installation of which I'd like to keep the history, too, I can't simply copy and paste the Moonraker database files ( .mdb ) located at ~/.moonraker_database from the old to the new installation.

I decided to retrieve the old history in JSON format via the Moonraker Client API to merge it with the new history by going to {printers_local_ip}/server/database/item?namespace=history in my browser.
I also retrieved the new history and, with some regex shenanigans in Notepad++, merged them together and prepared the JSON-RPC requests:

1. I did a case insensitive regex search for ("[0-9a-z]{6}": {"end_time":) and replaced it with \r\n\1 :
   

2. I removed the first line ( {"result": {"namespace": "history", "key": null, "value": { ) and all but one closing curly brackets ( } ) from the end of the last line.
   I also added a comma ( , ) at the end of the last line of the old history.

3. I added the new history at the end of the old history, disabled word wrap and used the Column Editor ( as per https://stackoverflow.com/a/7602876/9248774 ) to adjust the key values of the new history:
   

4. I added 2 additional leading zeroes by doing a regex search for ^" and replaced it with "00 , because the key needs to be 6 characters long:
   

5. I did another case insensitive regex search for ^("[0-9a-z]{6}"): (.*), and replaced it with { "jsonrpc": "2.0", "method": "server.database.post_item", "params": { "namespace": "history", "key": \1, "value": \2 }, "id": 4654 } to prepare the JSON-RPC requests:
   

6. Add an empty line at the end of the file.

After installing npm to install wscat, I established a connection to the Moonraker Client API using wscat in PowerShell 5.1:

wscat -c "ws://{printers_local_ip}/websocket"

Getting constant Moonraker process statistic updates, I decided to pipe the output of wscat through a filter to hide them:

# Connect to websocket and hide 'notify_proc_stat_update'
wscat -c "ws://{printers_local_ip}/websocket" | ? {$_ -notmatch 'notify_proc_stat_update'}

So far so good, but when I try to add a database item to the (empty) history namespace like so:

{"jsonrpc":"2.0","method":"server.database.post_item","params":{"namespace":"history","key":"000000","value":{"end_time":1661002450.9432285,"filament_used":0,"filename":"[misc.gcode","metadata":{"size":10438959,"modified":1661001409.616721,"uuid":"aeade097-cd06-4b65-9350-1867aa4bd180","slicer":"SuperSlicer","slicer_version":"2.4","gcode_start_byte":177843,"gcode_end_byte":10424781,"layer_count":89,"object_height":16.24,"estimated_time":17192,"nozzle_diameter":0.4,"layer_height":0.2,"first_layer_height":0.25,"first_layer_extr_temp":245,"first_layer_bed_temp":110,"chamber_temp":50,"filament_name":"\"eSun ABS+\"","filament_type":"ABS+","filament_total":31664.02,"filament_weight_total":80.73,"thumbnails":[{"width":32,"height":32,"size":2068,"relative_path":".thumbs/[misc-32x32.png"},{"width":400,"height":300,"size":120819,"relative_path":".thumbs/[misc-400x300.png"}]},"print_duration":0,"status":"error","start_time":1661002163.0869668,"total_duration":287.7618266249997}},"id":4654}

... this error is thrown:

{"jsonrpc": "2.0", "error": {"code": 403, "message": "Write access to namespace 'history' is forbidden"}, "id": 4654}

What's the problem here?

[FatalBulletHit]

The "problem" is, that the history namespace is protected.
There was an enable_database_debug option available as part of the [database] section of the moonraker.config which disabled the protection, but that has since been removed.

However, using git checkout <branch> it is possible to revert to a version where the enable_database_debug option is still available:

0. CREATE A BACKUP!
   I used VirtualBox to create an Ubuntu VM in which I created a drive image of the SD card, but there are other ways to achieve this, too.

1. Follow the steps above to retrieve the current history in JSON format and merge it with your old history.
   Once that is done, remove the entire current history (I did so in the History tab of Mainsail, it is also possible to do this with JSON-RPC requests).
   You can go to {printers_local_ip}/server/database/item?namespace=history to verify your changes.

2. Enable the database debug option by adding the following to your moonraker.conf:

[database]
enable_database_debug: True

3. SSH into your RPi (I used PuTTY) and run the following to switch to Moonraker branch 0a2c190:

cd ~/moonraker
git checkout 0a2c190 -b database_debug
systemctl restart moonraker

4. Establish a connection to the Moonraker Client API (e.g. using wscat in PowerShell as described above).
5. Copy all the JSON-RPC requests that you prepared earlier and paste them to the console by right clicking.
   As the requests are newline separated, they should all be execute one after another in a few seconds (the longer your history, the more requests, the longer this will take).
6. Go to {printers_local_ip}/server/database/item?namespace=history again to verify your changes.
7. In PuTTY run the following to switch back to the latest Moonraker branch again:

git checkout master
systemctl restart moonraker

There are probably other ways to achieve this and maybe some more correct ones, too, but this worked fine for me and hasn't caused me any issues yet.

Ideally, if you do a new installation of e.g. MainsailOS, just copy the Moonraker database files ( .mdb ) located at ~/.moonraker_database from the old to the new installation.