All the chartplotters need to be setup to use same chart directory to re-use charts

[mgrouch]

All the chartplotters need to be setup to use same chart directory to re-use charts

[FredericGuilbault]

yes, in the folder /srv/charts

The folder /home /user/charts bind to /srv/charts OpenCpn is pre-configured to use this folder,
freeboard-sk rely on the sk charts server which is instructed to store/query mbtitles charts from /srv/charts

There is a known problem with having xygrib and opencpn both packaging the same costal line seperately, I contacted both regarding the issue and the answer where :

xygrib: we lack of resource to make it append.
opencpn: we don't see that as a problem, windows users don't use package managers. Their concern was mainly about having the coastline blob in their git repo or not...

is there some other place where charts are stored ?

[mgrouch]

They need to have single place for original downloaded charts which we have I think. OpenCpn one.
All signalK based ones will use it as primary source to generate mbtiles from it.
Then there is AvNav and qtVlm. they also should use it as primary local source.
AvNav also generates mbtiles from it.
qtVlm I need to take a closer look at what it does

[FredericGuilbault]

They need to have single place for original downloaded charts which we have I think. OpenCpn one.

Each app have their location... that's kinda the core of the problem.

All signalK based ones will use it as primary source to generate mbtiles from it.

no, the signalk user should not have read/write access to the user home.

When AvNav will be implemented, as it's a web server with write capability. It will have its own user and should have the most limited access to other users privileges.

No app should be the god app that hold the canonical location where all others app should bind to. specially if this live app only in the userspace.

In lysmarine. The core point of the decision of using /srv/charts was.

• A location that is app neutral (so app depend on another app location/existence)
• A location that is user neutral (cuz many users will need to access them: User, signalk, www-data, root )
• A location compliant to the FHS
• A location that is historically used to store large datasets of dynamic content.
• A location where human users could manage the dataset without root access.

Decision made considering that most apps have a config file where we can change the location, or we can link folders in the worst cases. It's possible to create a single location without having to sit every upstream at a table until they decide for a standard (cuz this likely won't happen)

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For the record /var/share/charts was my first guess. But after discussion on IRC with hardcore linux devs /srv/charts was found more appropriate.