editing policies.json in linux

rodrick · 09-24-2019, 07:58 AM

Hi
I'm running Debian 10 with firefox snap and now need to edit the policies.json file in order to change the Disableappupdate to false. ls -l shows that I have rw as root. However when I edit this with vim and then attempt to save the change it returns an error 212: Can't open file for writing.
Can someone please tell me what I'm missing here?

Thanx

TB0ne · 09-24-2019, 08:20 AM

Quote:

Originally Posted by rodrick

Hi
I'm running Debian 10 with firefox snap and now need to edit the policies.json file in order to change the Disableappupdate to false. ls -l shows that I have rw as root. However when I edit this with vim and then attempt to save the change it returns an error 212: Can't open file for writing.
Can someone please tell me what I'm missing here?

Thanx

Yes; you're not editing the file with root permissions. Either run "sudo vim <filename>", or run "su", and enter your root password, then edit the file.

Firerat · 09-24-2019, 08:32 AM

Quote:

Originally Posted by rodrick

Hi

Quote:

Originally Posted by rodrick

I'm running Debian 10 with firefox snap

I assume you mean you have installed Firefox on Debian 10 via snap.

Quote:

Originally Posted by rodrick

and now need to edit the policies.json file in order to change the Disableappupdate to false.

sounds technical
are you following some guide?

Quote:

Originally Posted by rodrick

ls -l shows that I have rw as root.

ls -l lists the files/dirs in long format
without a dir/or file the current working dir.
I would like to know what dir you are in

Quote:

Originally Posted by rodrick

However when I edit this with vim and then attempt to save the change it returns an error 212: Can't open file for writing.

what do you get from

Code:

lsattr ./policies.json

Quote:

Originally Posted by rodrick

Can someone please tell me what I'm missing here?
Thanx

tbh, I would imagine there is some other way of managing the configuration options for that snappackage

I suspect the policies.json file is set immutable

Code:

A file with the 'i' attribute cannot be modified: it cannot be deleted or renamed, no link can be  created  to  this
       file, most of the file's metadata can not be modified, and the file can not be opened in write mode.  Only the supe‐
       ruser or a process possessing the CAP_LINUX_IMMUTABLE capability can set or clear this attribute.

that is a complete guess

rodrick · 09-24-2019, 09:18 AM

Thanks for your prompt reply.
To answer your questions:
1) Yes I installed firefox snap on Debian.
2) No, I'm not following any guide
3) The directory I was in was home/username#. the command was: vim /snap/firefox/266/distribution/policies.json.
4) Executing lsattr ./policies.json elicits: No such file or directory while trying to stat ./policies.json

If there is some other way of managing the configuration options for that snappackage I haven't found it. I think the key to this may lie in the fact that .json is a standard java interchange format. I know this can be edited with jq as I have seen numerous examples of this but that's way over my head at this point. I can't understand why firefox snap would intentionally block updates. Of course I could simply delete the firefox snap and download a conventional firefox tar.gz. But then I would have learned nothing.

Thanks again

Firerat · 09-24-2019, 09:41 AM

Quote:

Originally Posted by rodrick

Thanks for your prompt reply.
To answer your questions:
1) Yes I installed firefox snap on Debian.
2) No, I'm not following any guide
3) The directory I was in was home/username#. the command was: vim /snap/firefox/266/distribution/policies.json.
4) Executing lsattr ./policies.json elicits: No such file or directory while trying to stat ./policies.json

well, I based everything on the assumption you were in the same dir as the file you wanted to edit, since you only checked the permission of the dir you were in.

that looks like it may be a loopback device ( a file mounted like a block device )
It is probably readonly

confirm that with

Code:

mount | grep firefox

Quote:

Originally Posted by rodrick

If there is some other way of managing the configuration options for that snappackage I haven't found it. I think the key to this may lie in the fact that .json is a standard java interchange format. I know this can be edited with jq as I have seen numerous examples of this but that's way over my head at this point. I can't understand why firefox snap would intentionally block updates. Of course I could simply delete the firefox snap and download a conventional firefox tar.gz. But then I would have learned nothing.

Thanks again

I have never used snap
but I would start here
https://snapcraft.io/install/snapd/debian

jq doesn't edit files, it can query and output json which can be put in a new file.

does Debian not have Firefox installed by default?

rodrick · 09-24-2019, 10:32 AM

mount | grep firefox /var/lib/snapd/snaps/firefox_266.snap on /snap/firefox/266 type sqashfs (ro,nodev,relatime,x-gdu.hide)
What does this tell you?

Debian does ship with firefox but it's the ESR version. ESR is meant for deployments, doesn't receive all security patches, and will be a year behind the current technology before you get a major update.

Thanks for the link.I think I'll hit them with my question about the update block.

Firerat · 09-24-2019, 10:36 AM

Quote:

Originally Posted by rodrick

mount | grep firefox /var/lib/snapd/snaps/firefox_266.snap on /snap/firefox/266 type sqashfs (ro,nodev,relatime,x-gdu.hide)
What does this tell you?

Debian does ship with firefox but it's the ESR version. ESR is meant for deployments, doesn't receive all security patches, and will be a year behind the current technology before you get a major update.

Thanks for the link.I think I'll hit them with my question about the update block.

what did rw tell you?

Edit, that was kind of evil

RO = Read Only

rodrick · 09-24-2019, 12:34 PM

The ro part I got. It was the rest of it that I was hoping you'd elucidate. Not to be obtuse but does this mean that there is absolutely no way to unlock this file?

Firerat · 09-24-2019, 01:31 PM

you shoudl have said

so , the ro is read only.. what are the others?

one of the great things about Linux is the documentation that comes with it.

Code:

man mount

snippets

Quote:

nodev Do not interpret character or block special devices on the file system.

relatime
Update inode access times relative to modify or change time. Access time is only updated if the previous access time was ear‐lier than the current modify or change time. (Similar to noatime, but it doesn't break mutt or other applications that need to know if a file has been read since the last time it was modified.)

X-*
All options prefixed with "X-" are interpreted as comments or as userspace application-specific options. These options are not
stored in the user space (e.g. mtab file), nor sent to the mount.type helpers nor to the mount(2) system call. The suggested
format is X-appname.option.

x-*
The same as X-* options, but stored permanently in the user space. It means the options are also available for umount or another
operations. Note that maintain mount options in user space is tricky, because it's necessary use libmount based tools and there
is no guarantee that the options will be always available (for example after a move mount operation or in unshared namespace).

Note that before util-linux v2.30 the x-* options have not been maintained by libmount and stored in user space (functionality
was the same as have X-* now), but due to growing number of use-cases (in initrd, systemd etc.) the functionality have been ex‐
tended to keep existing fstab configurations usable without a change.

rodrick · 09-24-2019, 03:06 PM

Thank you for that.