Request for classic confinement highlighterpdf

store-requests
1

There seems to be a problem with java and printing in strict mode.
Printing is a key feature of my app.
Even though I have cups-control in my plugs it will not work in strict confinement.
Everything works in classic.
Following symlinks is a minor casualty of the strict environment.
Looking back through the files there seems to be an issue with java and cups-control for some time.
So I make a request for you to allow me classic confinement so I can publish my app.

Here is my scanlog

= AppArmor =
Time: May 9 18:17:48
Log: apparmor=“DENIED” operation=“connect” profile=“snap.highlighterpdf.highlighterpdf” name="/run/cups/cups.sock" pid=20475 comm=“AWT-EventQueue-” requested_mask=“wr” denied_mask=“wr” fsuid=1000 ouid=0
File: /run/cups/cups.sock (write)

2

The cups-control interface is not automatically connected when a snap is installed - you need to manually connect it first:
sudo snap connect highlighterpdf:cups-control

3

This connection must be by console? or you can use the store gui for permissions?

4

Yes you can also use the snap-store / ubuntu-software GUI for this (and even the Settings application in Ubuntu 20.04 etc) for managing snap permissions. If you feel printing is a critical function for this snap and that most users would expect printing to work automatically you can always request auto-connection of cups-control instead. In that case, you can reuse this request and just change the title and add a new comment to this effect.

5

sorry I am such a newb

But I use

sudo snap connect highlighterpdf:cups-control

already and it still does not work

6

Can you please post the contents of the snapcraft.yaml for this snap? I suspect that you have:

apps:
  highlighterpdf:
   plugs:
     - cups-control

But from the AppArmor denial listed in your first post the process which causes the denial is not highlighterpdf but AWT-EventQueue - so instead you should plug the cups-control interface at the top-level of the snapcraft.yaml - ie define a top-level plugs entry as:

plugs:
  - cups-control
apps:
  highlighterpdf:
    ...

This way the cups-control interface is available to all binaries / processes launched by the snap, not just the highlighterpdf process.

7

Hi here is my Yaml:

name: highlighterpdf
title: HighlighterPdf
version: 1.0.2
summary: Highiight the text in a Pdf.
description:
        HighlighterPdf  is a free and open source software application that you can use to 
        highlight text in your pdf document. You can select text in a colour of your choice        
        and then save it.
confinement: strict
grade: stable


base: core18
           
apps:
 highlighterpdf:
   extensions: [gnome-3-28]
   command: java -jar $SNAP/highlighterpdf.jar
   environment:
         JAVA_HOME: $SNAP/usr/lib/jvm/java-11-openjdk-amd64
         PATH: $JAVA_HOME/bin:$PATH
   plugs:
      - home
      - network
      - cups-control
      
      
   
parts:
  highlighterpdf:
       source: https://github.com/gerry136/highlighterpdf.git
       plugin: dump

       build-packages:
           - openjdk-11-jdk
           
       
       stage-packages:
           - unzip
           - openjdk-11-jdk
           - lpr

When I try to put in plugs as you suggested I get
"
Issues while validating snapcraft.yaml: The ‘plugs’ property does not match the required schema: ‘-cups-control’ is not of type ‘object’ "

8 
   plugs:
      - home
      - network
      - cups-control

your indendation for all the plugs is broken, it needs to be an even number of spaces (2 or 4) not 3 … i.e.

    plugs:
      - home
      - network
      - cups-control

your toplevel “highlighterpdf:” in the “apps:” section is also wrong (1 space) … you are giving the yaml parser a hard time here …

9

thanks for your answer Ogra
I have changed the Yaml as follows;

name: highlighterpdf
title: HighlighterPdf
version: 1.0.2
summary: Highiight the text in a Pdf.
description:
        HighlighterPdf  is a free and open source software application that you can use to 
        highlight text in your pdf document. You can select text in a colour of your choice        
        and then save it.
confinement: strict
grade: stable


base: core18

    plugs:
        - cups-control    
         
           
apps:
  highlighterpdf:
   extensions: [gnome-3-28]
   command: java -jar $SNAP/highlighterpdf.jar
   environment:
         JAVA_HOME: $SNAP/usr/lib/jvm/java-11-openjdk-amd64
         PATH: $JAVA_HOME/bin:$PATH

    plugs:
        - home
        - network
        - cups-control

      
   
parts:
  highlighterpdf:
       source: https://github.com/gerry136/highlighterpdf.git
       plugin: dump

       build-packages:
           - openjdk-11-jdk
           
       
       stage-packages:
           - unzip
           - openjdk-11-jdk
           - lpr
now I am getting the error message:
" Issues while validating snapcraft.yaml: mapping values are not allowed in this context on line 15, column 10"
10

now you only have one space here …

  highlighterpdf:
   extensions: [gnome-3-28]
   command: java -jar $SNAP/highlighterpdf.jar
   environment:

just try to generally stick to two spaces everywhere, that makes it easily readable too …

11

ok determined to get this right:

name: highlighterpdf
title: HighlighterPdf
version: 1.0.2
summary: Highiight the text in a Pdf.
description:
        HighlighterPdf  is a free and open source software application that you can use to 
        highlight text in your pdf document. You can select text in a colour of your choice        
        and then save it.
confinement: strict
grade: stable

plugs:
    - cups-control  

base: core18

      
         
           
apps:
  highlighterpdf:
    extensions: [gnome-3-28]
    command: java -jar $SNAP/highlighterpdf.jar
    environment:
        JAVA_HOME: $SNAP/usr/lib/jvm/java-11-openjdk-amd64
        PATH: $JAVA_HOME/bin:$PATH

    plugs:
        - home
        - network
        

      
   
parts:
  highlighterpdf:
       source: https://github.com/gerry136/highlighterpdf.git
       plugin: dump

       build-packages:
           - openjdk-11-jdk
           
       
       stage-packages:
           - unzip
           - openjdk-11-jdk
           - lpr

When I try to build it I am getting:

Issues while validating snapcraft.yaml: The ‘plugs’ property does not match the required schema: [‘cups-control’] is not of type ‘object’

12

and when I change the indentation I get
“Issues while validating snapcraft.yaml: mapping values are not allowed in this context on line 12, column 10”

13 
name: highlighterpdf
title: HighlighterPdf
version: 1.0.2
summary: Highiight the text in a Pdf.
description:
  HighlighterPdf  is a free and open source software application that you can use to 
  highlight text in your pdf document. You can select text in a colour of your choice        
  and then save it.
confinement: strict
grade: stable  
base: core18

apps:
  highlighterpdf:
    extensions: [gnome-3-28]
    command: java -jar $SNAP/highlighterpdf.jar
    environment:
      JAVA_HOME: $SNAP/usr/lib/jvm/java-11-openjdk-amd64
      PATH: $JAVA_HOME/bin:$PATH
    plugs:
      - home
      - network
      - cups-control

parts:
  highlighterpdf:
    source: https://github.com/gerry136/highlighterpdf.git
    plugin: dump
    build-packages:
      - openjdk-11-jdk
    stage-packages:
      - unzip
      - openjdk-11-jdk
      - lpr
14

ok I have put plugs: cups control where suggested:

grade: stable

base: core18

plugs: cups-control      
apps:

but I am getting
Issues while validating snapcraft.yaml: The ‘plugs’ property does not match the required schema: ‘cups-control’ is not of type ‘object’

15

please just copy-paste the file i pasted above and start working off that …

it builds and runs fine here …

also drop the whole build-package block it isnt needed and makes the build just pointlessly longer (downloading java on teh build host without using it)…

16

ok thanks for your help ogra.

now when I put plugs in the place advised by alexmurray I get:

Issues while validating snapcraft.yaml: The ‘plugs’ property does not match the required schema: [‘cups-control’] is not of type ‘object’

17

the file should work fine as is without modifying it …

18

it does but it suffers from the original problem that it can not print in strict mode. that is why alexmurray came up with the solution of putting cups-control above apps.

19

so before we spend another week on this, i spent my lunch break on fixing it for you (note that i’m working on a hidpi display and the app was unreadable, thus i had to add he launcher/wrapper to set proper scaling values) …

snap/snapcraft.yaml:

name: highlighterpdf
title: HighlighterPdf
version: 1.0.2
summary: Highiight the text in a Pdf.
description:
  HighlighterPdf  is a free and open source software application that you can use to 
  highlight text in your pdf document. You can select text in a colour of your choice        
  and then save it.
confinement: strict
grade: stable  
base: core18

plugs:
  gtk-2-engines:
    interface: content
    target: $SNAP/lib/gtk-2.0
    default-provider: gtk2-common-themes
  gtk-3-themes:
    default-provider: gtk-common-themes:gtk-3-themes
    interface: content
    target: $SNAP/data-dir/themes
  sound-themes:
    default-provider: gtk-common-themes:sound-themes
    interface: content
    target: $SNAP/data-dir/sounds
  gnome-3-28-1804:
    default-provider: gnome-3-28-1804:gnome-3-28-1804
    interface: content
    target: $SNAP/gnome-platform
  icon-themes:
    default-provider: gtk-common-themes:icon-themes
    interface: content
    target: $SNAP/data-dir/icons

layout:
  /usr/bin/lpr:
    bind-file: $SNAP/usr/bin/lpr

apps:
  highlighterpdf:
    extensions: [gnome-3-28]
    command: desktop-launch launcher
    environment:
      JAVA_HOME: $SNAP/usr/lib/jvm/java-11-openjdk-amd64
      PATH: $JAVA_HOME/bin:$PATH
    plugs:
      - avahi-control
      - home
      - network
      - network-bind
      - cups-control

parts:
  highlighterpdf:
    source: https://github.com/gerry136/highlighterpdf.git
    plugin: dump
    stage-packages:
      - cups-bsd # for /usr/bin/lpr
      - unzip
      - openjdk-11-jdk
      - x11-xserver-utils # for xrdb
  launcher:
    source: .
    plugin: dump
    organize:
      launcher: bin/launcher

launcher (put it in the toplevel dir of your source tree, dont forget to make it executable):

#! /bin/sh

# scale according to dpi
DPI="$(xrdb -query 2>/dev/null| grep dpi | sed 's/^.*\t//;s/\..*$//')"
if [ -n "$DPI" ]; then
  if [ "$DPI" -le 96 ]; then
          SCALE=""
  elif [ "$DPI" -le 120 ]; then
          SCALE="-Dsun.java2d.uiScale=1.25"
  elif [ "$DPI" -le 144 ]; then
          SCALE="-Dsun.java2d.uiScale=1.5"
  elif [ "$DPI" -le 192 ]; then
          SCALE="-Dsun.java2d.uiScale=2"
  elif [ "$DPI" -le 240 ]; then
          SCALE="-Dsun.java2d.uiScale=2.5"
  elif [ "$DPI" -le 288 ]; then
          SCALE="-Dsun.java2d.uiScale=3"
  elif [ "$DPI" -le 384 ]; then
          SCALE="-Dsun.java2d.uiScale=4"
  fi
fi

exec java $SCALE -jar $SNAP/highlighterpdf.jar

make sure to connect the avahi-control and cups-control interfaces after installing the snap … it prints fine for me on a networked priner in my house…

20

Thank you so much Ogra I do appreiciate all the help you have given me.