How to persist user config data to SNAP_USER_DATA?

[ogra]

@m-yahya

1. create a config file inside SNAP_USER_DATA. From the stack overflow, I can do this by:

$ mkdir -p snap/hooks
$ echo "touch \$SNAP_USER_DATA/config.toml" >> snap/hooks/install
$ chmod a+x snap/hooks/install

the install hook runs as root so this would just install the config into SNAP_USER_DATA in roots homedir (/root) …

if you really need to pre-create the file (does the app not work if it is not existing ?) i’d suggest using a wrapper script like:

#! /bin/sh

[ -e "$SNAP_USER_DATA/config.toml" ] || touch $SNAP_USER_DATA/config.toml

exec "$@"

ship it in bin/ inside your snap and change your command: entry:

from:

apps:
  myapp:
    command: myapp

to:

apps:
  myapp:
    command: mylauncher.sh myapp

(or you could use a command chain)

@m-yahya

2. next either I directly want to save the user input into $SNAP_USER_DATA/config.toml or copy from config.toml to $SNAP_USER_DATA/config.toml .
3. finally, I want to use config from $SNAP_USER_DATA/config.toml inside my app.

well, then just make your app read and use the environment variable when handling the config file …