[Linux] Make INSTALL_ROOT_SYSTEMWIDE configurable

[ONL]

The install script defines several environment variables, some of which are configurable by the user, like UNATTENDED_INSTALLATION

However, the install script in oolite/installers/posix/setup.body defines INSTALL_ROOT_SYSTEMWIDE="/opt"

It would be nice, if this was customizable, like

if [ ! ${INSTALL_ROOT_SYSTEMWIDE} ]
then
INSTALL_ROOT_SYSTEMWIDE="/opt"
fi

to allow overriding the directory for a system wide installation. This would facilitate packaging the app as a flatpak, because it could directly be installed to /app

[KonstantinosSykas]

Hello ONL.
I am currently working on adding a command-line parameter.

Example
$ oolite-1.86.linux-x86.run --systemwide-path /app

Would this do the trick for flatpak?

[KonstantinosSykas]

Committed e1ffdb6 on that matter.
Checkout tonight's nightly build Linux binary.

Usage Example for 64bit distros
# ./oolite-trunk-1.87.0.e1ffdb6.linux-x86_64.run -- --systemwide-directory DIRECTORY

Note 1
'#' indicates root shell

Note 2
The '-- ' (dash dash space) before the actual argument, is NOT a typo. It is the correct syntax to differentiate between package arguments and setup arguments.

Note 3
If a preexisting /opt installation exists, it will remain as "orphan", and must be manually deleted, for the time being. Next version of script will try to remove a probable /opt installation too.

Edit01: add note on '--' strange syntax.
Edit02: updated usage example.

[ONL]

The automated build succeeds, going to test the generated flatpak on thursday but I don't expect any issues.

Thank you @KonstantinosSykas for the quick addition, this should be a major step to produce a flatpak, that would be accepted by flathub (it you guys are interested in having Oolite listed there).

My fallback was to use rsync (just like the updater) to populate /app, but that required building rsync from source inside flatpak-builder.

Update: Jul-05-2018
Seems to work fine. Since I clean up the uninstaller anyway, I am happy with the current state

[KonstantinosSykas]

The flathub opportunity is interesting indeed. However, let's lay low for the time being. I will take it to the boards on the relevant thread you have opened (http://aegidian.org/bb/viewtopic.php?f=9&t=19746).

Concerning the installer enhancement, it was a quick fix, as clean as possible, but there are still some things to consider. I am still working on the following issue that the current fix presents.

How to replicate the issue:

1. Install Oolite systemwide in one directory; e.g. /opt
2. Without uninstalling the first installation, proceed in installing Oolite systemwide in another directory; e.g. /usr/local/games

at this point you have an orphan installation in /opt and all execution shortcuts (i.e. desktop, command line) are linked to the new installation. Let's continue the scenario.

3. Execute /opt/Oolite/uninstall. This will uninstall the /opt/Oolite installation but... 😨
4. Your /usr/local/games is now orphan and all execution shortcuts (i.e. desktop, command line) are removed by the uninstall operation performed in Step 3. 🤦‍♂️

I am working on handling this by making uninstall aware of an orphan installation.

[ONL]

Question is, whether you want to allow arbitrary locations for installation. The "old" method of installing to /opt works fine, except for special use cases like flatpak
Maybe it should be --flatpak-install defaulting to /app instead of --systemwide-directory DIRNAME

Another option would be to place an uninstall-wrapper in /usr/local/bin where the other oolite-wrappers are stored. Then try to invoke the uninstall-wrapper if --systemwide-directory DIRNAME is provided during next install, thus cleaning up old installations.

[KonstantinosSykas]

Many thanks for the feedback @ONL ! 😎

Is the /app directory created by flatpak?
The installer assumes an existing system directory is given.
If the directory is not there then the installation is aborted.

[ONL]

Yes, /app already exists inside flatpak environments.

[KonstantinosSykas]

Orphan installations handled with commit 6174e69.
If no other objections exist, this case will be closed.

[KonstantinosSykas]

This is just to summarize the solution given, before closing the case.

The command line parameter [-- --systemwide-directory DIRECTORY] is now supported by the installer. This allows systemwide installations to be deployed to a configurable directory. The directory value used for DIRECTORY must exist or else the installation will terminate. The [-- ] (dash dash space) before the actual parameter is mandatory! The default systemwide installation directory is /opt.

Usage Example
# ./oolite-trunk-1.87.0.e1ffdb6.linux-x86_64.run -- --systemwide-directory /usr/local/games

Syntax help Example
To get help on the command line parameters syntax, use the --help parameter as shown in the example.
# ./oolite-trunk-1.87.0.e1ffdb6.linux-x86_64.run --help

Important Note
The installer will try to uninstall a previous systemwide installation deployed to a different directory. However, only some heuristics are applied on that purpose and not an exhaustive and explicit search.
It is strongly recommended to uninstall previous installations before proceeding to a new one.

Edited 12-Jul-2018 15:30 (UTC): Added syntax help example.