Need to improve the support for read-only installations

[wyldckat]

The current installer of blueCFD-Core 2016-1 requires the installation to be done with a permissive folder set-up. But when testing the installation as a read-only environment, it had a few problems:

1. The /tmp folder is broken (read-only) and needs to be mounted towards the current user's temp folder.

2. The ~/blueCFD and ~/AddOns folders were not mounted either, which means that the installer should already provide a working mount

3. The user folder ofuser-* should be automatically re-mounted to the current user's document folder or to the conventional folder where blueCFD-Core is usually installed as a normal user.

This is all related to issue #33, but it's not guaranteed that we'll have this operational for blueCFD-Core 2016-2.

[wyldckat]

First problem

The file msys64/home/ofuser/.blueCFDOrigin is created by the batch file msys64/blueCFD-Core_mingw64_shell.bat. This is a good thing when using a mobile installation (e.g. USB), but it's a pain for read-only installations.

One solution is to call a specialized edition of this batch file near the end of the installation, to ensure the file is created the first time around.

Done

Created a new batch file establishBlueCFDPath.bat for populating the msys64/home/ofuser/.blueCFDOrigin only when needed. It's now also called from the installer, to ensure it's set-up at installation time

[wyldckat]

Second problem

MSys2 will copy the following files:

'C:\\Windows\\system32\\drivers\\etc\\hosts' -> '/etc/hosts'
'C:\\Windows\\system32\\drivers\\etc\\protocol' -> '/etc/protocols'
'C:\\Windows\\system32\\drivers\\etc\\services' -> '/etc/services'
'C:\\Windows\\system32\\drivers\\etc\\networks' -> '/etc/networks'

So maybe the easiest is to have our installer do the same.

Done

The files are now copied when the task for making the installation writable is unchecked (e.g. when installing in C:\Program Files).

[wyldckat]

Third Problem

This can't be solved by the installer on its own. This has to be done by the msys*/etc/profile script or similar, so that the home is mounted to the current user instead.

[wyldckat]

Fourth Problem

MSys2 needs a few more folders with write permissions:

bash.exe: warning: could not find /tmp, please create!
mkdir: cannot create directory '/dev/shm': Read-only file system

Creating /dev/shm directory failed.
POSIX semaphores and POSIX shared memory will not work

mkdir: cannot create directory '/dev/mqueue': Read-only file system

Creating /dev/mqueue directory failed.
POSIX message queues will not work

ln: failed to create symbolic link '/dev/stdin': Read-only file system
ln: failed to create symbolic link '/dev/stdout': Read-only file system
ln: failed to create symbolic link '/dev/stderr': Read-only file system
ln: failed to create symbolic link '/dev/fd': Read-only file system
ln: cannot remove '/etc/mtab': Permission denied
Setting environment for OpenFOAM 4.x mingw-w64 Double Precision (of4-64), using MSMPI71 - please wait...
bash.exe: warning: could not find /tmp, please create!
bash.exe: warning: could not find /tmp, please create!
bash.exe: warning: could not find /tmp, please create!
bash.exe: warning: could not find /tmp, please create!
bash.exe: warning: could not find /tmp, please create!
bash.exe: warning: could not find /tmp, please create!
bash.exe: warning: could not find /tmp, please create!
bash.exe: warning: could not find /tmp, please create!
bash.exe: warning: could not find /tmp, please create!

[wyldckat]

Solutions for the 3rd third and fourth problems

1. The files blueCFD-Core_mingw64_shell.bat and etc/profile did need to be modified, so that the /tmp and /dev paths are mounted on the current user's own temporary path.

2. The /etc/mtab file had to be installed with the system attribute set, so that MSys2 will interpret it as a symbolic link.

3. The /home/ofuser folder has to be copied to a folder on the Windows-assigned user's own personal folder and then mounted accordingly.

4. The file 05-home-dir.post also needs a hack for re-mounting the ofuser folder in an actual user folder.

[wyldckat]

Implemented solution

1. msys64/blueCFD-Core_mingw64_shell.bat - creates the folders msys_dev and msys_tmp at the default %TEMP% path.

2. msys64/etc/post-install/05-home-dir.post - if the conventional $HOME folder is read-only, then the default installation folder /home/ofuser is copied to the user's own $USERPROFILE folder, specifically to $USERPROFILE/blueCFD-Core-2016/ofuser, where the blueCFD-Core-2016 name is retrieved from $HOME/.blueCFDOrigin. The path $USERPROFILE/blueCFD-Core-2016 is then used to request MSys2 to mount /home at this folder.

3. msys64/etc/profile - If /tmp is read-only, then the paths msys_dev and msys_tmp (created by blueCFD-Core_mingw64_shell.bat) are then used to mount to /dev and /tmp respectively.

4. msys64/home/ofuser/sourceOF - The shell environment variable WM_PROJECT_USER_DIR is defined as $HOME/$USER-$1 if the home folder is mounted. This is so that we can ensure the designated user-folder for OpenFOAM cases is read-write.

5. Installer notes:

6. The /etc/mtab file had to be installed with the system attribute set, so that MSys2 will interpret it as a symbolic link.

7. The folders msys64\tmp and msys64\dev are created as empty.

8. The Second problem is handled by the installer, when the folder it in read-only mode.

With these implementations, as of blueCFD-Core 2016-2, it is possible to install it as read-only and have it automatically operate on the user's own Windows-assigned folders.

[wyldckat]

This is also documented in the FAQ entry: Read-only installation of blueCFD-Core