If possible how can one embed PostgreSQL? - database

If it's possible, I'm interested in being able to embed a PostgreSQL database, similar to sqllite. I've read that it's not possible. I'm no database expert though, so I want to hear from you.
Essentially I want PostgreSQL without all the configuration and installation. If it's possible, tell me how.

Run postgresql in a background process.
Start a separate thread in your application that would start a postgresql server in local mode either by binding it to localhost with some random free port or by using sockets (does windows support sockets?). That should be fairly easy, something like:
system("C:\Program Files\MyApplication\pgsql\postgres.exe -D C:\Documents and Settings\User\Local Settings\MyApplication\database -h 127.0.0.1 -p 12345");
and then just connect to 127.0.0.1:12345.
When your application quits, you can always send a SIGTERM to your thread and then wait a few seconds for postgresql to quit (ie join the thread).
PS: You can also use pg_ctl to control your "embedded" database, even without threads, just do a "pg_ctl start" (with appropriate options) when starting the application and "pg_ctl stop" when quitting it.

You cannot embed it, nor should you try.
For embedding you should use sqlite as you mentioned or firebird rdbms.

Unless you do a major rewrite of code, it is not possible to run Postgres "embedded". Either run it as a separate process or use something else. SQLite is an excellent choice. But there are others. MySQL has an embedded version. See it at http://mysql.com/oem/. Also several java choices, and Mac has Core Data you can write too. Hell, you can even use FoxPro. What OS you on and what services you need from the database?

You can't embed it as a in process type thing like sqlite etc, but you can easily embed it into your application setup using Inno setup at http://www.innosetup.org. Search their mailing list archive and you will find someone did most of the work for you and all you have to to is grab the zipped distro and you can easily have postgresql installed when the user installs your app. You can then use the pg_hba.conf file to restrict the server to local host only. Not a true embedded DB, but it would work.

PostgreSQL is intended to run as a stand-alone server; it's probably possible to embed it if you hack at it hard and long enough, but it would be much easier to just run it as intended in a separate process.

HSQLDB (http://hsqldb.org/) is another db which is easily embedded. Requires Java, but is an excellent and often-used choice for Java applications.

Anyone tried on Mac OS X:
http://pagesperso-orange.fr/bruno.gaufier/xhtml/prod_postgresql.xhtml
http://www.macosxguru.net/article.php?story=20041119135924825
(Of course sqlite would be my embedded db of choice as well)

Well, I know this is a very very very old post, but if anyone has nowadays this question, I would refer to:
You can use containers running Postgres. Here's a post that could be helpful, doing something along this line using R:
https://rsangole.netlify.app/post/2021/08/07/docker-based-rstudio-postgres/?utm_source=pocket_mylist
Take a look at duckdb https://duckdb.org/docs/installation/ It is relatively new and still needs to mature. But it works pretty much like an embedded database ("In-process, serverless"), with bindings for several languages (Python, R, Java, ...)

Related

c-icap with Windows Defender

I was tasked to set up an open-source icap-server to scan files that are uploaded in one of our web applications.
The files base64-encoded withing the upload method and this seems to lead to the fortigate not being able to scan it properly.
Now I managed to set up an icap-server using "c-icap" and tested it with "clamav". So far it seems to work, at least EICAR files are detected.
Now the problem is, that my boss is basically a "Windows-only" person who says that any open-source AV can´t be trusted enough.
He wants me to try to have the requests/uploads sent to the c-icap server, but scanned with Windows Defender. ß Is there any - useful - way to accomplish this? Also, since I am super new to ICAP - are there any restrictions regarding which icap-server can be used?Like, is there any way to force requests to be handled with a metadefender-icap only, and not any other icap server?
Sorry if these questions are a bit unspecific and basic, but just started with ICAP yesterday!
Thank you!
Check out this link: https://techcommunity.microsoft.com/t5/windows-it-pro-blog/metadefender-icap-with-windows-defender-antivirus-world-class/ba-p/800234 to see what Microsoft offers regarding Defender+ICAP.
I have used commercial ICAP solutions in the past (like Bluecoat) that allow plugging in multiple commercial virus engines (Kaspersky, Sophos, ...).
These are appliances, and you don't need to tell your boss their internals are probably some sort of Linux ;-)
You can probably also set up a commercial antivirus solution on your Linux system and use that.
Looking at this link: https://learn.microsoft.com/en-us/windows/security/threat-protection/microsoft-defender-atp/microsoft-defender-atp-linux it may even be possible to run Microsoft's Defender on Linux. I haven't tried it myself though.
Unlike your boss, Microsoft realizes software shouldn't be made to just run on Windows anymore (even MS-SQL Server now runs on Linux).

Is it possible to use a GUI based text editor (e.g. Eclipse) from the terminal?

I'd like to use terminal for all of my normal git and compiling and running processes (my school has a server that is linked to my repo on bitbucket), but I really don't like terminal-based text editing software such as Emacs and Vim. Is it possible to open and edit files from the terminal using a GUI based text editor? The reason I'm asking is because the terminal is the only way I can access the server files. Thanks in advance!
Aw, but vim is the best! :) Well, you can use nano, which is friendlier. Or, if you insist: if you are using SSH to connect to the server (and the server has an X server running !) then you can look into the ssh -X option to view X windows on your remote machine.
Oh and you could look into scp command as well (behaves almost just like regular cp, but the destination is on another host). That way you could edit on your machine, then copy it via SSH (although you'd want to be careful when copying files directly to the server filesystem)
Edit: Also, if you really don't like using the terminal (why though? (-: ), some file managers allow you to get the same functionality of the previous commands purely via GUI (for example).
You've left out some important information that someone would need to know to answer your questions. The other posters have made some assumptions.
You've mentioned this "terminal", but it's not clear exactly what that is, or how you're getting to it. What kind of computer do you have in front of you? What shell is running in that terminal? Is the shell running on your local computer, or have you remotely connected to a server and running that shell on the remote computer?
Based on what you said, I have a feeling you're making a remote connection to a server, perhaps using ssh. You likely have either a Windows or Mac PC in front of you. In those circumstances, running a GUI editor like Eclipse is possible, but likely not practical. You would have to have Eclipse installed on that remote computer, and you would be displaying the Eclipse window on your local computer using the X11 protocol. That takes a lot of bandwidth.
If my assumptions are correct, my recommendations depend on how long you expect you're going to want to stay familiar with this environment. If you intend to do this sort of work forever, then you should learn vi and Emacs to the best of your ability. As someone who's been using Emacs likely longer than you've been alive, I'd recommend you learn it, but vi is also a critical skill.
UNIXY systems provide open or gopen, depending on your OS, that should get the job done. From the man page:
By default, gopen will open filename with the application currently assigned to the file's extension. But by specifing the -a flag on the command line you can tell gopen to open the file with another application.
This means that you can use it to open files in your preferred editor
with a line like
gopen -a Eclipse file

Real remote editing without X-Forwarding, using Vim or the like

I'm currently working an a rather large web project which is written using C servlets ( utilizing GWAN Web server ). In the past I've used a couple of IDEs for my LAMP/PHP jobs, like Eclipse.
My problems with Eclipse are that you can either mirror the project locally, which isn't possible in this case as I'm working on a Mac (server does not run on OSX), or use the "remote" view, which would re-upload files when you save them.
In the later case, the file is only partly written while uploading, which makes this a no-go for a running web server, or the file could become corrupted if the connection was lost during uploading. Also, for changing some character, uploading the whole file seems rather inefficient to me.
So I was thinking:
Wouldn't it be possible to have the IDE open Vim per SSH and mirror my changes there, and then just :w (save) ? Or use some kind of diff-files for changes?
The first one would be preffered, as it has the added advantage of Vim .swp files, which makes it possible that others know when someone is already editing the file.
My current solution is using ssh+vim, but then I lose all the cool features I have with Eclipse and other more advanced IDEs.
Also, regarding X-Forwarding: The reason I don't like it is speed. It feels way slower than just editing locally, and takes up unneeded bandwidth, when all I want to do is basically "text editing".
P.S.: I couldn't find any more appropriate tags for the question, especially no "remote" tag, but if you know any, feel free to add them. Also, if there is another similar question, feel free to point it out - I couldn't find any.
Thank you very much.
If you're concerned about having to transmit the entire file for minor changes, the only solution that comes to my mind is running (either continuously, or on demand) an rsync job that mirrors the remote site to your local system (and back). The rsync protocol just transmits the delta information. According to Are rsync operations atomic at file level?, the change is atomic.
Another possibility: run everything in a virtual machine on your Mac. The server and the IDE/text editor are both on the same virtual machine so you don't have to fear network issues.
Because the source code on the virtual machine is under some kind of VCS the classic code → test → commit process is trivial (at least theoretically).

Database replication with Slony-I alternative Linux setup to Shell Scripts

As title suggests,
Current tutorials i have found thus far use embedded SLON commands in Shell Script files to setup the required configuration for Slony-I master to slave replication.
For example: Slony-I Setup Tutorial
I was wondering if it was possible to embedd the SLON setup commands and have them called within another language Eg C/C++/Python working within a linux environment?
SLONIK scripts generally work by writing through STDOUT to the slonik binary. Any language should have the ability to replicate this style, but there's little difference than using the shell script method and in my experience it tends to occlude what is being done. You are still, after all, writing to the STDOUT and sending that information to the slonik binary.
I have in the past written perl modules to assist with this but they felt very kludgey and I've only employed them when needing to dynamically modify replication setups. I find it is rare that something like this is required and for the vast majority of slony work a shell script is much simpler to manage.
To sum up: Yes you can, but it is probably only making things more complex.
An example of how you could do it in python would be:
p = subprocess.Popen('/usr/bin/slonik',stdout=subprocess.PIPE,stdin=subprocess.PIPE)
p.stdin.write('<slon commands here>')
p.stdin.close()

Two way sync with rsync

I have a folder a/ and a remote folder A/.
I now run something like this on a Makefile:
get-music:
rsync -avzru server:/media/10001/music/ /media/Incoming/music/
put-music:
rsync -avzru /media/Incoming/music/ server:/media/10001/music/
sync-music: get-music put-music
when I make sync-music, it first gets all the diffs from server to local and then the opposite, sending all the diffs from local to server.
This works very well only if there are just updates or new files on the future. If there are deletions, it doesn't do anything.
In rsync there is --delete and --delete-after options to help accomplish what I want but thing is, it doesn't work on a 2-way-sync.
If I want to delete server files on a syn, when local files have been deleted, it works, but if, for some reason (explained after) I have some files that aren't in the server but exist locally and they were deleted, I want locally to remove them and not server copied (as it happens).
Thing is I have 3 machines in context:
desktop
notebook
home-server
So, sometimes, server will have files that were deleted with a notebook sync, for example and then, when I run a sync with my desktop (where the deleted server files still exist on) I want these files to be deleted and not to be copied again to the server.
I guess this is only possible with a database and track of operations :P
Any simpler solutions?
Thank you.
Try Unison: http://www.cis.upenn.edu/~bcpierce/unison/
Syntax:
unison dirA/ dirB/
Unison asks what to do when files are different, but you can automate the process by using the following which accepts default (nonconflicting) options:
unison -auto dirA/ dirB/
unison -batch dirA/ dirB/ asks no questions at all, and writes to output how many files were ignored (because they conflicted).
Note: I am no longer using Unison (I use NextCloud, which doesn't address the original use case). However, note that rsync is not designed for bidirectional sync, while unison is. unison may have its bugs (as any other piece of software) and its wrinkles. I am surprised it seems to be actively maintained now (last time I looked I think I thought it looked dead), but I'm not sure what's the state nowadays. I haven't had the need to have a two-way file synchronizer, so there may be better options, though.
Since the original question also involves a desktop and laptop and example involving music files (hence he's probably using a GUI), I'd also mention one of the best bi-directional, multi-platform, free and open source programs to date: FreeFileSync.
It's GUI based, very fast and intuitive, comes with filtering and many other options, including the ability to remote connect, to view and interactively manage "collisions" (in example, files with similar timestamps) and to switch between bidirectional transfer, mirroring and so on.
FreeFileSync can easily sync two computers on the same network and also sync two computers on different and remote networks.
On same network: have FreeFileSync use the local file system on one side and a shared network drive / path on the other. On Windows systems you enable file / disk sharing on one computer and access that share from the other. I use FreeFileSync this way to keep my main development PC source code synced with my 2 laptops.
I have also synced one of these laptops with a Linux server with Samba installed and sharing one of its directories.
Across networks: create a VPN and do the same as above. FreeFileSync will see the remote disk as it was on the local network. Or buy one router that allows you to connect a USB disk to it and share over the internet. I have installed a VPN on a remote Linux server and used it through the OpenVPN Windows client.
You could also try bitpocket: https://github.com/sickill/bitpocket
Try this,
get-music:
rsync -avzru --delete-excluded server:/media/10001/music/ /media/Incoming/music/
put-music:
rsync -avzru --delete-excluded /media/Incoming/music/ server:/media/10001/music/
sync-music: get-music put-music
I just test this and it worked for me. I'm doing a 2-way sync between Windows7 (using cygwin with the rsync package installed) and FreeNAS fileserver (FreeNAS runs on FreeBSD with rsync package pre-installed).
You might use Osync: http://www.netpower.fr/osync , which is rsync based with intelligent deletion propagation. it has also multiple options like resuming a halted execution, soft deletion, and time control.
You could try csync, it is the sync engine under the hood of owncloud.
I'm surprised no one has mentioned Syncthing yet. I have been using it for years to synchronize my phone, my tablet and my two laptops. One time I also used it to send 10 GB of photos to my family ~600 km away, straight from my machine to their machine, and it was incredibly fast (despite the data getting routed through Syncthing's discovery server to work around NAT issues). I also tried OwnCloud/NextCloud at some point but Syncthing has been much more reliable and, also, much faster.
I'm now using SparkleShare https://www.sparkleshare.org/
works on mac, linux and windows.
I'm not sure whether it works with two syncing but for the --delete to work you also need to add the --recursive parameter as well.
Rclone is what you are looking for. Rclone ("rsync for cloud storage") is a command line program to sync files and directories to and from different cloud storage providers including local filesystems. Rclone was previously known as Swiftsync and has been available since 2013.

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