Not with Git

Git is not designed to pull specific files or directories only. It's a directed acyclic graph with binary blobs as objects and sometimes multiple objects get compacted into a single larger object.

Due to Git design, your specific request is not possible.

Alternatives

post-receive hook

If your website only contains simple static files then it's okay to push to a git repository over SSH. In reality, it's unlikely your repository will be large as long as you don't have non-text files.

Take for example the following setup.

• /var/lib/www - apache web dir which is the cloned copy of www.git
• /var/lib/www.git - a bare git repository.
• /var/lib/www.git/hooks/post-recieve - A server side git hook. It can be a shell script that pulls the www repository when this repository is updated.

Sample post-recieve hook script:

#!/bin/bash
cd /home/sam/sandbox/git-hooks/www
unset GIT_DIR
git fetch origin master
git reset --hard origin/master

Zip up build in a tar.gz

At the end of your build you can zip up your files in a tar.gz. This file should be hosted somewhere (perhaps GitHub releases if you're using GitHub). Some enterprises use on premise artifact hosting like Nexus or Artifactory.

The idea being: you have a tested artifact that has a specific sha256sum. The artifact you test is the exact same artifact which eventually goes to production.

Diving into more detail such as continuous integration, continuous delivery, and the software development life cycle might be out of scope for your question.

No best practice.

Git is for source control, not for deployment. There is no best practice for using git this way because git is not a deployment tool. You also don't need git history on your server. In fact, you don't need git at all unless you insist on using it for deployment. You are welcome to use it this way but it's not ideal because of exactly the kind of problem you're asking about.

What is the best practice?

There are a number of tools you could use to handle your deployments. Most of the tools generally let you set up a series of steps that let you deploy the code you want into the environment you want. You could go with simple tools such as Phing or Deployer in the PHP world, or something more sophisticated like Puppet or Chef if you have more complex needs. You could just write your own bash scripts if what you need is really very simple. I recommend Phing or Deployer given the info you've provided. https://deployer.org/ https://www.phing.info/

You'll just configure whichever tool you want to ssh into your target box and copy over only the files you want into the directory you want on the server, in whatever way you would like to do that. Usually, you have the script copy files into a temp dir, tarball them up, ssh them over and untar them. After that, you'll usually do some additional work on the server to move files around, change symlinks, whatever else you might need to do.

What about compiled SASS, ES6 js files, or modern static stuff?

All you need to do is add steps to the handle the static files and where you want them to go. Include the generated static files in your tarball when you push stuff up, and put them in the right directories in the server once you untar it.

When you configured your SASS compiler, and whatever other pre-compiled static code you may have - you configured it to create a destination file. That is, the file(s) of actual CSS and JS that they generate. That's all you need to bring along - and if you have the destination directory set to be inside your wordpress theme, you may not even have to pay all that much special attention to it's handling. You may need to move them somewhere else once they are on the server but that all depends on the specific setup in your server, which I think is outside the scope of this question.

Additional Notes:

You didn't ask about this but I thought it was worth mentioning, that you shouldn't be sending the entire wordpress repository every time you update. Just like you don't need the uncompiled SASS code, you also don't need to be repackaging core WordPress. You don't even need to be commiting core WordPress, its a dependency and you don't need to be changing it.

All that should be getting committed by you is your theme and plugin code, and the uncompiled static files. Compiled static files and external dependencies like the WordPress core don't belong in your git history. For deployment purposes, WordPress should already be installed. The stuff in your tarballs should just be plugins and themes, and additional static files if they aren't already in there for some reason.

TLDR;

Don't use git for this. Use a tool like Phing or Deployer. Build your static files into your theme, and create phing/deployer scripts that tarball up only the code you want, SSH's it over to your server, and untars it into the directories you want. If you have some special location on the server for your static files, just make sure to add steps in your script for that.

So, based on your question and comment, there are three computers involved. There is a web server (when you say "server", I take it as a Web server in this scenario, or the server computer that runs a Web server program). There is another server where your git repo is hosted. And, there is your dev workstation. Is this correct?

It seems like, you have a cloned git repo on your Web server. Your current practice/workflow appears to be (1) (based on your expression "SSH'ed into my server") you log into the web server via SSH (just like Telnet) from your workstation (SSH is just a protocol, which can be used for different purposes). (2) you pull from your repo on hosted service (e.g., github), and (3) deploy it to your "www" directory on the same server. Is this correct?

(I can think of an alternative scenario based on your use of the word "FTP", etc., but let's focus on the above scenario, for now.)

Now, your question is, whenever you "pull" (on your Web server), you feel like you are pulling everything from your repo on your hosted service. And, is there a better way? Am I understanding your question correctly?

If so, as another commenter suggested, git (and, any version control system, in general) is very good at fetching "deltas" only. If you are worried about "fetching everything" every time you pull (the step (2) above), then your worry is unfounded.

Now, the question is, why do you have a git repo on your Web server, if that is indeed the case? This is a pretty legit setup and I've done this before (e.g., on EC2). But, as a best practice, people generally don't do that on "production" servers. It's because you have to "build" your web app, and you really don't want to do that on production servers.

The next question is, what do you exactly do in Step (3)? The build process (whatever process you use) typically generates an "output" which can be directly deployed to the web server. (The convention is the output is generally a single folder, "public", "www", "dist", or whatever, or a single file (e.g., tar.gz, zip, jar, war), etc.) Regardless of whether you build the deployable output on your dev workstation (or, a build machine) or on your Web server, you don't generally do "deltas" in this context. Even if you've only changed a single file (say, a CSS file), you generally build the whole output again (instead of, say, just replacing the changed CSS file only). When you use FTP to upload files, etc., you can selectively upload certain files and/or directories, etc., but as a general practice, we don't do that. We always build the complete output from scratch and deploy it to the Web server. (This is mainly to reduce the potential deployment errors and increase the reliability.)

So, to answer your question, (A) If you are pulling git repo on your Web server, you should really change that practice, and move the build process to your dev computer or a dedicated build machine. (BTW, services like github, gitlab, TFS, ... provide the build service for you.) (B) If you are currently selectively FTP'ing your web app files to your Web server, then you should really consider adopting some kind of formal build, and deployment, process moving forward.

After your SASS build process is done use scp or rsync to move the files to the prod server:

scp -r /[local wordpress dir]/wp-content/themes/your-theme/ username@your.prod.server.com:/path/to/dir/wordpress/wp-content/themes/

scp -r /[local wordpress dir]/wp-content/plugins/* username@your.prod.server.com:/path/to/dir/wordpress/wp-content/plugins/

I am working in a project and using git ssh with bitbucket following is the process i am using it may work for you also if not please correct me :

Step 1 ->I have setup git and create repo in bit-bucket.
Step 2 ->And setup project with my local and linked with my repo.
Step 3 ->connect my server using ssh.
Step 4 ->Work in my local and commit and push all changes in my git repo.
Step 5 ->Run git pull on ssh so all changes deployed in my server.

I am using above process and i love this process.i have used .gitignore  file that is not required for push on my repo.

Thanks