Month: November 2020

Categories
Resources Software Development

Linux commands resources and links

Difference between Ubuntu apt-get autoclean, clean, autoremove commands – it is important to know the difference.

Cleaning up with apt-get – how to clean up with apt clean command

How To Upgrade Ubuntu Using Command Line?

Linux << heredoc syntax info – great link has lots of good linux information

Here is an excellent link to a shell command cheatsheet. This lists the most commonly used shell programs.

An A-Z Index of the Linux command line: bash + utilities. – about the same as the list of shell commands above.20 Shell Scripting Questions for Practice

Writing text to files from shell or shell scripts

Awesome linux software – a list/article about awesome useful linux programs
Understanding Shell Initialization Files and User Profiles in Linux

20 Shell Scripting Questions for Practiceuses opensshLinux visudo command

Linux /etc/profile file information

Understanding a little more about /etc/profile and /etc/bashrc20 Shell Scripting Questions for Practice

Why and How to Edit Your Sudoers File in Linux

LINUX DIRECTORY STRUCTURE:/ETC EXPLAINED

Tutorialspoint Linux tutorials and really good information.20 Shell Scripting Questions for Practice

How to Use Sudo and the Sudoers File – very good article

Ubuntu Environmental variables – Ubuntu Documentation link

How to prompt for input from user in a linux shell script – article 20 Shell Scripting Questions for Practicecovers two ways to prompt users for input in shell scripts.

How to prompt and read user input in a Bash shell script – A good example of a script that prompts users for input and uses it.

Bash read builtin command – this command is built into bash meaning available without installing etc.

Linux while loop explained with examples of alternate syntaxes

How to create a self signed SSL certificate 

20 Shell Scripting Questions for Practice – article showing how to prompt users for input and how to answer prompts.

Categories
Resources Web Development

How to list and install php modules on ubuntu linux

I always, always forget how to do this and it takes an hour of googling to figure this out again. Basically I often need to see not just what php modules are installed on my system, but also what can be installed.

For example you can see what is already installed and available to you on your current system you simply type php -m in your command line. This command will list all of what is installed currently on your system.

But that is not what I want and probably not what you want if you are reading this. What I want is to know what is available for installing, or better what are the exact names of the packages. For this information you need a different command.

sudo apt-cache search php7*

This command searches the apt cache for packages that contain php7* the * is a wildcard meaning anything that looks like php7 such as php7.4-mysql. Try the command above and you will get a list of all of the php modules specifically for version 7.4. Not all modules will be listed. You can use another command to see all of the available php modules even if they don’t contain 7.4 in the name you can install them.

To see all php modules available use this command.

sudo apt-cache search php*

Minus the 7 and it will return every last module that contains the word php.

Then to install anything you need you use a command like the following

sudo apt install php7.4-mysql php7.4-curl php7.4-json php7.4-cgi php7.4-xsl

And that is how you list and install php modules/extensions.

Here is an interesting article about how apt-cache works on linux
Here is a link to some more resources about this topic.

Categories
Resources Web Development

How to get TinyMCE to not destroy image upload URL’s

Came across a weird not so feature of TinyMCE where it munges the URL your upload script returns when it uploads an image. For example if your upload script returns a url of http://example.com/folder/image.jpg. TinyMCE takes it upon itself to rewrite that URL breaking it to ../../folder/image.jpg  I am not sure why but I think it is trying to help you in some way.

The best clue I could find in the docs as to why this happens is at the bottom of the page in the CORS section here. It appears TinyMCE is removing the domain you add to the url then it cuts from the current page. The problem I encountered was if my page was blog it would remove the http://example.com part and replace it with ../../blog/folder/image.jpg which is not what I wanted.

I was about to replace TinyMCE but I decided to try something else. I did some googling and found this in the docs.  

I included this in my tinymce configs.

relative_urls : false,
remove_script_host : false,
document_base_url :  "{{ prependURL }}"

Those 3 lines of code fixed it all. Totally didn’t expect TinyMCE to munge the URL’s I returned. This ate up an entire day as I kept thinking the reason the image didn’t display was because my code wasn’t creating the URL’s correctly. Then I thought it was my Nginx configs. Then before giving up on TinyMCE  I did this last thing.

prependURL is a variable that contains the url of website hosting the image such as https://example.com TinyMCE prepends that to the url you return to it, even if https://example.com is already part of it. Otherwise it removes https://example.com and replaces it with a relative URL such as ../../folder/image.jpg

I hope this saves someone else time.

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Uncategorized

Symfony doctrine remove column from entity table

I had to dig and dig and dig to find this. Explanation here.

php bin/console doctrine:migrations:diff

instead of making a migration, this command makes the migration file for you. Then you can run this command

php bin/console doctrine:migrations:migrate

To actually change the table.

Categories
Resources Software Development Web Security

AWS autoscaling links and resources

AWS autoscaling lets you set up groups of EC2 instances which are controlled by a load balancer. The load balancer in turn makes sure your app has the correct number of EC2 instances running at all times. If your traffic is high it adds the maximum that you set. If traffic goes down it adjust to have the minimum EC2 instances that you set.

This system is great for startups who have no idea if their app will go viral or just flop. Often they just flop. But if you are lucky and it takes off you want to be able to handle the traffic so you don’t lose users.

Documentation link to AWS autoscaling

Running EC2 instances at Scale with autoscaling groups – small Ebook that walks through the whole process including using CodeDeploy.

Categories
Resources Software Development

AWS resources and links

AWS Parameter Store vs. AWS Secrets Manager – great short article that covers use cases and information about each and when to use.