DevOps/CSS/JS/HTML Flashcards
6 stages of SDLC
~Planning/Requirement Analysis ~Define the Project Requirements ~Design Product Architecture ~Building/Developing the product ~Testing the product ~Deployment and Maintenance
Agile
more of a concept that an actual methodology
You consistently communicate with the client and stakeholders about what they want in the project (little to no documentation)
Scrum
Implementation of Agile concept
framework that helps teams work together
collaboration and helping each other to solve problems one person might have during a sprint
It consists of a series of sprints where each team has specific user stories to tackle
Sprints
It is a short period that completes a set amount of work
Usually lasts around 2-4 weeks of work
During a sprint
Daily, weekly, or bi-weekly standups
You specify what you did
You specify what you’ll do before the next standup
What blockers (problems) you have
Iaas
Infastructure as a Service
Instant computing infastructure, provisioned and managed over the internet
Configure the actual server themselves
You have the most control over your cloud service
PaaS
Platform as a Service removes the need for the organization to manage the underlying infastructure
Allows you to focus on deployment and management of your application
Ex: Azure Services
SaaS
Software as a Service
You access the software and the cloud provided will run and manage it with the services
Cloud Deployment Models
PRIVATE
Only accessible by a certain organization or just your organization
PUBLIC
Open for use by the general public
Ex: Gmail, yahoo mail, google website search engine, etc.
HYBRID
Some resources are private and some resources are public
COMMUNITY
Sharing resources when you are part of a community
Ex: Universities, only their students have access to their cloud services
DOCKER
packaging our application that has a bunch of dependencies that we had to install (SDK, external packages, etc.) into one single package that we can send to multiple computers and have it run flawlessly without the need of any installation process or setup process
It is a containerization ecosystem which helps to build and ship the package(application) for deployment and it can run in any machine.
It works the very same way it works in a developer machine.
Containerization
isolated environment for running an application.
Involved bundling an application together with all the configuration files, libraries, and dependencies required
Basically get everything the application needs to run it
Meaning it will use as much resources the container needs to run the application
Virtualization?
It is a creation of a virtual machine that simulates a real computer with an operating system
Cons:
When you create virtual machine, the allocation of resource is static
Meaning once you start a virtual machine, you have to specify how much gbs of ram needed and will not dynamically change depending on the workload
So it is like taking a piece of your computer’s resource and will keep that piece until you close down the VM
Ex: We have 16 gb of ram in my computer, I stated the VM to use 8 gb of ram then my computer will only have 8 gb of ram and the VM will only have 8 gb of ram and that will not change until I close the VM
Needs full blown OS (licensing and update is a troublesome)
Slow to start
Container over VM
Allowing running multiple apps in isolation
lightweight
No need of full blown OS but use OS of the host
Start quickly in seconds
Needs less hardware resources
YML
Another mark up language that just tells the computer what to do so it can build, test, and deploy our application to setup a CI/CD pipeline
Pipeline keywords
●Trigger
We set some sort of event that needs to happen to trigger/execute the entire process of CI/CD
●Job
This is the actual “work” the computer needs to do to start the entire process
You can have multiple jobs that is responsible to do something
Ex: Deploy the application job, Dockerize the app job, Code analysis job
●Steps
They are the tiny operations required for the computer to finish one job
This might be executing a bunch of CLI commands in sequence or installing certain SDKs to do the operation, etc.
●Approval
Some sort of a check after a job or multiple jobs to see that everything work as expected
Scope
Global: variables declared outside of a block
Block: local variables declared withing the block of code
HTML
●Hypertext Markup Language
Anothermarkup language telling the computer what to do but does not compiling it into machine code
similar to xml (our .csproj files) ●HTML is used to define the structure of our webpages
●Our browser
read these files and interpret it to display something on the browser
We are currently on version HTML 5
HTML elements
includes the start/ending tag
attribute name and value &
the content
HTML Attribute
They are used to provide extra information that the tag can use
consist of a name(class) and value”paragrapgh”
Web Accessibility
Web accessiblity is configuring your website in a way so it is also readable beyond pc users such as phone, tablets, gaming consoles, etc.
This is usually done by manipulating CSS
CSS
Cascading Style Sheets
Cascading is in the name because it uses a cascading algorithm to determine what style it should apply
CSS Selectors
●select specific or group HTML elements the basic ones include: ☆Element selector - When you want to select multiple elements of the same tag ☆Class selector - When you want to select multiple elements of different tags by using the class attribute ☆Id selector - When you want to select one (mostly) or a couple elements using the id attribute
Ways to Include CSS
External CSS
Internal CSS
Inline CSS
Inline CSS
Applies CSS to a single element
It uses the style attribute
Has the highest priority
Internal CSS
●Applies CSS by using the style tag inside of a HTML doc
●Used to apply multiple css to multiple elements
●Second priority
External CSS
Creating an external .css file to apply css to multiple HTML docs (you can just apply it to one HTML but that kind of defeats the purpose of using an external css)
●HTML doc must use the link tag to reference the external css
●Used to apply multiple css to multiple elements in multiple HTML docs
So useful to create a universal theme of your website
Least priority
Responsive Web Design
Making your elements not have rigid size but changes its size based on the viewport
Viewport is just how big the window of the browser is (small for phones, big for computers)
Useful to accomodate for every devices out there that might access your website
●bootstrap libraries
FUN0NE
False Undefined Null 0 (-0 and +0 as well) NaN (Not A Number) Empty String
Truthy & Falsey
In JS, all values have Boolean equivalent to it
Meaning you can do “hello”==97.6 perfectly just fine in JS
Scopes
The scope of a variable determines where it has access to
Block
Function
Global
Var Keywords
let x = 2 var x = 2 const x = 2
let keyword
limits the scope of the variable depending on where it was declared
Mostly use “let” to try your best to avoid conflicting variable names
Global (Scope)
Can be access anywhere in JS
Var keyword that will give variable a global scope
{
var x = 2;
}
//Anything outside this block scope still has access to x because it is globalFunction
Each function you create is a new scope
Kinda like methods in C# in that variables created in the function only stays in that function
Block (Scope)
Cannot be access from outside {}
{
let x = 2;
}
//Anything outside cannot see that x variablePromises
Represents either the completion or failure of an asynchronous operation
Allows you to “setup” what to do after a completion of a promise and get its result and also account for a failure of a promise and what to do using “then()”.
Fetch
Similar to AJAX except less syntaxes or prepping needed to call on backend
Main difference from AJAX is it uses promises to achieve asynchrnous operations
AJAX
Asynchronous JS and XML
Used to grab information only with XML type backend server hence the name
But now updated for the object to also include JSON to be relevant
Security w/ HTTP
CORS
CSRF
XSS
(CROSS-SITE SCRIPTING) XSS
A hidden segment of JS coupled with HTML and CSS to emulate a harmless website
●job is to grab any tokens, cookies, or other session information from the user
●Hidden in a way that JS is within HTML doc and is done through multiple tools
●There are so many ways to achieve XSS
● the best way to avoid XSS follow given rules of OWASP docs
● You don’t need to know all/any the rules however a free resource called OWASP to check the rules and other vulnerabilities
CSRF
●Cross-Site Request Forgery-a web security vulnerability that attackers use
●It bypasses CORS by using you/user to essentially do a request (usually on a bank account website) to ask to withdraw money from your account and send it they want.
●Tokens are a way to combat CSRF
CORS
Cross Origin Resource Sharing
● way for you to share your resource to other people
● its a mechanism that checks the current origin of where that request comes from and see if they have permission to access your resource
●General workflow: a user will send a request and the browser will send a mini request to first check if you have access, the backend server will recognize the CORS check and will send a response if you do have permission. If so, your browser will send the real request. If not, you will have a CORS error
Define JS HTML DOM, What does it do?
●Allows JavaScript to specifically pick certain elements in the HTML and change/manipulate them somehow based on whatever function you created
●This is what makes JS a powerful tool to making your html page dynamically change based on whatever the user is doing
● DOM= Document object Model
Classes
Has most of the OOP pillars we discussed and implements them easily except abstraction
Prototypal Inheritance
● inherit other prototypes for code re-usability
Prototype
It is like a field in C# in a form of a key-value pair Every function (and other things) have prototypes and you can add prototypes as well
NO.NU.BS (datatypes)
Numbers Objects Null Undefined Boolean String
JAVASCRIPT
compiled and interpreted Essentially, if a function keeps getting called multiple times, it will compile that code into an optimized native machine code to be more efficient loosely typed Meaning every variable you create can hold any datatype and will have no issues switching between datatypes It is both a functional language and object-oriented programming language (ever since ES6) Functional language just means that it uses a lot of functions and you can also use them as variables, parameters inside of other functions and it makes things look... very complicated You can think of functions as methods in C# just with a different name and doesn't need a class attached to it to make one
