Terragrunt local module development - terraform

We are looking for a better way to swap out local modules via Terragrunt CLI. Currently engineers must comment out the module source (private git repo) and add a local path reference to their module. This is intrusive for many reasons, and has led to accidentally checking in the temporary pathing changes many times. Also, our TG project leverages module composition in both Root and Component modules. When working with a component module, this means we have 2 source references that need to be changed to test local module changes.
We've attempted to use --terragrunt-source and supplying the absolute path to the local module we would like to use, however, that does not work. When providing a path to local module for a component module, it results in variables being dropped and not getting passed from the root module (where we instantiate component module) to the component module.
This screenshot shows us trying to run live/dev/backends/app which instantiates the root module, tfm_10k_app module. The tfm_10k_app module instantiates the component module, tfm_10k_ecs_fargate. The tags are loaded from an external module git repo in the Root module, and passed as a variable to the Component module. However, the tags are not lost. It's not clear why when supplying the --terragrunt-source the tags are lost.
Would love some guidance around how to best leverage local modules for iterative development when adopting module composition best practices.

Related

Nestjs: Set global prefix for dynamic modules

I'm trying to set a global prefix for a dynamic module that I'm going to provide as npm dependency.
It works fine when I'm running the project as a stand alone app, but when I integrate the dependency in another Nestjs project, the prefix doesn't show as part of the url.
Any clue what is the reason of such behavior?
Also I tried to set the global prefix in the main project, but it was applied to all apis including those of the dynamic module.
Is there a way to set different global prefixes one for the dependency and another for the project using it?

Node Module Paths in Host Application

just like to add a short preface to this question - It may be a true issue of how Node functions, or it may be a fundamental misunderstanding on my part of how modules in Node work.
Recently, I've been working on a new project, specifically, a new Node module that requires some configuration via a .json file. I've had quite a few issues with this, being tested via linking the module to an Angular 2 (v5) project, and attempting to use the module in a service.
As I have the module set up right now, the configuration is loaded immediately as the module is initialized. It attempts to look for a config.json file, and read values from aforementioned file. I have this working, to an extent. I am able to require the file, read the file, and throw an error if the file is not found - but only in the same directory as the module's main file. The issue that I've come across is trying to determine how to find the path to the host project's root path - in this case, the Angular project. For example, say the absolute path to my module's root is /home/dev/angular2project/src/node_modules/module/. How can I determine the root path of the host, in this case /home/dev/angular2project/? What if the module has been installed globally?
I have attempted to use my weak understanding of the path module, paired with various searches of SO, to resolve this issue. I've tried using path.resolve(__dirname) to no avail path.resolve(process.cwd). This works well when debugging the module by itself. When attempted to be run from the Angular project, it simply returns / as the path, despite the actual root of the Angular project being home/dev/Desktop/angular2proj.

Serverless Node.js Project Structure

I am building a RESTful API with the serverless framework to run on AWS (API Gateway + Lambda + DynamoDB). It's my first Node project and my first serverless production project and I have no idea how to structure it. So far I have the following
|--Functions
|-----Function1
|--------InternalModule
|-----Function2
|-----Function3
|--------InternalModule
|-----Function4
|--Shared
|-----Module1
|-----Module2
|-----Module3
|--Tests
|-----Functions
|--------Function1
|-----------InternalModule
|--------Function2
|-----------InternalModule
|--------Function3
|-----------InternalModule
|--------Function4
|-----------InternalModule
|-----Modules
|--------Module1
|-----------InternalModule
|--------Module2
|-----------InternalModule
|--------Module3
|-----------InternalModule
I keep my API endpoints (Lambda handlers) in Functions. Some of them have internal modules which they only use and there are some who use modules from Shared. I want to have unit tests for all my modules - inner and shared as well as API testing on the lambda functions. I am using mocha and chai and want to integrate everything in a pipeline which on a git push runs the linters and tests and if they are successful deploy the API to the appropriate stage. The problem is that in order to test each module I have to have chai as a local node module in every folder where I have a test file and reference the modules to be tested by a relative path. In most cases it looks really ugly because of the nesting. If I want to test an internal module from
Tests/Functions/Function1/InternalModule
and I require it on top of the test like so
require('../../../../Tests/Functions/Function1/InternalModule')
+ I have to install chai in every folder so it's reachable. The same goes for mocha and all the dependencies needed for the test and I haven't even mentioned configuration. The main idea I am now considering is weather or not I should bring all modules to a folder called modules and require them when needed - worst case
from Functions/Function1
require('../../Modules/Module1')
Also keep the test files in the module folder and run them inside, but that would require the assertion library installed in every folder. I've read about npm link and symlinks but I want to keep track of what dependencies each folder has so I can install them on the CI environment after the clean project is downloaded from GitHub where I can't do links (or I've got the whole concept wrong?)
If anyone can suggest a better solution I would highly appreciate it!
the way Node uses require is so much more than I thought!
First, Node.js looks to see if the given module is a core module - Node.js comes with many modules compiled directly into the executable binary (ex. http, fs, sys, events, path, etc.). These core modules will always take precedence in the loading algorithm.
If the given module is not a core module, Node.js will then begin to search for a directory named, "node_modules". It will start in the current directory (relative to the currently-executing Javascript file in Node) and then work its way up the folder hierarchy, checking each level for a node_modules folder.
read more here
I will try out Putting all modules in a separate folder each with it's own Folder prefixed with FunctionName_ so I know where each module is used, and the test file + package.json file. Then if I need a module I can require it from the functions with shallow nesting which would look not so bad:
from Functions/Function1
require('module-1');
with package.json
"dependencies":{
"module-1":"file:../../Modules/Function1_Module1"
}
and have a separate folder Shared where I keep the shared Modules.
I am still open for better ideas!

Typescript Custom Node Modules

I'm trying to fully understand how Typescript works in a Node.js project. To accomplish this I have created my own custom_modules folder with a separate #types folder underneath for my declarations while the actual implementation is under the custom_modules attempting to mimic the structure of node_modules. My goal is to make this module usable in the project non-relatively with separate declaration and implementation. I have been able to setup a project that compiles with this setup, but running it errors with:
Cannot find module 'foo'
The source is available here:
https://github.com/anorborg/learn-ts
The node_modules folder is a somewhat special case in how typings get handeled. This is a result of how nodejs works. Take a look at the [module-resolution] doucmentation (https://www.typescriptlang.org/docs/handbook/module-resolution.html), it describes more in depth how module resolution work in typescript.
But in short to answer your question: you can not use non-relative module paths in this way. Node will look for the file in node_modules at runtime, and will not find it there. The paths property in the tsconfig.json is there to solve problems that can occur in other cases, as when targeting RequireJS or SystemJS for example, but not when targeting node.

Browserify require clashes with node require

As the title suggests, i use browserify for my internal requires and on my node server that interferes with the require of global modules.
My solution now is to build the server script with browserify on the side, and then append a file that holds all my requires of global variables that are later gonna be used by the script. This renders browserify unable to try to put my global npm modules into my server script.
Is there a prettier solution to this? Because this way feels like a heap of dung.
-- EDIT --
The code runs only on backend, however - the problem is partially due to how i compile the code that is to be run on that backend. Initially the require keyword is used to get global node modules, e.g express or http. In my case, i need both that functionality as well as reference my own modules compiled with browserify.
My solution right now is to overwrite the global 'define' parameter with amdefine after i've saved references to the the global node modules that i will later use.
Code to bundle node modules into global parameters, require looks for global node modules
My Main, everything from this point forward, require looks for modules inside my own code
I guess I could make a duplicate of nodes require and make a new global reference to it, i.e, require becomes requireNodeModule, i feel as if that's an even worse solution to the one i have at present though...
It sounds like you have some code that runs both on the front-end and back-end, but at present this question is too broad for me to give you useful advice.
Can you narrow it down to a single, specific module that you want to run both in the browser and on your server, where the require clash is evident?

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