3 ms·

This is very useful right now because I'm about to embark on learning js to be able to write aws-cdk infrastructure code, after finding Terraform to be annoying

This is very useful right now because I'm about to embark on learning js to be able to write aws-cdk infrastructure code, after finding Terraform to be annoying in some ways. (mostly its declarative nature means any logic can be difficult to shoehorn in). Decided to buy the javascript for impatient persons book and start reading it on my tablet. (more offtopic, but we'll be using TypeScript, so I'm going to need to find some good guides for that too - any suggestions?)

andrewl-hn 5y ago
I you are just learning the language, I'd suggest skipping this particular book altogether for now. I'd start with a "Re-introduction" tutorial on MDN [1] followed by another Axel's book - "JavaScript for impatient programmers" [2]. Don't read the whole book at first, focus on specific chapters: parts on Modularity, Collections and Asynchronicity. As for TypeScript, the official Handbook [3] is great. Don't dwell much on intricacies of TS type system. Use it here and there to aid your editor or IDE in highlighting mistakes in your code, and get deeper into it once you get a good grip with JavaScript in general. [1] https://developer.mozilla.org/en-US/docs/Web/JavaScript/A_re-introduction_to_JavaScript https://developer.mozilla.org/en-US/docs/Web/JavaScript/A_re... [2] https://exploringjs.com/impatient-js/toc.html https://exploringjs.com/impatient-js/toc.html [3] https://www.typescriptlang.org/docs/handbook/intro.html https://www.typescriptlang.org/docs/handbook/intro.html
- bloopernova 5y ago
  Excellent, thank you! I bought the impatient book, and I'll check out the TypeScript handbook too. It's going to be a shock going from declarative DSLs like Puppet and Terraform to a real coding language! Most of my coding experience has been in shell scripting and some Perl/Ruby from ages ago.
  - k__ 5y ago
    I used the CDK for quite some time now and I can say that it's usually simpler to write things in TS than YAML. Being able to throw in some loops here and there is quite a simplification on its own.
  - fimbulvetr 5y ago
    IMO you should try to keep the code as DSL as possible, and only use the imperative features when it makes a lot of sense. For instance if you have like 10 security groups to add and you just put it in a for loop. You should not embed actual account numbers, regions, etc etc in your code (i.e. a cdk synth should not show arns with arn:aws:1283830383 but rather arn:aws:ACCOUNT_NUMBER) you do that by doing something like: resources: [`arn:aws:${cdk.Aws.AccountNubmer}`] (I know I got the arn format wrong and probably messed up the account number, but you get the gist I hope) The reason is if you follow those rules strictly enough, you can still deploy that template in most accounts (dev, test, prod and so on), which has always been one of the core strengths of CF (and others) when done properly. And I prefer to NOT use If statements in typescript if it can be done in Cloudformation with conditions or other items. For instance, if you only want to deploy a secondary rds slave in prod, use a CF condition and not a typescript 'if (accountNumber === myProdAccount)' because that means your typescript needs to know which account it's synthing for, which by default it does not. IOW, try to use typescript to build DSL that's still in the spirit of DSL and you'll avoid a lot of traps that novices get themselves into.
richeyryan 5y ago
I'm pretty comfortable with JS and Typescript so I might be at an advantage that I don't perceive but CDK stuff doesn't require a good grasp of either language. If you are familiar with at least one other typed language you'll be fine. You'll spend more time digging through the Github issue tracker trying to figure which parts of AWS functionality are supported in the CDK and the assumptions the whole thing is built on.
- fimbulvetr 5y ago
  This is true. Have guys new to JS/TS doing stuff in cdk quite a bit. Fortunately there's not much complexity to CDK's framework and if you stick to L1 constructs it's very very close to just writing the YAML (Minus minor casing conventions and other relatively trivial things)
blacktriangle 5y ago
Assuming you're already familiar with other programming languages, I'd strongly recommend O'Reilly's JavaScript The Definitive Guide. The 7th edition came out not long ago, and it is by far the best version. They've pared down the section on the JS in browser to focus on all of the new JS functionality and a bit on server side with node. It covers async, generators, and modules in detail. It includes detailed sections on JS's annoying type conversion behavior. It doesn't have anything on TypeScript however, oddly choosing to talk about Flow instead.
rauschma 5y ago
You can check out my book (it’s free to read online): https://exploringjs.com/tackling-ts/ https://exploringjs.com/tackling-ts/
- bloopernova 5y ago
  I bought it, thank you for taking the time to write such a good book!
  - rauschma 5y ago
    Thanks! I’m glad to hear that.

andrewl-hn 5y ago

I you are just learning the language, I'd suggest skipping this particular book altogether for now. I'd start with a "Re-introduction" tutorial on MDN [1] followed by another Axel's book - "JavaScript for impatient programmers" [2]. Don't read the whole book at first, focus on specific chapters: parts on Modularity, Collections and Asynchronicity. As for TypeScript, the official Handbook [3] is great. Don't dwell much on intricacies of TS type system. Use it here and there to aid your editor or IDE in highlighting mistakes in your code, and get deeper into it once you get a good grip with JavaScript in general. [1] https://developer.mozilla.org/en-US/docs/Web/JavaScript/A_re-introduction_to_JavaScript https://developer.mozilla.org/en-US/docs/Web/JavaScript/A_re... [2] https://exploringjs.com/impatient-js/toc.html https://exploringjs.com/impatient-js/toc.html [3] https://www.typescriptlang.org/docs/handbook/intro.html https://www.typescriptlang.org/docs/handbook/intro.html

bloopernova 5y ago
Excellent, thank you! I bought the impatient book, and I'll check out the TypeScript handbook too. It's going to be a shock going from declarative DSLs like Puppet and Terraform to a real coding language! Most of my coding experience has been in shell scripting and some Perl/Ruby from ages ago.
- k__ 5y ago
  I used the CDK for quite some time now and I can say that it's usually simpler to write things in TS than YAML. Being able to throw in some loops here and there is quite a simplification on its own.
- fimbulvetr 5y ago
  IMO you should try to keep the code as DSL as possible, and only use the imperative features when it makes a lot of sense. For instance if you have like 10 security groups to add and you just put it in a for loop. You should not embed actual account numbers, regions, etc etc in your code (i.e. a cdk synth should not show arns with arn:aws:1283830383 but rather arn:aws:ACCOUNT_NUMBER) you do that by doing something like: resources: [`arn:aws:${cdk.Aws.AccountNubmer}`] (I know I got the arn format wrong and probably messed up the account number, but you get the gist I hope) The reason is if you follow those rules strictly enough, you can still deploy that template in most accounts (dev, test, prod and so on), which has always been one of the core strengths of CF (and others) when done properly. And I prefer to NOT use If statements in typescript if it can be done in Cloudformation with conditions or other items. For instance, if you only want to deploy a secondary rds slave in prod, use a CF condition and not a typescript 'if (accountNumber === myProdAccount)' because that means your typescript needs to know which account it's synthing for, which by default it does not. IOW, try to use typescript to build DSL that's still in the spirit of DSL and you'll avoid a lot of traps that novices get themselves into.

richeyryan 5y ago

I'm pretty comfortable with JS and Typescript so I might be at an advantage that I don't perceive but CDK stuff doesn't require a good grasp of either language. If you are familiar with at least one other typed language you'll be fine. You'll spend more time digging through the Github issue tracker trying to figure which parts of AWS functionality are supported in the CDK and the assumptions the whole thing is built on.

fimbulvetr 5y ago
This is true. Have guys new to JS/TS doing stuff in cdk quite a bit. Fortunately there's not much complexity to CDK's framework and if you stick to L1 constructs it's very very close to just writing the YAML (Minus minor casing conventions and other relatively trivial things)

blacktriangle 5y ago

Assuming you're already familiar with other programming languages, I'd strongly recommend O'Reilly's JavaScript The Definitive Guide. The 7th edition came out not long ago, and it is by far the best version. They've pared down the section on the JS in browser to focus on all of the new JS functionality and a bit on server side with node. It covers async, generators, and modules in detail. It includes detailed sections on JS's annoying type conversion behavior. It doesn't have anything on TypeScript however, oddly choosing to talk about Flow instead.

rauschma 5y ago

You can check out my book (it’s free to read online): https://exploringjs.com/tackling-ts/ https://exploringjs.com/tackling-ts/

bloopernova 5y ago
I bought it, thank you for taking the time to write such a good book!
- rauschma 5y ago
  Thanks! I’m glad to hear that.