My Opinionated Guide To Go

http://blog.hackingthought.com/2014/05/my-opinionated-guide-to-go-golang.html

by lateefj • 12 years ago

41 70 12 years ago

blog.hackingthought.com

sergiotapia2• 12 years ago

I just wish Go would let me compile and run with a flag -allowing- unused imports. I find myself wasting a lot of time hunting down unused imports or variables and commenting them out.

Maybe that'll be a non-issue the more I use Go, but so far it's a bit of a time waster.

AYBABTME• 12 years ago

https://github.com/bradfitz/goimports

artursapek2• 12 years ago

Exactly. I have vim handle it for me every time I save. No problemo.

jerf2• 12 years ago

To explain to those who may not know what's going on here:

Go forbids importing modules that you then don't use in the source code. This is particularly annoying with the "fmt" module, which contains things like Printf that are useful for debugging, but you may only be using fmt.Printf for one debugging statement in the code. Consequently, if you're developing, and you're adding and removing it over and over you also have to add and remove it to and from your import list over and over, which is very annoying since it's likely to be relatively distant from your use location, and it's mandatory that all imports are listed at the top of the file. (So, you can't do what you can do in perl and say "use Data::Dumper; print Dumper($debugging_stuff);" all on one line, without even being concerned about whether Dumper may already be imported.)

goimports is a source filter that cleans out any unused modules, and tries its best to add modules that you only reference. It's pretty good. You can confuse it if you have two modules with the same last bit of the name, but the standard library doesn't have that anyhow, and for the most part you can deal with that. Since it also runs gofmt for you on save, it's also a drop-in replacement for gofmt, which you should configure your editor to run on every save even if you for some reason don't want the goimports functionality. (Seriously. Just do it. There's no excuse not to. There's no excuse to ever commit code that was not gofmt'ed.)

If you do that, the problem goes away. Typing "fmt.Printf" pulls fmt in automatically, removing the one line removes it automatically, the import list is always accurate, and it's smart enough that if it isn't the only usage it doesn't remove it.

That said, I also strongly recommend setting up automatic syntax checking by compilation (flymake in emacs, don't know what in vim, etc), so that you also avoid the "Save -> switch windows to terminal -> compile -> get smacked in face with an error that feels stupidly persnickety" psychological torture. If the errors highlight in your editor on save or something, you go through that much less. Those who lived in the C#/Java etc world have long had this... a lot of people coming from the scripting side would be advised to pick up a bit more of the helpful tools the static side has to offer.

kevrone2• 12 years ago

It's worth mentioning that the author of this tool is Brad Fitzpatrick, one of the main contributors to the Go standard library and, in my opinion, the most "entrenched" Go developer on the team. And by that I mean he uses Go to build large and practical projects on his own (See Camlistore), so he knows what the language feels like from a perspective similar to the rest of us. He's also one of the only advocates on the team for the inclusion of generics.

mattgreenrocks2• 12 years ago

Maybe Go is trying to tell you that the "move fast and break things" methodology is not how it should be used?

sergiotapia2• 12 years ago

I know right? I do feel a warm fuzzy feeling when things compile and I generally feel much safer than when building things in Ruby.

rthomas66• 12 years ago

Why does this article only compare Go with interpreted languages at the top? Go is a compiled language; wouldn't it be more fair to compare it with other languages that can be compiled, like C++, Rust, Haskell, or Lisp/Scheme?

I mention this because the article acts as if getting rid of abstraction layers between the OS and the code is a new idea. No, that's how all compiled languages are... that's the point of compiled languages. I suppose Go's most common use case lines it up against a bunch of slow interpreted languages, but really there's no reason except good libraries that you can't use the other compiled languages I mentioned for web apps.

kasey_junk5• 12 years ago

Well to be fair it does mention Java (though the deployment model expressed is, shall we say, Byzantine).

rthomas66• 12 years ago

Java, while compiled, isn't compiled to machine code, and the bytecode to which it is compiled is run on a virtual machine. For this reason, I consider Java more of an interpreted language than a compiled language per se.

pjmlp4• 12 years ago

That's quite common when selling Go.

Go advocacy tends to ignore what other modular languages with native compilers offer since the early 80's, as well as, present a cut down version of what modern runtimes are capable of.

kyrra2• 12 years ago

If you read any posts or listen to any talks by Google's Go team, they are a fairly modest about Go. They know it isn't as fast as it could be (since they don't have decades of compiler optimizations yet that GCC or other compilers would give). As well, it's just a newer language. One thing a lot of people don't always realize is Golang started with the Plan9 C compiler[0]. So they actually generate all the way from source to machine code with their own compiler toolchain (no LLVM, GCC, or other compiler required).

When you look at the people coming to Go, most are coming from Python or Ruby, not C, C++, or Java. So a lot of the experience Go developers have are those other languages. As Rob Pike pointed out 2 years ago[1], while they set out for Go to replace C++, it ended up actually being a much better fit for Python and Ruby developers.

[0] http://adventgo.blogspot.ca/2014/05/origin-of-go-toolchain.h...

[1] http://commandcenter.blogspot.com/2012/06/less-is-exponentia...

psankar• 12 years ago

that's how all compiled languages are

You mean, like Java and C# ?!

rthomas66• 12 years ago

No I mean languages compiled to machine code. I guess that happens sometimes with JIT or with some implementations of these languages? In general Java and C# are run on top of portable virtual machine layers, right?

lateefj3• 12 years ago

Author here. I was comparing things that I have developed software in. It would seem unfair to compare things that I have not actively contributed production code and deploy. I mainly write web applications (services) of which C++, Rust, Haskell or Lisp/Scheme are not languages I find compelling to write web applications with. Would love to hear if you find this otherwise.

rthomas66• 12 years ago

No, I honestly know next to nothing about web apps programming. I do know there exists decent-looking support for web apps for Rust, Haskell, and Scheme (Racket, but Racket isn't compiled to a binary), but I don't have the knowledge base to assess how good web programming is in these languages, if it's even good at all. I know this website is written in Arc (a Lisp). https://github.com/wting/hackernews

wtbob• 12 years ago

There are some nice things about writing web apps in Lisps, since one can represent HTML as s-expressions, e.g. (:html (:body ((:p (:class "main")) "Foo bar baz."))). And of course macros mean that one can create nice abstractions quite difficult or impossible in other languages.

bsg75• 12 years ago

Because that is the trend of adoption. More people are using Go who also use Perl/Python/Ruby than C/C++/Java. It was originally targeted at the latter, but the actual result was from the scripting language set.

I am one of them - have used (and still use) Python since v1.52, but found Go an excellent option when performance / concurrency was needed.

ZenoArrow3• 12 years ago

Have noted this 'opinionated' trend going for quite a while, so this comment isn't about this article in particular, but can someone break down why an opinionated guide to something technical would be preferable to an impartial one? The only thing it seems to imply is that bias adds value in its own right.

lmm• 12 years ago

It's a pre-emptive disclaimer "I know this isn't objective, don't complain about that". And it tells you that the guide isn't going to offer you confusing choices, it's going to tell you one way to do things. For some people that's an advantage.

ZenoArrow3• 12 years ago

Thanks for your reply lmm. I can see what you mean. However, I do think it has a high risk of building new dogmas without the understanding of when these dogmas should be broken.

rthomas66• 12 years ago

I see value in educated opinions. For instance a while back I was trying to figure out how to make a web app in Python (keep in mind that, while I can program, I have zero knowledge about web things). This is what I saw: https://wiki.python.org/moin/WebFrameworks

Which framework is the best? Why are there so many? Which is the easiest for my specific goals? An opinionated guide that said something like "Use Flask because X" or "Use Django because Y" would have been pretty useful.

ZenoArrow3• 12 years ago

Beginners guides are a special case, the main focus is in getting something working with the minimum of fuss that you can understand. I do understand that expert opinions can help build confidence, but perhaps it's even better to explain matters clearly so you can make your own opinions.

cmhamill• 12 years ago

Not entirely on-topic, but the mention of the various language "stacks" at the beginning of the article reminded me of something I've been wondering.

Why does the de facto standard for web apps in Go-land seem to be using the built-in HTTP server provided by net/http, or otherwise having the program server as its own HTTP server?

Most other languages seem to have converged on FastCGI or some similar model ({W,P}SGI, Rack, etc.).

It irks me a bit because I don't understand why you'd want to do it this way; it seems preferable to have a dedicated HTTP server in pretty much every way I can think of.

Does anyone have any insight there?

mwsherman• 12 years ago

Well, I think one answer if that you can quickly have a running web app without another piece of software. This is an attractive quality of Node, too. In fact, if a language doesn’t have a “5 lines to a web app” demo, I consider it insufficient.

I’d posit that 90+% of apps don’t need another http server. Big apps have good reasons for a dedicated http server – unifying SSL termination, load balancing – but they are a minority.

There is nothing to to prevent you from putting nginx in front of the Go app if that’s better.

kaoD• 12 years ago

I guess it's because the HTTP module works out of the box and you can still have the dedicated HTTP server using a reverse proxy like Nginx.

jksmith• 12 years ago

Custom windows servers that do failover and interceptor pattern at the same time. Try that with IIS without pulling your hair out.

jerf2• 12 years ago

"Most other languages seem to have converged on FastCGI or some similar model ({W,P}SGI, Rack, etc.)."

The languages you are citing are slow enough that the scripting language would like to slice away as much of the brute web serving load as possible so the slow scripting language can concentrate its power on the real task at hand.

Go is more on the compiled side. It's not C-fast quite yet (I expect it to eventually converge somewhere around 1.5x as fast, it's not quite there yet), but currently around 2-3x slower only (and net/http is seeing a lot of direct work on it, it's quite fast now). You don't get the big win that you get with letting nginx handle the brute string manipulation of HTTP and prechewing on it for the 20-100x slower scripting language.

Also, remember that you can view HTTP itself as a form of CGI request... really, FastCGI etc. doesn't do anything that an already very multi-threading-friendly language can't do with straight HTTP. Those standards are solving a lot of problems that Go just doesn't have, and straight HTTP is actually more general and flexible if you can afford it (no problems with Nginx being unable to stream FastCGI, etc).

kyrra2• 12 years ago

For Go, you probably don't want to use their net/http server if you will also have it doing SSL/TLS. Go's TLS implementation doesn't support a lot of older cipher suites which could be a problem for some clients. As well, it is not as hardened as OpenSSL and others (such as possibly being vulnerable to timing attacks[0]).

[0] https://code.google.com/p/go/issues/detail?id=2445

zsombor• 12 years ago

OTH there was no Heartbleed bug in the SSL implementation of Go's net/http. So much for hardened implementation. Secondly you can use go behind a http proxy, or even in an FCGI etc environment with minimal change to the code.

paukiatwee2• 12 years ago

"Go: Code -> Operating System -> Hardware"

Is there any reason to use RVM, PVM on production while Go does not required one?

I believe should be install one and only one Ruby/Python version on production.

Why Ruby/Python does not required application server like unicorn/wcgi, etc?

The article clearly try to make other deployment more complicated.

treystout• 12 years ago

A lot of python shops I've come across don't use the system installed python or ruby. In python land at least it's exceedingly common to deploy a virtualenv with a separate python runtime and isolated 3rd party libs. This makes pinning your version deps easier and doesn't matter if the underlying server is ubuntu or centos or whatever.

paukiatwee2• 12 years ago

That is true, what if in future ubuntu/centos include Go by default (which might not the version you use)? I believe then will have some GVM or similar tool to solve the problem.

Edit: As others pointed out, Go is compiled binary and does not required runtime (like JVM) so versionning is not issue. Thanks for clearing up.

NateDad7• 12 years ago

Yeah, many of the ruby applications I've seen recommend RVM so that you can isolate yourself from the system-installed version of ruby. That's the nice thing about go - each application carries around everything it needs to run in total isolation from the rest of the machine.

herge• 12 years ago

One version of python on a modern linux OS? How do you mesh the default version of python used by the os with the version of python required by your application code?

microtonal2• 12 years ago

It's a nonsense comparison anyway. E.g. with Java I don't have to care much about the hardware an operating system (e.g. we develop on Mac and deploy on Linux).

And sure, you can use an application container. But you can also embed a webserver. E.g., we Jetty embedded and use a strict SecurityManager policy[1]. So it's more like:

Code -> JVM (with security manager)

[1] http://docs.oracle.com/javase/tutorial/essential/environment...

lateefj3• 12 years ago

Not sure I follow? With Go we develop on Mac and deploy on Linux. Just change the environment variable. Linux has some great built in tools for "security management".

regularfry4• 12 years ago

There's no reason to do it, but people do.

icebraining4• 12 years ago

Docker -> Operating System

This makes no sense. The runtime of Docker is the Operating System. There's no extra layer, as it's being implied.

And there's no difference between Go and the other languages that makes Docker more or less useful. You can have separate Python processes without Docker, just like you'd have separate Go processes.

I like Go, but this article just sets up strawmen to bring down.

regularfry4• 12 years ago

The question he's addressing isn't what you can do, but what is commonly being done. You don't need RVM, you don't need Docker. Hell, you don't need Rails. But those are the idiomatic layers of the stack, for a non-trivial part of the Ruby development community.

lateefj3• 12 years ago

Sorry for the confusion JVM = Java Virtual Machine, RVM = Ruby Virtual Machine, PVM = Python Virtual Machine. What I was trying to point out the layers of vitalization just to run an application. Docker is yet another layer on top of the operating system (a virtual machine running inside an operating system inside an operating system possible ect).

icebraining4• 12 years ago

Docker is used by a non-trivial part of the Ruby community? I find that hard to believe.

My Opinionated Guide To Go

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