Spark web server(github.com)

54 pointsby rifvor 12 Jahren49 comments

https://github.com/rif/spark

Little web server for emergencies

10 comments

rektidevor 12 Jahren

As opposed to Spark, the microcontroller platform. As opposed to Spark, the resilient distributed data system. As opposed to Spark, the open source IM client.

kitdvor 12 Jahren

... as opposed to Spark (http://www.sparkjava.com/), the Java web server.

qrohlfvor 12 Jahren

...as opposed to Spark[1], the tool by @holman.

[1]http://zachholman.com/spark/

Zikesvor 12 Jahren

Yep, should've gone with Zitser or Poppler.

drvvor 12 Jahren

You were probably being facetious, but Poppler is already used too (PDF rendering library).

agretvor 12 Jahren

Would've made more sense for a POP email library.

dangerlibraryvor 12 Jahren

Is it really that hard to add 5 lines of boilerplate to your nginx conf? You can probably just copy-paste an existing server{} block or sites-available file and change the root directory. As a bonus, you'll learn a bit about how to configure the same tool you'll use later in production.

Oh. It's written in Go. Got it.

sanderjdvor 12 Jahren

I'm so sick of seeing this pattern of 1) person makes tool they find useful, 2) person releases tool publicly for free, 3) other person comes across tool but doesn't find it useful, 4) other person publicly denigrates tool as being universally not-useful.

I just don't get it.

tzuryvor 12 Jahren

@dangerlibrary simply says: Do not re-invent the wheel. I cannot see any real-world production environment where this new server is better approach then activating a tiny config file. Thus, it is a very good lesson to the author: Use what is out there and build what is missing.

sanderjdvor 12 Jahren

I very rarely see a "hey I made this!" post here that doesn't include one or more comments along the lines of "this already exists!". I don't mind these sorts of comments when they tell me something I didn't know - "you can achieve something similar by doing coodle with well-known tool doodle!", "there is somewhat-obscure tool foodle that does exactly this!" - there are some comments like that in this thread. What I dislike is when these sorts of comments are along the lines of, "you should have just done the thing that you made the tool to avoid having to do!". It is just dismissal and leaves nobody the wiser.

It seems delusional to think that this sort of comment is somehow a good learning experience for a library author. Everyone knows that you shouldn't reinvent the wheel, but there are reasonable disagreements on what exactly that means.

dangerlibraryvor 12 Jahren

I don't think I said anything negative about the tool itself, or about the author of the tool, who seems perfectly happy with it.

You're right that I don't think it's useful to have a proliferation of tools that do one thing worse than a general-purpose tool.

I don't want an avocado peeler - I'll use a knife and I'll recommend using a knife to others.

reesesvor 12 Jahren

It's your tone more than anything. I read some of your previous posts to see if you were a d-bag and I came to the conclusion that you're not[1]. This reads more like the post was a button-pusher for you. I can relate. :)

Unfortunately, even with the tone removed, the comment hits that "top-voted middlebrow" button for many of the other people on the site. I would however say that for TFA itself as well.

[1] the opinion of some random interdweeb carries a lot of weight, I know. :)

mverwijsvor 12 Jahren

Great. Good for you.

Your initial comment, however, is filled with a denigrating tone. It is that tone your parent is addressing. Not so much the content. The tone. It is unkind.

[deleted]vor 12 Jahren

rifvor 12 Jahren

Does nginx have a directive for serving this text quickliy:

<h1>Maintenance</h1><p>will be back soon!</p>

Oh. It's written in C. Got it.

dangerlibraryvor 12 Jahren

You still need to stop the existing web server to get spark to take over port 80, and restart it when you are done, so it's not quite that simple.

Also, it's not hard to keep a maintenance conf file around, pointing to a different directory. At least, it's certainly no harder than downloading a second web server. Then it's just "sudo ln /etc/sites-available/maintenance /etc/sites-enabled/conf"

rifvor 12 Jahren

You are so right, still I had a need for such a little tool and I don't regret any of it's 48 lines of code so far :)

theonewolfvor 12 Jahren

The way I'd do this is have front-end load balancers just re-direct to a nginx configured just for this purpose.

dangaylevor 12 Jahren

Yes it does, although not out of the box:

http://wiki.nginx.org/HttpEchoModule

georgebashivor 12 Jahren

You don't actually need echo, you can use return from the rewrite module (which is compiled in by default).

    return 503 "<h1>Maintenance</h1><p>will be back soon!</p>";

rifvor 12 Jahren

lol, I love hackers :)

dangaylevor 12 Jahren

Oh yeah. That's rad.

rifvor 12 Jahren

a-nom-a-lyvor 12 Jahren

    # pgrep nginx
    #

raimuevor 12 Jahren

You could achieve something similar using the simple HTTP server shipped with python: python -m SimpleHTTPServer

kordlessvor 12 Jahren

Which will melt with any sort of sustained traffic.

hysanvor 12 Jahren

Except, that's not the use case for Spark so it's an apt comparison.

> Emergency web server

> For those occasions when your webserver is down and you want to display a quick maintainance note. Or just want to quickly demo a static site. Or whatever :)

dkuntz2vor 12 Jahren

Yes it is. The use case is when your site is down and you want to tell people that. If you have even a small amount of traffic `python -m http.server` is going to die, this isn't.

How is that not an apt comparison?

deweyvor 12 Jahren

If you just want a small httpd there's also gatling and fnord.

[0] http://www.fefe.de/gatling/ [1] http://www.fefe.de/fnord/

justincormackvor 12 Jahren

Or webfsd. or bozohttpd or...

rifvor 12 Jahren

this one has 45 lines of code :)

besthamvor 12 Jahren

Well, the binary contains a lot of go.

dkuntz2vor 12 Jahren

That's true of anything written in Go.

ploxilnvor 12 Jahren

Yes, but, trivial c programs statically linked with glibc can be in the ballpark of 500KiB, trivial c programs statically linked with uclibc or similar can be in the ballpark of 100KiB, and trivial go programs (always statically compiled) can be 2-5 MiB. They're huge.

rifvor 12 Jahren

The go team is aware of this and I think it will improve soon: http://talks.golang.org/2014/go1.3.slide#1

dkuntz2vor 12 Jahren

Which is what I was getting at...

besthamvor 12 Jahren

What I meant was that almost all the HTTP stuff is in "net/http".

michaelmiorvor 12 Jahren

I was wondering why I would want this, but being able to pass some HTML on the command line is pretty cool.

[deleted]vor 12 Jahren

(1)

Alan_vor 12 Jahren

I can't see anywhere in the code so assume this returns a 200 code for requests. If was using this to show maintenance for my website would want it to return 503.

rifvor 12 Jahren

Added a parameter to stet the desired status

rifvor 12 Jahren

Good point!

jjoevor 12 Jahren

python -m SimpleHTTPServer 8080

Above will serve whatever files you have in $PWD

dbpattersonvor 12 Jahren

And be _insanely_ slow (not just the normal, python is slow comment - there are fast web servers in python; SimpleHTTPServer is not).

incidencevor 12 Jahren

Thanks! I have have been using "python -m SimpleHTTPServer" a lot, it is kind of a pain in the ass since it hangs sometimes in a weird way.

swahvor 12 Jahren

Can someone explain this function signature? I can't grep it.

func (h bytesHandler) ServeHTTP(w http.ResponseWriter, req *http.Request)

BarkMorevor 12 Jahren

The type bytesHandler is a slice of bytes:

    type bytesHandler []byte

The code

    func (h bytesHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
	w.Write(h)
    }

is a method declaration for the type bytesHandler. The (h bytesHandler) specifies id and type of the method receiver.

zekvor 12 Jahren

you have to get used to get go's backwards type declaration. This is defining a method on h which is a byteHandler struct called serve which takes a http.ResponseWriter and Request and returns nothing.

This is from the http.Handler interface, so defining this method causes byteHandler to conform to the http.Handler interface.

zapharvor 12 Jahren

byteHandler is not a struct it's a byte slice. This is actually somewhat important since it highlights a nice feature of go where you can declare methods on any baseType by aliasing them to your own type.

There is no struct involved here and there doesn't need to be which is nice.

ihswvor 12 Jahren

I've found that when discussing Go, the terms `struct` and `type` are usually used interchangeably. Yes it's factually incorrect, but the message is at least intelligible.