http and your angry dog

HTTP

ZendCon 2014

& Your Angry Dog

Ross Tuck

Freerange CodemonkeyKnow-It-All

Hot-Air Balloon

@rosstuckrosstuck.com

http://twitter.com/rosstuck

http://rosstuck.com/

Today's topic:

HTTP & Dogs

The Agenda

Basics

Client Server

Request

Response

POST /gists HTTP/1.1

Authorization: Basic xxxxxxxx

Host: api.github.com

Content-Length: 146

{

"description": "the description for this gist",

"public": false,

"files": {

...

Request




Content-Length: 146

{


"public": false,

"files": {

...

Request

2 Parts




Content-Length: 146

{


"public": false,

"files": {

...

Request

The body




Content-Length: 146

<!DOCTYPE html>

<html>

<head>

<meta charset='utf-8'>

<title>My application</title>

...

Request

The body




Content-Length: 146

{


"public": false,

"files": {

...

Request

The body




Content-Length: 146

{


"public": false,

"files": {

...

Request




Content-Length: 146

{


"public": false,

"files": {

...

Request

The headers




Content-Length: 146

{


"public": false,

"files": {

...

Request

The good stuf




Content-Length: 146

{


"public": false,

"files": {

...

Request




Content-Length: 146

{


"public": false,

"files": {

...

Request

GET, POST, PUT, DELETE




Content-Length: 146

{


"public": false,

"files": {

...

Request Relative URLHTTP version




Content-Length: 146

{


"public": false,

"files": {

...

Request

Key/Value pairs




Content-Length: 146

{


"public": false,

"files": {

...

Request

HTTP/1.1 201 Created

Date: Sun, 09 Sep 2012 11:42:41 GMT

Content-Length: 1848

Location: https://api.github.com/gists/a43a0cf58

{


"comments": 0,

"created_at": "2012-09-09T11:42:40Z",

...

ResponseStatus code

• 2xx

• 3xx

• 4xx

• 5xx

OK!

Over there!

Client screwed up!

Server screwed up!

Content Negotiation

GET /dogs/corgi HTTP/1.1

Host: api.example.com

Request

HTTP/1.1 200 OK

Date: Sun, 26 Aug 2012 18:00:43 GMT

{

"cute": true,

"big": false,

"data_dog": true

}

Response

HTTP/1.1 200 OK

Date: Sun, 26 Aug 2012 18:00:43 GMT

<dog breed="corgi">

<cute>true</cute>

<data capacity="on" />

</dog>

Response



Request

GET /dogs/corgi.json HTTP/1.1


Request

/dogs/corgi.json !== /dogs/corgi.xml

Imagine the URL as your primary key.



Request

GET /dogs/corgi?_format=json HTTP/1.1


Request

POST /dogs/corgi?_format=json HTTP/1.1


Request



Request



Accept: application/json

Request

More POWAH



Accept: application/json

Request



Accept: application/json, application/xml

Request

How do I choose?




Request

HTTP/1.1 200 OK

Date: Sun, 26 Aug 2012 18:00:43 GMT

Content-Type: application/json

{

"cute": true,

"big": false,

"data_dog": true

}

Response

Nifty.




Request

text/html, text/plain

text/html;key=value, text/plain

text/html;key=value;foo=bar, text/plain

text/html, text/plain

text/html, text/plain;q=0.5

Quality(Default 1.0)

text/html, text/plain;q=0.5, text/*;q=0.1

Wildcards

text/html, text/plain;q=0.5, */*;q=0.1

Anything at all

Accept HeadersLittle weird...

But not so scary.

text/html,application/xhtml+xml,

application/xml;q=0.9,*/*;q=0.8

Cool...

What the heck is it good for?

Accept is a “Pattern”

Accept-LanguageAccept-EncodingAccept-CharsetAccept-Ranges

Content-LanguageContent-Encoding(works differently)

Content-Range

Resource vs Representation

/dog/corgi

JSON, Dutch,Gzipped,/dog/corgi

Resource vs Representation

Best way to version your API.

Arguably.Right now.

/v1/dogs/corgi

Accept: application/vnd.dogipedia-v1+json

Accept: application/vnd.dogipedia-v2+json

Client Server



Client ServerProxy



Client ServerProxy



Accept: application/json, text/plain

User-Species: cat

Same URL.Different output.

WTF should I return?

Client ServerProxy



Accept: application/json, text/plain

User-Species: cat

Client ServerProxy

Here's how.

Hint:Involves theVary header!

Client ServerProxy

/dogs/corgiAccept: application/json, text/plainUser-Species: cat

HTTP/1.1 200 OK

Date: Sun, 26 Aug 2012 18:00:43 GMT


Vary: Accept

{“json”: “omgz”}

Response

Client ServerProxy

URL and Accept?Okay, I got this.

Some time later...

Client ServerProxy

/dogs/corgiAccept: application/json, text/plainUser-Species: aardvark

Client ServerProxy

Valid cache.I has it.

Client ServerProxy

ZZ ZZZ

Z

HTTP/1.1 200 OK

Date: Sun, 26 Aug 2012 18:00:43 GMT


Vary: Accept


Response

HTTP/1.1 200 OK

Date: Sun, 26 Aug 2012 18:00:43 GMT


Vary: Accept, User-Species


Response

HTTP/1.1 200 OK

Date: Sun, 26 Aug 2012 18:00:43 GMT


Vary: Accept, User-Species

{“json”: “dogs rule, cats drool”}

Response

Request headers.Not Response!

Bad Reputation?2 Reasons

1. Accept-Encoding -Language

2. Internet Explorer

Caching

ExpiresPragma

Cache-Control

Expires

Cache-Control

HTTP 1.0

HTTP 1.1

HTTP/1.1 200 OK

Expires: Wed, 29 Oct 2014 22:00:00 GMT

{“herp”: “derp”}

Response

HTTP/1.1 200 OK

Cache-Control: max-age=120


Response

HTTP/1.1 200 OK


Response

Expires

Cache-Control

HTTP 1.0

HTTP 1.1

HTTP/1.1 200 OK



Response

HTTP/1.1 200 OK

Cache-Control: max-age=120, s-maxage=120


Response

Dude, Where's my dash?

publicprivate

no-storeno-cache

no-transform

must-revalidateproxy-revalidate

Mark Nottingham's Caching Tutorialhttp://www.mnot.net/cache_docs/

Much better than me.

Conditional Requests

The Part About ETags

http://www.mnot.net/cache_docs/

Conditional Requests

DELETE /ross/reputation HTTP/1.1

Host: api.joind.in

If-Talk-Quality: Crap

Request

if ($talkQuality === 'Crap') {

delete($rossReputation);

}

Not real code

Server

What kind of conditions?

If-MatchIf-None-Match

If-Modified-SinceIf-Unmodified-Since

If-Range

ETags

Datetimes

Either

Wait a second, Ross.

Audience

What the heck is an ETag?

A string.Any string.

One rule:

Represent the current state.

“14”“a381bedb5d4478053eb04be35f8798dd”

“winnie-the-pooh”

...for the current representation.

etag(“v14-json-en”) !== etag(“v14-xml-en”)

Don't cross the streams

Server

Last Modified Date sounds easier...

Audience

Wed, 15 Nov 1995 04:58:08 GMT

One second of precision

Caching With Conditionals

Use Case

GET /gists/3481910 HTTP/1.1


Accept: */*

Request

HTTP/1.1 200 OK

Server: nginx/1.0.13

Date: Sun, 26 Aug 2012 18:00:43 GMT

Vary: Accept

ETag: "f4e15911542b92b44bb38186e71cc8f5"

"history": [

{

"version": "529f6311d5518977534b6e1fd313...",

...

Response

...

"user": {

"gravatar_id": "c26bfcbd5f786591e036fa0",

"avatar_url": "https://secure.gravatar...",

"login": "rosstuck",

"url": "https://api.github.com/users/rosstuck",

"id": 146766

},

"change_status": {

"additions": 1,

"deletions": 0,

"total": 1

},

Response

"url": "https://api.github.com/gists/348...",

"committed_at": "2012-08-26T17:40:03Z"

}

],

"git_pull_url": "git://gist.github.com/34819...",

"forks": [

],

"html_url": "https://gist.github.com/3481910",

"git_push_url": "[email protected]:3481910.git",

"comments": 0,

"user": {

Response

HTTP/1.1 200 OK


Date: Sun, 26 Aug 2012 18:00:43 GMT

Vary: Accept

ETag: "f4e15911542b92b44bb38186e71cc8f5"

{

"history": [

{

"version": "529f6311d5518970903cb5427534b6e1fd313aca",

"user": {

"gravatar_id": "c26bfcbd5f786591e036fa0958a11e8b",

"avatar_url": "https://secure.gravatar.com/avatar/c26bfcbd5f786591e036fa0958a11e8b?d=https://a2...



"id": 146766

},

"change_status": {

"additions": 1,

"deletions": 0,

"total": 1

},

"url": "https://api.github.com/gists/3481910/529f6311d5518970903cb5427534b6e1fd313aca",

"committed_at": "2012-08-26T17:40:03Z"

}

],

"git_pull_url": "git://gist.github.com/3481910.git",

Response

"forks": [

],

"html_url": "https://gist.github.com/3481910",

"git_push_url": "[email protected]:3481910.git",

"comments": 0,

"user": {

"gravatar_id": "c26bfcbd5f786591e036fa0958a11e8b",

"avatar_url": "https://secure.gravatar.com/avatar/c26bfcbd5f78659....",}



"id": 146766

},

"public": true,

"created_at": "2012-08-26T17:40:03Z",

"files": {

"gistfile1.txt": {

"type": "text/plain",

"filename": "gistfile1.txt",

"raw_url": "https://gist.github.com/raw/3481910/8b6946739e8098408ee3af96...

"content": "Hello PFC!",

"language": null,

"size": 10

}

},

"description": "",

"url": "https://api.github.com/gists/3481910",

"updated_at": "2012-08-26T17:40:03Z",

"id": "3481910"

}



Accept: */*

If-None-Match: "f4e15911542b92b44bb38186e71cc8f5"

Request

HTTP/1.1 304 Not Modified


Date: Sun, 26 Aug 2012 18:00:43 GMT

Vary: Accept

ETag: "f4e15911542b92b44bb38186e71cc8f5"

Response

https://secure.gravatar.com/avatar/c26bfcbd5f786591e036fa0958a11e8b?d=https://a248.e.akamai.net/assets.github.com/images/gravatars/gravatar-user-420.png



Date: Sun, 26 Aug 2012 18:00:43 GMT

Vary: Accept

ETag: "f4e15911542b92b44bb38186e71cc8f5"

Response



Date: Sun, 26 Aug 2012 18:00:43 GMT

Vary: Accept

ETag: "f4e15911542b92b44bb38186e71cc8f5"

Response

No giant body!

Caching.You has it.



Accept: */*

If-None-Match: "a381bedb5d4478053eb04be35f8798dd"

Request



Accept: */*

If-None-Match: "ross-is-a-poo-poo-head"

Request

HTTP/1.1 200 OK


Date: Sun, 26 Aug 2012 18:00:43 GMT

Vary: Accept

ETag: "f4e15911542b92b44bb38186e71cc8f5"

"history": [

{

"version": "529f6311d5518977534b6e1fd313...",

Response

No ETag Old ETag Matching ETag

Full BodyFull BodyNo Body

→

→

→

...on supported servers.

ParsingBandwidth

Response time

Probably

.Maybe

However...

“The fastest request is one you don't make.”

- Jesus

More Fun With ETags

Optimistic Concurrency Control

“Record Versioning”

Request



Accept: */*


Request

PATCH /gists/3481910 HTTP/1.1


Accept: */*


Request



Accept: */*

If-Match: "f4e15911542b92b44bb38186e71cc8f5"

Request



Accept: */*


{ "description": "cheese om nom nom" }

Request

Response

Response

HTTP/1.1 200 OK


Date: Sat, 01 Sep 2012 14:01:38 GMT

ETag: "899b76047a5e68445668374c2e0faa32"

{

"description": "cheese om nom nom",

"user": {


...

It works.

So what?

What if I send something...



Accept: */*

If-Match: "899b76047a5e68445668374c2e0faa32"


Request



Accept: */*

If-Match: "stay-puft-marshmellow-dog!"


Request

HTTP/1.1 412 Precondition Failed


Date: Sun, 26 Aug 2012 18:00:43 GMT

Response

Response

if (“stay-puft-marshmellow-dog” == “f4e1591..”) {

patchTheRecord();

}

Server

if (“stay-puft-marshmellow-dog” == “f4e1591..”) {

patchTheRecord();

} else {

sendScary412Message();

}

Server

Your ETag is out of date.

“Two guys on the same record” problem

Scary Precondition Error pt. 2

DisclaimerNew Stuff Ahead

DELETE /gists/3481910 HTTP/1.1


Request

HTTP/1.1 428 Precondition Required


Date: Sun, 26 Aug 2012 18:00:43 GMT

Response

Am I operating on the latest version?



Request

HTTP/1.1 204 No Content


Date: Sun, 26 Aug 2012 18:00:43 GMT

Response

Look before you leap.

Tooling

Epilogue: HTTP & Dogs

Content NegotiationVary

CachingPreconditions

Treat it like your framework.

Questions?

Resources

• RFC 7231–Sections 4 - 7

• http://redbot.org/

• http://mnot.net/cache_docs/

• http://charlesproxy.com/

• http://guzzlephp.org/

Image Credits• http://www.sxc.hu/photo/555539• http://www.flickr.com/photos/thedalogs/2953136078/• http://www.sxc.hu/photo/678952• http://www.flickr.com/photos/designgate/8317884432/• http://www.flickr.com/photos/barretthall/3289317664/• http://www.flickr.com/photos/binaryape/3702275400/lightbox/• http://www.flickr.com/photos/istolethetv/2956799679/in/photostream/• http://theflashbackspodcast.blogspot.nl/2012/01/30-day-film-challenge-day-8.html• http://www.flickr.com/photos/jonomueller/6906420190/• http://www.flickr.com/photos/cookbookman/6175752147• http://www.flickr.com/photos/creativedc/2913123330/• http://www.flickr.com/photos/epc/44053757/• http://www.flickr.com/photos/soggydan/4698849104/• http://www.flickr.com/photos/owldreams/4430175427/• http://www.flickr.com/photos/piddleville/2499539542/• http://www.flickr.com/photos/danja/5665671907/• http://www.flickr.com/photos/cradlehall/3574160744/• http://www.flickr.com/photos/ironypoisoning/7114801437/• http://www.flickr.com/photos/piddleville/2499539542/lightbox/• http://everydayidrawadog.blogspot.nl/2009_02_01_archive.html

joind.in/12071

@rosstuck

Ross Tuckrosstuck.com

http and your angry dog

Technology