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I gave a modified version of my talk at Google.
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WEB HOOKSProgrammable World of Tomorrow
and the
Jeff Lindsaythree years after coining web hooks, people are starting to get excited about them.i’m going to share what they are, why they’re significant, and what’s going on in the growing web hooks ecosystem
WEB HOOKSProgrammable World of Tomorrow
and the
Jeff Lindsayi’ve given a version of this talk before, but this time i’d like to try and focus on this “programmable” idea that helped inspire web hooks.
WARNING:
Emergent dynamics described ahead.
was a guy really excited hearing about web hooks, but was disappointed to see what they are.i’m describing a game changer based on a mechanism that takes one line of code to describe.seems so simple, people assume you can only do simple things. quite the contrary...
go. simple mechanisms can create rich dynamics.easily teach somebody the rules, doesn’t mean they see the implications of those rules.i want to share the implications of this simple mechanism.
in 1997, jon udell talks about websites as data sources that can be reused and remixedtoday that idea isn’t very novel
“a new programming paradigm that takes the whole Internet
as its platform”he envisions the Internet as a programming paradigm
The Programmable Web“The Web as Platform”
it starts to manifest as the programmable web and talk of “the web as a platform”
The Programmable WebAPIs and Mashups
john musser here starts to track apis and mashups in 2005. there are now over 1k apis and increasingly more.apis and mashups became the foundation of the programmable web...
The Programmable WebProgrammatic
APIs and Mashups
but are they? after thinking about web hooks and what they can give us, i realized apis and mashupsdon’t make a programmable web. they make a programmatic web
The Programmable WebTwitter API lets you use Twitter programmatically.It does not let you program Twitter to do more.
Programmatic
they let you use web apps programmatically. they don’t let you program them to do more, whereas web hooks can. so i like to argue that web hooks will bring about the *real* programmable web.
interwebz
User
Web Service
so let’s get specific. here’s an example scenario showing the use of web hooks.
interwebz
User
Web ServiceHi, I’m Twickr,
a new web service.
interwebz
User
“Twickr”
Cool. Sign me up.
interwebz
User
“Twickr”Okay, you’re all set. Now listen...
interwebz
User
“Twickr”I might find myself with some
data you might be interested in.
interwebz
User
“Twickr”
Alight, hold on a sec...
interwebz
User
“Twickr”
hack hackety hack
interwebz
User
“Twickr”
Could you just post it here when you have any?
http://tinyurl.com/6pln4u
interwebz
User
“Twickr”...sure, why not.
Hmm, what is that URL?
interwebz
User
“Twickr”
It’s a tiny handler I putup on App Engine.
interwebz
User
“Twickr”
What does it do?
interwebz
User
“Twickr”
It doesn’t matter to you.Whatever I want...
web hooks are just user-defined http callbacks
interwebz
UserEMPOWERED
EXTENSIBLEWeb Service
but do you see what they did? they made the web service extensible and empowered the user.
a friend of mine got me to explain web hooks to her. not a programmer, but has iphone.she compared it to jailbreaking the iphone: letting users do what they want, customize, add apps, etchaving web hooks is like jailbreaking your web apps. opens functional extensibility.
a pseudo code example of what the heart of implementing web hooks looks like.SIMPLE: make an HTTP request to a user-specified URL on major events
paypal represents on the oldest web hook implementors
their instant payment notification is a web hook
“When a customer pays you, PayPal posts a notification to your server at a URL you specify.”
its framed as a notification, but that doesn’t properly imply the usage its intended for: integration.
started thinking about this in 2006.everything flashed before my eyes and was very confused why it wasn’t used more.felt like i was taking crazy pills. today i know why...
compare to REST.
both have been around longer. rest is simpler.. in fact, it’s almost described as “using HTTP properly”but not until it got a name could it be used in discourse to make it popular
REST
Hooks
rest apis and web hooks are two sides of the same cointhey complement each other in ways i’ll get to laterbut i just want to give this pattern a name, and start associating some ideas with it
Push
Pipes
Plugins
talk is split into three sectionsways to look at the use of web hooksicons will hopefully make more sense as i talk about them
Pushlet’s get started with pushpeople are starting to talk about push and pubsub on the web... although its not the first time
1998 (predating rss) microsoft submitted an internet draft to extend httpto provide a basic pubsub framework called GENA
it had your standard pubsub terms
and added 4 new methods to http.
it expired a year later in 1999 and the group behind it seemed to disappear.however...
Sneaky!
the methods and protocol ended up in the webdav implemented for exchange
but then in 2000, rss 0.92 was released. five years later it gets an icon and widespread adoption.it started with blog feeds, then comment feeds...
then soon exploded into twitter feeds, photo feeds, activity feeds, event feeds, bookmark feedseven feeds of feeds
then soon exploded into twitter feeds, photo feeds, activity feeds, event feeds, bookmark feedseven feeds of feeds
then soon exploded into twitter feeds, photo feeds, activity feeds, event feeds, bookmark feedseven feeds of feeds
then soon exploded into twitter feeds, photo feeds, activity feeds, event feeds, bookmark feedseven feeds of feeds
then soon exploded into twitter feeds, photo feeds, activity feeds, event feeds, bookmark feedseven feeds of feeds
then soon exploded into twitter feeds, photo feeds, activity feeds, event feeds, bookmark feedseven feeds of feeds
then soon exploded into twitter feeds, photo feeds, activity feeds, event feeds, bookmark feedseven feeds of feeds
it makes you think of feeds like in the telecom world
data coming directly to you
but we know that’s not how it works
?
instead we have to go request the data
then it gives it to us. and we do this over and over. are we there yet? are we there yet?
?
feeds made sense in a world where feed readers ran on desktops that couldn’t be pushed to over http
?
of course, now we have other web applications consuming feeds and it doesn’t make sense.even most of our feed readers have become web applications
SUP is a recent incremental solution to increase the efficiency of consuming large amounts of feeds.however, its based on polling and is essentially yet another feed, so i couldn’t help...
SUP DAWG, WE HEARD YOU LIKE FEEDSSO WE MADE YOU A FEED OF OUR FEEDS
evan and kellan gave a great talk a while back about this push issue, and their proposed solution: xmppi have a condensed version of this talk. the slides speak for themselves
(aka XMPP)
they have a great point. polling sucks, and xmpp is a pretty good solution for data streams
but it’s kind of heavy weight. it does a lot and makes a decently complex little system.luckily it’s not *that* hard to use with today’s library support
evan and kellan did point out there are extremes when it comes to data streams.most data streams will probably fall somewhere in between,but i do think xmpp is suited for the fast and furious end
joshua schachter of delicious responded to this talk in a blog post.he basically suggests web hooks as an alternative
“One solution that occurred to me at the time was to build a simple callback system over HTTP.This would fall comfortably between full polling and full persistent publish/subscribe.”
he says they fall comfortably between polling and xmpp. i agree, and think they can cover most use-cases
others seem to agree....this is a standard for discovering and subscribing to content changes.they let you use web hooks OR xmpp, which is nice.good idea, but (like GENA) standard specs alone don’t get very far
gnip is a service that some may have heard of (but don’t understand)
Polling
their main goal is to stop polling as a service in the middle.
RSSAtomXML
Format
Web HooksXMPP
REST
Protocol + Mechanism
Web HooksXMPP
REST
Protocol + Mechanism
RSSAtomXML
Format
Source Destination
Publisher Consumer
they’re basically an adaptor for data streams, letting you pick your own protocol and mechanism, no matter what the feed publisher is providing.
RSSAtomXML
Format
Web HooksXMPP
REST
Protocol + Mechanism
Web HooksXMPP
REST
Protocol + Mechanism
RSSAtomXML
Format
Source Destination
Publisher Consumer
however, they recently dropped support to consume via xmpp, making web hooks their primary push mechanism for consuming data streams.
RSSAtomXML
Format
Web HooksXMPP
REST
Protocol + Mechanism
Web HooksXMPP
REST
Protocol + Mechanism
RSSAtomXML
Format
Source
Publisher Consumer
as an example, if i wanted to get digg updates via web hooks, gnip will poll digg for me and invoke my callback with the content as new updates come in.
RSSAtomXML
Format
Web HooksXMPP
REST
Protocol + Mechanism
Web HooksXMPP
REST
Protocol + Mechanism
RSSAtomXML
Format
Source
Publisher Consumer
alternatively, i could even poll gnip for digg updates. although seemingly redundant, it helps ease the load on digg and allows gnip to provide filtering functionality.
RSSAtomXML
Format
Web HooksXMPP
REST
Protocol + Mechanism
Web HooksXMPP
REST
Protocol + Mechanism
RSSAtomXML
Format
Publisher Consumer
but another example might be if twitter provides an xmpp stream, but i already have a polling setup... gnip would let me poll instead of integrate xmpp.
microformats
in promoting web hooks, i sort of look up to the way microformats work in values and process.very ground up, grassroots... take existing popular use-patterns and make it a convention.microformats can be viewed as an alternative xml+rdf
“Here's a new language we want you to learn, and now you need to output these additional files on your server. It's a hassle. (Microformats) lower the barrier to entry.”
xml+rdf vs microformats
tantek is a big microformats evangelist. he says....
so i told him about web hooks. “what are they?” “push over http” “how are they diff than xmpp?” “they’re a lightweight alternative” lower the barrier to entry...
“Good. XMPP needs a competitor.”
xmpp vs web hooks
he says...
this was encouraging. i mean, when tantek talks, you listen...if for no other reason than
he gets the chicks
unfortunately, xmpp has many features and proposals to do pubsub that web hooks doesn’t.... after all, it’s just a creative use of http requests, not a messaging protocol. so in order to do pubsub with web hooks, you need more to be implemented. well, brad fitzpatrick and brett slatkin are working on that.
Push is good.
so the moral here is that push is good and there’s finally a demand for it. we have some good solutions waiting adoption...
XMPP is ideal when needed,but Web Hooks generally do the job.
as far as xmpp vs web hooks, i think they both have their place. web hooks are easier, so you might as well default to web hooks unless you really need xmpp.
But push is not the point.
however, as i framed this talk, it’s really not about push. it’s a nice way to get the social media kids into bed with web hooks, but hooks are really about more than pubsub and notifications. otherwise i would have called them web notifications or something...
Pipesinstead of push, i was more drawn by the pipes metaphor. i wanted to integrate and orchestrate the web applications i use, conceptually similar to unix pipelining.
so i thought about it. pipes were a really amazing feature that let you get more out of your commands by letting you chain them together. it sort of let you program without programming, combining commands in ways that weren’t necessarily intended by the author.
Program
Input Output
all from a bit of infrastructure involving input and output
Program
STDIN STDOUT
STDERR
stdin, stdout were available to reroute wherever the user wantedmost common use was chaining commands together: piping
cat
xargs
wc
mailecho
grep
wget
so you had all these simple little programs, that might not even be useful alone
cat
xargs
wc
mailecho
grep
wget
string them together...
grepcat
xargs
wc
mailecho
wget
mailgrepcat
xargs
wc
echowget
and you have something more useful than the sum of the parts
Write programs to work together.
Write programs that do one thing and do it well.
Write programs that handle text streams, because that is a universal interface.
this helped put forth the unix philosophy and encouraged building these small composable commands
Program
STDIN
but it doesn’t work without the output. it just breaks.
Web App
API
unfortunately that’s how the web is today. we can talk to web apps, but they really can’t talk to us. or anything else really.
Web App
API Hooks
it’s not that they can’t, they just don’t. we just need to start putting hooks in so they can.those roles are best played by mechanisms that use the protocol the web is built on: http
backhoe
+
front-loader + excavator
Basecamp
mailgrepcat
so we want to combine web applications like we can CLI programs.get more than the sum of the parts. web hooks open up this possibility, but need like APIs, need to be implemented
Basecamp
imagine basecamp with a bunch of hooks for events
Basecamp
Project finished
Todo completed
Milestone created
Contact added
File uploaded
Basecamp
My handlerhttp://example.com/handler
users can write handlers that are just web scripts. they have a url, and thats what you give basecamp
Basecamp
My handlerhttp://example.com/handler
it’s code. it can do anything from there. integrate with other services, make a phone call, order pizza, whatever
Basecamp
Todos
for example, all these apps share data about todos. they each have respective specialized talents,but all work with todos. by putting hooks on todo CRUD, you can use their apis to keep them synced pretty well. magically. real-time.
Service integration
web hooks enable service integration
Composability
adding composability to web apps
Code as glue
based on the idea that web urls can run code. and code can do anything.
when i first thought about this, cheap PHP hosting was all over, but it could be even simpler.there are paste bins like this one. made to share formatted code with people over IRC or email
put in some code you want to share or ask a question about
http://pastie.org/84826
hit save and you get a URL you can share when you ask “where’s the data stored?”
i’m thinking of the same thing, but that you write handlers with
http://pastie.org/run/24576
and saving doesn’t just give a url to view, but to run. pass that url into an app with web hooks
Basecamp
Project finishedhttp://pastie.org/run/24576
for example, basecamp. now when you finish a project, everybody meets for shots in the break room.
fortunately, we have this. it’s called appjet by ex googlers.
just hit a button, write code, hit save, share the url. it’s javascript
obviously app engine, although it’s a little more involved than appjet for quick handlers.but it is an option for python.and there are ruby/rails hosts like heroku
one thing i’ve been working on is an extension to play with ways end-users might interact with web hooks
Hey, there’s an event hook here!
by detecting some markup in a page, it discovers hooks. like say for new photos from contacts.you want to do something when that happens, click it
Save
and write some code. hit save, it posts to AppJet (or wherever), registers the handler (assuming a standard protocol), and done. all inline.go back and change the code.
Real world examples
but these are all mockups and what-ifs... there is a world of web hooks already evolving...
i started by exposing svn hooks as web hooks in devjavu
i talked about web hooks enough using pbwiki as an example, their mysterious cto decided to implement them
and apparently really liked what he found
went all out on hooked events. not sure if it’s made it to production, but really cool
“Building projects with web hooks in mind lets me keep the core Lighthouse source focused, while external services live in their own libraries.”
--Rick Olson
the idea silently spread to rails guys.rick olson used them in lighthouse
“We implemented web hooks a while ago and people have been building all sorts of unexpected stuff on top of it.”
--Tobias Lütke
tobias used them in shopify. i’m told he’s revamping their api to have more hooks. they were one of the earliest adopters and recently had their 1 yr anniversary using web hooks
google code recently caught up other code hosts by providing a post commit hook. it was very well done, as you’d expect from google and in particular shows that authentication can be done with hmac signatures
github was one of the first majorly popular site to use and promote web hooks.
they’ve been doing really well with their post-receive hook. users have used it to integrate with mailing lists, chat, other project management tools, continuous integration, etc
they were so successful with the adhoc integration, they formalized it.but in the best way! using their existing web hook infrastructure. they just have modules running in a separate but local web service.
in fact, that lets them open source it. letting people fork, write new handlers, and push back.this is probably going to be the standard model of service integration.
and a great example of services integrated with github, besides lighthouse, is runcoderun.they run your regression tests for you. continuous integration in the sky. love it.they sign you up automatically if you put their hook in github.
and of course i mentioned paypal. but i should mention, web hooks make so much sensefor paypal... they’re not so much about pushing content, but INTEGRATING. that’s whatweb hooks are great for, even though they can be used for content push.
jott is another example of a web hook implementer that doesn’t know it. they parse voice over the phone and do stuff with it, like post to twitter, etc
they do it with “Links”... which are just hooks. they post to a script that does something with the parsed text. really cool for todos.
User jotts toa Jott Link
The message isconvertedinto text
Message is sent viaHTTP Post to a
web page
Jott reads back theresponse and sendsit via SMS & SMTP
User receivesinformation back
here’s their diagram. totally web hooks.
it become obvious making adaptor services would not only be useful in specific cases, but in general, it makes sense to have services that will turn other protocols into inputs to the web hook ecosystem. the first was email... i built mailhook...
GAE community made one because GAE doesn’t have a way to accept email (but will soon). web hooks were the obvious solution.
rick olson has an open source non-hosted ruby version that will do xmpp.he uses it for lighthouse.
but smtp2web is interesting because it was made because of the limitations of GAE...
in fact a lot of people made these kinds of “micro webservices” to do simple things GAE didn’t do. it was the first glimpse at small, focused services that are like the equivalent of grep, cat, wordcount, etc in the command line piping ecosystem.
then there’s martyn and andy. two guys in the uk that love web hooks.they built this thing called spaghetti junction at a hackday. it involved into...
switchub. i REALLY love this. i knew this sort of thing would emerge, but i didn’t think it would happen until web hooks were more popular. kind of like the pastinbin code runner, they let you create hook inputs with urls to put in apps that you can route to various output handlers: email, irc, etc
my example switchboard. this kind of feels like gnip, only more focused and more about web hooks. so i like it lots.
opening handlers up like github. anybody can write handlers soon.working with them a little to make it real awesome.
switchub would benefit from builtin inputs from various other protocols like email, rss, etc... but instead of having them builtin, they can work with other services to support those kinds of inputs. for example, rssfwd could easily be modified to provide a web hook for rss
switchub is a lot like how i visualized a way for regular users to orchestrate web apps. was inspired by reason: virtual rack mounts
flip it around and wire them together however you like. totally cool.
Pluginsthere’s one more thing i want to talk about.
web was a bunch of pages linked together.
but people kept wanting to access other things through the web (like me today)
so they developed cgi
tangent: this is a neat find. was on reddit. andreessen proposing IMG tag.people fought it, said it needed to be more generalized.he just put it on mosaic and that was that
so these pages... today... because of cgi
are actually the result
of these higher order nodes... the code... the apps. this is most of the web today. neat how that evolved
so you have these applications
and the difference you might think is backend and frontend.but there is a subtly different way to think about it
PagesApplication
logic and content. the read-write web gave us user contributed content...i want user contributed (democratized) logic.
ContentFunction
logic and content. the read-write web gave us user contributed content...i want user contributed (democratized) logic.
ContentFunction
Integrate
not just integrating and composing apps
ContentFunction
IntegrateExtend
but extending apps...
almost called this section Platforms.platforms are really cool. we all love them.i LOVE them, so fb platform was really cool.asked a friend how it worked. he said “web hooks”
sure enough, this looks like web hooks to me. as long as it’s http, calling out... but then using the results in their app? thats different...
in fact a few people have used web hooks for plugins. dabble is a great example.
they do online databased for people that use excel as a database.
their plugin API is great. it uses web hooks!
“Dabble plugins allow Dabble applications to create new, derived fields by calling out to external HTTP-accessible applications. This solves the problem of safely enabling
extension of a centrally-located hosted application, in that, while you’re writing code to extend and enhance the behavior of a Dabble application, your code never
actually runs inside Dabble.”
[General]Name = Amazon Sales Rank
[Sales Rank by ISBN]URL = http://chadfowler.com/dabble/amazon_sales_rank.cgiInput = TextOutput = Number
only they have an extra layer for meta data. but that’s a cool pattern.
“If you’ve used a UNIX-based operating system, you’re probably familiar with the notion of pipes. The output of one program is piped into the input of another, creating a filter chain. This is conceptually the same as the way Dabble’s plugin IO works.
Nice and simple.”
of course, they compare it to pipes. the simplicity. the natural fit of it.
of course, i think they should have web hooks for all their standard CRUD events... this way their database apps can integrate (like PayPal) with the rest of your workflow
in fact, all these “app platforms” like coghead and salesforce should have web hooks.that would make them more useful, less silo’d off into just processing data in their world
IMified uses web hooks. sells the tech too: “allows anyone with basic web programming skills to quickly and easily create ...”
General SystemsTheory
close by dropping some GST on you
General SystemsTheory
central tenet is value is not in the elements or parts of a system
General SystemsTheory
the real value is in the interactions, how they work together. this creates the emergent phenomenon of a system, and defines its behavior
Degrees of freedom
increase the ways to work together, the means of combination, increases the DoF
Increase possibility space
uncover new opportunities in business, tools, and empowerment
“a new programming paradigm that takes the whole Internet
as its platform”this vision for a programming paradigm that IS the internet/web is very compelling... but we’re not there yet.
The Programmable WebAPIs and Hooks
the real programmable web will require
http://flickr.com/photos/nikonfans/439432049/http://flickr.com/photos/omegaman/477866054/http://flickr.com/photos/aquan/2780542698/http://flickr.com/photos/lucky_13/191038503/http://flickr.com/photos/narwhal85/1290912011/http://flickr.com/photos/thomashawk/521532598/http://flickr.com/photos/bendodson/2601002535/http://flickr.com/photos/ntr23/218966763/http://flickr.com/photos/shrimphead/2259353414/http://flickr.com/photos/raphaelmuli/2913907316/http://flickr.com/photos/x180/467764284/http://flickr.com/photos/x180/1704475856/
Thanks!webhooks.org
“What is the equivalent of the pipein the age of the web?”
in 2000, just as rss 0.92 was being released, tim oreilly asks...
since we had nothing better, we assumed the answer was feeds.
this eventually gave us yahoo pipes. which just didn’t seem to change the game like you would think... perhaps feeds just aren’t the answer. or maybe they are and the problem is using the pipes analogy. it’s definitely a stretch...