GeekOut 2016; Tallinn, Estonia; 9 June 2016. Video is here: https://www.youtube.com/watch?v=7yTIWFZrXpg

1. /17@yegor256 1
Chat Bot
Architecture
Yegor Bugayenko

2. /17@yegor256 2
www.rultor.com

3. /17@yegor256 3
#45
@rultor deploy
@yegor256 will try
@yegor256 done
@yegor256

4. /17@yegor256 4
1. No schema
2. No mess
3. No DB server

5. /17@yegor256 5
talks
name xml
yegor256/takes#123 <talk>
<server>
...
</server>
<daemon>
...
</daemon>
</talk>

6. /17@yegor256 6
active = // from github notifications
for (Talk talk : active) {
talk.modify(
patch.apply(
talk.read()
)
);
}

7. /17@yegor256 7
interface Patch {
Directives apply(XML talk);
}
xembly

8. /17@yegor256 8
XPATH “/garage”;
ADD “car”;
ADD “name”;
SET “Toyota”;
UP;
ADD ”price”;
SET “$15,000”;
<garage/>
<garage>
<car>
<name>Toyota</name>
<price>$15,000</price>
</car>
</garage>
xembly.org

9. /17@yegor256 9
Patch
XML1
XML2
?

10. /17@yegor256 10
new Patch.Iterative(
new Understood(),
new RequestBuilt(),
new DaemonStarted(),
new DaemonEnded()
);
over
20

11. /17@yegor256 11
class Understood implements Patch {
@Override
public Directives apply(XML xml) {
// read github and understand request
return new Directives()
.xpath(“/talk”)
.add(“request”)
.add(“type”)
.set(“deploy”); // here!
}
}

12. /17@yegor256 12
<talk>
</talk>
<talk>
<request>
<type>deploy</type>
</request>
</talk>
Understood

13. /17@yegor256 13
class RequestBuilt implements Agent {
@Override
public Directives apply(XML xml) {
String type = xml.xpath(
“/talk/request/type/text()”
).get(0);
return new Directives()
.xpath(“/talk/request”)
.add(“script”)
.set(“mkdir tmp; chmod ...”);
}
}

14. /17@yegor256 14
<talk>
<request>
<type>deploy</type>
<script>
mkdir tmp;
cd tmp;
...
</script>
</request>
</talk>
RequestBuilt
<talk>
<request>
<type>deploy</type>
</request>
</talk>

15. /17@yegor256 15
new Patch.Iterative(
new Understood(),
new Patch.If(
new RequestBuilt(),
“/talk/request/type”
),
new Patch.If(
new DaemonStarted(),
“/talk/request/script”
),
new DaemonEnded()
);

16. /17@yegor256 16
1. Easy to extend
2. Still strict (XSD)
3. Small objects (patches)
4. Easy to test/reproduce
5. High visibility

17. /17@yegor256 17
www.yegor256.com
make sense?