CloStack
CloStack is a Clojure client for Apache CloudStack. Clojure is a dynamic programming language for the Java Virtual Machine (JVM). It is compiled directly in JVM bytecode but offers a dynamic and interactive nature of an interpreted language like Python. Clojure is a dialect of LISP and as such is mostly a functional programming language.
You can try Clojure in your browser and get familiar with its read eval loop (REPL). To get started, you can follow the tutorial for non-LISP programmers through this web based REPL.
To give you a taste for it, here is how you would 2 and 2:
user=> (+ 2 2)
4And how you would define a function:
user=> (defn f [x y]
#_=> (+ x y))
#'user/f
user=> (f 2 3)
5This should give you a taste of functional programming :)
Install Leinigen
leiningen is a tool for managing Clojure projects easily. With lein you can create the skeleton of clojure project as well as start a read eval loop (REPL) to test your code.
Installing the latest version of leiningen is easy, get the script and set it in your path. Make it executable and your are done.
The first time your run lein repl it will boostrap itself:
$ lein repl
Downloading Leiningen to /Users/sebgoa/.lein/self-installs/leiningen-2.3.4-standalone.jar now...
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 13.0M 100 13.0M 0 0 1574k 0 0:00:08 0:00:08 --:--:-- 2266k
nREPL server started on port 58633 on host 127.0.0.1
REPL-y 0.3.0
Clojure 1.5.1
Docs: (doc function-name-here)
(find-doc "part-of-name-here")
Source: (source function-name-here)
Javadoc: (javadoc java-object-or-class-here)
Exit: Control+D or (exit) or (quit)
Results: Stored in vars *1, *2, *3, an exception in *e
user=> exit
Bye for now!Download CloStack
To install CloStack, clone the github repository and start lein repl:
git clone https://github.com/pyr/clostack.git
$ lein repl
Retrieving codox/codox/0.6.4/codox-0.6.4.pom from clojars
Retrieving codox/codox.leiningen/0.6.4/codox.leiningen-0.6.4.pom from clojars
Retrieving leinjacker/leinjacker/0.4.1/leinjacker-0.4.1.pom from clojars
Retrieving org/clojure/core.contracts/0.0.1/core.contracts-0.0.1.pom from central
Retrieving org/clojure/core.unify/0.5.3/core.unify-0.5.3.pom from central
Retrieving org/clojure/clojure/1.4.0/clojure-1.4.0.pom from central
Retrieving org/clojure/core.contracts/0.0.1/core.contracts-0.0.1.jar from central
Retrieving org/clojure/core.unify/0.5.3/core.unify-0.5.3.jar from central
Retrieving org/clojure/clojure/1.4.0/clojure-1.4.0.jar from central
Retrieving codox/codox/0.6.4/codox-0.6.4.jar from clojars
Retrieving codox/codox.leiningen/0.6.4/codox.leiningen-0.6.4.jar from clojars
Retrieving leinjacker/leinjacker/0.4.1/leinjacker-0.4.1.jar from clojars
Retrieving org/clojure/clojure/1.3.0/clojure-1.3.0.pom from central
Retrieving org/clojure/data.json/0.2.2/data.json-0.2.2.pom from central
Retrieving http/async/client/http.async.client/0.5.2/http.async.client-0.5.2.pom from clojars
Retrieving com/ning/async-http-client/1.7.10/async-http-client-1.7.10.pom from central
Retrieving io/netty/netty/3.4.4.Final/netty-3.4.4.Final.pom from central
Retrieving org/clojure/data.json/0.2.2/data.json-0.2.2.jar from central
Retrieving com/ning/async-http-client/1.7.10/async-http-client-1.7.10.jar from central
Retrieving io/netty/netty/3.4.4.Final/netty-3.4.4.Final.jar from central
Retrieving http/async/client/http.async.client/0.5.2/http.async.client-0.5.2.jar from clojars
nREPL server started on port 58655 on host 127.0.0.1
REPL-y 0.3.0
Clojure 1.5.1
Docs: (doc function-name-here)
(find-doc "part-of-name-here")
Source: (source function-name-here)
Javadoc: (javadoc java-object-or-class-here)
Exit: Control+D or (exit) or (quit)
Results: Stored in vars *1, *2, *3, an exception in *e
user=> exitThe first time that you start the REPL lein will download all the dependencies of clostack.
Prepare environment variables and make your first clostack call
Export a few environmen variables to define the cloud you will be using, namely:
export CLOUDSTACK_ENDPOINT=http://localhost:8080/client/api
export CLOUDSTACK_API_KEY=HGWEFHWERH8978yg98ysdfghsdfgsagf
export CLOUDSTACK_API_SECRET=fhdsfhdf869guh3guwghseruigThen relaunch the REPL
$lein repl
nREPL server started on port 59890 on host 127.0.0.1
REPL-y 0.3.0
Clojure 1.5.1
Docs: (doc function-name-here)
(find-doc "part-of-name-here")
Source: (source function-name-here)
Javadoc: (javadoc java-object-or-class-here)
Exit: Control+D or (exit) or (quit)
Results: Stored in vars *1, *2, *3, an exception in *e
user=> (use 'clostack.client)
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
nilYou can safely discard the warning message which only indicates that 'clostack' is meant to be used as a library in a clojure project.
Define a client to your CloudStack endpoint
user=> (def cs (http-client))
#'user/csAnd call an API like so:
user=> (list-zones cs)
{:listzonesresponse {:count 1, :zone [{:id "1128bd56-b4d9-4ac6-a7b9-c715b187ce11", :name "CH-GV2", :networktype "Basic", :securitygroupsenabled true, :allocationstate "Enabled", :zonetoken "ccb0a60c-79c8-3230-ab8b-8bdbe8c45bb7", :dhcpprovider "VirtualRouter", :localstorageenabled true}]}}To explore the API calls that you can make, the REPL features tab completion. Enter list or de and press the tab key you should see:
user=> (list
list list* list-accounts list-async-jobs
list-capabilities list-disk-offerings list-event-types list-events
list-firewall-rules list-hypervisors list-instance-groups list-ip-forwarding-rules
list-iso-permissions list-isos list-lb-stickiness-policies list-load-balancer-rule-instances
list-load-balancer-rules list-network-ac-ls list-network-offerings list-networks
list-os-categories list-os-types list-port-forwarding-rules list-private-gateways
list-project-accounts list-project-invitations list-projects list-public-ip-addresses
list-remote-access-vpns list-resource-limits list-security-groups list-service-offerings
list-snapshot-policies list-snapshots list-ssh-key-pairs list-static-routes
list-tags list-template-permissions list-templates list-virtual-machines
list-volumes list-vp-cs list-vpc-offerings list-vpn-connections
list-vpn-customer-gateways list-vpn-gateways list-vpn-users list-zones
list?
user=> (de
dec dec' decimal? declare def
default-data-readers definline definterface defmacro defmethod
defmulti defn defn- defonce defprotocol
defrecord defreq defstruct deftype delay
delay? delete-account-from-project delete-firewall-rule delete-instance-group delete-ip-forwarding-rule
delete-iso delete-lb-stickiness-policy delete-load-balancer-rule delete-network delete-network-acl
delete-port-forwarding-rule delete-project delete-project-invitation delete-remote-access-vpn delete-security-group
delete-snapshot delete-snapshot-policies delete-ssh-key-pair delete-static-route delete-tags
delete-template delete-volume delete-vpc delete-vpn-connection delete-vpn-customer-gateway
delete-vpn-gateway deliver denominator deploy-virtual-machine deref
derive descendants destroy-virtual-machine destructure detach-iso
detach-volumeTo pass arguments to a call follow the syntax:
user=> (list-templates cs :templatefilter "executable")Start a virtual machine
To deploy a virtual machine you need to get the serviceofferingid or instance type, the templateid also known as the image id and the zoneid, the call is then very similar to CloudMonkey and returns a jobid
user=> (deploy-virtual-machine cs :serviceofferingid "71004023-bb72-4a97-b1e9-bc66dfce9470" :templateid "1d961c82-7c8c-4b84-b61b-601876dab8d0" :zoneid "1128bd56-b4d9-4ac6-a7b9-c715b187ce11")
{:deployvirtualmachineresponse {:id "d0a887d2-e20b-4b25-98b3-c2995e4e428a", :jobid "21d20b5c-ea6e-4881-b0b2-0c2f9f1fb6be"}}You can pass additional parameters to the deploy-virtual-machine call, such as the keypair and the securitygroupname:
user=> (deploy-virtual-machine cs :serviceofferingid "71004023-bb72-4a97-b1e9-bc66dfce9470" :templateid "1d961c82-7c8c-4b84-b61b-601876dab8d0" :zoneid "1128bd56-b4d9-4ac6-a7b9-c715b187ce11" :keypair "exoscale")
{:deployvirtualmachineresponse {:id "b5fdc41f-e151-43e7-a036-4d87b8536408", :jobid "418026fc-1009-4e7a-9721-7c9ad47b49e4"}}To query the asynchronous job, you can use the query-async-job api call:
user=> (query-async-job-result cs :jobid "418026fc-1009-4e7a-9721-7c9ad47b49e4")
{:queryasyncjobresultresponse {:jobid "418026fc-1009-4e7a-9721-7c9ad47b49e4", :jobprocstatus 0, :jobinstancetype "VirtualMachine", :accountid "b8c0baab-18a1-44c0-ab67-e24049212925", :jobinstanceid "b5fdc41f-e151-43e7-a036-4d87b8536408", :created "2013-12-16T12:25:21+0100", :jobstatus 0, :jobresultcode 0, :cmd "com.cloud.api.commands.DeployVMCmd", :userid "968f6b4e-b382-4802-afea-dd731d4cf9b9"}}And finally to destroy the virtual machine you would pass the id of the VM to the destroy-virtual-machine call like so:
user=> (destroy-virtual-machine cs :id "d0a887d2-e20b-4b25-98b3-c2995e4e428a")
{:destroyvirtualmachineresponse {:jobid "8fc8a8cf-9b54-435c-945d-e3ea2f183935"}}With these simple basics you can keep on exploring clostack and the CloudStack API.
Use CloStack within your own clojure project
Hello World in clojure
To write your own clojure project that makes user of clostack, use leiningen to create a project skeleton
lein new totoLein will automatically create a src/toto/core.clj file, edit it to replace the function foo with -main. This dummy function returns Hellow World !. Let's try to execute it. First we will need to define the main namespace in the project.clj file. Edit it like so:
defproject toto "0.1.0-SNAPSHOT" :description "FIXME: write description" :url "http://example.com/FIXME" :license {:name "Eclipse Public License" :url "http://www.eclipse.org/legal/epl-v10.html"} :main toto.core :dependencies [[org.clojure/clojure "1.5.1"]])
Note the :main toto.core
You can now execute the code with lein run john . Indeed if you check the -main function in src/toto/core.clj you will see that it takes an argument. Surprisingly you should see the following output:
$ lein run john
john Hello, World!Let's now add the CloStack dependency and modify the main function to return the zone of the CloudStack cloud.
Adding the Clostack dependency
Edit the project.clj to add a dependency on clostack and a few logging packages:
:dependencies [[org.clojure/clojure "1.5.1"]
[clostack "0.1.3"]
[org.clojure/tools.logging "0.2.6"]
[org.slf4j/slf4j-log4j12 "1.6.4"]
[log4j/apache-log4j-extras "1.0"]
[log4j/log4j "1.2.16"
:exclusions [javax.mail/mail
javax.jms/jms
com.sun.jdkmk/jmxtools
com.sun.jmx/jmxri]]])
lein should have created a resources directory. In it, create a log4j.properties file like so:
$ more log4j.properties
# Root logger option
log4j.rootLogger=INFO, stdout
# Direct log messages to stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%nA discussion on logging is beyond the scope of this recipes, we merely add it in the configuration for a complete example.
Now you can edit the code in src/toto/core.clj with some basic calls.
(ns testclostack.core
(:require [clostack.client :refer [http-client list-zones]]))
(defn foo
"I don't do a whole lot."
[x]
(println x "Hello, World!"))
(def cs (http-client))
(defn -main [args]
(println (list-zones cs))
(println args "Hey Wassup")
(foo args)
)Simply run this clojure code with lein run joe in the source of your project. And that's it, you have sucessfully discovered the very basics of Clojure and used the CloudStack client clostack to write your first Clojure code. Now for something more significant, look at Pallet
