1 ====================================
2 Setup PVE v2 Development Environment
3 ====================================
5 1. Install Debian 'wheezy'
6 2. Install prerequisites for development environment:
8 apt-get -y install build-essential git-core debhelper autotools-dev \
9 doxygen check pkg-config libnss3-dev groff quilt dpatch libxml2-dev \
10 libncurses5-dev libslang2-dev libldap2-dev xsltproc python-pexpect \
11 python-pycurl libdbus-1-dev openipmi sg3-utils libnet-snmp-perl \
12 libnet-telnet-perl snmp python-openssl libxml2-utils automake autoconf \
13 libsqlite3-dev sqlite3 libfuse-dev libglib2.0-dev librrd-dev \
14 librrds-perl rrdcached lintian libdevel-cycle-perl libjson-perl \
15 liblinux-inotify2-perl libio-stringy-perl unzip fuse-utils \
16 libcrypt-openssl-random-perl libcrypt-openssl-rsa-perl \
17 libauthen-pam-perl libterm-readline-gnu-perl libssl-dev open-iscsi \
18 libapache2-mod-perl2 libfilesys-df-perl libfile-readbackwards-perl \
19 libpci-dev texi2html libgnutls-dev libsdl1.2-dev bridge-utils \
20 libvncserver0 rpm2cpio apache2-mpm-prefork libintl-perl \
21 libapache2-request-perl libnet-dns-perl vlan libio-socket-ssl-perl \
22 libfile-sync-perl ifenslave-2.6 libnet-ldap-perl console-data \
23 libtool dietlibc-dev liblocale-po-perl libstring-shellquote-perl \
24 libio-multiplex-perl liblockfile-simple-perl
26 3. Download and install the following git modules in order from top to bottom:
28 # git clone git://git.proxmox.com/git/<PACKAGE.git>
30 You currently need the following packages:
36 redhat-cluster-pve.git
38 pve-access-control.git
46 resource-agents-pve.git
51 ksm-control-daemon.git
53 Most packages can be installed with 'make dinstall' command.
56 5. Learn to use the quilt patch scripts.
59 There is an experimental package containing the API documentation
64 You can view the source code at:
66 https://git.proxmox.com
72 We decided to change our SOAP API (1.X) and use a REST like API. The
73 concept is described in [1] (Resource Oriented Architecture
74 (ROA)). The main advantage is that we are able to remove a lot of code
75 (the whole SOAP stack) to reduce software complexity.
77 We also moved away from server side content generation. Instead we use
78 the ExtJS Rich Internet Application Framework
79 (http://www.sencha.com).
81 That framework, like any other AJAX toolkit, can talk directly to the
82 REST API using JSON. So we were able to remove the server side
83 template toolkit completely.
88 We use JSON as data format, because it is simple and parse-able by any
91 Additionally, we use JSON Schema [2] to formally describe our API. So
92 we can automatically generate the whole API Documentation, and we can
93 verify all parameters and return values.
95 A great side effect was that we are able to use JSON Schema to
96 produce command line argument parsers automatically. In fact, the REST
97 API and the command line tools use the same code.
99 Object linkage is done using the JSON Hyper Schema (links property).
101 A small utility called 'pvesh' exposes the whole REST API on the command
104 So here is a summary of the advantage:
106 - easy, human readable data format (native web browser format)
107 - automatic parameter verification (we can also verify return values)
108 - automatic generation of API documentation
109 - easy way to create command line tools (using same API).
111 API Implementation (PVE::RESTHandler)
112 =====================================
114 All classes exposing methods on the API use PVE::RESTHandler as base class.
116 use base qw(PVE::RESTHandler);
118 To expose methods, one needs to call register_method():
120 __PACKAGE__->register_method ($schema);
122 Where $schema is a PVE method schema as described in
123 PVE::JSONSchema. It includes a description of parameters and return
124 values, and a reference to the actual code
126 __PACKAGE__->register_method ({
130 description => "simple return value of parameter 'text'",
132 additionalProperties => 0,
143 my ($conn, $resp, $param) = @_;
145 return $param->{text};
149 The 'name' property is only used if you want to call the method
150 directly from Perl. You can do that using:
152 print __PACKAGE__->echo({ text => "a test" });
154 We use Perl's AUTOLOAD feature to implement this. Note: You need to
155 pass parameters a HASH reference.
157 There is a special helper method called cli_handler(). This is used by
158 the CLIHandler Class for command line tools, where you want to pass
159 arguments as array of strings. This uses Getopt::Long to parse parameters.
161 There is a second way to map names to methods - using the 'path'
162 property. And you can register subclasses. That way you can set up a
163 filesystem like hierarchy to access methods.
166 ----------------------------
169 __PACKAGE__->register_method ({
175 __PACKAGE__->register_method ({
184 __PACKAGE__->register_method ({
190 -------------------------------
192 The utily method find_handler (in PVE::RESTHandler) can be use to do
193 'path' related method lookups.
195 C1->find_handler('GET', "/index") => C1::list1
196 C1->find_handler('GET', "/sub2/index") => C2::list2
198 The HTTP server use the URL (a path) to find the corresponding method.
203 [1] RESTful Web Services
204 Web services for the real world
207 Leonard Richardson, Sam Ruby
213 [2] JSON Schema links: http://json-schema.org/