1 ====================================
2 Setup PVE v2 Development Environment
3 ====================================
5 1. Install Debian 'squeeze'
6 2. Install prerequisites for development environment:
8 apt-get -y install build-essential subversion 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
24 3. Download and install the following svn modules in order from top to bottom:
26 svn://devel.proxmox.com/var/svn/pve/
34 pve-access-control/trunk
40 pve-kernel-2.6.32-rh/pve2
42 Most source can be installed with 'make dinstall' command.
45 5. Learn to use the quilt patch scripts.
48 There is an experimental package containing the API documentation
57 We decided to change our SOAP API (1.X) and use a REST like API. The
58 concept is described in [1] (Resource Oriented Architecture
59 (ROA)). The main advantage is that we are able to remove a lot of code
60 (the whole SOAP stack) to reduce software complexity.
62 We also moved away from server side content generation. Instead we use
63 the ExtJS Rich Internet Application Framework
64 (http://www.sencha.com).
66 That framework, like any other AJAX toolkit, can talk directly to the
67 REST API using JSON. So we were able to remove the server side
68 template toolkit completely.
73 We use JSON as data format, because it is simple and parse-able by any
76 Additionally, we use JSON Schema [2] to formally describe our API. So
77 we can automatically generate the whole API Documentation, and we can
78 verify all parameters and return values.
80 An great side effect was that we are able to use JSON Schema to
81 produce command line argument parsers automatically. In fact, the REST
82 API and the command line tools use the same code.
84 Object linkage is done using the JSON Hyper Schema (links property).
86 A small utility called 'pvesh' exposes the whole REST API on the command
89 So here is a summary of the advantage:
91 - easy, human readable data format (native web browser format)
92 - automatic parameter verification (we can also verify return values)
93 - automatic generation of API documentation
94 - easy way to create command line tools (using same API).
96 API Implementation (PVE::RESTHandler)
97 =====================================
99 All classes exposing methods on the API use PVE::RESTHandler as base class.
101 use base qw(PVE::RESTHandler);
103 To expose methods, one needs to call register_method():
105 __PACKAGE__->register_method ($schema);
107 Where $schema is a PVE method schema as described in
108 PVE::JSONSchema. It includes a description of parameters and return
109 values, and a reference to the actual code
111 __PACKAGE__->register_method ({
115 description => "simple return value of parameter 'text'",
117 additionalProperties => 0,
128 my ($conn, $resp, $param) = @_;
130 return $param->{text};
134 The 'name' property is only used if you want to call the method
135 directly from Perl. You can do that using:
137 print __PACKAGE__->echo({ text => "a test" });
139 We use Perl's AUTOLOAD feature to implement this. Note: You need to
140 pass parameters a HASH reference.
142 There is a special helper method called cli_handler(). This is used by
143 the CLIHandler Class for command line tools, where you want to pass
144 arguments as array of strings. This uses Getopt::Long to parse parameters.
146 There is a second way to map names to methods - using the 'path'
147 property. And you can register subclasses. That way you can set up a
148 filesystem like hierarchy to access methods.
151 ----------------------------
154 __PACKAGE__->register_method ({
160 __PACKAGE__->register_method ({
169 __PACKAGE__->register_method ({
175 -------------------------------
177 The utily method find_handler (in PVE::RESTHandler) can be use to do
178 'path' related method lookups.
180 C1->find_handler('GET', "/index") => C1::list1
181 C1->find_handler('GET', "/sub2/index") => C2::list2
183 The HTTP server use the URL (a path) to find the corresponding method.
188 [1] RESTful Web Services
189 Web services for the real world
192 Leonard Richardson, Sam Ruby
198 [2] JSON Schema links: http://json-schema.org/