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 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
24 3. Download and install the following git modules in order from top to bottom:
26 # git clone git://git.proxmox.com/git/<PACKAGE.git>
28 You currently need the following packages:
35 redhat-cluster-pve.git
36 pve-access-control.git
45 Most source can be installed with 'make dinstall' command.
48 5. Learn to use the quilt patch scripts.
51 There is an experimental package containing the API documentation
56 You can view the source code at:
58 https://git.proxmox.com
64 We decided to change our SOAP API (1.X) and use a REST like API. The
65 concept is described in [1] (Resource Oriented Architecture
66 (ROA)). The main advantage is that we are able to remove a lot of code
67 (the whole SOAP stack) to reduce software complexity.
69 We also moved away from server side content generation. Instead we use
70 the ExtJS Rich Internet Application Framework
71 (http://www.sencha.com).
73 That framework, like any other AJAX toolkit, can talk directly to the
74 REST API using JSON. So we were able to remove the server side
75 template toolkit completely.
80 We use JSON as data format, because it is simple and parse-able by any
83 Additionally, we use JSON Schema [2] to formally describe our API. So
84 we can automatically generate the whole API Documentation, and we can
85 verify all parameters and return values.
87 An great side effect was that we are able to use JSON Schema to
88 produce command line argument parsers automatically. In fact, the REST
89 API and the command line tools use the same code.
91 Object linkage is done using the JSON Hyper Schema (links property).
93 A small utility called 'pvesh' exposes the whole REST API on the command
96 So here is a summary of the advantage:
98 - easy, human readable data format (native web browser format)
99 - automatic parameter verification (we can also verify return values)
100 - automatic generation of API documentation
101 - easy way to create command line tools (using same API).
103 API Implementation (PVE::RESTHandler)
104 =====================================
106 All classes exposing methods on the API use PVE::RESTHandler as base class.
108 use base qw(PVE::RESTHandler);
110 To expose methods, one needs to call register_method():
112 __PACKAGE__->register_method ($schema);
114 Where $schema is a PVE method schema as described in
115 PVE::JSONSchema. It includes a description of parameters and return
116 values, and a reference to the actual code
118 __PACKAGE__->register_method ({
122 description => "simple return value of parameter 'text'",
124 additionalProperties => 0,
135 my ($conn, $resp, $param) = @_;
137 return $param->{text};
141 The 'name' property is only used if you want to call the method
142 directly from Perl. You can do that using:
144 print __PACKAGE__->echo({ text => "a test" });
146 We use Perl's AUTOLOAD feature to implement this. Note: You need to
147 pass parameters a HASH reference.
149 There is a special helper method called cli_handler(). This is used by
150 the CLIHandler Class for command line tools, where you want to pass
151 arguments as array of strings. This uses Getopt::Long to parse parameters.
153 There is a second way to map names to methods - using the 'path'
154 property. And you can register subclasses. That way you can set up a
155 filesystem like hierarchy to access methods.
158 ----------------------------
161 __PACKAGE__->register_method ({
167 __PACKAGE__->register_method ({
176 __PACKAGE__->register_method ({
182 -------------------------------
184 The utily method find_handler (in PVE::RESTHandler) can be use to do
185 'path' related method lookups.
187 C1->find_handler('GET', "/index") => C1::list1
188 C1->find_handler('GET', "/sub2/index") => C2::list2
190 The HTTP server use the URL (a path) to find the corresponding method.
195 [1] RESTful Web Services
196 Web services for the real world
199 Leonard Richardson, Sam Ruby
205 [2] JSON Schema links: http://json-schema.org/