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 \
23 libtool dietlibc-dev liblocale-po-perl
25 3. Download and install the following git modules in order from top to bottom:
27 # git clone git://git.proxmox.com/git/<PACKAGE.git>
29 You currently need the following packages:
36 redhat-cluster-pve.git
38 pve-access-control.git
48 Most source can be installed with 'make dinstall' command.
51 5. Learn to use the quilt patch scripts.
54 There is an experimental package containing the API documentation
59 You can view the source code at:
61 https://git.proxmox.com
67 We decided to change our SOAP API (1.X) and use a REST like API. The
68 concept is described in [1] (Resource Oriented Architecture
69 (ROA)). The main advantage is that we are able to remove a lot of code
70 (the whole SOAP stack) to reduce software complexity.
72 We also moved away from server side content generation. Instead we use
73 the ExtJS Rich Internet Application Framework
74 (http://www.sencha.com).
76 That framework, like any other AJAX toolkit, can talk directly to the
77 REST API using JSON. So we were able to remove the server side
78 template toolkit completely.
83 We use JSON as data format, because it is simple and parse-able by any
86 Additionally, we use JSON Schema [2] to formally describe our API. So
87 we can automatically generate the whole API Documentation, and we can
88 verify all parameters and return values.
90 An great side effect was that we are able to use JSON Schema to
91 produce command line argument parsers automatically. In fact, the REST
92 API and the command line tools use the same code.
94 Object linkage is done using the JSON Hyper Schema (links property).
96 A small utility called 'pvesh' exposes the whole REST API on the command
99 So here is a summary of the advantage:
101 - easy, human readable data format (native web browser format)
102 - automatic parameter verification (we can also verify return values)
103 - automatic generation of API documentation
104 - easy way to create command line tools (using same API).
106 API Implementation (PVE::RESTHandler)
107 =====================================
109 All classes exposing methods on the API use PVE::RESTHandler as base class.
111 use base qw(PVE::RESTHandler);
113 To expose methods, one needs to call register_method():
115 __PACKAGE__->register_method ($schema);
117 Where $schema is a PVE method schema as described in
118 PVE::JSONSchema. It includes a description of parameters and return
119 values, and a reference to the actual code
121 __PACKAGE__->register_method ({
125 description => "simple return value of parameter 'text'",
127 additionalProperties => 0,
138 my ($conn, $resp, $param) = @_;
140 return $param->{text};
144 The 'name' property is only used if you want to call the method
145 directly from Perl. You can do that using:
147 print __PACKAGE__->echo({ text => "a test" });
149 We use Perl's AUTOLOAD feature to implement this. Note: You need to
150 pass parameters a HASH reference.
152 There is a special helper method called cli_handler(). This is used by
153 the CLIHandler Class for command line tools, where you want to pass
154 arguments as array of strings. This uses Getopt::Long to parse parameters.
156 There is a second way to map names to methods - using the 'path'
157 property. And you can register subclasses. That way you can set up a
158 filesystem like hierarchy to access methods.
161 ----------------------------
164 __PACKAGE__->register_method ({
170 __PACKAGE__->register_method ({
179 __PACKAGE__->register_method ({
185 -------------------------------
187 The utily method find_handler (in PVE::RESTHandler) can be use to do
188 'path' related method lookups.
190 C1->find_handler('GET', "/index") => C1::list1
191 C1->find_handler('GET', "/sub2/index") => C2::list2
193 The HTTP server use the URL (a path) to find the corresponding method.
198 [1] RESTful Web Services
199 Web services for the real world
202 Leonard Richardson, Sam Ruby
208 [2] JSON Schema links: http://json-schema.org/