Prerequisites for the installation

To be able to use the CometVisu the system needs to fulfill a few prerequisites.

These are

a backend to connect the KNX bus
[optional] rrdtool for diagrams
[optional] InfluxDB for diagrams
a web server with (optional but recommended) PHP support
the CometVisu software package

Note

To be able to use the Manager or the Editor the prerequisite is PHP 7. The core of the CometVisu itself can be used without PHP though.

Backend

To be able to connect the devices with the CometVisu you need a “backend”.

Note

The CometVisu supports only one backend at the same time. The simultaneous connection to multiple backends is not supported.

There are different possibilities:

knxd / eibd

For a direct connection to the KNX bus the knxd is used. The installation of the backend is described under Install eibd.

openHAB

To use openHAB as backend you can refer to Installation on a Debian System with openHAB and Installing on an Ubuntu system with openHAB and Docker.

MQTT

To use the CometVisu as one of the MQTT participant you need a MQTT broker that can be contacted with WebSockets.

Backend configuration

To configure the CometVisu to use a given backend different possibilities are available, listed below. There a later listed method overrules those above it, e.g. the values from the config file will be used even when those are set differently with docker environment variables.

HTTP header / Docker environment variable

The web server can pass setup information in the HTTP header of the config file. By using the official docker image of the CometVisu this can be achieved by setting the corresponding ENVIRONMENT parameters.

HTTP header	`ENVIRONMENT`	use
X-CometVisu-Backend-Name	BACKEND_NAME	Name like `knxd`, `openhab` or `mqtt`
X-CometVisu-Backend-KNXD-Url	BACKEND_KNXD	URL of the knxd login resource
X-CometVisu-Backend-MQTT-Url	BACKEND_MQTT	URL of the MQTT login resource
X-CometVisu-Backend-OpenHAB-Url	BACKEND_OPENHAB	Only openHAB: path to the REST-API
X-CometVisu-Backend-LoginUrl	CGI_URL_PATH	Deprecated: URL of the knxd or openHAB login resource
X-CometVisu-Backend-User	BACKEND_USERNAME	Deprecated: user name, when needed for the MQTT broker or openHAB
X-CometVisu-Backend-Pass	BACKEND_PASSWORD	Deprecated: password, when needed for the MQTT broker or openHAB

Warning

The user name and password for the MQTT broker are stored in pain text and are transported like that over the network!

Config file

In the all containing <pages> element the different parameters can be set as attributes:

attribute	use
backend	Name like `knxd`, `openhab` or `mqtt`
backend-knxd-url	URL of the knxd login resource
backend-mqtt-url	URL of the MQTT login resource
backend-openhab-url	Only openHAB: path to the REST-API
backend-url	Deprecated: URL of the MQTT WebSocket
username	Deprecated: User name, when needed for openHAB
password	Deprecated: Password, when needed for openHAB

Example:

<?xml version="1.0" encoding="UTF-8"?>
<pages backend="mqtt" backend-url="wss://web.server:443/mqtt/ws" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" lib_version="9" design="pure" xsi:noNamespaceSchemaLocation="../visu_config.xsd">
  <meta>
    <plugins>
...

URL

By the URL parameter backend the backend can also be selected. This is only relevant for special cases like development or testing. It also requires that the access URLs are set by one of the other methods.

Graph tool - RRDtool

An optional but much-recommended component is rrdtool to provide the data for creating graphs. There are many ways to pass data to rrds and the use of rrdtool is documented in depth. The installation of rrdtool for CometVisu is described under RRDtool.

Time series from an InfluxDB database are supported without any additional external software, only PHP is required.

Web server

The relevant files to connect via eibd/knxd are CGI programs, usually located at /usr/lib/cgi-bin/. They must be executable for the account of the web server. This could be enforced by:

chmod +x /usr/lib/cgi-bin/r
chmod +x /usr/lib/cgi-bin/l
chmod +x /usr/lib/cgi-bin/w
chmod +x /usr/lib/cgi-bin/rrdfetch

When these files are symbolic links also the link targets (located e.g. at /usr/local/bin or /usr/share/knxd/examples/bin) must be executable as well.

To be able to use additional components like the editor the web server must support PHP.

lighttpd

For the lighttpd web server an example configuration is given. (Other web servers are also possible, of course). Please make sure that you are changing the example parameters to fit your need.

To install lighttpd on a Debian or Ubuntu system:

apt-get install lighttpd

/etc/lighttpd/lighttpd.conf

server.modules = (
        "mod_access",
        "mod_alias",
        "mod_compress",
        "mod_redirect",
#       "mod_rewrite",
)

server.document-root        = "/var/www"
server.upload-dirs          = ( "/var/cache/lighttpd/uploads" )
server.errorlog             = "/var/log/lighttpd/error.log"
server.pid-file             = "/var/run/lighttpd.pid"
server.username             = "www-data"
server.groupname            = "www-data"

index-file.names            = ( "index.php", "index.html",
                                "index.htm", "default.htm",
                               " index.lighttpd.html" )

url.access-deny             = ( "~", ".inc" )

static-file.exclude-extensions = ( ".php", ".pl", ".fcgi" )

## Use ipv6 if available
#include_shell "/usr/share/lighttpd/use-ipv6.pl"

dir-listing.encoding        = "utf-8"
server.dir-listing          = "enable"

compress.cache-dir          = "/var/cache/lighttpd/compress/"
compress.filetype           = ( "application/x-javascript", "text/css", "text/html", "text/plain" )

include_shell "/usr/share/lighttpd/create-mime.assign.pl"
include_shell "/usr/share/lighttpd/include-conf-enabled.pl"

/etc/lighttpd/conf-enabled/10-cgi.conf

# /usr/share/doc/lighttpd-doc/cgi.txt

server.modules += ( "mod_cgi" )

$HTTP["url"] =~ "^/cgi-bin/" {
        cgi.assign = ( "" => "" )
}

## Warning this represents a security risk, as it allow to execute any file
## with a .pl/.py even outside of /usr/lib/cgi-bin.
#
cgi.assign      = (
        ".pl"  => "/usr/bin/perl",
        ".php" => "/usr/bin/php-cgi",
        ".py"  => "/usr/bin/python",
)

/etc/lighttpd/conf-enabled/11-cgi-cometvisu.conf

### Add cgi for cometvisu
alias.url += ( "/cgi-bin/" => "/usr/lib/cgi-bin/" )
compress.filetype += ("application/javascript", "application/xml", "application/octet-stream")

Installing CometVisu

The CometVisu can be downloaded at https://github.com/CometVisu/CometVisu and unpacked at the web root, most likely in it’s own directory (e.g. /var/www/visu/).

The released versions of the CometVisu are located at https://github.com/CometVisu/CometVisu/releases.

A documentation of an install procedure for the Raspberry Pi is available under CometVisu auf Raspberry Pi.

Testing the installed CometVisu

Just open http://MyServer/visu/ in the browser.

Have fun!