Virtualization is an emerging technology on x86 platform simplifying deployment and configuration of complex information technologies. In free and open source software for geoinformatics area, however, this trend is not yet fully reflected or leveraged. Contribution introduces results and experiences with FOSS geospatial virtual appliance called ‘MapSnack’. MapSnack is a fully pre-installed and pre-configured geospatial virtual appliance that runs on any standard x86 machine in a self-contained, isolated environment.
A vision of MapSnack is to accompany raw geospatial data which comes in different formats with functionality to explore, query, share and manage content. That is merge data with functionality logic to simplify their absorption by consumer. MapSnack eliminates the installation, configuration and maintenance effort associated with deploying complex stacks of software for web mapping.
There are basically two approaches how to achieve that. First is traditional and nowadays very popular LiveCD appliance, second is a virtual appliance
1. Geospatial LiveCD Appliance:
This approach takes Knoppix LiveCD concept for fast deployment on user’s machine. LiveCD on one hand simplifies deployment and readiness to use geospatial appliance but on other hand remastering and maintenance of such system is difficult since intrinsic system is read only. LiveCD advantage is however in that it can run on any virtual or real machine which supports x86 ISA (Instruction Set Architecture) thus decision to let geospatial appliance run on real or virtualized (partitioned) hardware is left up to user. Another advantage of LiveCD system is embedded compressed file system which is automatically extracted during the boot up.
2. Geospatial Virtual Appliance – Mapsnack
Recently much attention of IT have been drawn towards virtualization on x86 platform. Although there are many different levels of virtualization (hardware, operating system, application) virtualization in this contribution is treated as ability to run multiple operating system on one CPU or one single computer. Important differentiation from the term emulation is that virtualization partition real hardware into multiple running context while emulation does it all in (higher) software layer. Virtualization is used in different areas such as server consolidation, running legacy applications within legacy OS’es, running untrusted applications in secure isolated sandboxes, application mobility, clean/single service design and many others. MapSnack as geospatial virtual appliance is minimum sized Linux virtual machine with web user interfaces for deploying instant geospatial infrastructure and applications. Thus provides to the consumer advantage of quick deployment with nearly zero-based installation and minimum skills to get it running.
MapSnack consist of latest UMN MapServer and P.Mapper with sample dataset. Underlying operating system is Debian Sarge 3.1r2 with latest updates. VMware Player has been chosen as virtualization platform to run MapSnack. Since it is not optimal to stick to one virtualization platform, future version will be virtualization platform independable, thus running a microinstall in the first run of appliance. Virtualized environment has an advantage that anybody can extend or modify it. User gets all necessary preinstalled and preconfigured software without even need to change his current production environment. This opens doors for Windows users who would like to combine comfort of Windows based GUI with performance and effectivity of single service virtual appliance based on Linux..
This approach of geospatial virtual appliance answers also areas of MapSnack usability :
1. Portable map browsing – nowadays map browsers rely on internet connections. In case connection or server is broken and maps are urgently needed MapSnack can be quickly deployed as off-line /backup (or stand alone) map server.
2. Encapsulating geospatial data with functionality – geospatial data providers might want to add value to customers by providing not only processed data coming from various electromagnetic sensors but also by providing software appliance for viewing and manipulating geospatial content.
3. Education of OGC standards (WxS) on stable and ‘always available’ source of geospatial content.
MapSnack can be downloaded from :http://mapsnack.mendelu.cz