Components of GeoServer

Krishna G. Lodha

Introduction to GeoServer

What is GeoServer?

Open-source server for sharing geospatial data.
Supports OGC standards (WMS, WFS, WCS, WMTS, WPS).

GeoServer

Key features and benefits.

Cross-platform compatibility.
- Tomcat .war file
- Platform independent binary .zip is available
- Docker Image available
High scalability and flexibility for enterprise GIS applications.
- Cloud first approach ( https://geoserver.org/geoserver-cloud/ )

How GeoServer fits into the GIS ecosystem

Integration with QGIS for desktop GIS.

QGIS Stores

Compatibility with web mapping libraries like OpenLayers and Leaflet.

Checkout code at Openlayers Example

Core Structure of GeoServer

Setting up GeoServer

Workspaces

Logical grouping of layers and styles for better data management.
Useful for organizing data by projects, clients, or themes.
Restricting access to layers and services within specific workspaces.

Data Stores

What are Data Stores? Connecting to data sources.
Supported databases: PostGIS, Oracle Spatial, MySQL, SQL Server.
Supported Files : Shapefile, GeoPackages
Supported Rasters : GeoTiff, COGs, ECW, Image Mosaics etc.

Layers

Creating Vector and Raster Layers from Data Stores.
Configuring Layer Properties: Bounding Box, Coordinate Reference System (CRS).

Layers

Styles

SLD (Styled Layer Descriptor):
- XML-based styling for complex cartography.
GeoServer CSS:
- Using CSS-like syntax for simpler styling.
Advanced Styling Techniques:
- Labeling, custom symbols, and dynamic filters.
- Using external graphic symbols in SLD.

<?xml version="1.0" encoding="UTF-8"?>
<StyledLayerDescriptor version="1.0.0" 
xsi:schemaLocation="http://www.opengis.net/sld StyledLayerDescriptor.xsd" 
xmlns="http://www.opengis.net/sld" 
xmlns:ogc="http://www.opengis.net/ogc" 
xmlns:xlink="http://www.w3.org/1999/xlink" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <NamedLayer>
    <Name>generic</Name>
    <UserStyle>
      <Title>Generic</Title>
      <Abstract>Generic style</Abstract>
      <FeatureTypeStyle>
        <Rule>
          <Name>raster</Name>
          <Title>Opaque Raster</Title>
          <ogc:Filter>
            <ogc:PropertyIsEqualTo>
              <ogc:Function name="isCoverage"/>
              <ogc:Literal>true</ogc:Literal>
            </ogc:PropertyIsEqualTo>
          </ogc:Filter>
          <RasterSymbolizer>
            <Opacity>1.0</Opacity>
          </RasterSymbolizer>
        </Rule>
        <Rule>
          <Name>Polygon</Name>
          <Title>Grey Polygon</Title>
          <ogc:Filter>
            <ogc:PropertyIsEqualTo>
              <ogc:Function name="dimension">
                <ogc:Function name="geometry"/>
              </ogc:Function>
              <ogc:Literal>2</ogc:Literal>
            </ogc:PropertyIsEqualTo>
          </ogc:Filter>
          <PolygonSymbolizer>
            <Fill>
              <CssParameter name="fill">#AAAAAA</CssParameter>
            </Fill>
            <Stroke>
              <CssParameter name="stroke">#000000</CssParameter>
              <CssParameter name="stroke-width">1</CssParameter>
            </Stroke>
          </PolygonSymbolizer>
        </Rule>
        <Rule>
          <Name>Line</Name>
          <Title>Blue Line</Title>
          <ogc:Filter>
            <ogc:PropertyIsEqualTo>
              <ogc:Function name="dimension">
                <ogc:Function name="geometry"/>
              </ogc:Function>
              <ogc:Literal>1</ogc:Literal>
            </ogc:PropertyIsEqualTo>
          </ogc:Filter>
          <LineSymbolizer>
            <Stroke>
              <CssParameter name="stroke">#0000FF</CssParameter>
              <CssParameter name="stroke-opacity">1</CssParameter>
            </Stroke>
          </LineSymbolizer>
        </Rule>
        <Rule>
          <Name>point</Name>
          <Title>Red Square Point</Title>
          <ElseFilter/>
          <PointSymbolizer>
            <Graphic>
              <Mark>
                <WellKnownName>square</WellKnownName>
                <Fill>
                  <CssParameter name="fill">#FF0000</CssParameter>
                </Fill>
              </Mark>
              <Size>6</Size>
            </Graphic>
          </PointSymbolizer>
        </Rule>
        <VendorOption name="ruleEvaluation">first</VendorOption>
      </FeatureTypeStyle>
    </UserStyle>
  </NamedLayer>
</StyledLayerDescriptor>

Layer groups

Combining multiple layers for better visualization and management.
Setting opacity, order, and visibility for Layer Groups.

OGC Web Services Overview

Supported Formats

WMS (Web Map Service):

Publishing maps as images with various styles.
Supports GetMap, GetCapabilities, and GetFeatureInfo requests.

WFS (Web Feature Service):

Serving vector data with options for querying and editing.
WFS versions: WFS 1.0.0 (GML2), WFS 1.1.0 (GML3), WFS 2.0.0 (GML3.2).

WCS (Web Coverage Service):

Serving raster data for scientific analysis (e.g., satellite imagery, DEMs).
Supports GetCoverage requests for downloading raster data.
It’s similar to a Web Feature Service (WFS) , but for raster data. Instead of retrieving raw vector features, it provides the source code of the map as raw imagery.

WMTS (Web Map Tile Service):

Tiled map services for faster rendering.
Serving pre-rendered map tiles for faster loading and zooming.
Comparison with WMS: Better performance but less flexibility.
This can be done using GeoWebCache.

WPS (Web Processing Service)

Performing spatial analysis on the server (e.g., buffer, intersection).
Supports custom processes using JTS Topology Suite.

GeoWebCache

GWC

Caches map tiles for faster rendering and reduced server load.

Tile Caching Mechanism
- How tiles are generated and stored.
- Configuring tile layers, gridsets, and caching strategies.

GWC tile setup

Cache Management and Clearing
- Clearing cache for updated layers.
- Configuring expiration policies for cache invalidation.

GWC tile quota

Security and User Management

Authentication and Authorization:
- Securing GeoServer with basic authentication, LDAP, and OAuth.

Authorization Type

Role-based Access Control:
- Creating user roles (Admin, Editor, Viewer).
- Controlling layer visibility and access based on roles.

Data Security

Extensions

What are GeoServer Extensions?
- Plugins that extend the core functionality of GeoServer.
- Examples: WPS, CSW, GeoFence, and ImageMosaic.
Installing and Managing Extensions:
- Downloading extensions from the GeoServer website.
- Placing extension JAR files in the GeoServer WEB-INF/lib directory.
- Restarting GeoServer to activate extensions.

Popular Extensions and Use Cases:
- WPS (Web Processing Service): Spatial analysis and geoprocessing.
- GeoFence: Advanced security and role-based access control.
- ImageMosaic: Efficiently handling large raster datasets.

Q&A Session

Email : office@rottengrapes.tech

Website : rottengrapes.tech