GIS » Gisaf

h1. Software

Gisaf (for, eg, GIS Auroville Front-end) is a web application that is under development.

[[User manual]]
[[Server]]
[[Client]]
[[Stack]]
[[Mapbox]]

h2. Database

Gisaf uses a Postgis database.

h3. Creation

To create an appropriate database, run these commands:
<pre>
createuser avgis -P
createdb avgis -O avgis
psql avgis -c "CREATE EXTENSION postgis;"
</pre>

h3. Notes

The geometry features' metadata MUST be set with the proper SRID, which can be tricky. See below.

h3. Import files

h2. Development

See the README file

h2. Configuration

TODO: more about parameters of the conf file

h3. Map

The default view of the map can be configured in the gisaf yaml config, eg:

<pre>
map:
openMapTilesKey: cS3lrAfYXoM4MDooT6aS
zoom: 14
pitch: 45
lat: 12.0000
lng: 79.8106
bearing: 0
style: OSM (vector)
opacity: 0.3
tilesUrl: /tiles/data/india-vector.json
</pre>

h3. Production

Gisaf reads the file @/etc/gisaf/prod.yml@ at boot.

h3. Development

Gisaf reads the @~/.gisaf/prod.yml@ file at boot.

h2. Third party

h3. TileServer

Serve the "TileServer-gl":https://github.com/klokantech/tileserver-gl is a small node application that can serve vector tiles (mbtiles) for mapbox-gl locally: [[ TileServer ]] mapbox without the need for an external provider.

The maps Gisaf base layers (the definition file being located in @gisaf-app/src/app/map/base_styles.ts@) in can be parametered such that a base layer is hosted locally (see the gisaf config file).

h4. Install tileserver-gl-light

Unfortunately, it requires a much older version of node (6.x).

<pre>
yarn global add tileserver-gl-light
</pre>

h4. Download the mbtiles

From: https://openmaptiles.com/downloads/planet/ , and store the relevant one on the server's filesystem (eg. @/usr/local/2017-07-03_asia_india.mbtiles@)

h4. Service

A systemd service configuration file, in @/etc/systemd/system/tileserver-gl-light.service@:

<pre>
[Service]
ExecStart=/usr/bin/node /usr/lib/node_modules/tileserver-gl-light/src/main.js --cors true -c /etc/tileserver/conf.json
Restart=always
User=www-data
Group=www-data
Environment=NODE_ENV=production

[Install]
WantedBy=multi-user.target
</pre>

h4. Configuration

Eg, in @/etc/tileserver/conf.json@:

<pre>
{
"options": {
"paths": {
"root": "",
"sprites": "/usr/lib/node_modules/tileserver-gl-light/node_modules/tileserver-gl-styles/styles/osm-bright"
},
"domains": [
"gis.auroville.org.in"
],
"styles": {}
},
"data": {
"india-vector": {
"mbtiles": "/usr/local/2017-07-03_asia_india.mbtiles"
}
}
}
</pre>

h4. Run the service

<pre>
systemctl enable --now tileserver-gl-light.service
</pre>

h4. nginx proxy

In order the mbtiles to be served by tileserver, add in the nginx conf (adjust eventually):

<pre>
location /tiles/ {
proxy_pass http://127.0.0.1:8080/;
}
</pre>

h4. Alternative for getting mbtiles: generation from osm data

Download from an OSM mirror:
<pre>
curl -O http://download.openstreetmap.fr/extracts/asia/india/tamil_nadu.osm.pbf
curl -O http://download.openstreetmap.fr/extracts/asia/india/puducherry.osm.pbf
</pre>

TODO: generation of mbtiles:

<pre>
## Need to generate a single .osm.pdf files
ogr2ogr -f MBTILES target.mbtiles puducherry.osm.pbf -dsco MAXZOOM=15
</pre>

h4. Alternative for serving mbtiles

TODO: try

* tegola: https://github.com/go-spatial/tegola
* mbtiles-server: https://github.com/tobinbradley/mbtiles-server