Requirements¶

Besides a running CouchDB you will need the Python requests package. You can install it the usual way, for example pip install requests.

Configuration¶

You can configure the database and database name and the tile ID and additional metadata.

Available options:

url:

The URL of the CouchDB server. Defaults to http://localhost:5984.

db_name:

The name of the database MapProxy uses for this cache. Defaults to the name of the cache.

tile_lock_dir:

Directory where MapProxy should write lock files when it creates new tiles for this cache. Defaults to cache_data/tile_locks.

New in version 1.6.0.

tile_id:

Each tile document needs a unique ID. You can change the format with a Python format string that expects the following keys:

x, y, z:

The tile coordinate.

grid_name:

The name of the grid.

The default ID uses the following format:

%(grid_name)s-%(z)d-%(x)d-%(y)d

Note

You can’t use slashes (/) in CouchDB IDs.

tile_metadata:

MapProxy stores a JSON document for each tile in CouchDB and you can add additional key-value pairs with metadata to each document. There are a few predefined values that MapProxy will replace with tile-depended values, all other values will be added as they are.

Predefined values:

{{x}}, {{y}}, {{z}}:

The tile coordinate.

{{timestamp}}:

The creation time of the tile as seconds since epoch. MapProxy will add a timestamp key for you, if you don’t provide a custom timestamp key.

{{utc_iso}}:

The creation time of the tile in UTC in ISO format. For example: 2011-12-31T23:59:59Z.

{{tile_centroid}}:

The center coordinate of the tile in the cache’s coordinate system as a list of long/lat or x/y values.

{{wgs_tile_centroid}}:

The center coordinate of the tile in WGS 84 as a list of long/lat values.

Example¶

caches:
  mycouchdbcache:
    sources: [mywms]
    grids: [mygrid]
    cache:
      type: couchdb
      url: http://localhost:9999
      db_name: mywms_tiles
      tile_metadata:
        mydata: myvalue
        tile_col: '{{x}}'
        tile_row: '{{y}}'
        tile_level: '{{z}}'
        created_ts: '{{timestamp}}'
        created: '{{utc_iso}}'
        center: '{{wgs_tile_centroid}}'

MapProxy will place the JSON document for tile z=3, x=1, y=2 at http://localhost:9999/mywms_tiles/mygrid-3-1-2. The document will look like:

{
    "_attachments": {
        "tile": {
            "content_type": "image/png",
            "digest": "md5-ch4j5Piov6a5FlAZtwPVhQ==",
            "length": 921,
            "revpos": 2,
            "stub": true
        }
    },
    "_id": "mygrid-3-1-2",
    "_rev": "2-9932acafd060e10bc0db23231574f933",
    "center": [
        -112.5,
        -55.7765730186677
    ],
    "created": "2011-12-15T12:56:21Z",
    "created_ts": 1323953781.531889,
    "mydata": "myvalue",
    "tile_col": 1,
    "tile_level": 3,
    "tile_row": 2
}

The _attachments-part is the internal structure of CouchDB where the tile itself is stored. You can access the tile directly at: http://localhost:9999/mywms_tiles/mygrid-3-1-2/tile.

Requirements¶

You will need the Python Riak client version 2.0 or newer. You can install it in the usual way, for example with pip install riak. Environments with older version must be upgraded with pip install -U riak.

Configuration¶

Available options:

nodes:

A list of riak nodes. Each node needs a host and optionally a pb_port and an http_port if the ports differ from the default. A single localhost node is used if you don’t configure any nodes.

protocol:

Communication protocol. Allowed options is http, https and pbc. Defaults to pbc.

bucket:

The name of the bucket MapProxy uses for this cache. The bucket is the namespace for the tiles and needs to be unique for each cache. Defaults to cache name suffixed with grid name (e.g. mycache_webmercator).

default_ports:

Default pb and http ports for pbc and http protocols. Will be used as the default for each defined node.

secondary_index:

If true enables secondary index for tiles. This improves seed cleanup performance but requires that Riak uses LevelDB as the backend. Refer to the Riak documentation. Defaults to false.

Example¶

myriakcache:
    sources: [mywms]
    grids: [mygrid]
    type: riak
    nodes:
        - host: 1.example.org
          pb_port: 9999
        - host: 1.example.org
        - host: 1.example.org
    protocol: pbc
    bucket: myriakcachetiles
    default_ports:
        pb: 8087
        http: 8098