Example of cartopy source in mapproxy

README.md

Example mapproxy configuration for cartopy

See demo of this configuration at https://gist.github.com/pelson/682c09838cb3f93cef77922b12fb0ed5. This repo has been deployed to Heroku to serve the WMS defined by the functions in this config. It is required that @pelson's cartopy_source branch is installed. The full diff of this branch can be found at https://github.com/mapproxy/mapproxy/compare/61bf3ada315591207fade42888a3e1060703ccbf...pelson:cartopy_source?expand=1.

arrows.py

from cartopy.examples.arrows import sample_data


def arrows(ax):
    x, y, u, v, vector_crs = sample_data()
    ax.quiver(x, y, u, v, transform=vector_crs)

buildpack-run.sh

#!/usr/bin/env bash
set -x

mkdir -p "$1" "$2" "$3"
build=$(cd "$1/" && pwd)
cache=$(cd "$2/" && pwd)
env_dir=$(cd "$3/" && pwd)


# -------

wget --quiet https://repo.continuum.io/miniconda/Miniconda3-latest-Linux-x86_64.sh -O miniconda.sh
bash miniconda.sh -b -p $HOME/.conda
export PATH=$HOME/.conda/bin:$PATH

# -------

# Build the environment.
source create_env.sh $HOME/env

# Copy the environment to the Heroku build directory.
cp -rf $HOME/env $build/

create_env.sh

#!/usr/bin/env bash

# Makes the lightest weight environment possible to run mapproxy with cartopy. If there is no size constraint,
# we would just use conda directly, but as we want to run in Heroku, we must realise an environment <=300 Mb.

export ENV=$1

conda create --yes -c conda-forge -p ${ENV} nomkl python pip pillow pyyaml cartopy

source activate $ENV
pip install git+https://github.com/pelson/mapproxy/@cartopy_source

python -c "import mapproxy; print(mapproxy);"

export PREFIX=$ENV

du -hs $PREFIX
rm -rf $PREFIX/share/doc $PREFIX/share/gtk-doc 
rm -rf $PREFIX/lib/libicu* $PREFIX/lib/libxml* $PREFIX/lib/libQt*
rm -rf $PREFIX/bin/sqlite3
export SP_DIR=$PREFIX/lib/python*/site-packages
rm -rf $SP_DIR/scipy/stats
du -hs $PREFIX

logo.py

import cartopy.crs as ccrs
import matplotlib.textpath
import matplotlib.patches
from matplotlib.font_manager import FontProperties
import numpy as np


def main(ax):
    # Comes from the cartopy gallery: http://scitools.org.uk/cartopy/docs/latest/examples/logo.html

    # generate a matplotlib path representing the word "cartopy"
    fp = FontProperties(family='Bitstream Vera Sans', weight='bold')
    logo_path = matplotlib.textpath.TextPath((-175, -35), 'cartopy',
                                             size=80, prop=fp)
    # scale the letters up to sensible longitude and latitude sizes
    logo_path._vertices *= np.array([1, 2])

    im = ax.stock_img()

    def on_draw(event=None):
        """
        Hooks into matplotlib's event mechanism to define the clip path of the
        background image.

        """
        plate_carree_transform = ccrs.PlateCarree()._as_mpl_transform(ax)
        im.set_clip_path(logo_path, transform=plate_carree_transform)

    # Register the on_draw method and call it once now.
    ax.figure.canvas.mpl_connect('draw_event', on_draw)
    on_draw()

    # add the path as a patch, drawing black outlines around the text
    patch = matplotlib.patches.PathPatch(logo_path,
                                         antialiased=True,
                                         facecolor='none', edgecolor='black',
                                         transform=ccrs.PlateCarree())
    ax.add_patch(patch)

mapproxy.yaml

services:
#  demo:
#  tms:
#    use_grid_names: true
#    # origin for /tiles service
#    origin: 'nw'
#  kml:
#      use_grid_names: true
#  wmts:
  wms:
    md:
      title: Cartopy WMS demo
      abstract: Cartopy demonstration WMS.

layers:
  - name: wind
    title: Wind arrows
    sources: [wind]

  - name: logo
    title: Cartopy logo
    sources: [logo]

  - name: coastlines
    title: Cartopy coastlines
    sources: [coastlines]


sources:
  wind:
    type: cartopy
    module: arrows.py
    function: arrows

  logo:
    type: cartopy
    module: logo.py
    function: main

  coastlines:
    type: cartopy
    module: misc.py
    function: coastlines

misc.py

def coastlines(ax):
    ax.coastlines('10m')

Procfile

web: env/bin/mapproxy-util serve-develop mapproxy.yaml --bind 0.0.0.0:${PORT:=8080}