datasette publish/package --spatialite, closes #243

New command-line argument which causes SpatiaLite to be installed and
configured for the published Datasette.

	datasette publish now --spatialite mydb.db

README.md

@@ -179,6 +179,7 @@ This will create a docker image containing both the datasette application and th
       --static STATIC MOUNT     mountpoint:path-to-directory for serving static
                                 files
       --install TEXT            Additional packages (e.g. plugins) to install
+      --spatialite              Enable SpatialLite extension
       --title TEXT              Title for metadata
       --license TEXT            License label for metadata
       --license_url TEXT        License URL for metadata
@@ -206,6 +207,7 @@ If you have docker installed you can use `datasette package` to create a new Doc
       --static STATIC MOUNT     mountpoint:path-to-directory for serving static
                                 files
       --install TEXT            Additional packages (e.g. plugins) to install
+      --spatialite              Enable SpatialLite extension
       --title TEXT              Title for metadata
       --license TEXT            License label for metadata
       --license_url TEXT        License URL for metadata

datasette/cli.py

@@ -122,6 +122,9 @@ def inspect(files, inspect_file, sqlite_extensions):
     help="Additional packages (e.g. plugins) to install",
     multiple=True,
 )
+@click.option(
+    "--spatialite", is_flag=True, help="Enable SpatialLite extension"
+)
 @click.option("--title", help="Title for metadata")
 @click.option("--license", help="License label for metadata")
 @click.option("--license_url", help="License URL for metadata")
@@ -139,6 +142,7 @@ def publish(
     plugins_dir,
     static,
     install,
+    spatialite,
     **extra_metadata
 ):
     """
@@ -183,6 +187,7 @@ def publish(
             plugins_dir,
             static,
             install,
+            spatialite,
             extra_metadata,
         ):
             if force:
@@ -335,6 +340,9 @@ def skeleton(files, metadata, sqlite_extensions):
     help="Additional packages (e.g. plugins) to install",
     multiple=True,
 )
+@click.option(
+    "--spatialite", is_flag=True, help="Enable SpatialLite extension"
+)
 @click.option("--title", help="Title for metadata")
 @click.option("--license", help="License label for metadata")
 @click.option("--license_url", help="License URL for metadata")
@@ -350,6 +358,7 @@ def package(
     plugins_dir,
     static,
     install,
+    spatialite,
     **extra_metadata
 ):
     "Package specified SQLite files into a new datasette Docker container"
@@ -372,6 +381,7 @@ def package(
         plugins_dir,
         static,
         install,
+        spatialite,
         extra_metadata,
     ):
         args = ["docker", "build"]

datasette/utils.py

@@ -31,6 +31,13 @@ reserved_words = set((
     'vacuum values view virtual when where with without'
 ).split())
 
+SPATIALITE_DOCKERFILE_EXTRAS = r'''
+RUN apt-get update && \
+    apt-get install -y python3-dev gcc libsqlite3-mod-spatialite && \
+    rm -rf /var/lib/apt/lists/*
+ENV SQLITE_EXTENSIONS /usr/lib/x86_64-linux-gnu/mod_spatialite.so
+'''
+
 
 class InterruptedError(Exception):
     pass
@@ -241,7 +248,7 @@ def escape_sqlite(s):
         return '[{}]'.format(s)
 
 
-def make_dockerfile(files, metadata_file, extra_options, branch, template_dir, plugins_dir, static, install):
+def make_dockerfile(files, metadata_file, extra_options, branch, template_dir, plugins_dir, static, install, spatialite):
     cmd = ['"datasette"', '"serve"', '"--host"', '"0.0.0.0"']
     cmd.append('"' + '", "'.join(files) + '"')
     cmd.extend(['"--cors"', '"--port"', '"8001"', '"--inspect-file"', '"inspect-data.json"'])
@@ -266,9 +273,10 @@ def make_dockerfile(files, metadata_file, extra_options, branch, template_dir, p
         install = ['datasette'] + list(install)
 
     return '''
-FROM python:3
+FROM python:3.6-slim-stretch
 COPY . /app
 WORKDIR /app
+{spatialite_extras}
 RUN pip install {install_from}
 RUN datasette inspect {files} --inspect-file inspect-data.json
 EXPOSE 8001
@@ -276,6 +284,7 @@ CMD [{cmd}]'''.format(
         files=' '.join(files),
         cmd=', '.join(cmd),
         install_from=' '.join(install),
+        spatialite_extras=SPATIALITE_DOCKERFILE_EXTRAS if spatialite else '',
     ).strip()
 
 
@@ -290,6 +299,7 @@ def temporary_docker_directory(
     plugins_dir,
     static,
     install,
+    spatialite,
     extra_metadata=None
 ):
     extra_metadata = extra_metadata or {}
@@ -320,6 +330,7 @@ def temporary_docker_directory(
             plugins_dir,
             static,
             install,
+            spatialite,
         )
         os.chdir(datasette_dir)
         if metadata_content: