'datasette serve -i immutable.db' option, refs #419

datasette/app.py

@@ -121,6 +121,7 @@ class Datasette:
     def __init__(
         self,
         files,
+        immutables=None,
         cache_headers=True,
         cors=False,
         inspect_data=None,
@@ -133,7 +134,9 @@ class Datasette:
         config=None,
         version_note=None,
     ):
-        self.files = files
+        immutables = immutables or []
+        self.files = files + immutables
+        self.immutables = set(immutables)
         if not self.files:
             self.files = [MEMORY]
         elif memory:
@@ -322,7 +325,7 @@ class Datasette:
                     raise Exception("Multiple files with same stem %s" % name)
                 try:
                     with sqlite3.connect(
-                        "file:{}?immutable=1".format(path), uri=True
+                        "file:{}?mode=ro".format(path), uri=True
                     ) as conn:
                         self.prepare_connection(conn)
                         self._inspect[name] = {
@@ -426,8 +429,13 @@ class Datasette:
                 if info["file"] == ":memory:":
                     conn = sqlite3.connect(":memory:")
                 else:
+                    # mode=ro or immutable=1?
+                    if info["file"] in self.immutables:
+                        qs = "immutable=1"
+                    else:
+                        qs = "mode=ro"
                     conn = sqlite3.connect(
-                        "file:{}?immutable=1".format(info["file"]),
+                        "file:{}?{}".format(info["file"], qs),
                         uri=True,
                         check_same_thread=False,
                     )

datasette/cli.py

@@ -267,6 +267,13 @@ def package(
 
 @cli.command()
 @click.argument("files", type=click.Path(exists=True), nargs=-1)
+@click.option(
+    "-i",
+    "--immutable",
+    type=click.Path(exists=True),
+    help="Database files to open in immutable mode",
+    multiple=True,
+)
 @click.option(
     "-h", "--host", default="127.0.0.1", help="host for server, defaults to 127.0.0.1"
 )
@@ -332,6 +339,7 @@ def package(
 )
 def serve(
     files,
+    immutable,
     host,
     port,
     debug,
@@ -376,9 +384,10 @@ def serve(
     if metadata:
         metadata_data = json.loads(metadata.read())
 
-    click.echo("Serve! files={} on port {}".format(files, port))
+    click.echo("Serve! files={} (immutables={}) on port {}".format(files, immutable, port))
     ds = Datasette(
         files,
+        immutables=immutable,
         cache_headers=not debug and not reload,
         cors=cors,
         inspect_data=inspect_data,

docs/datasette-serve-help.txt

@@ -5,6 +5,7 @@ Usage: datasette serve [OPTIONS] [FILES]...
   Serve up specified SQLite database files with a web UI
 
 Options:
+  -i, --immutable PATH      Database files to open in immutable mode
   -h, --host TEXT           host for server, defaults to 127.0.0.1
   -p, --port INTEGER        port for server, defaults to 8001
   --debug                   Enable debug mode - useful for development