datasette install -r requirements.txt, closes #2033

datasette/cli.py

@@ -341,15 +341,25 @@ def package(
 
 
 @cli.command()
-@click.argument("packages", nargs=-1, required=True)
+@click.argument("packages", nargs=-1)
 @click.option(
     "-U", "--upgrade", is_flag=True, help="Upgrade packages to latest version"
 )
-def install(packages, upgrade):
+@click.option(
+    "-r",
+    "--requirement",
+    type=click.Path(exists=True),
+    help="Install from requirements file",
+)
+def install(packages, upgrade, requirement):
     """Install plugins and packages from PyPI into the same environment as Datasette"""
+    if not packages and not requirement:
+        raise click.UsageError("Please specify at least one package to install")
     args = ["pip", "install"]
     if upgrade:
         args += ["--upgrade"]
+    if requirement:
+        args += ["-r", requirement]
     args += list(packages)
     sys.argv = args
     run_module("pip", run_name="__main__")

docs/cli-reference.rst

@@ -345,13 +345,14 @@ Would install the `datasette-cluster-map <https://datasette.io/plugins/datasette
 
 ::
 
-    Usage: datasette install [OPTIONS] PACKAGES...
+    Usage: datasette install [OPTIONS] [PACKAGES]...
 
       Install plugins and packages from PyPI into the same environment as Datasette
 
     Options:
-      -U, --upgrade  Upgrade packages to latest version
-      --help         Show this message and exit.
+      -U, --upgrade           Upgrade packages to latest version
+      -r, --requirement PATH  Install from requirements file
+      --help                  Show this message and exit.
 
 
 .. [[[end]]]

docs/plugins.rst

@@ -51,7 +51,16 @@ This command can also be used to upgrade Datasette itself to the latest released
 
     datasette install -U datasette
 
-These commands are thin wrappers around ``pip install`` and ``pip uninstall``, which ensure they run ``pip`` in the same virtual environment as Datasette itself.
+You can install multiple plugins at once by listing them as lines in a ``requirements.txt`` file like this::
+
+    datasette-vega
+    datasette-cluster-map
+
+Then pass that file to ``datasette install -r``::
+
+    datasette install -r requirements.txt
+
+The ``install`` and ``uninstall`` commands are thin wrappers around ``pip install`` and ``pip uninstall``, which ensure that they run ``pip`` in the same virtual environment as Datasette itself.
 
 One-off plugins using --plugins-dir
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

tests/test_cli.py

@@ -178,6 +178,24 @@ def test_install_upgrade(run_module, flag):
     assert sys.argv == ["pip", "install", "--upgrade", "datasette"]
 
 
+@mock.patch("datasette.cli.run_module")
+def test_install_requirements(run_module):
+    runner = CliRunner()
+    with runner.isolated_filesystem():
+        with open("requirements.txt", "w") as fp:
+            fp.write("datasette-mock-plugin\ndatasette-plugin-2")
+        runner.invoke(cli, ["install", "-r", "requirements.txt"])
+    run_module.assert_called_once_with("pip", run_name="__main__")
+    assert sys.argv == ["pip", "install", "-r", "requirements.txt"]
+
+
+def test_install_error_if_no_packages():
+    runner = CliRunner()
+    result = runner.invoke(cli, ["install"])
+    assert result.exit_code == 2
+    assert "Error: Please specify at least one package to install" in result.output
+
+
 @mock.patch("datasette.cli.run_module")
 def test_uninstall(run_module):
     runner = CliRunner()