Add remote source plugin

Add a plugin that supports downloading files verbatim from a source with
an optional overridable filename and destination directory. Bumps bst
format version to 10.

Fixes #163

16 files changed, 261 insertions, 1 deletions

diff --git a/buildstream/_versions.py b/buildstream/_versions.py
index 28f00f8ca..19699e125 100644
--- a/buildstream/_versions.py
+++ b/buildstream/_versions.py
@@ -23,7 +23,7 @@
 # This version is bumped whenever enhancements are made
 # to the `project.conf` format or the core element format.
 #
-BST_FORMAT_VERSION = 9
+BST_FORMAT_VERSION = 10
 
 
 # The base BuildStream artifact version
diff --git a/buildstream/plugins/sources/remote.py b/buildstream/plugins/sources/remote.py
new file mode 100644
index 000000000..77c4ce17d
--- /dev/null
+++ b/buildstream/plugins/sources/remote.py
@@ -0,0 +1,80 @@
+#
+#  Copyright Bloomberg Finance LP
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU Lesser General Public
+#  License as published by the Free Software Foundation; either
+#  version 2 of the License, or (at your option) any later version.
+#
+#  This library is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+#  Lesser General Public License for more details.
+#
+#  You should have received a copy of the GNU Lesser General Public
+#  License along with this library. If not, see <http://www.gnu.org/licenses/>.
+#
+#  Authors:
+#        Ed Baunton <ebaunton1@bloomberg.net>
+
+"""
+remote - stage files from remote urls
+=====================================
+
+**Usage:**
+
+.. code:: yaml
+
+   # Specify the remote source kind
+   kind: remote
+
+   # Optionally specify a relative staging directory
+   # directory: path/to/stage
+
+   # Optionally specify a relative staging filename.
+   # If not specified, the basename of the url will be used.
+   # filename: customfilename
+
+   # Specify the url. Using an alias defined in your project
+   # configuration is encouraged. 'bst track' will update the
+   # sha256sum in 'ref' to the downloaded file's sha256sum.
+   url: upstream:foo
+
+   # Specify the ref. It's a sha256sum of the file you download.
+   ref: 6c9f6f68a131ec6381da82f2bff978083ed7f4f7991d931bfa767b7965ebc94b
+
+.. note::
+
+   The ``remote`` plugin is available since :ref:`format version 10 <project_format_version>`
+
+"""
+import os
+from buildstream import SourceError, utils
+from ._downloadablefilesource import DownloadableFileSource
+
+
+class RemoteSource(DownloadableFileSource):
+    # pylint: disable=attribute-defined-outside-init
+
+    def configure(self, node):
+        super().configure(node)
+
+        self.filename = self.node_get_member(node, str, 'filename', os.path.basename(self.url))
+
+        if os.sep in self.filename:
+            raise SourceError('{}: filename parameter cannot contain directories'.format(self))
+        self.node_validate(node, DownloadableFileSource.COMMON_CONFIG_KEYS + ['filename'])
+
+    def get_unique_key(self):
+        return super().get_unique_key() + [self.filename]
+
+    def stage(self, directory):
+        # Same as in local plugin, don't use hardlinks to stage sources, they
+        # are not write protected in the sandbox.
+        dest = os.path.join(directory, self.filename)
+        with self.timed_activity("Staging remote file to {}".format(dest)):
+            utils.safe_copy(self._get_mirror_file(), dest)
+
+
+def setup():
+    return RemoteSource
diff --git a/doc/source/core_plugins.rst b/doc/source/core_plugins.rst
index 2951e00cf..da7c607c8 100644
--- a/doc/source/core_plugins.rst
+++ b/doc/source/core_plugins.rst
@@ -50,6 +50,7 @@ Sources
    :maxdepth: 1
 
    sources/local
+   sources/remote
    sources/tar
    sources/zip
    sources/git
diff --git a/tests/sources/remote.py b/tests/sources/remote.py
new file mode 100644
index 000000000..f0f695c4f
--- /dev/null
+++ b/tests/sources/remote.py
@@ -0,0 +1,133 @@
+import os
+import pytest
+
+from buildstream._exceptions import ErrorDomain
+from buildstream import _yaml
+from tests.testutils import cli
+
+DATA_DIR = os.path.join(
+    os.path.dirname(os.path.realpath(__file__)),
+    'remote',
+)
+
+
+def generate_project(project_dir, tmpdir):
+    project_file = os.path.join(project_dir, "project.conf")
+    _yaml.dump({
+        'name': 'foo',
+        'aliases': {
+            'tmpdir': "file:///" + str(tmpdir)
+        }
+    }, project_file)
+
+
+# Test that without ref, consistency is set appropriately.
+@pytest.mark.datafiles(os.path.join(DATA_DIR, 'no-ref'))
+def test_no_ref(cli, tmpdir, datafiles):
+    project = os.path.join(datafiles.dirname, datafiles.basename)
+    generate_project(project, tmpdir)
+    assert cli.get_element_state(project, 'target.bst') == 'no reference'
+
+
+# Here we are doing a fetch on a file that doesn't exist. target.bst
+# refers to 'file' but that file is not present.
+@pytest.mark.datafiles(os.path.join(DATA_DIR, 'missing-file'))
+def test_missing_file(cli, tmpdir, datafiles):
+    project = os.path.join(datafiles.dirname, datafiles.basename)
+    generate_project(project, tmpdir)
+
+    # Try to fetch it
+    result = cli.run(project=project, args=[
+        'fetch', 'target.bst'
+    ])
+
+    result.assert_main_error(ErrorDomain.STREAM, None)
+    result.assert_task_error(ErrorDomain.SOURCE, None)
+
+
+@pytest.mark.datafiles(os.path.join(DATA_DIR, 'path-in-filename'))
+def test_path_in_filename(cli, tmpdir, datafiles):
+    project = os.path.join(datafiles.dirname, datafiles.basename)
+    generate_project(project, tmpdir)
+
+    # Try to fetch it
+    result = cli.run(project=project, args=[
+        'fetch', 'target.bst'
+    ])
+
+    # The bst file has a / in the filename param
+    result.assert_main_error(ErrorDomain.SOURCE, None)
+
+
+@pytest.mark.datafiles(os.path.join(DATA_DIR, 'single-file'))
+def test_simple_file_build(cli, tmpdir, datafiles):
+    project = os.path.join(datafiles.dirname, datafiles.basename)
+    generate_project(project, tmpdir)
+    checkoutdir = os.path.join(str(tmpdir), "checkout")
+
+    # Try to fetch it
+    result = cli.run(project=project, args=[
+        'fetch', 'target.bst'
+    ])
+    result.assert_success()
+
+    result = cli.run(project=project, args=[
+        'build', 'target.bst'
+    ])
+    result.assert_success()
+
+    result = cli.run(project=project, args=[
+        'checkout', 'target.bst', checkoutdir
+    ])
+    result.assert_success()
+    # Note that the url of the file in target.bst is actually /dir/file
+    # but this tests confirms we take the basename
+    assert(os.path.exists(os.path.join(checkoutdir, 'file')))
+
+
+@pytest.mark.datafiles(os.path.join(DATA_DIR, 'single-file-custom-name'))
+def test_simple_file_custom_name_build(cli, tmpdir, datafiles):
+    project = os.path.join(datafiles.dirname, datafiles.basename)
+    generate_project(project, tmpdir)
+    checkoutdir = os.path.join(str(tmpdir), "checkout")
+
+    # Try to fetch it
+    result = cli.run(project=project, args=[
+        'fetch', 'target.bst'
+    ])
+    result.assert_success()
+
+    result = cli.run(project=project, args=[
+        'build', 'target.bst'
+    ])
+    result.assert_success()
+
+    result = cli.run(project=project, args=[
+        'checkout', 'target.bst', checkoutdir
+    ])
+    result.assert_success()
+    assert(not os.path.exists(os.path.join(checkoutdir, 'file')))
+    assert(os.path.exists(os.path.join(checkoutdir, 'custom-file')))
+
+
+@pytest.mark.datafiles(os.path.join(DATA_DIR, 'unique-keys'))
+def test_unique_key(cli, tmpdir, datafiles):
+    '''This test confirms that the 'filename' parameter is honoured when it comes
+    to generating a cache key for the source.
+    '''
+    project = os.path.join(datafiles.dirname, datafiles.basename)
+    generate_project(project, tmpdir)
+    assert cli.get_element_state(project, 'target.bst') == "fetch needed"
+    assert cli.get_element_state(project, 'target-custom.bst') == "fetch needed"
+    # Try to fetch it
+    result = cli.run(project=project, args=[
+        'fetch', 'target.bst'
+    ])
+
+    # We should download the file only once
+    assert cli.get_element_state(project, 'target.bst') == 'buildable'
+    assert cli.get_element_state(project, 'target-custom.bst') == 'buildable'
+
+    # But the cache key is different because the 'filename' is different.
+    assert cli.get_element_key(project, 'target.bst') != \
+        cli.get_element_key(project, 'target-custom.bst')
diff --git a/tests/sources/remote/missing-file/target.bst b/tests/sources/remote/missing-file/target.bst
new file mode 100644
index 000000000..53aeb3522
--- /dev/null
+++ b/tests/sources/remote/missing-file/target.bst
@@ -0,0 +1,7 @@
+kind: autotools
+description: The kind of this element is irrelevant.
+sources:
+- kind: remote
+  url: tmpdir:/file
+  ref: abcdef
+  filename: filename
diff --git a/tests/sources/remote/no-ref/file b/tests/sources/remote/no-ref/file
new file mode 100644
index 000000000..7b4a53b4b
--- /dev/null
+++ b/tests/sources/remote/no-ref/file
@@ -0,0 +1 @@
+filecontent
diff --git a/tests/sources/remote/no-ref/target.bst b/tests/sources/remote/no-ref/target.bst
new file mode 100644
index 000000000..b4f5f58af
--- /dev/null
+++ b/tests/sources/remote/no-ref/target.bst
@@ -0,0 +1,5 @@
+kind: autotools
+description: The kind of this element is irrelevant.
+sources:
+- kind: remote
+  url: tmpdir:/file
diff --git a/tests/sources/remote/path-in-filename/dir/file b/tests/sources/remote/path-in-filename/dir/file
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/sources/remote/path-in-filename/dir/file
diff --git a/tests/sources/remote/path-in-filename/target.bst b/tests/sources/remote/path-in-filename/target.bst
new file mode 100644
index 000000000..ea0c96b44
--- /dev/null
+++ b/tests/sources/remote/path-in-filename/target.bst
@@ -0,0 +1,7 @@
+kind: import
+description: test
+sources:
+- kind: remote
+  url: tmpdir:/dir/file
+  ref: e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
+  filename: path/to/file
diff --git a/tests/sources/remote/single-file-custom-name/dir/file b/tests/sources/remote/single-file-custom-name/dir/file
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/sources/remote/single-file-custom-name/dir/file
diff --git a/tests/sources/remote/single-file-custom-name/target.bst b/tests/sources/remote/single-file-custom-name/target.bst
new file mode 100644
index 000000000..e8f95ad1a
--- /dev/null
+++ b/tests/sources/remote/single-file-custom-name/target.bst
@@ -0,0 +1,7 @@
+kind: import
+description: test
+sources:
+- kind: remote
+  url: tmpdir:/dir/file
+  ref: e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
+  filename: custom-file
diff --git a/tests/sources/remote/single-file/dir/file b/tests/sources/remote/single-file/dir/file
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/sources/remote/single-file/dir/file
diff --git a/tests/sources/remote/single-file/target.bst b/tests/sources/remote/single-file/target.bst
new file mode 100644
index 000000000..f4642e3aa
--- /dev/null
+++ b/tests/sources/remote/single-file/target.bst
@@ -0,0 +1,6 @@
+kind: import
+description: test
+sources:
+- kind: remote
+  url: tmpdir:/dir/file
+  ref: e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
diff --git a/tests/sources/remote/unique-keys/dir/file b/tests/sources/remote/unique-keys/dir/file
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/sources/remote/unique-keys/dir/file
diff --git a/tests/sources/remote/unique-keys/target-custom.bst b/tests/sources/remote/unique-keys/target-custom.bst
new file mode 100644
index 000000000..cd00ab611
--- /dev/null
+++ b/tests/sources/remote/unique-keys/target-custom.bst
@@ -0,0 +1,7 @@
+kind: import
+description: test
+sources:
+- kind: remote
+  url: tmpdir:/dir/file
+  ref: e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
+  filename: some-custom-file
diff --git a/tests/sources/remote/unique-keys/target.bst b/tests/sources/remote/unique-keys/target.bst
new file mode 100644
index 000000000..f4642e3aa
--- /dev/null
+++ b/tests/sources/remote/unique-keys/target.bst
@@ -0,0 +1,6 @@
+kind: import
+description: test
+sources:
+- kind: remote
+  url: tmpdir:/dir/file
+  ref: e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855