Add support for local charms
authorTim Van Steenburgh <tvansteenburgh@gmail.com>
Thu, 5 Jan 2017 20:55:44 +0000 (15:55 -0500)
committerTim Van Steenburgh <tvansteenburgh@gmail.com>
Fri, 6 Jan 2017 17:43:04 +0000 (12:43 -0500)
- Adds support for deploying local charms.
- Adds support for using local charm paths in bundles.

docs/narrative/application.rst
examples/localcharm.py [new file with mode: 0644]
juju/client/connection.py
juju/model.py
juju/tag.py

index 01d5bc0..148f1fa 100644 (file)
@@ -32,6 +32,30 @@ To deploy a new application, connect a model and then call its
   )
 
 
+Deploying a Local Charm
+-----------------------
+To deploy a local charm, first upload it to the model, then
+deploy it using the returned charm url.
+
+.. code:: python
+
+  from juju.model import Model
+
+  model = Model()
+  await model.connect_current()
+
+  # Upload local charm to the model.
+  # The returned 'local:' url can be used to deploy the charm.
+  charm_url = await model.add_local_charm_dir(
+      '/home/tvansteenburgh/src/charms/ubuntu', 'trusty')
+
+  # Deploy the charm using the 'local:' charm.
+  await model.deploy(
+      charm_url,
+      application_name='ubuntu',
+  )
+
+
 Adding Units
 ------------
 To add units to a deployed application, use the
diff --git a/examples/localcharm.py b/examples/localcharm.py
new file mode 100644 (file)
index 0000000..bc92914
--- /dev/null
@@ -0,0 +1,40 @@
+"""
+This example shows how to deploy a local charm. It:
+
+1. Connects to current model.
+2. Uploads a local charm (directory on filesystem) to the model.
+3. Deploys the uploaded charm.
+
+"""
+import asyncio
+import logging
+
+from juju.model import Model
+
+
+async def run():
+    model = Model()
+    await model.connect_current()
+
+    # Upload local charm to the model.
+    # The returned 'local:' url can be used to deploy the charm.
+    charm_url = await model.add_local_charm_dir(
+        '/home/tvansteenburgh/src/charms/ubuntu', 'trusty')
+
+    # Deploy the charm using the 'local:' charm.
+    await model.deploy(
+        charm_url,
+        application_name='ubuntu',
+    )
+
+    await model.disconnect()
+    model.loop.stop()
+
+
+logging.basicConfig(level=logging.DEBUG)
+ws_logger = logging.getLogger('websockets.protocol')
+ws_logger.setLevel(logging.INFO)
+loop = asyncio.get_event_loop()
+loop.set_debug(False)
+loop.create_task(run())
+loop.run_forever()
index 5ed073f..9e8cb8f 100644 (file)
@@ -9,9 +9,11 @@ import ssl
 import string
 import subprocess
 import websockets
+from http.client import HTTPSConnection
 
 import yaml
 
+from juju import tag
 from juju.errors import JujuAPIError, JujuConnectionError
 
 log = logging.getLogger("websocket")
@@ -93,6 +95,52 @@ class Connection:
             raise JujuAPIError(result)
         return result
 
+    def http_headers(self):
+        """Return dictionary of http headers necessary for making an http
+        connection to the endpoint of this Connection.
+
+        :return: Dictionary of headers
+
+        """
+        if not self.username:
+            return {}
+
+        creds = u'{}:{}'.format(
+            tag.user(self.username),
+            self.password or ''
+        )
+        token = base64.b64encode(creds.encode())
+        return {
+            'Authorization': 'Basic {}'.format(token.decode())
+        }
+
+    def https_connection(self):
+        """Return an https connection to this Connection's endpoint.
+
+        Returns a 3-tuple containing::
+
+            1. The :class:`HTTPSConnection` instance
+            2. Dictionary of auth headers to be used with the connection
+            3. The root url path (str) to be used for requests.
+
+        """
+        endpoint = self.endpoint
+        host, remainder = endpoint.split(':', 1)
+        port = remainder
+        if '/' in remainder:
+            port, _ = remainder.split('/', 1)
+
+        conn = HTTPSConnection(
+            host, int(port),
+            context=self._get_ssl(self.cacert),
+        )
+
+        path = (
+            "/model/{}".format(self.uuid)
+            if self.uuid else ""
+        )
+        return conn, self.http_headers(), path
+
     async def clone(self):
         """Return a new Connection, connected to the same websocket endpoint
         as this one.
index c6c01f6..e3a6fea 100644 (file)
@@ -1,9 +1,13 @@
 import asyncio
 import collections
+import json
 import logging
 import os
 import re
+import stat
+import tempfile
 import weakref
+import zipfile
 from concurrent.futures import CancelledError
 from functools import partial
 from pathlib import Path
@@ -419,6 +423,59 @@ class Model(object):
             await self.connection.close()
             self.connection = None
 
+    async def add_local_charm_dir(self, charm_dir, series):
+        """Upload a local charm to the model.
+
+        This will automatically generate an archive from
+        the charm dir.
+
+        :param charm_dir: Path to the charm directory
+        :param series: Charm series
+
+        """
+        fh = tempfile.NamedTemporaryFile()
+        CharmArchiveGenerator(charm_dir).make_archive(fh.name)
+        with fh:
+            func = partial(
+                self.add_local_charm, fh, series, os.stat(fh.name).st_size)
+            charm_url = await self.loop.run_in_executor(None, func)
+
+        log.debug('Uploaded local charm: %s -> %s', charm_dir, charm_url)
+        return charm_url
+
+    def add_local_charm(self, charm_file, series, size=None):
+        """Upload a local charm archive to the model.
+
+        Returns the 'local:...' url that should be used to deploy the charm.
+
+        :param charm_file: Path to charm zip archive
+        :param series: Charm series
+        :param size: Size of the archive, in bytes
+        :return str: 'local:...' url for deploying the charm
+        :raises: :class:`JujuError` if the upload fails
+
+        Uses an https endpoint at the same host:port as the wss.
+        Supports large file uploads.
+
+        .. warning::
+
+           This method will block. Consider using :meth:`add_local_charm_dir`
+           instead.
+
+        """
+        conn, headers, path_prefix = self.connection.https_connection()
+        path = "%s/charms?series=%s" % (path_prefix, series)
+        headers['Content-Type'] = 'application/zip'
+        if size:
+            headers['Content-Length'] = size
+        conn.request("POST", path, charm_file, headers)
+        response = conn.getresponse()
+        result = response.read().decode()
+        if not response.status == 200:
+            raise JujuError(result)
+        result = json.loads(result)
+        return result['charm-url']
+
     def all_units_idle(self):
         """Return True if all units are idle.
 
@@ -882,8 +939,10 @@ class Model(object):
                 for k, v in storage.items()
             }
 
-        is_local = not entity_url.startswith('cs:') and \
+        is_local = (
+            entity_url.startswith('local:') or
             os.path.isdir(entity_url)
+        )
         entity_id = await self.charmstore.entityId(entity_url) \
             if not is_local else entity_url
 
@@ -916,7 +975,8 @@ class Model(object):
             log.debug(
                 'Deploying %s', entity_id)
 
-            await client_facade.AddCharm(channel, entity_id)
+            if not is_local:
+                await client_facade.AddCharm(channel, entity_id)
             app = client.ApplicationDeploy(
                 application=application_name,
                 channel=channel,
@@ -1303,6 +1363,21 @@ class Model(object):
         return metrics
 
 
+def get_charm_series(path):
+    """Inspects the charm directory at ``path`` and returns a default
+    series from its metadata.yaml (the first item in the 'series' list).
+
+    Returns None if no series can be determined.
+
+    """
+    md = Path(path) / "metadata.yaml"
+    if not md.exists():
+        return None
+    data = yaml.load(md.open())
+    series = data.get('series')
+    return series[0] if series else None
+
+
 class BundleHandler(object):
     """
     Handle bundles by using the API to translate bundle YAML into a plan of
@@ -1324,6 +1399,54 @@ class BundleHandler(object):
         self.ann_facade = client.AnnotationsFacade()
         self.ann_facade.connect(model.connection)
 
+    async def _handle_local_charms(self, bundle):
+        """Search for references to local charms (i.e. filesystem paths)
+        in the bundle. Upload the local charms to the model, and replace
+        the filesystem paths with appropriate 'local:' paths in the bundle.
+
+        Return the modified bundle.
+
+        :param dict bundle: Bundle dictionary
+        :return: Modified bundle dictionary
+
+        """
+        apps, args = [], []
+
+        default_series = bundle.get('series')
+        for app_name in self.applications:
+            app_dict = bundle['services'][app_name]
+            charm_dir = os.path.abspath(os.path.expanduser(app_dict['charm']))
+            if not os.path.isdir(charm_dir):
+                continue
+            series = (
+                app_dict.get('series') or
+                default_series or
+                get_charm_series(charm_dir)
+            )
+            if not series:
+                raise JujuError(
+                    "Couldn't determine series for charm at {}. "
+                    "Add a 'series' key to the bundle.".format(charm_dir))
+
+            # Keep track of what we need to update. We keep a list of apps
+            # that need to be updated, and a corresponding list of args
+            # needed to update those apps.
+            apps.append(app_name)
+            args.append((charm_dir, series))
+
+        if apps:
+            # If we have apps to update, spawn all the coroutines concurrently
+            # and wait for them to finish.
+            charm_urls = await asyncio.gather(*[
+                asyncio.ensure_future(self.model.add_local_charm_dir(*params))
+                for params in args
+            ])
+            # Update the 'charm:' entry for each app with the new 'local:' url.
+            for app_name, charm_url in zip(apps, charm_urls):
+                bundle['services'][app_name]['charm'] = charm_url
+
+        return bundle
+
     async def fetch_plan(self, entity_id):
         is_local = not entity_id.startswith('cs:') and os.path.isdir(entity_id)
         if is_local:
@@ -1333,7 +1456,10 @@ class BundleHandler(object):
                                                       filename='bundle.yaml',
                                                       read_file=True)
         self.bundle = yaml.safe_load(bundle_yaml)
-        self.plan = await self.client_facade.GetBundleChanges(bundle_yaml)
+        self.bundle = await self._handle_local_charms(self.bundle)
+
+        self.plan = await self.client_facade.GetBundleChanges(
+            yaml.dump(self.bundle))
 
         if self.plan.errors:
             raise JujuError('\n'.join(self.plan.errors))
@@ -1362,6 +1488,11 @@ class BundleHandler(object):
             Series holds the series of the charm to be added
             if the charm default is not sufficient.
         """
+        # We don't add local charms because they've already been added
+        # by self._handle_local_charms
+        if charm.startswith('local:'):
+            return charm
+
         entity_id = await self.charmstore.entityId(charm)
         log.debug('Adding %s', entity_id)
         await self.client_facade.AddCharm(None, entity_id)
@@ -1571,3 +1702,79 @@ class CharmStore(object):
             setattr(self, name, coro)
             wrapper = coro
         return wrapper
+
+
+class CharmArchiveGenerator(object):
+    def __init__(self, path):
+        self.path = os.path.abspath(os.path.expanduser(path))
+
+    def make_archive(self, path):
+        """Create archive of directory and write to ``path``.
+
+        :param path: Path to archive
+
+        Ignored::
+
+            * build/\* - This is used for packing the charm itself and any
+                          similar tasks.
+            * \*/.\*    - Hidden files are all ignored for now.  This will most
+                          likely be changed into a specific ignore list
+                          (.bzr, etc)
+
+        """
+        zf = zipfile.ZipFile(path, 'w', zipfile.ZIP_DEFLATED)
+        for dirpath, dirnames, filenames in os.walk(self.path):
+            relative_path = dirpath[len(self.path) + 1:]
+            if relative_path and not self._ignore(relative_path):
+                zf.write(dirpath, relative_path)
+            for name in filenames:
+                archive_name = os.path.join(relative_path, name)
+                if not self._ignore(archive_name):
+                    real_path = os.path.join(dirpath, name)
+                    self._check_type(real_path)
+                    if os.path.islink(real_path):
+                        self._check_link(real_path)
+                        self._write_symlink(
+                            zf, os.readlink(real_path), archive_name)
+                    else:
+                        zf.write(real_path, archive_name)
+        zf.close()
+        return path
+
+    def _check_type(self, path):
+        """Check the path
+        """
+        s = os.stat(path)
+        if stat.S_ISDIR(s.st_mode) or stat.S_ISREG(s.st_mode):
+            return path
+        raise ValueError("Invalid Charm at % %s" % (
+            path, "Invalid file type for a charm"))
+
+    def _check_link(self, path):
+        link_path = os.readlink(path)
+        if link_path[0] == "/":
+            raise ValueError(
+                "Invalid Charm at %s: %s" % (
+                    path, "Absolute links are invalid"))
+        path_dir = os.path.dirname(path)
+        link_path = os.path.join(path_dir, link_path)
+        if not link_path.startswith(os.path.abspath(self.path)):
+            raise ValueError(
+                "Invalid charm at %s %s" % (
+                    path, "Only internal symlinks are allowed"))
+
+    def _write_symlink(self, zf, link_target, link_path):
+        """Package symlinks with appropriate zipfile metadata."""
+        info = zipfile.ZipInfo()
+        info.filename = link_path
+        info.create_system = 3
+        # Magic code for symlinks / py2/3 compat
+        # 27166663808 = (stat.S_IFLNK | 0755) << 16
+        info.external_attr = 2716663808
+        zf.writestr(info, link_target)
+
+    def _ignore(self, path):
+        if path == "build" or path.startswith("build/"):
+            return True
+        if path.startswith('.'):
+            return True
index d36316d..92c54c1 100644 (file)
@@ -21,3 +21,7 @@ def credential(cloud, user, credential_name):
 
 def model(cloud_name):
     return _prefix('model-', cloud_name)
+
+
+def user(username):
+    return _prefix('user-', username)