github-lambda: initial implementation of AWS Lambda function

1 files changed, 127 insertions, 0 deletions

diff --git a/src/blogc-github-lambda/lambda_function.py b/src/blogc-github-lambda/lambda_function.py
new file mode 100644
index 0000000..e456397
--- /dev/null
+++ b/src/blogc-github-lambda/lambda_function.py
@@ -0,0 +1,127 @@
+# coding: utf-8
+"""
+  blogc: A blog compiler.
+  Copyright (C) 2016 Rafael G. Martins <rafael@rafaelmartins.eng.br>
+
+  This program can be distributed under the terms of the BSD License.
+  See the file LICENSE.
+"""
+
+from contextlib import closing
+from StringIO import StringIO
+
+import base64
+import boto3
+import hashlib
+import json
+import mimetypes
+import os
+import subprocess
+import sys
+import tarfile
+import urllib2
+import shutil
+
+cwd = os.path.dirname(os.path.abspath(__file__))
+
+GITHUB_AUTH = os.environ.get('GITHUB_AUTH')
+if GITHUB_AUTH is not None and ':' not in GITHUB_AUTH:
+    GITHUB_AUTH = boto3.client('kms').decrypt(
+        CiphertextBlob=base64.b64decode(GITHUB_AUTH))['Plaintext']
+
+
+def get_tarball(repo_name):
+    tarball_url = 'https://api.github.com/repos/%s/tarball/master' % repo_name
+    request = urllib2.Request(tarball_url)
+
+    if GITHUB_AUTH is not None:
+        auth = base64.b64encode(GITHUB_AUTH)
+        request.add_header("Authorization", "Basic %s" % auth)
+
+    with closing(urllib2.urlopen(request)) as fp:
+        tarball = fp.read()
+
+    rootdir = None
+    with closing(StringIO(tarball)) as fp:
+        with tarfile.open(fileobj=fp, mode='r:gz') as tar:
+            for f in tar.getnames():
+                if '/' not in f:
+                    rootdir = f
+                    break
+            if rootdir is None:
+                raise RuntimeError('Failed to find a directory in tarball')
+            rootdir = '/tmp/%s' % rootdir
+
+            if os.path.isdir(rootdir):
+                shutil.rmtree(rootdir)
+
+            tar.extractall('/tmp/')
+
+    return rootdir
+
+
+def sync_s3(src, dest):
+    s3 = boto3.resource('s3')
+    bucket = s3.Bucket(dest)
+
+    remote_files = {}
+    for obj in bucket.objects.all():
+        if not obj.key.endswith('/'):
+            remote_files[obj.key] = obj
+
+    local_files = []
+    for root, dirs, files in os.walk(src):
+        real_root = root[len(src):].lstrip('/')
+        for file in files:
+            local_files.append(os.path.join(real_root, file))
+
+    to_upload = []
+    for file in local_files:
+        if file not in remote_files:
+            to_upload.append(file)
+
+    to_delete = []
+    for file in remote_files:
+        if file in local_files:
+            with open(os.path.join(src, file)) as fp:
+                l = hashlib.sha1(fp.read())
+
+            with closing(remote_files[file].get()['Body']) as fp:
+                r = hashlib.sha1(fp.read())
+
+            if l.hexdigest() != r.hexdigest():
+                to_upload.append(file)
+        else:
+            to_delete.append(file)
+
+    for file in to_upload:
+        with open(os.path.join(src, file), 'rb') as fp:
+            print 'Uploading file:', file
+            mime, _ = mimetypes.guess_type(file)
+            if mime is not None:
+                bucket.put_object(Key=file, Body=fp, ContentType=mime)
+            else:
+                bucket.put_object(Key=file, Body=fp)
+
+    for file in to_delete:
+        print 'Deleting file:', file
+        remote_files[file].delete()
+
+
+def lambda_handler(event, context):
+    message = event['Records'][0]['Sns']['Message']
+    payload = json.loads(message)
+
+    debug = 'DEBUG' in os.environ
+
+    if payload['ref'] == 'refs/heads/master':
+        repo_name = payload['repository']['name']
+        repo_full_name = payload['repository']['full_name']
+        rootdir = get_tarball(repo_full_name)
+        rv = subprocess.call(['make', '-C', rootdir, 'OUTPUT_DIR=_build',
+                              'BLOGC=%s' % os.path.join(cwd, 'blogc')],
+                             stdout=None if debug else subprocess.PIPE,
+                             stderr=None if debug else subprocess.PIPE)
+        if rv != 0:
+            raise RuntimeError('Failed to run make')
+        sync_s3(os.path.join(rootdir, '_build'), repo_name)