import cStringIO
import hashlib
import json
import requests
import tarfile
import urlparse
import uuid
from django.conf import settings
from docker.utils import utils
from api.utils import encode
[docs]def publish_release(source, config, target):
"""
Publish a new release as a Docker image
Given a source image and dictionary of last-mile configuration,
create a target Docker image on the registry.
For example::
publish_release('registry.local:5000/gabrtv/myapp:v22',
{'ENVVAR': 'values'},
'registry.local:5000/gabrtv/myapp:v23')
results in a new Docker image at 'registry.local:5000/gabrtv/myapp:v23' which
contains the new configuration as ENV entries.
"""
try:
repo, tag = utils.parse_repository_tag(source)
src_image = repo
src_tag = tag if tag is not None else 'latest'
nameparts = repo.rsplit('/', 1)
if len(nameparts) == 2:
if '/' in nameparts[0]:
# strip the hostname and just use the app name
src_image = '{}/{}'.format(nameparts[0].rsplit('/', 1)[1],
nameparts[1])
elif '.' in nameparts[0]:
# we got a name like registry.local:5000/registry
src_image = nameparts[1]
target_image = target.rsplit(':', 1)[0]
target_tag = target.rsplit(':', 1)[1]
image_id = _get_tag(src_image, src_tag)
except RuntimeError:
if src_tag == 'latest':
# no image exists yet, so let's build one!
_put_first_image(src_image)
image_id = _get_tag(src_image, src_tag)
else:
raise
image = _get_image(image_id)
# construct the new image
image['parent'] = image['id']
image['id'] = _new_id()
config['DEIS_APP'] = target_image
config['DEIS_RELEASE'] = target_tag
image['config']['Env'] = _construct_env(image['config']['Env'], config)
# update and tag the new image
_commit(target_image, image, _empty_tar_archive(), target_tag)
# registry access
def _commit(repository_path, image, layer, tag):
_put_image(image)
cookies = _put_layer(image['id'], layer)
_put_checksum(image, layer, cookies)
_put_tag(image['id'], repository_path, tag)
def _put_first_image(repository_path):
image = {
'id': _new_id(),
'parent': '',
'config': {
'Env': []
}
}
# tag as v0 in the registry
_commit(repository_path, image, _empty_tar_archive(), 'v0')
def _api_call(endpoint, data=None, headers={}, cookies=None, request_type='GET'):
base_headers = {'user-agent': 'docker/1.0.0'}
r = None
if len(headers) > 0:
for header, value in headers.viewitems():
base_headers[header] = value
if request_type == 'GET':
r = requests.get(endpoint, headers=base_headers)
elif request_type == 'PUT':
r = requests.put(endpoint, data=data, headers=base_headers, cookies=cookies)
else:
raise AttributeError("request type not supported: {}".format(request_type))
return r
def _get_tag(repository, tag):
path = "/v1/repositories/{repository}/tags/{tag}".format(**locals())
url = urlparse.urljoin(settings.REGISTRY_URL, path)
r = _api_call(url)
if not r.status_code == 200:
raise RuntimeError("GET Image Error ({}: {})".format(r.status_code, r.text))
return r.json()
def _get_image(image_id):
path = "/v1/images/{image_id}/json".format(**locals())
url = urlparse.urljoin(settings.REGISTRY_URL, path)
r = _api_call(url)
if not r.status_code == 200:
raise RuntimeError("GET Image Error ({}: {})".format(r.status_code, r.text))
return r.json()
def _put_image(image):
path = "/v1/images/{id}/json".format(**image)
url = urlparse.urljoin(settings.REGISTRY_URL, path)
r = _api_call(url, data=json.dumps(image), request_type='PUT')
if not r.status_code == 200:
raise RuntimeError("PUT Image Error ({}: {})".format(r.status_code, r.text))
return r.json()
def _put_layer(image_id, layer_fileobj):
path = "/v1/images/{image_id}/layer".format(**locals())
url = urlparse.urljoin(settings.REGISTRY_URL, path)
r = _api_call(url, data=layer_fileobj.read(), request_type='PUT')
if not r.status_code == 200:
raise RuntimeError("PUT Layer Error ({}: {})".format(r.status_code, r.text))
return r.cookies
def _put_checksum(image, layer, cookies):
path = "/v1/images/{id}/checksum".format(**image)
url = urlparse.urljoin(settings.REGISTRY_URL, path)
h = hashlib.sha256(json.dumps(image) + '\n')
h.update(layer.getvalue())
layer_checksum = "sha256:{0}".format(h.hexdigest())
headers = {'X-Docker-Checksum-Payload': layer_checksum}
r = _api_call(url, headers=headers, cookies=cookies, request_type='PUT')
if not r.status_code == 200:
raise RuntimeError("PUT Checksum Error ({}: {})".format(r.status_code, r.text))
def _put_tag(image_id, repository_path, tag):
path = "/v1/repositories/{repository_path}/tags/{tag}".format(**locals())
url = urlparse.urljoin(settings.REGISTRY_URL, path)
r = _api_call(url, data=json.dumps(image_id), request_type='PUT')
if not r.status_code == 200:
raise RuntimeError("PUT Tag Error ({}: {})".format(r.status_code, r.text))
# utility functions
def _construct_env(env, config):
"Update current environment with latest config"
new_env = []
# see if we need to update existing ENV vars
for e in env:
k, v = e.split('=', 1)
if k in config:
# update values defined by config
v = config.pop(k)
new_env.append("{}={}".format(encode(k), encode(v)))
# add other config ENV items
for k, v in config.viewitems():
new_env.append("{}={}".format(encode(k), encode(v)))
return new_env
def _new_id():
"Return 64-char UUID for use as Image ID"
return ''.join(uuid.uuid4().hex * 2)
def _empty_tar_archive():
"Return an empty tar archive (in memory)"
data = cStringIO.StringIO()
tar = tarfile.open(mode="w", fileobj=data)
tar.close()
data.seek(0)
return data
