def get_image(gs, docker_host, container):
"""Gets the information of the given image in the given host.
Args:
gs: global state.
docker_host: Docker host name. Must not be empty.
container: the container which runs the image.
Returns:
If image was found, returns the wrapped image object, which is the result of
utilities.wrap_object(image, 'Image', ...)
If the image was not found, returns None.
Raises:
CollectorError: in case of failure to fetch data from Docker.
ValueError: in case the container does not contain a valid image ID.
Other exceptions may be raised due to exectution errors.
"""
assert utilities.is_wrapped_object(container, 'Container')
# The 'image_id' should be a long hexadecimal string.
image_id = utilities.get_attribute(container, ['properties', 'Image'])
if not utilities.valid_hex_id(image_id):
msg = 'missing or invalid image ID in container ID=%s' % container['id']
gs.logger_error(msg)
raise ValueError(msg)
# The 'image_name' should be a symbolic name (not a hexadecimal string).
image_name = utilities.get_attribute(
container, ['properties', 'Config', 'Image'])
if ((not utilities.valid_string(image_name)) or
utilities.valid_hex_id(image_name)):
msg = 'missing or invalid image name in container ID=%s' % container['id']
gs.logger_error(msg)
raise ValueError(msg)
cache_key = '%s|%s' % (docker_host, image_id)
image, timestamp_secs = gs.get_images_cache().lookup(cache_key)
if timestamp_secs is not None:
gs.logger_info('get_image(docker_host=%s, image_id=%s) cache hit',
docker_host, image_id)
return image
# A typical value of 'docker_host' is:
# k8s-guestbook-node-3.c.rising-apricot-840.internal
# Use only the first period-seperated element for the test file name.
# The typical value of 'image_name' is:
# brendanburns/php-redis
# We convert embedded '/' and ':' characters to '-' to avoid interference with
# the directory structure or file system.
url = 'http://{docker_host}:{port}/images/{image_id}/json'.format(
docker_host=docker_host, port=gs.get_docker_port(), image_id=image_id)
fname = '{host}-image-{id}'.format(
host=docker_host.split('.')[0],
id=image_name.replace('/', '-').replace(':', '-'))
try:
image = fetch_data(gs, url, fname, expect_missing=True)
except ValueError:
# image not found.
msg = 'image not found for image_id: %s' % image_id
gs.logger_info(msg)
return None
except collector_error.CollectorError:
raise
except:
msg = 'fetching %s failed with exception %s' % (url, sys.exc_info()[0])
gs.logger_exception(msg)
raise collector_error.CollectorError(msg)
now = time.time()
# compute the two labels of the image.
# The first is a 12-digit hexadecimal number shown by "docker images".
# The second is the symbolic name of the image.
full_hex_label = image.get('Id')
if not (isinstance(full_hex_label, types.StringTypes) and full_hex_label):
msg = 'Image id=%s has an invalid "Id" attribute value' % image_id
gs.logger_error(msg)
raise collector_error.CollectorError(msg)
short_hex_label = utilities.object_to_hex_id(image)
if short_hex_label is None:
msg = 'Could not compute short hex ID of image %s' % image_id
gs.logger_error(msg)
raise collector_error.CollectorError(msg)
wrapped_image = utilities.wrap_object(
image, 'Image', full_hex_label, now,
label=short_hex_label, alt_label=image_name)
ret_value = gs.get_images_cache().update(cache_key, wrapped_image, now)
gs.logger_info('get_image(docker_host=%s, image_id=%s, image_name=%s)',
docker_host, image_id, image_name)
return ret_value
def get_version(gs):
"""Returns a human-readable information of the currently running image.
Args:
gs: global state.
Returns:
A string of the form:
<symbolic container name> <container hex ID> <creation date and time>
Raises:
CollectorError: in case of any error to compute the running image
information.
"""
version, timestamp_secs = gs.get_version_cache().lookup('')
if timestamp_secs is not None:
assert utilities.valid_string(version)
gs.logger_info('get_version() cache hit')
return version
if gs.get_testing():
fname = 'testdata/proc-self-cgroup.txt'
else:
fname = '/proc/self/cgroup'
try:
f = open(fname, 'r')
cgroup = f.read()
f.close()
except IOError:
# file not found
msg = 'failed to open or read %s' % fname
gs.logger_exception(msg)
raise collector_error.CollectorError(msg)
except:
msg = 'reading %s failed with exception %s' % (fname, sys.exc_info()[0])
gs.logger_exception(msg)
raise collector_error.CollectorError(msg)
# The file must contain an entry for '\d+:cpu:/...'.
m = re.search(r'\b\d+:cpu:/([0-9a-fA-F]+)\b', cgroup)
if not m:
msg = 'could not find an entry for "cpu:/docker/..." in %s' % fname
gs.logger_error(msg)
raise collector_error.CollectorError(msg)
hex_container_id = m.group(1)
if gs.get_testing():
# This pod name is guaranteed to match a pod in the testdata directory.
my_pod_name = 'kube-dns-bqw5e'
else:
my_pod_name = os.uname()[1]
assert utilities.valid_string(my_pod_name)
# Find my node name from my pod.
my_node_name = None
for pod in kubernetes.get_pods(gs):
assert utilities.is_wrapped_object(pod, 'Pod')
if pod['id'] == my_pod_name:
my_node_name = utilities.get_attribute(
pod, ['properties', 'spec', 'nodeName'])
break
if not utilities.valid_string(my_node_name):
msg = ('could not find pod %s or this pod does not contain a valid '
'node name' % my_pod_name)
gs.logger_error(msg)
raise collector_error.CollectorError(msg)
# inspect the running container.
# Must specify an explicit host name (not "localhost").
url = 'http://{host}:{port}/containers/{container_id}/json'.format(
host=my_node_name, port=gs.get_docker_port(),
container_id=hex_container_id)
container = fetch_data(gs, url, 'container-' + hex_container_id[:12])
# Fetch the image symbolic name and hex ID from the container information.
symbolic_image_id = utilities.get_attribute(container, ['Config', 'Image'])
hex_image_id = utilities.get_attribute(container, ['Image'])
# Verify the image symbolic name and the image hex ID.
if not (utilities.valid_string(symbolic_image_id) and
not utilities.valid_hex_id(symbolic_image_id) and
utilities.valid_hex_id(hex_image_id)):
msg = 'could not find or invalid image information in container %s' % url
gs.logger_error(msg)
raise collector_error.CollectorError(msg)
# Fetch image information.
# Must specify an explicit host name (not "localhost").
url = 'http://{host}:{port}/images/{image_id}/json'.format(
host=my_node_name, port=gs.get_docker_port(),
image_id=hex_image_id)
image = fetch_data(gs, url, 'image-' + hex_image_id[:12])
# Fetch the image creation timestamp.
created = utilities.get_attribute(image, ['Created'])
if not utilities.valid_string(created):
msg = 'could not find image creation timestamp in %s' % url
gs.logger_error(msg)
raise collector_error.CollectorError(msg)
# Remove the trailing subsecond part of the creation timestamp.
created = re.sub(r'\.[0-9]+Z$', '', created)
version = '%s %s %s' % (symbolic_image_id, hex_image_id[:12], created)
ret_value = gs.get_version_cache().update('', version)
gs.logger_info('get_version() returns: %s', ret_value)
return ret_value
def get_version(gs):
"""Returns a human-readable information of the currently running image.
Args:
gs: global state.
Returns:
A string of the form:
<symbolic container name> <container hex ID> <creation date and time>
Raises:
CollectorError: in case of any error to compute the running image
information.
"""
version, timestamp_secs = gs.get_version_cache().lookup('')
if timestamp_secs is not None:
assert utilities.valid_string(version)
gs.logger_info('get_version() cache hit')
return version
if gs.get_testing():
fname = 'testdata/proc-self-cgroup.txt'
else:
fname = '/proc/self/cgroup'
try:
f = open(fname, 'r')
cgroup = f.read()
f.close()
except IOError:
# file not found
msg = 'failed to open or read %s' % fname
gs.logger_exception(msg)
raise collector_error.CollectorError(msg)
except:
msg = 'reading %s failed with exception %s' % (fname, sys.exc_info()[0])
gs.logger_exception(msg)
raise collector_error.CollectorError(msg)
# The file must contain an entry for 'cpu:/docker/...'.
m = re.search(r'\b[0-9]+:cpu:/docker/([0-9a-fA-F]+)\b', cgroup)
if not m:
msg = 'could not find an entry for "cpu:/docker/..." in %s' % fname
gs.logger_error(msg)
raise collector_error.CollectorError(msg)
hex_container_id = m.group(1)
# inspect the running container.
url = 'http://localhost:{port}/containers/{container_id}/json'.format(
port=gs.get_docker_port(), container_id=hex_container_id)
container = fetch_data(gs, url, 'container-' + hex_container_id[:12])
# Fetch the image symbolic name and hex ID from the container information.
symbolic_image_id = utilities.get_attribute(container, ['Config', 'Image'])
hex_image_id = utilities.get_attribute(container, ['Image'])
# Verify the image symbolic name and the image hex ID.
if not (utilities.valid_string(symbolic_image_id) and
not utilities.valid_hex_id(symbolic_image_id) and
utilities.valid_hex_id(hex_image_id)):
msg = 'could not find or invalid image information in container %s' % url
gs.logger_error(msg)
raise collector_error.CollectorError(msg)
# Fetch image information.
url = 'http://localhost:{port}/images/{image_id}/json'.format(
port=gs.get_docker_port(), image_id=hex_image_id)
image = fetch_data(gs, url, 'image-' + hex_image_id[:12])
# Fetch the image creation timestamp.
created = utilities.get_attribute(image, ['Created'])
if not utilities.valid_string(created):
msg = 'could not find image creation timestamp in %s' % url
gs.logger_error(msg)
raise collector_error.CollectorError(msg)
# Remove the trailing subsecond part of the creation timestamp.
created = re.sub(r'\.[0-9]+Z$', '', created)
version = '%s %s %s' % (symbolic_image_id, hex_image_id[:12], created)
ret_value = gs.get_version_cache().update('', version)
gs.logger_info('get_version() returns: %s', ret_value)
return ret_value
def get_image(gs, docker_host, container):
"""Gets the information of the given image in the given host.
Args:
gs: global state.
docker_host: Docker host name. Must not be empty.
container: the container which runs the image.
Returns:
If image was found, returns the wrapped image object, which is the result of
utilities.wrap_object(image, 'Image', ...)
If the image was not found, returns None.
Raises:
CollectorError: in case of failure to fetch data from Docker.
ValueError: in case the container does not contain a valid image ID.
Other exceptions may be raised due to exectution errors.
"""
assert utilities.is_wrapped_object(container, 'Container')
# The 'image_id' should be a long hexadecimal string.
image_id = utilities.get_attribute(container, ['properties', 'Image'])
if not utilities.valid_hex_id(image_id):
msg = 'missing or invalid image ID in container ID=%s' % container['id']
gs.logger_error(msg)
raise ValueError(msg)
# The 'image_name' should be a symbolic name (not a hexadecimal string).
image_name = utilities.get_attribute(container,
['properties', 'Config', 'Image'])
if ((not utilities.valid_string(image_name))
or utilities.valid_hex_id(image_name)):
msg = 'missing or invalid image name in container ID=%s' % container[
'id']
gs.logger_error(msg)
raise ValueError(msg)
cache_key = '%s|%s' % (docker_host, image_id)
image, timestamp_secs = gs.get_images_cache().lookup(cache_key)
if timestamp_secs is not None:
gs.logger_info('get_image(docker_host=%s, image_id=%s) cache hit',
docker_host, image_id)
return image
# A typical value of 'docker_host' is:
# k8s-guestbook-node-3.c.rising-apricot-840.internal
# Use only the first period-seperated element for the test file name.
# The typical value of 'image_name' is:
# brendanburns/php-redis
# We convert embedded '/' and ':' characters to '-' to avoid interference with
# the directory structure or file system.
url = 'http://{docker_host}:{port}/images/{image_id}/json'.format(
docker_host=docker_host, port=gs.get_docker_port(), image_id=image_id)
fname = '{host}-image-{id}'.format(host=docker_host.split('.')[0],
id=image_name.replace('/', '-').replace(
':', '-'))
try:
image = fetch_data(gs, url, fname, expect_missing=True)
except ValueError:
# image not found.
msg = 'image not found for image_id: %s' % image_id
gs.logger_info(msg)
return None
except collector_error.CollectorError:
raise
except:
msg = 'fetching %s failed with exception %s' % (url, sys.exc_info()[0])
gs.logger_exception(msg)
raise collector_error.CollectorError(msg)
now = time.time()
# compute the two labels of the image.
# The first is a 12-digit hexadecimal number shown by "docker images".
# The second is the symbolic name of the image.
full_hex_label = image.get('Id')
if not (isinstance(full_hex_label, types.StringTypes) and full_hex_label):
msg = 'Image id=%s has an invalid "Id" attribute value' % image_id
gs.logger_error(msg)
raise collector_error.CollectorError(msg)
short_hex_label = utilities.object_to_hex_id(image)
if short_hex_label is None:
msg = 'Could not compute short hex ID of image %s' % image_id
gs.logger_error(msg)
raise collector_error.CollectorError(msg)
wrapped_image = utilities.wrap_object(image,
'Image',
full_hex_label,
now,
label=short_hex_label,
alt_label=image_name)
ret_value = gs.get_images_cache().update(cache_key, wrapped_image, now)
gs.logger_info('get_image(docker_host=%s, image_id=%s, image_name=%s)',
docker_host, image_id, image_name)
return ret_value
