def assign_metrics(pipeline: Pipeline, pipeline_metrics: dict):
"""Assign pipeline metrics to specific pipeline steps.
This assignment follows a similar logic to the detection of `out`
dependencies. Starting from a temporary step - child of all the leaf nodes,
all the nodes in the pipelines are traversed in reversed topological order.
When a step shows one of the metrics as part of its code, then that metric
is assigned to the step.
Args:
pipeline: Pipeline object
pipeline_metrics (dict): a dict of pipeline metrics where the key is
the KFP sanitized name and the value the name of the original
variable.
"""
# create a temporary step at the end of the pipeline to simplify the
# iteration from the leaf steps
tmp_step_name = "_tmp"
leaf_steps = pipeline.get_leaf_steps()
if not leaf_steps:
return
[pipeline.add_edge(step.name, tmp_step_name) for step in leaf_steps]
# pipeline_metrics is a dict having sanitized variable names as keys and
# the corresponding variable names as values. Here we need to refer to
# the sanitized names using the python variables.
# XXX: We could change parse_metrics_print_statements() to return the
# XXX: reverse dictionary, but that would require changing either
# XXX: rpc.nb.get_pipeline_metrics() or change in the JupyterLab Extension
# XXX: parsing of the RPC result
rev_pipeline_metrics = {v: k for k, v in pipeline_metrics.items()}
metrics_left = set(rev_pipeline_metrics.keys())
for anc in graphutils.get_ordered_ancestors(pipeline, tmp_step_name):
if not metrics_left:
break
anc_step = pipeline.get_step(anc)
anc_source = '\n'.join(anc_step.source)
# get all the marshal candidates from father's source and intersect
# with the metrics that have not been matched yet
marshal_candidates = kale_ast.get_marshal_candidates(anc_source)
assigned_metrics = metrics_left.intersection(marshal_candidates)
# Remove the metrics that have already been assigned.
metrics_left.difference_update(assigned_metrics)
# Generate code to produce the metrics artifact in the current step
if assigned_metrics:
code = METRICS_TEMPLATE % (" " + ",\n ".join([
'"%s": %s' % (rev_pipeline_metrics[x], x)
for x in sorted(assigned_metrics)
]))
anc_step.source.append(code)
# need to have a `metrics` flag set to true in order to set the
# metrics output artifact in the pipeline template
anc_step.metrics = True
pipeline.remove_node(tmp_step_name)
class NotebookProcessor:
"""Convert a Notebook to a Pipeline object."""
def __init__(self,
nb_path: str,
nb_metadata_overrides: Dict[str, Any] = None,
skip_validation: bool = False):
"""Instantiate a new NotebookProcessor.
Args:
nb_path: Path to source notebook
nb_metadata_overrides: Override notebook config settings
skip_validation: Set to True in order to skip the notebook's
metadata validation. This is useful in case the
NotebookProcessor is used to parse a part of the notebook
(e.g., retrieve pipeline metrics) and the notebook config (for
pipeline generation) might still be invalid.
"""
self.nb_path = os.path.expanduser(nb_path)
self.notebook = self._read_notebook()
nb_metadata = self.notebook.metadata.get(KALE_NB_METADATA_KEY, dict())
# fixme: needed?
nb_metadata.update({"notebook_path": nb_path})
if nb_metadata_overrides:
nb_metadata.update(nb_metadata_overrides)
# validate and populate defaults
# FIXME: Maybe improve this by implementing a "skip_validation" flag
# in the config class
self.config = None
if not skip_validation:
self.config = NotebookConfig(**nb_metadata)
self.pipeline = Pipeline(self.config)
def _read_notebook(self):
if not os.path.exists(self.nb_path):
raise ValueError("NotebookProcessor could not find a notebook at"
" path %s" % self.nb_path)
return nb.read(self.nb_path, as_version=nb.NO_CONVERT)
def to_pipeline(self):
"""Convert an annotated Notebook to a Pipeline object."""
(pipeline_parameters_source, pipeline_metrics_source,
imports_and_functions) = self.parse_notebook()
self.parse_pipeline_parameters(pipeline_parameters_source)
self.pipeline.set_volume_pipeline_parameters()
# get a list of variables that need to be logged as pipeline metrics
pipeline_metrics = astutils.parse_metrics_print_statements(
pipeline_metrics_source)
# run static analysis over the source code
self.dependencies_detection(imports_and_functions)
self.assign_metrics(pipeline_metrics)
# if there are multiple DAG leaves, add an empty step at the end of the
# pipeline for final snapshot
leaf_steps = self.pipeline.get_leaf_steps()
if self.config.autosnapshot and len(leaf_steps) > 1:
_name = "final_auto_snapshot"
self.pipeline.add_step(Step(name=_name, source=[]))
# add a link from all the last steps of the pipeline to
# the final auto snapshot one.
for step in leaf_steps:
self.pipeline.add_edge(step.name, _name)
# FIXME: Move this to a base class Processor, to be executed by default
# after `to_pipeline`, so that it is agnostic to the type of
# processor.
for step in self.pipeline.steps:
step.config.update(self.pipeline.config.steps_defaults)
# TODO: Additional action required:
# Run a static analysis over every step to check that pipeline
# parameters are not assigned with new values.
return self.pipeline
def parse_pipeline_parameters(self, source: str):
"""Get pipeline parameters from source code."""
pipeline_parameters = astutils.parse_assignments_expressions(source)
for name, (v_type, v_value) in pipeline_parameters.items():
pipeline_parameters[name] = PipelineParam(v_type, v_value)
self.pipeline.pipeline_parameters = pipeline_parameters
def parse_notebook(self):
"""Creates a NetworkX graph based on the input notebook's tags.
Cell's source code are embedded into the graph as node attributes.
"""
# will be assigned at the end of each for loop
prev_step_name = None
# All the code cells that have to be pre-pended to every pipeline step
# (i.e., imports and functions) are merged here
imports_block = list()
functions_block = list()
# Variables that will become pipeline parameters
pipeline_parameters = list()
# Variables that will become pipeline metrics
pipeline_metrics = list()
for c in self.notebook.cells:
if c.cell_type != "code":
continue
tags = self.parse_cell_metadata(c.metadata)
if len(tags['step_names']) > 1:
raise NotImplementedError("Kale does not yet support multiple"
" step names in a single notebook"
" cell. One notebook cell was found"
" with %s step names" %
tags['step_names'])
step_name = (tags['step_names'][0]
if 0 < len(tags['step_names']) else None)
if step_name == 'skip':
# when the cell is skipped, don't store `skip` as the previous
# active cell
continue
if step_name == 'pipeline-parameters':
pipeline_parameters.append(c.source)
prev_step_name = step_name
continue
if step_name == 'imports':
imports_block.append(c.source)
prev_step_name = step_name
continue
if step_name == 'functions':
functions_block.append(c.source)
prev_step_name = step_name
continue
if step_name == 'pipeline-metrics':
pipeline_metrics.append(c.source)
prev_step_name = step_name
continue
# if none of the above apply, then we are parsing a code cell with
# a block names and (possibly) some dependencies
# if the cell was not tagged with a step name,
# add the code to the previous cell
if not step_name:
if prev_step_name == 'imports':
imports_block.append(c.source)
elif prev_step_name == 'functions':
functions_block.append(c.source)
elif prev_step_name == 'pipeline-parameters':
pipeline_parameters.append(c.source)
elif prev_step_name == 'pipeline-metrics':
pipeline_metrics.append(c.source)
# current_block might be None in case the first cells of the
# notebooks have not been tagged.
elif prev_step_name:
# this notebook cell will be merged to a previous one that
# specified a step name
self.pipeline.get_step(prev_step_name).merge_code(c.source)
else:
# in this branch we are sure that we are reading a code cell
# with a step tag, so we must not allow for pipeline-metrics
if prev_step_name == 'pipeline-metrics':
raise ValueError("Tag pipeline-metrics must be placed on a"
" cell at the end of the Notebook."
" Pipeline metrics should be considered"
" as a result of the pipeline execution"
" and not of single steps.")
# add node to DAG, adding tags and source code of notebook cell
if step_name not in self.pipeline.nodes:
step = Step(name=step_name,
source=[c.source],
ins=set(),
outs=set(),
limits=tags.get("limits", {}),
labels=tags.get("labels", {}),
annotations=tags.get("annotations", {}))
self.pipeline.add_step(step)
for _prev_step in tags['prev_steps']:
if _prev_step not in self.pipeline.nodes:
raise ValueError("Step %s does not exist. It was "
"defined as previous step of %s" %
(_prev_step, tags['step_names']))
self.pipeline.add_edge(_prev_step, step_name)
else:
self.pipeline.get_step(step_name).merge_code(c.source)
prev_step_name = step_name
# Prepend any `imports` and `functions` cells to every Pipeline step
for step in self.pipeline.steps:
step.source = imports_block + functions_block + step.source
# merge together pipeline parameters
pipeline_parameters = '\n'.join(pipeline_parameters)
# merge together pipeline metrics
pipeline_metrics = '\n'.join(pipeline_metrics)
imports_and_functions = "\n".join(imports_block + functions_block)
return pipeline_parameters, pipeline_metrics, imports_and_functions
def parse_cell_metadata(self, metadata):
"""Parse a notebook's cell's metadata field.
The Kale UI writes specific tags inside the 'tags' field, as a list
of string tags. Supported tags are defined by _TAGS_LANGUAGE.
Args:
metadata (dict): a dict containing a notebook's cell's metadata
Returns (dict): parsed tags based on Kale tagging language
"""
parsed_tags = dict()
# `step_names` is a list because a notebook cell might be assigned to
# more than one Pipeline step.
parsed_tags['step_names'] = list()
parsed_tags['prev_steps'] = list()
# define intermediate variables so that dicts are not added to a steps
# when they are empty
cell_annotations = dict()
cell_labels = dict()
cell_limits = dict()
# the notebook cell was not tagged
if 'tags' not in metadata or len(metadata['tags']) == 0:
return parsed_tags
for t in metadata['tags']:
if not isinstance(t, str):
raise ValueError(
"Tags must be string. Found tag %s of type %s" %
(t, type(t)))
# Check that the tag is defined by the Kale tagging language
if any(re.match(_t, t) for _t in _TAGS_LANGUAGE) is False:
raise ValueError("Unrecognized tag: {}".format(t))
# Special tags have a specific effect on the cell they belong to.
# Specifically:
# - skip: ignore the notebook cell
# - pipeline-parameters: use the cell to populate Pipeline
# parameters. The cell must contain only assignment
# expressions
# - pipeline-metrics: use the cell to populate Pipeline metrics.
# The cell must contain only variable names
# - imports: the code of the corresponding cell(s) will be
# prepended to every Pipeline step
# - functions: same as imports, but the corresponding code is
# placed **after** `imports`
special_tags = [
'skip', 'pipeline-parameters', 'pipeline-metrics', 'imports',
'functions'
]
if t in special_tags:
parsed_tags['step_names'] = [t]
return parsed_tags
# now only `block|step` and `prev` tags remain to be parsed.
tag_parts = t.split(':')
tag_name = tag_parts.pop(0)
if tag_name == "annotation":
key, value = get_annotation_or_label_from_tag(tag_parts)
cell_annotations.update({key: value})
if tag_name == "label":
key, value = get_annotation_or_label_from_tag(tag_parts)
cell_labels.update({key: value})
if tag_name == "limit":
key, value = get_limit_from_tag(tag_parts)
cell_limits.update({key: value})
# name of the future Pipeline step
# TODO: Deprecate `block` in future release
if tag_name in ["block", "step"]:
if tag_name == "block":
warnings.warn(
"`block` tag will be deprecated in a future"
" version, use `step` tag instead", DeprecationWarning)
step_name = tag_parts.pop(0)
parsed_tags['step_names'].append(step_name)
# name(s) of the father Pipeline step(s)
if tag_name == "prev":
prev_step_name = tag_parts.pop(0)
parsed_tags['prev_steps'].append(prev_step_name)
if not parsed_tags['step_names'] and parsed_tags['prev_steps']:
raise ValueError(
"A cell can not provide `prev` annotations without "
"providing a `block` or `step` annotation as well")
if cell_annotations:
if not parsed_tags['step_names']:
raise ValueError(
"A cell can not provide Pod annotations in a cell"
" that does not declare a step name.")
parsed_tags['annotations'] = cell_annotations
if cell_limits:
if not parsed_tags['step_names']:
raise ValueError(
"A cell can not provide Pod resource limits in a"
" cell that does not declare a step name.")
parsed_tags['limits'] = cell_limits
return parsed_tags
def get_pipeline_parameters_source(self):
"""Get just pipeline parameters cells from the notebook.
Returns (str): pipeline parameters source code
"""
return self._get_reserved_tag_source(PIPELINE_PARAMETERS_TAG)
def get_pipeline_metrics_source(self):
"""Get just pipeline metrics cells from the notebook.
Returns (str): pipeline metrics source code
"""
# check that the pipeline metrics tag is only assigned to cells at
# the end of the notebook
detected = False
tags = _TAGS_LANGUAGE[:]
tags.remove(PIPELINE_METRICS_TAG)
for c in self.notebook.cells:
# parse only source code cells
if c.cell_type != "code":
continue
# if we see a pipeline-metrics tag, set the flag
if (('tags' in c.metadata and len(c.metadata['tags']) > 0 and any(
re.match(PIPELINE_METRICS_TAG, t)
for t in c.metadata['tags']))):
detected = True
continue
# if we have the flag set and we detect any other tag from the tags
# language, then raise error
if (detected and 'tags' in c.metadata
and len(c.metadata['tags']) > 0 and any([
any(re.match(tag, t) for t in c.metadata['tags'])
for tag in tags
])):
raise ValueError(
"Tag pipeline-metrics tag must be placed on a "
"cell at the end of the Notebook."
" Pipeline metrics should be considered as a"
" result of the pipeline execution and not of"
" single steps.")
return self._get_reserved_tag_source(PIPELINE_METRICS_TAG)
def _get_reserved_tag_source(self, search_tag):
"""Get just the specific tag's source code.
When searching for tag x, will return all cells that are tagged with x
and, if untagged, follow cells with tag x. The result is a multiline
string containing all the python code associated to x.
Note: This is designed for 'special' tags, as the STEP_TAG is excluded
from the match.
Args:
search_tag (str): the target tag
Returns: the unified code of all the cells belonging to `search_tag`
"""
detected = False
source = ''
language = _TAGS_LANGUAGE[:]
language.remove(search_tag)
for c in self.notebook.cells:
# parse only source code cells
if c.cell_type != "code":
continue
# in case the previous cell was a `search_tag` cell and this
# cell is not any other tag of the tag language:
if (detected and
(('tags' not in c.metadata or len(c.metadata['tags']) == 0)
or all([
not any(re.match(tag, t) for t in c.metadata['tags'])
for tag in language
]))):
source += '\n' + c.source
elif (
('tags' in c.metadata and len(c.metadata['tags']) > 0
and any(re.match(search_tag, t)
for t in c.metadata['tags']))):
source += '\n' + c.source
detected = True
else:
detected = False
return source.strip()
def assign_metrics(self, pipeline_metrics: dict):
"""Assign pipeline metrics to specific pipeline steps.
This assignment follows a similar logic to the detection of `out`
dependencies. Starting from a temporary step - child of all the leaf
nodes, all the nodes in the pipelines are traversed in reversed
topological order. When a step shows one of the metrics as part of its
code, then that metric is assigned to the step.
Args:
pipeline_metrics (dict): a dict of pipeline metrics where the key
always the KFP sanitized name and the value the name of the
original variable.
"""
# create a temporary step at the end of the pipeline to simplify the
# iteration from the leaf steps
tmp_step_name = "_tmp"
leaf_steps = self.pipeline.get_leaf_steps()
if not leaf_steps:
return
[
self.pipeline.add_edge(step.name, tmp_step_name)
for step in leaf_steps
]
# pipeline_metrics is a dict having sanitized variable names as keys
# and the corresponding variable names as values. Here we need to refer
# to the sanitized names using the python variables.
# XXX: We could change parse_metrics_print_statements() to return the
# XXX: reverse dictionary, but that would require changing either
# XXX: rpc.nb.get_pipeline_metrics() or change in the JupyterLab
# XXX: Extension parsing of the RPC result
rev_pipeline_metrics = {v: k for k, v in pipeline_metrics.items()}
metrics_left = set(rev_pipeline_metrics.keys())
for anc in graphutils.get_ordered_ancestors(self.pipeline,
tmp_step_name):
if not metrics_left:
break
anc_step = self.pipeline.get_step(anc)
anc_source = '\n'.join(anc_step.source)
# get all the marshal candidates from father's source and intersect
# with the metrics that have not been matched yet
marshal_candidates = astutils.get_marshal_candidates(anc_source)
assigned_metrics = metrics_left.intersection(marshal_candidates)
# Remove the metrics that have already been assigned.
metrics_left.difference_update(assigned_metrics)
# Generate code to produce the metrics artifact in the current step
if assigned_metrics:
code = METRICS_TEMPLATE % (" " + ",\n ".join([
'"%s": %s' % (rev_pipeline_metrics[x], x)
for x in sorted(assigned_metrics)
]))
anc_step.source.append(code)
# need to have a `metrics` flag set to true in order to set the
# metrics output artifact in the pipeline template
anc_step.metrics = True
self.pipeline.remove_node(tmp_step_name)
def dependencies_detection(self, imports_and_functions: str = ""):
"""Detect the data dependencies between nodes in the graph.
The data dependencies detection algorithm roughly works as follows:
1. Traversing the graph in topological order, for every node `step` do
2. Detect the `ins` of current `step` by running PyFlakes on the source
code. During this action the pipeline parameters are taken into
consideration
3. Parse `step`'s global function definitions to get free variables
(i.e. variables that would need to be marshalled in other steps that
call these functions) - in this action pipeline parameters are taken
into consideration.
4. Get all the function that `step` calls
5. For every `step`'s ancestor `anc` do
- Get all the potential names (objects, functions, ...) of `anc`
that could be marshalled (saved)
- Intersect this with the `step`'s `ins` (from action 2) and add
the result to `anc`'s `outs`.
- for every `step`'s function call (action 4), check if this
function was defined in `anc` and if it has free variables
(action 3). If so, add to `step`'s `ins` and to `anc`'s `outs`
these free variables.
Args:
imports_and_functions: Multiline Python source that is prepended to
every pipeline step
Returns: annotated graph
"""
# resolve the data dependencies between steps, looping through the
# graph
for step in self.pipeline.steps:
# detect the INS dependencies of the CURRENT node------------------
step_source = '\n'.join(step.source)
# get the variables that this step is missing and the pipeline
# parameters that it actually needs.
ins, parameters = self._detect_in_dependencies(
source_code=step_source,
pipeline_parameters=self.pipeline.pipeline_parameters)
fns_free_variables = self._detect_fns_free_variables(
step_source, imports_and_functions,
self.pipeline.pipeline_parameters)
# Get all the function calls. This will be used below to check if
# any of the ancestors declare any of these functions. Is that is
# so, the free variables of those functions will have to be loaded.
fn_calls = astutils.get_function_calls(step_source)
# add OUT dependencies annotations in the PARENT nodes-------------
# Intersect the missing names of this father's child with all
# the father's names. The intersection is the list of variables
# that the father need to serialize
# The ancestors are the the nodes that have a path to `step`,
# ordered by path length.
ins_left = ins.copy()
for anc in (graphutils.get_ordered_ancestors(
self.pipeline, step.name)):
if not ins_left:
# if there are no more variables that need to be
# marshalled, stop the graph traverse
break
anc_step = self.pipeline.get_step(anc)
anc_source = '\n'.join(anc_step.source)
# get all the marshal candidates from father's source and
# intersect with the required names of the current node
marshal_candidates = astutils.get_marshal_candidates(
anc_source)
outs = ins_left.intersection(marshal_candidates)
# Remove the ins that have already been assigned to an ancestor
ins_left.difference_update(outs)
# Include free variables
to_remove = set()
for fn_call in fn_calls:
anc_fns_free_vars = anc_step.fns_free_variables
if fn_call in anc_fns_free_vars.keys():
# the current step needs to load these variables
fn_free_vars, used_params = anc_fns_free_vars[fn_call]
# search if this function calls other functions (i.e.
# if its free variables are found in the free variables
# dict)
_left = list(fn_free_vars)
while _left:
_cur = _left.pop(0)
# if the free var is itself a fn with free vars
if _cur in anc_fns_free_vars:
fn_free_vars.update(anc_fns_free_vars[_cur][0])
_left = _left + list(
anc_fns_free_vars[_cur][0])
ins.update(fn_free_vars)
# the current ancestor needs to save these variables
outs.update(fn_free_vars)
# add the parameters used by the function to the list
# of pipeline parameters used by the step
_pps = self.pipeline.pipeline_parameters
for param in used_params:
parameters[param] = _pps[param]
# Remove this function as it has been served. We don't
# want other ancestors to save free variables for this
# function. Using the helper to_remove because the set
# can not be resized during iteration.
to_remove.add(fn_call)
# add the function and its free variables to the
# current step as well. This is useful in case
# *another* function will call this one (`fn_call`) in
# a child step. In this way we can track the calls up
# to the last free variable. (refer to test
# `test_dependencies_detection_recursive`)
fns_free_variables[fn_call] = anc_fns_free_vars[
fn_call]
fn_calls.difference_update(to_remove)
# Add to ancestor the new outs annotations. First merge the
# current outs present in the anc with the new ones
anc_step.outs.update(outs)
step.ins = sorted(ins)
step.parameters = parameters
step.fns_free_variables = fns_free_variables
def _detect_in_dependencies(self,
source_code: str,
pipeline_parameters: dict = None):
"""Detect missing names from one pipeline step source code.
Args:
source_code: Multiline Python source code
pipeline_parameters: Pipeline parameters dict
"""
commented_source_code = utils.comment_magic_commands(source_code)
ins = flakeutils.pyflakes_report(code=commented_source_code)
# Pipeline parameters will be part of the names that are missing,
# but of course we don't want to marshal them in as they will be
# present as parameters
relevant_parameters = set()
if pipeline_parameters:
# Not all pipeline parameters are needed in every pipeline step,
# these are the parameters that are actually needed by this step.
relevant_parameters = ins.intersection(pipeline_parameters.keys())
ins.difference_update(relevant_parameters)
step_params = {k: pipeline_parameters[k] for k in relevant_parameters}
return ins, step_params
def _detect_fns_free_variables(self,
source_code: str,
imports_and_functions: str = "",
step_parameters: dict = None):
"""Return the function's free variables.
Free variable: _If a variable is used in a code block but not defined
there, it is a free variable._
An Example:
```
x = 5
def foo():
print(x)
```
In the example above, `x` is a free variable for function `foo`,
because it is defined outside of the context of `foo`.
Here we run the PyFlakes report over the function body to get all the
missing names (i.e. free variables), excluding the function arguments.
Args:
source_code: Multiline Python source code
imports_and_functions: Multiline Python source that is prepended
to every pipeline step. It should contain the code cells that
where tagged as `import` and `functions`. We prepend this code
to the function body because it will always be present in any
pipeline step.
step_parameters: Step parameters names. The step parameters
are removed from the pyflakes report, as these names will
always be available in the step's context.
Returns (dict): A dictionary with the name of the function as key and
a list of variables names + consumed pipeline parameters as values.
"""
fns_free_vars = dict()
# now check the functions' bodies for free variables. fns is a
# dict function_name -> function_source
fns = astutils.parse_functions(source_code)
for fn_name, fn in fns.items():
code = imports_and_functions + "\n" + fn
free_vars = flakeutils.pyflakes_report(code=code)
# the pipeline parameters that are used in the function
consumed_params = {}
if step_parameters:
consumed_params = free_vars.intersection(
step_parameters.keys())
# remove the used parameters form the free variables, as they
# need to be handled differently.
free_vars.difference_update(consumed_params)
fns_free_vars[fn_name] = (free_vars, consumed_params)
return fns_free_vars