vdk-structlog 0.1.1190994517

Structured logging for versatile data kit

Structured Logging For VDK

This plugin allows users to:

• select the log output format
• configure the logging metadata
• display metadata added by bound loggers
• emit logs to syslog

For a more in-depth technical analysis, check out VEP-2448

Usage

pip install vdk-structlog

Configuration

(vdk config-help is a useful command to browse all config options of your installation of vdk)

Name	Description	Example Value	Possible Values
use_structlog	Use the structlog logging config instead of using the one in vdk-core (True by default).	"True"	"True", "False"
structlog_metadata	Configure the metadata that will be output along with the log message	"timestamp, level, logger_name, file_name, vdk_job_name	Any combination of the following: "timestamp, level, logger_name, file_name, line_number, function_name, vdk_job_name, vdk_step_name, vdk_step_type". Can be expanded by extra params and bound key-value pairs. See the bound logger examples for more information
structlog_format	Configure the logging output format. Available formats: json, console, ltsv	"console"	"console", "json", "ltsv"
structlog_console_log_pattern	Custom format string for console logging, applied only whenlogging_format is 'console'. Overrides logging_metadata. Note: For config.ini, %-signs should be escaped by doubling, e.g. %(asctime)s should become %%(asctime)s	"%(asctime)s %(name)-12s %(levelname)-8s %(message)s"	Any valid Python logging format string
structlog_config_preset	Choose a configuration preset. Any config options set together with the preset will override the preset options. Available presets: LOCAL, CLOUD.	"CLOUD"	"console", "json", "ltsv"
structlog_format_init_logs	Set to True to apply structlog formatting options to vdk initialization logs	"True"	"True", "False"
log_level_module	Configure the log level of different Python modules separately	"a.b.c=INFO;foo.bar=ERROR"	Semicolon-separated list of pairs of Python module paths and log level labels
syslog_host	Syslog host to which logs are emitted	"syslog.vmware.com"	Any valid host name
syslog_port	Syslog port used to emit logs	514	Any valid port number
syslog_protocol	Protocol used to emit logs	"UDP"	"TCP", "UDP"
syslog_enabled	Enable/disable syslog	"True"	"True", "False"

Example: Configure Custom Console Format

If you wish to apply a specific format to your console logs, you can define a custom format using the custom_console_log_pattern configuration. This custom format string will be used only when the logging_format is set to 'console'.

For example, add the following to your data job configuration:

[vdk]
custom_console_log_pattern=%(asctime)s %(name)-12s %(levelname)-8s %(message)s

When you run your data job, regardless of other logging settings, your logs will strictly follow this custom format, displaying the timestamp, logger's name, log level, and the log message as per the format string specified.

2023-10-17 11:20:59,202 managed_cursor    INFO     ingest-from-db-example-job - Executing query SUCCEEDED. Query duration 00h:00m:00s
2023-10-17 11:20:59,202 managed_connectio INFO     ingest-from-db-example-job - Fetching query result...
2023-10-17 11:20:59,202 managed_cursor    INFO     ingest-from-db-example-job - Fetching all results from query ...
2023-10-17 11:20:59,202 managed_cursor    INFO     ingest-from-db-example-job - Fetching all results from query SUCCEEDED.
2023-10-17 11:20:59,202 managed_cursor    INFO     ingest-from-db-example-job - Closing DB cursor ...
2023-10-17 11:20:59,202 managed_cursor    INFO     ingest-from-db-example-job - Closing DB cursor SUCCEEDED.
2023-10-17 11:20:59,203 file_based_step   INFO     ingest-from-db-example-job - Entering 30_ingest_to_table.py#run(...) ...
2023-10-17 11:20:59,203 ingester_router   INFO     ingest-from-db-example-job - Sending tabular data for ingestion with method: sqlite and target: None
2023-10-17 11:20:59,204 file_based_step   INFO     ingest-from-db-example-job - Exiting  30_ingest_to_table.py#run(...) SUCCESS

Example: Configure metadata

Create a data job and add the following config options

[vdk]
logging_metadata=timestamp,level,file_name,vdk_job_name
logging_format=console

Then run the data job. You should see just the configured tags where relevant. For example, you won't see the vdk_job_name outside of log statements directly related to job execution.

2023-10-17 11:20:59,202 [VDK] [INFO ]    managed_cursor.py ingest-from-db-example-job - Executing query SUCCEEDED. Query duration 00h:00m:00s
2023-10-17 11:20:59,202 [VDK] [INFO ] managed_connection_b ingest-from-db-example-job - Fetching query result...
2023-10-17 11:20:59,202 [VDK] [INFO ]    managed_cursor.py ingest-from-db-example-job - Fetching all results from query ...
2023-10-17 11:20:59,202 [VDK] [INFO ]    managed_cursor.py ingest-from-db-example-job - Fetching all results from query SUCCEEDED.
2023-10-17 11:20:59,202 [VDK] [INFO ]    managed_cursor.py ingest-from-db-example-job - Closing DB cursor ...
2023-10-17 11:20:59,202 [VDK] [INFO ]    managed_cursor.py ingest-from-db-example-job - Closing DB cursor SUCCEEDED.
2023-10-17 11:20:59,203 [VDK] [INFO ]   file_based_step.py ingest-from-db-example-job - Entering 30_ingest_to_table.py#run(...) ...
2023-10-17 11:20:59,203 [VDK] [INFO ]   ingester_router.py ingest-from-db-example-job - Sending tabular data for ingestion with method: sqlite and target: None
2023-10-17 11:20:59,204 [VDK] [INFO ]   file_based_step.py ingest-from-db-example-job - Exiting  30_ingest_to_table.py#run(...) SUCCESS

Now, let's remove the timestamp from the configuration and add the line number

[vdk]
logging_metadata=level,file_name,line_number,vdk_job_name
logging_format=console

And run the job again

[INFO ]    managed_cursor.py :97   ingest-from-db-example-job - Executing query SUCCEEDED. Query duration 00h:00m:00s
[INFO ] managed_connection_b :133  ingest-from-db-example-job - Fetching query result...
[INFO ]    managed_cursor.py :193  ingest-from-db-example-job - Fetching all results from query ...
[INFO ]    managed_cursor.py :196  ingest-from-db-example-job - Fetching all results from query SUCCEEDED.
[INFO ]    managed_cursor.py :203  ingest-from-db-example-job - Closing DB cursor ...
[INFO ]    managed_cursor.py :205  ingest-from-db-example-job - Closing DB cursor SUCCEEDED.
[INFO ]   file_based_step.py :103  ingest-from-db-example-job - Entering 30_ingest_to_table.py#run(...) ...
[INFO ]   ingester_router.py :106  ingest-from-db-example-job - Sending tabular data for ingestion with method: sqlite and target: None
[INFO ]   file_based_step.py :109  ingest-from-db-example-job - Exiting  30_ingest_to_table.py#run(...) SUCCESS

Example: Configure logging format

Create a data job and add the following config options

[vdk]
logging_metadata=timestamp,level,file_name,vdk_job_name
logging_format=json

And you should see json-formatted logs.

{"filename": "managed_cursor.py", "lineno": 97, "vdk_job_name": "ingest-from-db-example-job", "message": "Executing query SUCCEEDED. Query duration 00h:00m:00s", "vdk_step_name": "20_create_table.sql", "vdk_step_type": "sql", "timestamp": 1697532608.968082, "level": "INFO"}
{"filename": "managed_connection_base.py", "lineno": 133, "vdk_job_name": "ingest-from-db-example-job", "message": "Fetching query result...", "vdk_step_name": "20_create_table.sql", "vdk_step_type": "sql", "timestamp": 1697532608.9681149, "level": "INFO"}
{"filename": "managed_cursor.py", "lineno": 193, "vdk_job_name": "ingest-from-db-example-job", "message": "Fetching all results from query ...", "vdk_step_name": "20_create_table.sql", "vdk_step_type": "sql", "timestamp": 1697532608.968137, "level": "INFO"}
{"filename": "managed_cursor.py", "lineno": 196, "vdk_job_name": "ingest-from-db-example-job", "message": "Fetching all results from query SUCCEEDED.", "vdk_step_name": "20_create_table.sql", "vdk_step_type": "sql", "timestamp": 1697532608.9681568, "level": "INFO"}
{"filename": "managed_cursor.py", "lineno": 203, "vdk_job_name": "ingest-from-db-example-job", "message": "Closing DB cursor ...", "vdk_step_name": "20_create_table.sql", "vdk_step_type": "sql", "timestamp": 1697532608.968405, "level": "INFO"}
{"filename": "managed_cursor.py", "lineno": 205, "vdk_job_name": "ingest-from-db-example-job", "message": "Closing DB cursor SUCCEEDED.", "vdk_step_name": "20_create_table.sql", "vdk_step_type": "sql", "timestamp": 1697532608.9684658, "level": "INFO"}
{"filename": "file_based_step.py", "lineno": 103, "vdk_job_name": "ingest-from-db-example-job", "message": "Entering 30_ingest_to_table.py#run(...) ...", "vdk_step_name": "30_ingest_to_table.py", "vdk_step_type": "python", "timestamp": 1697532608.9734771, "level": "INFO"}
{"filename": "ingester_router.py", "lineno": 106, "vdk_job_name": "ingest-from-db-example-job", "message": "Sending tabular data for ingestion with method: sqlite and target: None", "vdk_step_name": "30_ingest_to_table.py", "vdk_step_type": "python", "timestamp": 1697532608.975029, "level": "INFO"}
{"filename": "file_based_step.py", "lineno": 109, "vdk_job_name": "ingest-from-db-example-job", "message": "Exiting  30_ingest_to_table.py#run(...) SUCCESS", "vdk_step_name": "30_ingest_to_table.py", "vdk_step_type": "python", "timestamp": 1697532608.976068, "level": "INFO"}

Example: Bound loggers

Python's logging module allows you to pass extra params as a dict. vdk-structlog takes this into account and displays the extra params, as long as they're added to structlog_metadata in config.ini

import logging
import uuid

log = logging.getLogger(__name__)

myid = uuid.uuid4()
log.info(f"Starting job step {__name__}")
log.info("This is an info log statement with extra stuff.", extra={"uuid": myid})

[vdk]
structlog_metadata=timestamp,level,logger_name,file_name,line_number,function_name,uuid
structlog_format=console

2024-01-16 10:16:53,237 [VDK] [INFO ] step_20_python_ste                20_python_step.py :21   run               - Starting job step step_20_python_ste
2024-01-16 10:16:53,237 [VDK] [INFO ] step_20_python_ste                20_python_step.py :22   run              78118954-fe0c-451d-80cf-9b9bc80b8140 - This is an info log statement with extra stuff

This is fine, however, if we want to have the same uuid with multiple log statements, it's not very convenient to pass it every time. vdk offers a function to solve this problem.

import logging
import uuid
from vdk.internal.core.logging import bind_logger

log = logging.getLogger(__name__)

log.info(f"Starting job step {__name__}")

myid = uuid.uuid4()
bound_log = bind_logger(log, {"uuid": myid})
bound_log.info("This is an info log statement with extra stuff")
bound_log.info("This is another log statement with uuid")

[vdk]
structlog_metadata=timestamp,level,logger_name,file_name,line_number,function_name,uuid
structlog_format=console

Now every time you log using the bound logger, you have the uuid attached.

2024-01-16 10:31:04,761 [VDK] [INFO ] step_20_python_ste                20_python_step.py :22   run               - Starting job step step_20_python_ste
2024-01-16 10:31:04,761 [VDK] [INFO ] step_20_python_ste                20_python_step.py :25   run              ed1e447d-3746-4068-8a83-353176327985 - This is an info log statement with extra stuff
2024-01-16 10:31:04,761 [VDK] [INFO ] step_20_python_ste                20_python_step.py :26   run              ed1e447d-3746-4068-8a83-353176327985 - This is another log statement with uuid

Bound loggers act the same as regular loggers. You can even pass extra params to them, or bind additional context.

import logging
import uuid
from vdk.internal.core.logging import bind_logger

log = logging.getLogger(__name__)

log.info(f"Starting job step {__name__}")

myid = uuid.uuid4()
bound_log = bind_logger(log, {"uuid": myid})
bound_log.info("This is an info log statement with extra stuff")
bound_log.info("This is another log statement with uuid")
bound_log.info("More stuff", extra={"new_key": "new_value", "extra_key":"more_value"})
rebound_log = bind_logger(bound_log, {"another_key": "another_value"})

[vdk]
structlog_metadata=timestamp,level,logger_name,file_name,line_number,function_name,uuid,new_key,another_key,extra_key
structlog_format=console

Syslog support

Outputting logs to a syslog server is supported with the following config options

[vdk]
syslog_host=localhost
syslog_port=514
syslog_protocol=UDP
syslog_enabled=True

The syslog output format is set to console and the following formatter string is used. These are currently not configurable.

DETAILED_FORMAT =
    "%(asctime)s [VDK] %(job_name)s [%(levelname)-5.5s] %(name)-30.30s %(filename)20.20s:%("
    "lineno)-4.4s %(funcName)-16.16s[id:%(attempt_id)s]- %(message)s"

Build and test

pip install -r requirements.txt
pip install -e .
pytest

The ../build-plugin.sh script can be used also.

Note about the CICD:

.plugin-ci.yaml is needed only for plugins part of Versatile Data Kit Plugin repo.

The CI/CD is separated in two stages, a build stage and a release stage. The build stage is made up of a few jobs, all which inherit from the same job configuration and only differ in the Python version they use (3.7, 3.8, 3.9 and 3.10). They run according to rules, which are ordered in a way such that changes to a plugin's directory trigger the plugin CI, but changes to a different plugin does not.