export_metrics.py 文件源码

def dump_app(app_args, path, begin, now, container_image_pattern = ""):

    # the app_args argument is supplied in the format 
    #   <app name>:<additional influxdb table 1>:<additional influxdb table 2>:...
    app_args = app_args.split(":")
    # get the tag (keys and values) and fields from the docker measurements and 
    # any additional tables
    app = dump_column_names(app_args)

    # build queries
    queries = []
    # always extract docker metrics (here referred to as 'system metrics')
    for system in SYSTEM_METRICS:
        pattern = CONTAINER_IMAGE_PATTERNS[app.name].format(container_image_pattern)
        q = """select * from "docker_container_{}" where
                container_name =~ /{}/
                and container_image =~ /{}/
                and time > '%s' and time < '%s'
            """.format(system, app.name, pattern)
        queries.append(scroll(q, begin, now))

    if len(app_args) > 1:
        for app_arg in app_args[1:]:
            q = "select * from \"{}\" where time > '%s' and time < '%s'".format(app_arg)
            print(q)
            queries.append(scroll(q, begin, now, prefix = app.name))

    path = os.path.join(path, app.filename)

    with gzip.open(path, "wb") as f:
        columns = app.fields + app.tags + ["time"]
        writer = csv.DictWriter(f, fieldnames=columns, dialect=csv.excel_tab, extrasaction='ignore')
        writer.writeheader()
        for _, row in heapq.merge(*queries):
            writer.writerow(row)
    return app

# in general, all apps have docker metrics for them, se we retrieve the 
# metrics stored in 'docker_container_*' tables by default. we save these 
# metrics under an app name equal to the first string in a sequence of strings 
# separated by a ':'. app-specific metrics for such app names are gathered from 
# the tables specified in subsequent strings.