`xamari xlog` can be used to maintin extra log for an Amarisoft LTE
service: in addition to native logs, xlog contains results of periodic
queries done via WebSocket. For example with the following aguments

	xamari xlog <wsuri>  stats/10s ue_get/3s erab_get/3s

xlog will emit results of stats query - every 10 seconds, results from
ue_get query - every 3 seconds, and similarly for erab_get query.

The results are saved into xlog in JSON Lines format for easy future
processing. For the reference below is a copy of corresponding help
entries:

    xlte$ xamari help xlog
    Usage: xamari xlog [OPTIONS] <wsuri> <logspec>+
    Maintain extra log for a service.

    The service is queried periodically according to logspec and results are saved
    in JSON format to a file (see 'xamari help jsonlog').

    <wsuri> is URI (see 'xamari help websock') of an Amarisoft-service.
    <logspec> is specification of what to log. It has the following parts:

        <query>[<options>]/<period>

    The query specifies a message, that should be used to query service. For
    example "stats", "ue_get", "erab_get", ... Query part is mandatory.

    Options specifies additional flags for the query. Options part can be omitted.

    Period specifies periodicity of how often the service should be queried.
    Period is optional and defaults to 60 seconds.

    Example for <logspec>+:

        stats[samples,rf]/30s  ue_get[stats]  erab_get/10s  qos_flow_get

    Options:

        -h  --help            show this help

    xlte$ xamari help jsonlog
    Some commands produce logs with JSON entries. Such logs are organized with JSON
    Lines format(*) with each entry occupying one line.

    Logs in JSON Lines format are handy to exchange in between programs, and with
    corresponding tools, e.g. jq(+), they can be also displayed in human-readable
    form and inspected quickly.

    (*) https://jsonlines.org/
    (+) https://stedolan.github.io/jq/

Example output:

(xlte3.venv) kirr@deca:~/src/wendelin/xlte$ xamari xlog ws://localhost:9001 ue_get/3s erab_get/3s
{"meta": {"event": "start", "time": "Wed, 19 Oct 2022 15:05:50 -0000", "generator": "xlog ws://localhost:9001 ue_get[]/3.0s erab_get[]/3.0s"}}
{"meta": {"event": "service attach", "time": "Wed, 19 Oct 2022 15:05:51 -0000", "srv_name": "ENB", "srv_type": "ENB", "srv_version": "2022-09-16"}}
{"message":"config_get","version":"2022-09-16","type":"ENB","name":"ENB","license_id":"d9a961c166d2d4b15249fc559cdec925efbbe942d73b143aff","license_user":"rapid.space","logs":{"layers":{"PHY":{"level":"error","max_size":0,"key":false,"crypto":false,"payload":false},"MAC":{"level":"error","max_size":0,"key":false,"crypto":false,"payload":false},"RLC":{"level":"error","max_size":0,"key":false,"crypto":false,"payload":false},"PDCP":{"level":"error","max_size":0,"key":false,"crypto":false,"payload":false},"RRC":{"level":"debug","max_size":1,"key":false,"crypto":false,"payload":false},"NAS":{"level":"debug","max_size":1,"key":false,"crypto":false,"payload":false},"S1AP":{"level":"debug","max_size":1,"key":false,"crypto":false,"payload":false},"NGAP":{"level":"error","max_size":0,"key":false,"crypto":false,"payload":false},"GTPU":{"level":"error","max_size":0,"key":false,"crypto":false,"payload":false},"X2AP":{"level":"debug","max_size":1,"key":false,"crypto":false,"payload":false},"XnAP":{"level":"error","max_size":0,"key":false,"crypto":false,"payload":false},"M2AP":{"level":"error","max_size":0,"key":false,"crypto":false,"payload":false},"LPPa":{"level":"error","max_size":0,"key":false,"crypto":false,"payload":false},"NRPPa":{"level":"error","max_size":0,"key":false,"crypto":false,"payload":false},"TRX":{"level":"error","max_size":0,"key":false,"crypto":false,"payload":false}},"bcch":false,"mib":false,"signal":false,"cch":false,"rep":false,"dci_size":false,"csi":false,"cell_meas":false,"count":8192,"rotate":250000000,"path":"/var/log/lte"},"tai":9610.092,"global_enb_id":{"plmn":"00101","enb_id_type":"macro","enb_id":107216,"enb_name":"enb1a2d0"},"cells":{"1":{"n_antenna_dl":2,"n_antenna_ul":2,"n_layer_dl":2,"n_layer_ul":1,"gain":0,"ul_disabled":false,"rf_port":0,"dl_qam":256,"ul_qam":64,"ecgi":{"plmn":"00101","eci":27447297},"n_id_cell":1,"n_rb_dl":100,"n_rb_ul":100,"dl_earfcn":38350,"ul_earfcn":38350,"band":39,"dl_freq":1890000000,"ul_freq":1890000000,"mode":"TDD","uldl_config":2,"sp_config":7,"prach_sequence_index":204,"dl_cyclic_prefix":"normal","ul_cyclic_prefix":"normal","prach_config_index":4,"prach_freq_offset":11,"delta_pucch_shift":2,"n_rb_cqi":1,"n_cs_an":0,"pucch_allocation":[{"type":"2/2a/2b","rbs":1,"n":6}],"pucch_ack_nack_start":11,"pucch_reserved_rbs":[0,0,22,0,0,0,0,22,0,0],"sr_resource_count":44,"cqi_resource_count":48,"srs_resources":{"offsets":16,"freqs":20,"total":640},"gbr":{"dl_limit":7123840,"ul_limit":1797120},"tac":1,"plmn_list":[{"plmn":"00101","reserved":false}]}},"rx_channels":[{"gain":9,"freq":1890,"port":0},{"gain":9,"freq":1890,"port":0}],"tx_channels":[{"gain":60,"freq":1890,"port":0},{"gain":60,"freq":1890,"port":0}],"rf_ports":[{"sample_rate":30720000}],"message_id":1,"time":9610.087}
{"message":"ue_get","ue_list":[],"message_id":2,"time":9613.347}
{"message":"erab_get","erab_list":[],"timestamp":9613704,"message_id":3,"time":9613.704}
{"message":"ue_get","ue_list":[],"message_id":4,"time":9616.355}
{"message":"erab_get","erab_list":[],"timestamp":9616618,"message_id":5,"time":9616.618}
{"message":"ue_get","ue_list":[],"message_id":6,"time":9619.272}
{"message":"erab_get","erab_list":[],"timestamp":9619547,"message_id":7,"time":9619.547}
{"message":"ue_get","ue_list":[],"message_id":8,"time":9622.319}
{"message":"erab_get","erab_list":[],"timestamp":9622588,"message_id":9,"time":9622.588}
{"message":"ue_get","ue_list":[],"message_id":10,"time":9625.263}
{"message":"erab_get","erab_list":[],"timestamp":9625663,"message_id":11,"time":9625.663}
{"message":"ue_get","ue_list":[],"message_id":12,"time":9628.403}
{"message":"erab_get","erab_list":[],"timestamp":9628725,"message_id":13,"time":9628.725}
{"message":"ue_get","ue_list":[],"message_id":14,"time":9631.381}
{"message":"erab_get","erab_list":[],"timestamp":9631798,"message_id":15,"time":9631.798}
{"message":"ue_get","ue_list":[],"message_id":16,"time":9634.303}
{"message":"erab_get","erab_list":[],"timestamp":9634596,"message_id":17,"time":9634.596}
{"message":"ue_get","ue_list":[],"message_id":18,"time":9637.268}
{"message":"erab_get","erab_list":[],"timestamp":9637568,"message_id":19,"time":9637.568}

    (below an UE registers with eNB)

{"message":"ue_get","ue_list":[{"enb_ue_id":8,"mme_ue_id":107,"rnti":68,"cells":[{"cell_id":1}]}],"message_id":20,"time":9640.296}
{"message":"erab_get","erab_list":[{"erab_id":5,"qci":9,"dl_total_bytes":0,"ul_total_bytes":0,"enb_ue_id":8}],"timestamp":9640831,"message_id":21,"time":9640.831}
{"message":"ue_get","ue_list":[{"enb_ue_id":8,"mme_ue_id":107,"rnti":68,"cells":[{"cell_id":1}]}],"message_id":22,"time":9643.268}
{"message":"erab_get","erab_list":[{"erab_id":5,"qci":9,"dl_total_bytes":0,"ul_total_bytes":0,"enb_ue_id":8}],"timestamp":9643555,"message_id":23,"time":9643.555}
{"message":"ue_get","ue_list":[{"enb_ue_id":8,"mme_ue_id":107,"rnti":68,"cells":[{"cell_id":1}]}],"message_id":24,"time":9646.326}
{"message":"erab_get","erab_list":[{"erab_id":5,"qci":9,"dl_total_bytes":0,"ul_total_bytes":0,"enb_ue_id":8}],"timestamp":9646850,"message_id":25,"time":9646.85}
{"message":"ue_get","ue_list":[],"message_id":26,"time":9649.287}
{"message":"erab_get","erab_list":[],"timestamp":9649646,"message_id":27,"time":9649.646}
^CTraceback (most recent call last):
  File "/home/kirr/src/wendelin/venv/xlte3.venv/bin/xamari", line 33, in <module>
    sys.exit(load_entry_point('xlte', 'console_scripts', 'xamari')())
  File "/home/kirr/src/wendelin/xlte/amari/xamari.py", line 130, in main
    return command_module.main(argv)
  File "/home/kirr/src/wendelin/xlte/amari/xlog.py", line 275, in main
    xlog(wsuri, logspecv)
  File "/home/kirr/src/wendelin/xlte/amari/xlog.py", line 108, in xlog
    xl.xlog1()
  File "/home/kirr/src/wendelin/venv/xlte3.venv/lib/python3.9/site-packages/decorator.py", line 232, in fun
    return caller(func, *(extras + args), **kw)
  File "/home/kirr/src/wendelin/venv/xlte3.venv/lib/python3.9/site-packages/golang/__init__.py", line 103, in _
    return f(*argv, **kw)
  File "/home/kirr/src/wendelin/xlte/amari/xlog.py", line 157, in xlog1
    xl._xlog1(conn)
  File "/home/kirr/src/wendelin/xlte/amari/xlog.py", line 208, in _xlog1
    time.sleep(δtsleep)
KeyboardInterrupt