name : nodejs_http_server.py #!/usr/bin/python # # nodejs_http_server Basic example of node.js USDT tracing. # For Linux, uses BCC, BPF. Embedded C. # # USAGE: nodejs_http_server PID # # Copyright 2016 Netflix, Inc. # Licensed under the Apache License, Version 2.0 (the "License") from __future__ import print_function from bcc import BPF, USDT from bcc.utils import printb import sys if len(sys.argv) < 2: print("USAGE: nodejs_http_server PID") exit() pid = sys.argv[1] debug = 0 # load BPF program bpf_text = """ #include <uapi/linux/ptrace.h> int do_trace(struct pt_regs *ctx) { uint64_t addr; char path[128]={0}; bpf_usdt_readarg(6, ctx, &addr); bpf_probe_read_user(&path, sizeof(path), (void *)addr); bpf_trace_printk("path:%s\\n", path); return 0; }; """ # enable USDT probe from given PID u = USDT(pid=int(pid)) u.enable_probe(probe="http__server__request", fn_name="do_trace") if debug: print(u.get_text()) print(bpf_text) # initialize BPF b = BPF(text=bpf_text, usdt_contexts=[u]) # header print("%-18s %-16s %-6s %s" % ("TIME(s)", "COMM", "PID", "ARGS")) # format output while 1: try: (task, pid, cpu, flags, ts, msg) = b.trace_fields() except ValueError: print("value error") continue except KeyboardInterrupt: exit() printb(b"%-18.9f %-16s %-6d %s" % (ts, task, pid, msg))