joshenders

Background

The current verison of NodeJS hardcodes the path where perf data is written when the --perf-basic-prof flag is used.

https://github.com/v8/v8/blob/061c2ab23a1d4cd192b935e7912e7dfb1fed845d/src/log.cc#L236

At Pinterest, /tmp has limited capacity and so we weren't able to utilize perf data to troubleshoot NodeJS without filling the disk and crashing the running system.

How to patch

First I'll copy the system node binary to my local directory so this set of actions isn't destructive to the running system:

joshenders

--- rules	2016-11-25 23:23:25.924313744 +0000
+++ rules.new	2016-11-25 23:23:17.788331016 +0000
@@ -15,7 +15,7 @@
 DEB_HOST_ARCH ?= $(shell dpkg-architecture -qDEB_HOST_ARCH)

 # Set local state dir for FHS
-LOCAL_CONFIGURE_FLAGS = --localstatedir=/var/lib
+LOCAL_CONFIGURE_FLAGS = --localstatedir=/var/lib --enable-debugging-symbols

 ifneq ($(filter $(DEB_HOST_ARCH),$(DISABLE_JEMALLOC_ARCH_LIST)),)

joshenders

--- debian/control	2012-06-18 18:59:16.000000000 +0000
+++ debian/control 	2016-11-03 07:10:00.536388796 +0000
@@ -36,13 +36,6 @@
   * URL rewriting
   * Graceful handling of "dead" backends

-Package: varnish-doc
-Architecture: all
-Section: doc
-Depends: ${misc:Depends}, libjs-jquery, libjs-underscore

joshenders

--- reload-vcl	2011-10-29 13:24:10.000000000 +0000
+++ /usr/share/varnish/reload-vcl	2016-12-11 09:51:08.696300339 +0000
@@ -1,9 +1,13 @@
 #!/bin/sh
-
+#
 # reload-varnish: Script to reload varnishd from VCL defined in
 # /etc/default/varnish.
 #
 # Stig Sandbeck Mathisen <ssm@debian.org>

joshenders

--- a/bin/varnishd/cache_gzip.c
+++ b/bin/varnishd/cache_gzip.c
@@ -646,9 +646,6 @@
		bytes -= w;
		VGZ_Ibuf(vg, st->ptr + st->len, w);
		st->len += w;
-		sp->obj->len += w;
-		if (sp->wrk->do_stream)
-			RES_StreamPoll(sp);

joshenders

diff --git a/bin/varnishncsa/varnishncsa.c b/bin/varnishncsa/varnishncsa.c
index ff07ed5..3af1367 100644
--- a/bin/varnishncsa/varnishncsa.c
+++ b/bin/varnishncsa/varnishncsa.c
@@ -98,6 +98,7 @@ static struct logline {
	struct tm df_t;			/* %t, Date and time */
	char *df_u;			/* %u, Remote user */
	char *df_ttfb;			/* Time to first byte */
+	char *df_ttlb;			/* Time to last byte */
	const char *df_hitmiss;		/* Whether this is a hit or miss */

joshenders

function certchain() {
    # Usage: certchain
    # Display PKI chain-of-trust for a given domain
    # GistID: https://gist.github.com/joshenders/cda916797665de69ebcd
    if [[ "$#" -ne 1 ]]; then
        echo "Usage: ${FUNCNAME} <ip|domain[:port]>"
        return 1
    fi

    local host_port="$1"

joshenders

function ylint() {
    if [[ "$#" -ne 1 ]]; then
        echo "Usage: ${FUNCNAME} <infile>"
        return 1
    fi

    ruby -e "require 'yaml'; YAML.load_file('$1')"
}

joshenders

Successful mitmproxy-3.7 setup tested on OS X 10.13.6 and iPhone X running 12.1.4

Enable IP forwarding and disable ICMP redirects to keep the iPad sending traffic to the proxy

sudo sysctl -w net.inet.ip.forwarding=1
sudo sysctl -w net.inet.ip.redirect=0

net.inet.ip.forwarding
Enable IP forwarding between interfaces

joshenders

#!/bin/bash
# https://gist.github.com/joshenders/52cb78bedaea6787faac

# This script uses the BSD variants of commands and is intended to
# be run on an unmodified installation of OSX.

pmset noidle &

now=$(date +%s)
duration=$((86400*3)) # 3days