hasher-firefox

#!/bin/ash -efux

export DISPLAY=:0
export LIBDIR="$(getconf LIBDIR)"

# $ hsh --init
# $ hsh-install firefox xauth
# $ hsh-install fonts-ttf-google-droid-sans fonts-ttf-google-droid-sans-mono fonts-ttf-google-droid-serif
# $ grep -v '^#' /etc/hasher-priv/fstab 
# tmpfs /dev/shm tmpfs size=500m,nr_inodes=4096 0 0

in_chroot_rooter()
{
	cat >"$TMPDIR/script"
	chmod +x "$TMPDIR/script"
	hsh-run --rooter --execute="$TMPDIR/script" </dev/null
}

in_chroot_rooter "Copy system resolv.conf ..." <<-EOF
	#!/bin/sh -efu
	cat >/etc/resolv.conf <<EOF1
	$(cat /etc/resolv.conf)
	EOF1
EOF

in_chroot_rooter "Customize firefox settings ..." <<-EOF
	#!/bin/sh -efu
	cat > $LIBDIR/firefox/browser/defaults/preferences/all-privacy.js <<EOF1
	pref("privacy.resistfingerprinting", true);                           /* Enable Fingerprint Resistance */
	pref("media.peerconnection.enabled", false);                          /* Disable WebRTC */
	pref("security.ssl3.rsa_des_ede3_sha", false);                        /* Disable the 3DES cipher */
	pref("security.ssl.require_safe_negotiation", true);                  /* Require Safe Negotiation */
	pref("security.ssl.treat_unsafe_negotiation_as_broken", true);
	pref("security.ssl.disable_session_identifiers", true);               /* Disable Session Identifiers */
	pref("security.ssl.enable_false_start", false);                       /* Disable TLS False Start */
	pref("security.tls.version.min", 3);                                  /* Disable TLS versions 1.0 and 1.1 */
	pref("security.tls.enable_0rtt_data", false);                         /* Disable 0-RTT – Zero Round Trip Time Resumption (0-RTT) is a feature that is new in TLS 1.3 */
	pref("browser.formfill.enable", false);                               /* Disable Automatic Formfill */
	pref("browser.cache.disk.enable", false);                             /* Disable All Disk Caching */
	pref("browser.cache.disk_cache_ssl", false);                          /* Disable All Disk Caching */
	pref("browser.cache.memory.enable", false);                           /* Disable All Disk Caching */
	pref("browser.cache.offline.enable", false);                          /* Disable All Disk Caching */
	pref("browser.cache.insecure.enable", false);                         /* Disable All Disk Caching */
	pref("geo.enabled", false);                                           /* Disable Geolocation Services */
	pref("plugin.scan.plid.all", false);                                  /* Disable Plugin Scanning */
	pref("browser.newtabpage.activity-stream.feeds.telemetry", false);    /* Disable ALL Telemetry Features */
	pref("browser.newtabpage.activity-stream.telemetry", false);          /* Disable ALL Telemetry Features */
	pref("browser.pingcentre.telemetry", false);                          /* Disable ALL Telemetry Features */
	pref("devtools.onboarding.telemetry-logged", false);                  /* Disable ALL Telemetry Features */
	pref("media.wmf.deblacklisting-for-telemetry-in-gpu-process", false); /* Disable ALL Telemetry Features */
	pref("toolkit.telemetry.archive.enabled", false);                     /* Disable ALL Telemetry Features */
	pref("toolkit.telemetry.bhrping.enabled", false);                     /* Disable ALL Telemetry Features */
	pref("toolkit.telemetry.firstshutdownping.enabled", false);           /* Disable ALL Telemetry Features */
	pref("toolkit.telemetry.hybridcontent.enabled", false);               /* Disable ALL Telemetry Features */
	pref("toolkit.telemetry.newprofileping.enabled", false);              /* Disable ALL Telemetry Features */
	pref("toolkit.telemetry.unified", false);                             /* Disable ALL Telemetry Features */
	pref("toolkit.telemetry.updateping.enabled", false);                  /* Disable ALL Telemetry Features */
	pref("toolkit.telemetry.shutdownpingsender.enabled", false);          /* Disable ALL Telemetry Features */
	pref("network.dns.disableprefetch", false);                           /* Disable DNS Prefetching */
	pref("network.prefetch-next", false);                                 /* Disable Network Prefetching */
	pref("network.http.sendRefererHeader", 0);                            /* Disable HTTP Referral Headers */
	pref("network.security.esni.enabled", true);                          /* Enable encrypted SNI */
	pref("webgl.disabled", true);                                         /* Disable WebGL  */
	pref("dom.battery.enabled", false);                                   /* Disable Battery API */
	pref("privacy.firstparty.isolate", true);                             /* Enable First-Party Isolation */
	EOF1
EOF

cat >"$TMPDIR/script" <<EOF
#!/bin/sh -efux
cat /proc/mounts
exec firefox
EOF
chmod +x "$TMPDIR/script"

env \
	share_network=1 \
	hsh-run --mountpoint=/proc,/dev/shm -X --execute="$TMPDIR/script"

Is your code

in_chroot_rooter "Copy system resolv.conf ..." <<-EOF
	#!/bin/sh -efu
	cat >/etc/resolv.conf <<EOF1
	$(cat /etc/resolv.conf)
	EOF1
EOF

any better than simply hsh-run --rooter -- sh -c 'cat >/etc/resolv.conf' </etc/resolv.conf ?

@imz In this particular case, yes. But I wanted to use a generic wrapper.