Update webtry setup docs to reflect new installation procedure

experimental/webtry/README.md

 WebTry Server
 =============
 
 Allows trying out Skia code in the browser. Run a local webserver
 and from the pages it serves try out Skia code and see the results
 immediately. To make sandboxing easier this must be built w/GPU off.
 
 
 Running Locally
 ===============
@@ skipping 28 matching lines @@
 
     gcutil --project=google.com:skia-buildbots ssh --ssh_user=default skia-webtry-b
 
 
 Do the first time
 =================
 
 The following things only need to be done once.
 
 1. SSH into the server as default.
+
 2. sudo apt-get install git schroot debootstrap

[tfarina, 2014/10/02 17:56:27]

As you noted, schroot and debootstrap are also installed by webtry_setup.sh ->
https://skia.googlesource.com/skia/+/master/experimental/webtry/setup/webtry_...

[humper, 2014/10/02 20:43:15]

Done.

-3. git clone https://skia.googlesource.com/skia
-4. cd ~/skia/experimental/webtry/setup
-5. ./webtry_setup.sh
 
-6. Add the following to /etc/fstab and reboot:
+3. Add the following to the /etc/schroot/minimal/fstab:

[tfarina, 2014/10/02 17:56:27]

Does this needs to happen before we call webtry_setup.sh?

[humper, 2014/10/02 20:43:15]

Not really -- the setup scripts just use regular chroot, since the schroot
environment isn't really set up yet :)

 
-    none /dev/shm tmpfs rw,nosuid,nodev,noexec 0 0
+  none /run/shm tmpfs rw,nosuid,nodev,noexec 0 0

[tfarina, 2014/10/02 18:55:27]

Should we do this in the script as well rather than by hand?

We write a line like this to '/srv/chroot/webtry_gyp/etc/fstab' at line 32:
https://skia.googlesource.com/skia/+/master/experimental/webtry/setup/webtry_...

[humper, 2014/10/02 20:43:15]

Well, line 32 only runs once, when the chroot is very first set up.  Since the
setup script can be run multiple times (to update the source code), I didn't
want to do it that way.

We *could* say that webtry_setup.sh is used for one-time-only setup, and after
that you run the continue_install.sh script to update skia; that would be OK. 
If you think that's worthwhile, feel free to file a bug and I'll do it.

+  /home/webtry/inout             /skia_build/inout  none    rw,bind         0       0
+  /home/webtry/cache             /skia_build/cache  none    rw,bind         0       0
 
-The above will allow ninja to run. See http://stackoverflow.com/questions/2009278/python-multiprocessing-permission-denied
 
-7. Add the following to the /etc/schroot/minimal/fstab:
+4. git clone https://skia.googlesource.com/skia
 
-    /home/webtry/inout             /inout  none    rw,bind         0       0
+5. cd ~/skia/experimental/webtry/setup
 
-8. Change /etc/monit/monitrc to:
+6. ./webtry_setup.sh
+
+7. Change /etc/monit/monitrc to:
 
     set daemon 2
 
 then run the following so it applies:
 
     sudo /etc/init.d/monit restart
 
 This means that monit will poll every two seconds that our application is up and running.
 
-9. Set the TCP keepalive. For more info see:
+8. Set the TCP keepalive. For more info see:
    https://developers.google.com/cloud-sql/docs/gce-access
 
     sudo bash -c 'echo 60 > /proc/sys/net/ipv4/tcp_keepalive_time'

[tfarina, 2014/10/02 17:56:27]

s/bash/sh?

[humper, 2014/10/02 20:43:15]

Done.

 
-Once, after setup
-=================
-
-Do this step only once, but only after running webtry_setup.sh the first time.
-
-    sudo debootstrap --variant=minbase wheezy /srv/chroot/webtry

[tfarina, 2014/10/02 17:56:27]

OK. This is done by webtry_setup.sh with:

sudo debootstrap --variant=minbase wheezy ${CHROOT_JAIL}

[humper, 2014/10/02 20:43:15]

Acknowledged.

-
-
 To update the code
 ==================
 
 1. SSH into the server as default.
 2. cd ~/skia/experimental/webtry/setup
 3. git pull
 4. ./webtry_setup.sh
 
-
 Third Party Code
 ================
 
   * res/js/polyfill.js - Various JS polyfill libraries. To rebuild or update
     see poly/README.md.