infra/go: Adding setup instructions and quick setup script.

go/quicksetup.sh

+#!/bin/bash
+# Copyright 2016 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+set -e
+
+mkdir cr-infra-go-area
+cd cr-infra-go-area
+
+# Download depot_tools
+echo "Getting Chromium depot_tools.."
+git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git depot_tools
+echo
+
+echo "Fetching the infra build..."
+"$PWD/depot_tools/fetch" infra

[tandrii(chromium), 2016/06/17 09:37:26]

I've just tried it with existing and dirty checkout of depot_tools already in
Path. Your script hangs ~2 minutes because `fetch` command runs `gclient` not
form the same depot_tools as `fetch` is, but from whatever is on $PATH. So, how
about exporting new $PATH prior to running fetch?

export PATH="$PWD/depot_tools:$PATH"
fetch infra

[mithro, 2016/06/18 07:13:18]

Done.

+
+echo "Creating enter script..."
+# Create a bashrc include file
+ENTER_SCRIPT=$PWD/enter-env.sh
+cat > $ENTER_SCRIPT <<EOF
+#!/bin/bash
+[[ "\${BASH_SOURCE[0]}" != "\${0}" ]] && SOURCED=1 || SOURCED=0
+if [ \$SOURCED = 0 ]; then
+        exec bash --init-file $ENTER_SCRIPT
+fi
+
+if [ -f ~/.bashrc ]; then . ~/.bashrc; fi
+
+export DEPOT_TOOLS="$PWD/depot_tools"
+export PATH="\$DEPOT_TOOLS:\$PATH"
+export PS1="[cr-infra-go-area] \$PS1"

[tandrii(chromium), 2016/06/17 09:37:26]

very nice!

[Vadim Sh., 2016/06/17 17:38:46]

we should add it to go/env.py instead, probably,  not everyone will be using
quicksetup.sh

[mithro, 2016/06/18 07:13:17]

Acknowledged.

[mithro, 2016/06/18 07:13:18]

I'm unsure the correct way to add this to go/env.py

I've added it to bootstrap.py in `def get_go_environ(` but unsure if that is
correct...

+
+cd $PWD/infra/go
+eval \$($PWD/infra/go/env.py)
+
+echo "Entered cr-infra-go-area setup at '$PWD'"
+cd "$PWD"
+EOF
+chmod a+x $ENTER_SCRIPT
+
+# Running the env setup for the first time
+source $ENTER_SCRIPT
+
+# Output usage instructions

[tandrii(chromium), 2016/06/17 09:37:26]

add extra echo here, so that instruction of what to run next stands out from
lots of output above.

[mithro, 2016/06/18 07:13:18]

Done.

+if [ -d ~/bin ]; then
+        ln -sf $ENTER_SCRIPT ~/bin/cr-infra-go-area-enter

[tandrii(chromium), 2016/06/17 09:37:25]

can we bail instead of overwriting existing file if any?
Alternatively maybe write at the top of the script (~line 23) "DO NOT MODIFY,
automatically generated, will be overwritten"

[Eric Burnett, 2016/06/17 17:23:31]

Up until here the created environment was self-contained, in that it had no
persistent impacts for anything outside cr-infra-go-area. I don't like the idea
of adding things to the users' bin directory, as that breaks the containment
(cannot be undone by just rm -rf cr-infra-go-area; installing again in a
different path will collide on the symlink). 

Can you stop at printing $ENTER_SCRIPT, and leave it to the user to symlink it
for their own benefit under whatever name they like?

[Vadim Sh., 2016/06/17 17:38:46]

+1

[mithro, 2016/06/18 07:13:17]

Acknowledged.

[mithro, 2016/06/18 07:13:18]

Acknowledged.

[mithro, 2016/06/18 07:13:18]

I've added a "DO NOT MODIFY" header and changed it to ask about adding the
script to ~/bin

Is that okay?

+        if which cr-infra-go-area-enter; then
+                echo "Enter the environment by running 'cr-infra-go-area-enter'"
+                exit 0
+        fi
+fi
+echo "Enter the environment by running '$PWD/enter-env.sh'"

[Eric Burnett, 2016/06/17 17:23:31]

Reference $ENTER_SCRIPT here for consistency?

[mithro, 2016/06/18 07:13:18]

Done.