Is it possible to see output startup script in compute engine

Question

My Compute Engine vm when deployed run a startup script. Everything seems working well, but there is one command in the startup script which I think it doesn't.

I run the command

apt-get update && apt-get upgrade -y

This should install the newest versions of all packages (right?)

When I do this by hand it works, but it takes a lot of time. If I let the script do it I don't see any output when I connect over ssh so I have to asume it's still running. Is there a way I can see if it is still working and if it has finished or not?

This is the script:

#! /bin/bash
file="/var/www/check.txt"

if [ -e $file ]
then
apt-get update && apt-get upgrade -y
git -C /var/www/html pull https://xxxxxx:[email protected]/xxxxxx/xxxxx.git
else
apt-get update
apt-get install apache2 php libapache2-mod-php php-mcrypt php-mysql mysql-client -y
a2dismod autoindex
service apache2 restart

cat <<EOF > /etc/apache2/mods-enabled/dir.conf
<IfModule mod_dir.c>
        DirectoryIndex index.php index.cgi index.pl index.html index.xhtml index.htm
</IfModule>

# vim: syntax=apache ts=4 sw=4 sts=4 sr noet
EOF

rm -rf /var/www/html
git clone https://xxxxxx:[email protected]/xxxxxx/xxxxx.git /var/www/html/

cat <<EOF > /etc/apache2/sites-available/xxxxx.conf
<VirtualHost *:80>
  ServerName  xxxxxx.com
  ServerAlias www.xxxxxx.com
  ServerAdmin [email protected]
  DocumentRoot /var/www/html/wwwroot
  ErrorLog ${APACHE_LOG_DIR}/error.log
  CustomLog ${APACHE_LOG_DIR}/access.log combined
 </VirtualHost>

# vim: syntax=apache ts=4 sw=4 sts=4 sr noet
EOF

cat <<EOF > /etc/apache2/sites-available/020-xxxxx_xxxx.conf
<VirtualHost *:80>
  ServerName  xxxx.xxxxx.xxx
  ServerAlias xxxx
  ServerAdmin [email protected]
  DocumentRoot /var/www/html/xxxxx
  ErrorLog ${APACHE_LOG_DIR}/error.log
  CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>

# vim: syntax=apache ts=4 sw=4 sts=4 sr noet
EOF

cat <<EOF > /var/www/html/wwwroot/.htaccess
RewriteEngine On
RewriteCond %{HTTPS} off
RewriteCond %{HTTP:X-Forwarded-Proto} !https
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
EOF

sed -i 's/AllowOverride None/AllowOverride All/g' /etc/apache2/apache2.conf

wget https://dl.google.com/cloudsql/cloud_sql_proxy.linux.amd64 -O cloud_sql_proxy
chmod +x cloud_sql_proxy
mkdir /cloudsql; sudo chmod 777 /cloudsql
./cloud_sql_proxy -dir=/cloudsql &

#rm /var/www/html/wwwroot/xxxxx/xxxxxx.php


#temporary for testing.
cat <<'EOF' > /var/www/html/wwwroot/includes/xxxxx.xxxx
<?php

error_reporting(E_ALL);
ini_set('display_errors', 1);




$username = "xxxxxx";
$password = "xxxxx";
$host = "/cloudsql/snappy-gantry-xxxxx:europe-west1:db1";
$dbname = "xxxxx";

  setlocale(LC_ALL, 'nld_nld');



$options = array(PDO::MYSQL_ATTR_INIT_COMMAND => 'SET NAMES utf8');
try {
    $db = new PDO("mysql:unix_socket={$host};dbname={$dbname};charset=utf8", $username, $password, $options);
    $db->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
    $db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    $db->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC);
} catch (PDOException $ex) {
    die("Failed to connect to the database: " . $ex->getMessage());
}
if (session_status() == PHP_SESSION_NONE) {
    session_start();
}
EOF


a2dissite 000-default
a2ensite 010-xxxxx_main
a2ensite 020-xxxx_help
a2enmod rewrite
service apache2 restart
apt-get update && apt-get upgrade -y
sudo cat <<EOF > /var/www/check.txt
aanwezig!
EOF
fi

Answer 1

Startup script output of Google Cloud Compute Engine instances is written to one of the following log files depending on the Linux distribution of the instance:

• CentOS and RHEL: /var/log/messages
• Debian: /var/log/daemon.log
• Ubuntu 14.04, 16.04, and 16.10: /var/log/syslog
• SLES 11 and 12: /var/log/messages

If for some reason you want to store updates of the script you may consider to redirect the output to a file and to upload id to Google Storage. For example:

  ...
$ command >> output
$ command >> output
$ gsutil cp output gs://yourbucketname/output
$ command >> output
  ...
$ command >> output
$ gsutil cp output gs://yourbucketname/output
$ ...

Note that you might consider to redirect as well the standard error with '2>>' to a file and upload it as well.

EDIT: I forgot to answer to one of your question. Yes you can check if the command is still running; since from the operating system point of view these commands are normal processes, therefore you will be able to check them running:

$ ps -aux

For example I got this output having a sleep as startup script

root       691  0.0  0.0   5840   696 ?        S    14:45   0:00 sleep 30

Answer 2

grep startup-scrip /var/log/syslog

Answer 3

For RHEL and CentOS you can also use journalctl command

$ journalctl

or if you want to follow the logs live as your startup script executes you, you can use the -f option:

$ journalctl -f

Answer 4

You can use journalctl on Debian as of 2022 like this

sudo journalctl -u google-startup-scripts.service

see https://cloud.google.com/compute/docs/instances/startup-scripts/linux