Cassandra mistakenly thinks it is running as root - cassandra

I am trying to run Cassandra on a MyBinder environment.
Locally it works just fine. On MyBinder, however, Cassandra mistakenly thinks it is running as root.
It is has the same java version, OS, etc.
Any ideas on why such behavior?
Thanks!
jovyan#jupyter-2dx66bgrd2:~$ tar xzvf apache-cassandra-4.0-beta1-bin.tar.gz
joyan#jupyter-2dx66bgrd2:~$ cd apache-cassandra-4.0-beta1
jovyan#jupyter-2dx66bgrd2:~/apache-cassandra-4.0-beta1$ ls
bin CASSANDRA-14092.txt CHANGES.txt conf doc lib LICENSE.txt NEWS.txt NOTICE.txt pylib tools
jovyan#jupyter-2dx66bgrd2:~/apache-cassandra-4.0-beta1$ ./bin/cassandra
Running Cassandra as root user or group is not recommended - please start Cassandra using a different system user.
If you really want to force running Cassandra as root, use -R command line option.
jovyan#jupyter-2dx66bgrd2:~/apache-cassandra-4.0-beta1$ ./bin/cassandra -R
jovyan#jupyter-2dx66bgrd2:~/apache-cassandra-4.0-beta1$

The issue is that the startup script thinks it's being run as a root user when running id -u or id -g in bin/cassandra (here):
if [ "`id -u`" = "0" ] || [ "`id -g`" = "0" ] ; then
echo "Running Cassandra as root user or group is not recommended - please start Cassandra using a different system user."
echo "If you really want to force running Cassandra as root, use -R command line option."
exit 1
fi
I suppose the id commands return 0 in MyBinder and confuses the startup script. This isn't a scenario we test so perhaps workaround it by disabling the check in the shell script. Cheers!

Related

How can I make my discord.js start at boot using node pi-4?

I am new to linux in general so I may not be aware of certain things. So, I have tried multitudes of solutions but I haven't succeeded in running the discord.js bot. I have used rc.local with other scripts like writing date on a file on startup date > <file-path> and it works properly, but somehow running bot on startup fails and can't quite read any errors either.
rc.local file:
#!/bin/sh -e
_IP=$(hostname -I) || true
if [ "$_IP" ]; then
printf "My IP address is %s\n" "$_IP"
fi
/bin/sh /home/pi/superscript.sh
exit 0
superscript.sh file:
#!/bin/sh
date > /home/pi/boot.log
( cd /home/pi/Desktop/discord-bot; /usr/bin/node /home/pi/Desktop/discord-bot/index.js ) &
The bot works completely fine when I manually execute it node ~/Desktop/discord-bot/index.js & and it even works if I manually execute superscript.sh, so I can't really find the problem. Can anyone help me out please I would really appreciate it.
Thank You.
easiest way is to use crontab to execute commands on startup
# Edit cron
crontab -e
# type following to start a script-file.sh on startup
#reboot script-file.sh
reference: https://www.simplified.guide/linux/automatically-run-program-on-startup

How would you make a shell script to monitor mounts and log issues?

I am looking for a good way monitor and log mounts on a CentOS 6.5 box. Since I am new to Linux shell scripting I am somewhat at a loss as to if there is something that is already around and proven which I could just plug in or is there a good method I should direct my research toward to build my own.
In the end what I am hoping to have running is a check of each of the 9 mounts on the server to confirm they are up and working. If there is an issue I would like to log the information to a file, possibly email out the info, and check the next mount. 5-10 minutes later I would like to run it again. I know that probably this isn't needed but we are trying to gather evidence if there is an issue or show to a vendor that what they are saying is the issue is not a problem.
This shell script will test each mountpoint and send mail to root if any of them is not mounted:
#!/bin/bash
while sleep 10m;
do
status=$(for mnt in /mnt/disk1 /mnt/disk2 /mnt/disk3; do mountpoint -q "$mnt" || echo "$mnt missing"; done)
[ "$status" ] && echo "$status" | mail root -s "Missing mount"
done
My intention here is not to give a complete turn-key solution but, instead, to give you a starting point for your research.
To make this fit your precise needs, you will need to learn about bash and shell scripts, cron jobs, and other of Unix's very useful tools.
How it works
#!/bin/bash
This announces that this is a bash script.
while sleep 10m; do
This repeats the commands in the loop once every 10 minutes.
status=$(for mnt in /mnt/disk1 /mnt/disk2 /mnt/disk3; do mountpoint -q "$mnt" || echo "$mnt missing"; done)
This cycles through mount points /mnt/disk1, /mnt/disk2, and /mnt/disk3 and tests that each one is mounted. If it isn't, a message is created and stored in the shell variable status.
You will want to replace /mnt/disk1 /mnt/disk2 /mnt/disk3 with your list of mount points, whatever they are.
This uses the command mountpoint which is standard on modern linux versions. It is part of the util-linux package. It might be missing on old installations.
[ "$status" ] && echo "$status" | mail root -s "Missing mount"
If status contains any messages, they will be mailed to root with the subject line Missing mount.
There are a few different versions of the mail command. You may need to adjust the argument list to work with the version on your system.
done
This marks the end of the while loop.
Notes
The above script uses a while loop that runs the tests every ten minutes. If you are familiar with the cron system, you may want to use that to run the commands every 10 minutes instead of the while loop.

bash doesn't load node on remote ssh command

Excuse me if the subject is vague, but I tried to describe my problem to the best of my possibilities. I have my raspberry pi which I want to deploy to using codeship. Rsyncing the files works perfectly, but when I am to restart my application using pm2 my problem occurs.
I have installed node and pm2 using the node version manager NVM.
ssh pi#server.com 'source /home/pi/.bashrc; cd project; pm2 restart app.js -x -- --prod'0 min 3 sec
bash: pm2: command not found
I have even added:
shopt -s expand_aliases in the bottom of my bashrc but it doesn't help.
How can I make it restart my application after I have done a deploy? Thanks in advance for your sage advice and better wisdom!
EDIT 1: My .bashrc http://pastie.org/10529200
My $PATH: /home/pi/.nvm/versions/node/v4.2.0/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/local/games:/usr/games
EDIT 2: I added /home/pi/.nvm/versions/node/v4.2.0/bin/pm2 which is the full path to pm2 and now I get the following error: /usr/bin/env: node: No such file or directory
It seems that even if I provide the full path, node isn't executed.
I think the problem is the misinterpretation that the shell executing node has a full environment like an interactive ssh session does. Most likely this is not the case.
When a SSH session spawns a shell it goes through a lot of gyrations to build an environment suitable to work with interactively. Things like inheriting from the login process, reading /etc/profile, reading ~/.profile. But in the cases where your executing bash directly this isn't always guaranteed. In fact the $PATH might be completely empty.
When /usr/bin/env node executes it looks for node in your $PATH which in a non-interactive shell could be anything or empty.
Most systems have a default PATH=/bin:/usr/bin typically /usr/local/bin is not included in the default environment.
You could attempt to force a login with ssh using ssh … '/bin/bash -l -c "…"'.
You can also write a specialized script on the server that knows how the environment should be when executed outside of an interactive shell:
#!/bin/bash
# Example shell script; filename: /usr/local/bin/my_script.sh
export PATH=$PATH:/usr/local/bin
export NODE_PATH=/usr/local/share/node
export USER=myuser
export HOME=/home/myuser
source $HOME/.nvm/nvm.sh
cd /usr/bin/share/my_script
nvm use 0.12
/usr/bin/env node ./script_name.js
Then call it through ssh: ssh … '/usr/local/bin/my_script.sh'.
Beyond these ideas I don't see how to help further.
Like Sukima said, the likelihood is that this is due to an environment issue - SSH'ing into a server does not set up a full environment. You can, however, get around much of this by simply calling /etc/profile yourself at the start of your command using the . operator (which is the same as the "source" command):
ssh pi#server.com '. /etc/profile ; cd project; pm2 restart app.js -x -- --prod'
/etc/profile should itself be set up to call the .bashrc of the relevant user, which is why I have removed that part. I used to have to do this quite a lot for quick proof-of-concept scripts at a previous workplace. I don't know if it would be considered a nasty hack for a more permanent script, but it certainly works, and would require minimal modification to your existing script should that be an issue.
For me I have to load :nvm as I installed node and yarn using :nvm
To load :nvm when ssh remote execution, we call
ssh :user#:host 'source ~/.nvm/nvm.sh; :other_commands_here'
Try:
ssh pi#server.com 'bash -l -c "source /home/pi/.bashrc; cd project; pm2 restart app.js -x -- --prod"'
You should enable some environment values by "source" or dot command ".". Here is an example.
ssh pi#server.com '. /home/pi/.nvm/nvm.sh; cd project; pm2 restart app.js -x -- --prod'
What worked for me was adding this to my .bash_profile:
if [ -f ~/.bashrc ]; then
. ~/.bashrc
fi
Source: https://stackoverflow.com/a/820533/1824444

Automatically starting Celery from within Django app

I am getting a Django 1.6 set up started on a Linux (Debian Whiskey) server on Google Compute Engine. I've got Celery 3.1 running in the background to help with some processes. When I start a new instance (using a snapshot I've created), I always need to start Celery. I am looking for a way to start Celery automatically on server-load. This is particularly helpful if the server decides to restart, as they seem to do now and then. To achieve this, I've edited the rc.local file:
$ sudo nano /etc/rc.local
It used to contain the following:
exit 0
[ -x /sbin/initctl ] && initctl emit --no-wait google-rc-local-has-run || true
I've edited the file such that it now reads:
cd /home/user/gce_app celery -A myapp.tasks --concurrency=1 --loglevel=info worker > output.log 2> errors.log &
exit 0
[ -x /sbin/initctl ] && initctl emit --no-wait google-rc-local-has-run || true
The directory:
/home/user/gce_app
is where my Django project resides and the directory I need to be in to start Celery. However, after restarting the instance, when I type in:
$ celery status
Error: No nodes replied within time constraint.
Opening the errors.log file, I see:
/etc/rc.local: 14: /etc/rc.local: celery: not found
Surely the cd at the start of that code string should address this? Is there a way (within the Django project itself) to start the Celery instance when the project is started to make the code more platform-independent and immune to inevitable OS updates?
I think you're missing a semicolon between your 'cd' and celery invocations. Also, I suspect rc.local may not be searching your path, so you may need to give an absolute path to celery. e.g.
cd /home/user/gce_app; /usr/bin/celery ...
Alternatively, you might look at using a startup script from the GCE metadata to avoid needing to modify rc.local.
Since you seem to be using upstart this might help you:
description "runs celery"
start on runlevel [2345]
stop on runlevel [!2345]
console log
env VENV='/srv/myvirtualenv'
env PROJECT='/srv/run/mydjangoproject'
exec su -s /bin/sh -c 'exec "$0" "$#"' www-data -- /usr/bin/env PATH=$VENV:$PATH $VENV/python $PROJECT/manage.py celeryd
respawn
respawn limit 10 5

Automatically start forever (node) on system restart

I am using node's forever module to keep my node server running. Forever however terminates when there is a system restart. Is there any way I can automatically start the node server (with forever) when the system restarts?
I would suggest using crontab. It's easy to use.
How to
To start editing run the following replacing the "testuser" with your desired runtime user for the node process. If you choose a different user other than yourself, you will have to run this with sudo.
$ crontab -u testuser -e
If you have never done this before, it will ask you which editor you wish to edit with. I like vim, but will recommend nano for ease of use.
Once in the editor add the following line:
#reboot /usr/local/bin/forever start /your/path/to/your/app.js
Save the file. You should get some feedback that the cron has been installed.
For further confirmation of the installation of the cron, execute the following (again replacing "testuser" with your target username) to list the currently installed crons:
$ crontab -u testuser -l
Note that in my opinion, you should always use full paths when executing binaries in cron.
Also, if the path to your forever script is not correct, run which forever to get the full path.
Given that forever calls node, you may also want to provide the full path to node:
#reboot /usr/local/bin/forever start -c /usr/local/bin/node /your/path/to/your/app.js
Further Reading
crontab Man Page
Ubuntu Cron HowTo
You can use forever-service for doing this.
npm install -g forever-service
forever-service install test
This will provision app.js in the current directory as a service via forever. The service will automatically restart every time system is restarted. Also when stopped it will attempt a graceful stop. This script provisions the logrotate script as well.
Github url: https://github.com/zapty/forever-service
NOTE: I am the author of forever-service.
Install PM2 globally using NPM
npm install pm2 -g
Start your script with pm2
pm2 start app.js
generate an active startup script
pm2 startup
NOTE: pm2 startup is for startting the PM2 when the system reboots. PM2 once started, restarts all the processes it had been managing before the system went down.
In case you want to disable the automatic startup, simply use pm2 unstartup
If you want the startup script to be executed under another user, just use the -u <username> option and the --hp <user_home>:
This case is valid for Debian.
Add the following to /etc/rc.local
/usr/bin/sudo -u {{user}} /usr/local/bin/forever start {{app path}}
{{user}} replaces your username.
{{app path}} replaces your app path. For example, /var/www/test/app.js
An alternative crontab method inspired by this answer and this blog post.
1. Create a bash script file (change bob to desired user).
vi /home/bob/node_server_init.sh
2. Copy and paste this inside the file you've just created.
#!/bin/sh
export NODE_ENV=production
export PATH=/usr/local/bin:$PATH
forever start /node/server/path/server.js > /dev/null
Make sure to edit the paths above according to your config!
3. Make sure the bash script can be executed.
chmod 700 /home/bob/node_server_init.sh
4. Test the bash script.
sh /home/bob/node_server_init.sh
5. Replace "bob" with the runtime user for node.
crontab -u bob -e
6. Copy and paste (change bob to desired user).
#reboot /bin/sh /home/bob/node_server_init.sh
Save the crontab.
You've made it to the end, your prize is a reboot (to test) :)
Copied answer from the attached question.
You can use PM2, it's a production process manager for Node.js applications with a built-in load balancer.
Install PM2
$ npm install pm2 -g
Start an application
$ pm2 start app.js
If you using express then you can start your app like
pm2 start ./bin/www --name="app"
Listing all running processes:
$ pm2 list
It will list all process. You can then stop / restart your service by using ID or Name of the app with following command.
$ pm2 stop all
$ pm2 stop 0
$ pm2 restart all
To display logs
$ pm2 logs ['all'|app_name|app_id]
You need to create a shell script in the /etc/init.d folder for that. It's sort of complicated if you never have done it but there is plenty of information on the web on init.d scripts.
Here is a sample a script that I created to run a CoffeeScript site with forever:
#!/bin/bash
#
# initd-example Node init.d
#
# chkconfig: 345
# description: Script to start a coffee script application through forever
# processname: forever/coffeescript/node
# pidfile: /var/run/forever-initd-hectorcorrea.pid
# logfile: /var/run/forever-initd-hectorcorrea.log
#
# Based on a script posted by https://gist.github.com/jinze at https://gist.github.com/3748766
#
# Source function library.
. /lib/lsb/init-functions
pidFile=/var/run/forever-initd-hectorcorrea.pid
logFile=/var/run/forever-initd-hectorcorrea.log
sourceDir=/home/hectorlinux/website
coffeeFile=app.coffee
scriptId=$sourceDir/$coffeeFile
start() {
echo "Starting $scriptId"
# This is found in the library referenced at the top of the script
start_daemon
# Start our CoffeeScript app through forever
# Notice that we change the PATH because on reboot
# the PATH does not include the path to node.
# Launching forever or coffee with a full path
# does not work unless we set the PATH.
cd $sourceDir
PATH=/usr/local/bin:$PATH
NODE_ENV=production PORT=80 forever start --pidFile $pidFile -l $logFile -a -d --sourceDir $sourceDir/ -c coffee $coffeeFile
RETVAL=$?
}
restart() {
echo -n "Restarting $scriptId"
/usr/local/bin/forever restart $scriptId
RETVAL=$?
}
stop() {
echo -n "Shutting down $scriptId"
/usr/local/bin/forever stop $scriptId
RETVAL=$?
}
status() {
echo -n "Status $scriptId"
/usr/local/bin/forever list
RETVAL=$?
}
case "$1" in
start)
start
;;
stop)
stop
;;
status)
status
;;
restart)
restart
;;
*)
echo "Usage: {start|stop|status|restart}"
exit 1
;;
esac
exit $RETVAL
I had to make sure the folder and PATHs were explicitly set or available to the root user since init.d scripts are ran as root.
Use the PM2
Which is the best option to run the server production server
What are the advantages of running your application this way?
PM2 will automatically restart your application if it crashes.
PM2 will keep a log of your unhandled exceptions - in this case, in a file at /home/safeuser/.pm2/logs/app-err.log.
With one command, PM2 can ensure that any applications it manages restart when the server reboots. Basically, your node application will start as a service.
ref: https://www.digitalocean.com/community/tutorials/how-to-use-pm2-to-setup-a-node-js-production-environment-on-an-ubuntu-vps
Forever was not made to get node applications running as services. The right approach is to either create an /etc/inittab entry (old linux systems) or an upstart (newer linux systems).
Here's some documentation on how to set this up as an upstart:
https://github.com/cvee/node-upstart
crontab does not work for me on CentOS x86 6.5. #reboot seems to be not working.
Finally I got this solution:
Edit: /etc/rc.local
sudo vi /etc/rc.local
Add this line to the end of the file. Change USER_NAME and PATH_TO_PROJECT to your own. NODE_ENV=production means the app runs in production mode. You can add more lines if you need to run more than one node.js app.
su - USER_NAME -c "NODE_ENV=production /usr/local/bin/forever start /PATH_TO_PROJECT/app.js"
Don't set NODE_ENV in a separate line, your app will still run in development mode, because forever does not get NODE_ENV.
# WRONG!
su - USER_NAME -c "export NODE_ENV=production"
Save and quit vi (press ESC : w q return). You can try rebooting your server. After your server reboots, your node.js app should run automatically, even if you don't log into any account remotely via ssh.
You'd better set NODE_ENV environment in your shell. NODE_ENV will be set automatically when your account USER_NAME logs in.
echo export NODE_ENV=production >> ~/.bash_profile
So you can run commands like forever stop/start /PATH_TO_PROJECT/app.js via ssh without setting NODE_ENV again.
I wrote a script that does exactly this:
https://github.com/chovy/node-startup
I have not tried with forever, but you can customize the command it runs, so it should be straight forward:
/etc/init.d/node-app start
/etc/init.d/node-app restart
/etc/init.d/node-app stop
The problem with rc.local is that the commands are accessed as root which is different than logging to as a user and using sudo.
I solved this problem by adding a .sh script with the startup commands i want to etc/profile.d. Any .sh file in profile.d will load automatically and any command will be treated as if you used the regular sudo.
The only downside to this is the specified user needs to loggin for things to start which in my situation was always the case.
I tried lots of the above answers. None of them worked for me. My app is installed in /home and as user, not as root. This probably means that when the above mentioned start scripts run, /home is not mounted yet, so the app is not started.
Then I found these instructions by Digital Ocean:
https://www.digitalocean.com/community/tutorials/how-to-use-pm2-to-setup-a-node-js-production-environment-on-an-ubuntu-vps
Using PM2 as explained was very simple and works perfectly: My virtual servers had two physical crashes since - downtime was only about a minute.
complete example crontab (located at /etc/crontab) ..
#!/bin/bash
# edit this file with .. crontab -u root -e
# view this file with .. crontab -u root -l
# put your path here if it differs
PATH=/root/bin:/root/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin
# * * * * * echo "executes once every minute" > /root/deleteme
#reboot cd /root/bible-api-dbt-server; npm run forever;
#reboot cd /root/database-api-server; npm run forever;
#reboot cd /root/mailer-api-server; npm run forever;
I have found my own solution by using serve & npm as follows:
Install serve package: npm install -g serve
Then have the command serve -s /var/www/sitename to execute on reboot.
This is what works for me on my VPS.
You can use the following command in your shell to start your node forever:
forever app.js //my node script
You need to keep in mind that the server on which your app is running should always be kept on.

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