I am struggling to write a script to check a particular service running on my server and then send me mails.
So should this script be the part of bash profile so that its always running..
regards
rick
The .profile, .bashrc and friends will be run on login, so they are of no good use for background monitoring. Two solutions come to mind:
Either use cron to run your script at predefined intervals
Or make it loop and use your system's init environment (SysV, Upstart, SystemD, ...) to control it
My recommendation is to stick with cron - it even makes the mailing of results dead easy - just create output.
Related
I am developing processes for collecting, cleaning and storing various data sets. The development is done with RStudio projects. I won't say I'm following every tidyverse/RStudio workflow recommendation but in general I'm using that framework-- relevant now is that I'm using standard subdirectories and the here package for referencing them.
Every project has a MAIN.R script that ultimately sources the functions from the other scripts-- one only needs to run MAIN.R to execute the process. I did this not only for simplicity but also because the long-term intent is to have this be a scheduled process.
For now at least my method for scheduling R Scripts is with Windows Task Scheduler. Getting an R Script scheduled and running is not a problem. The issue is the contextual assumptions of developing within a project: source(here("CODE", "some-file.R")) fails when I run MAIN.R outside of the scope of the project.
One obvious solution would be to hard-code the project location as one of the parameters. I would need to have two different MAIN.R files, one for development that uses the project and one that uses that parameter for scheduling. I don't hate that idea, don't love it as it someone nullifies the whole point of the project/here approach. Is there a more elegant solution that someone else has created that I couldn't find on Google, or better workaround ideas?
I ended up using the solution described here: https://community.rstudio.com/t/how-to-play-nice-with-taskscheduler-r-studio-projects-and-here/24406/2 .
I didn't have to make any changes to the MAIN.R script. Instead, I scheduled it directly but added the project directory to the "Starts In" argument of the Windows Task Scheduler task.
I have an R script that I run every day that scrapes data from a couple of different websites, and then writes the data scraped to a couple of different CSV files. Each day, at a specific time (that changes daily) I open RStudio, open the file, and run the script. I check that it runs correctly each time, and then I save the output to a CSV file. It is often a pain to have to do this everyday (takes ~10-15 minutes a day). I would love it if someway I could have this script run automatically at a pre-defined specific time, and a buddy of mine said AWS is capable of doing this?
Is this true? If so, what is the specific feature / aspect of AWS that is able to do this, this way I can look more into it?
Thanks!
Two options come to mind thinking about this:
Host a EC2 Instance with R on it and configure a CRON-Job to execute your R-Script regularly.
One easy way to get started: Use this AMI.
To execute the script R offers a CLI rscript. See e.g. here on how to set this up
Go Serverless: AWS Lambda is a hosted microservice. Currently R is not natively supported but on the official AWS Blog here they offer a step by step guid on how to run R. Basically you execute R from Python using the rpy2-Package.
Once you have this setup schedule the function via CloudWatch Events (~hosted cron-job). Here you can find a step by step guide on how to do that.
One more thing: You say that your function outputs CSV files: To save them properly you will need to put them to a file-storage like AWS-S3. You can do this i R via the aws.s3-package. Another option would be to use the AWS SDK for python which is preinstalled in the lambda-function. You could e.g. write a csv file to the /tmp/-dir and after the R script is done move the file to S3 via boto3's S3 upload_file function.
IMHO the first option is easier to setup but the second-one is more robust.
It's a bit counterintuitive but you'd use Cloudwatch with an event rule to run periodically. It can run a Lambda or send a message to an SNS topic or SQS queue. The challenge you'll have is that a Lambda doesn't support R so you'd either have to have a Lambda kick off something else or have something waiting on the SNS topic or SQS queue to run the script for you. It isn't a perfect solution as there are, potentially, quite a few moving parts.
#stdunbar is right about using CloudWatch Events to trigger a lambda function. You can set a frequency of the trigger or use a Cron. But as he mentioned, Lambda does not natively support R.
This may help you to use R with Lambda: R Statistics ready to run in AWS Lambda and x86_64 Linux VMs
If you are running windows, one of the easier solution is to write a .BAT script to run your R-script and then use Window's task scheduler to run as desired.
To call your R-script from your batch file use the following syntax:
C:\Program Files\R\R-3.2.4\bin\Rscript.exe" C:\rscripts\hello.R
Just verify the path to the "RScript" application and your R code is correct.
Dockerize your script (write a Dockerfile, build an image)
Push the image to AWS ECR
Create an AWS ECS cluster and AWS ECS task definition within the cluster that will run the image from AWS ECR every time it's spun-up
Use EventBridge to create a time-based trigger that will run the AWS ECS task definition
I recently gave a seminar walking through this at the Why R? 2022 conference.
You can check out the video here: https://www.youtube.com/watch?v=dgkm0QkWXag
And the GitHub repo here: https://github.com/mrismailt/why-r-2022-serverless-r-in-the-cloud
I've found several rsync commands for moving my wordpress site from one local machine to a remote server. I've successfully used the following command suggested by another Stackoverflow user:
rsync -aHvz /path/to/sfolder name#remote.server:/path/to/remote/dfolder
Would you say that it's enough, or would you suggest other attributes?
It's my understanding that an SSH connection would be safer. How does this command change if I want to make it over SSH. Also are there other things to be done besides including the SSH command ( like generating/installing the keys etc etc ). I just starting so a detailed explanation for a noob would be very much appreciated.
Pakal
There are thousands of ways in which you can customize this powerful command. Don't worry about SSH, by default its using SSH. Rest of the options depend on your requirement. You can consider '--perms' to preserve permissions. Similarly '-t' preserves times. I don't know if its relevant in transfer of a site.
Also '-n' would show you a dry run of transfer scenario. '-B' switch allows you to override custom block size.
Probably you should have a look at options yourself and find the appropriate ones by running 'info rsync'.
the above command will use ssh and i see no problems with it's general usage.
I use Scrum methodology and deploy functionality in builds every sprint.
There is necessity to perform different changes in the stored data (I mean data in database and on filesystem). I'd like to implement it as a PHP scripts invoked from console. But they should be executed only once, during the deployment.
Is there any way to implement it through app/console without listing it in the list of registered Console commands? Or is there any other way to implement runonce scripts?
DoctrineMigrations covers some part of my requirements, but it's hard to implement complex changes in Model. And it does not cover changes in files on the filesystem.
I don't think symfony has a facility for that, and besides, hiding the command is not the same as securing the command.
Instead, I would make the script determine if it has been run already (could be as simple as adding a version number to a file and checking that number before running) and stop if it detects it has already run before.
I know barely more than zero about R: until yesterday I didn't know how to spell it. But I'm suicidal: for my web site, I'm thinking about letting a visitor type in an R "program" ( is it even called a "program") and then, at submit time, blindly calling the R interpreter from my CGI. I'd then return the interpreter's output to the visitor.
Does this make sense? Or does it amount to useless noise?
If it's workable, what are the pitfalls in this approach? For example, what are the security issues, if any? Is it possible to make R crash, killing my CGI program? Do I have to clean up the R code before calling the interpreter? And the like.
you could take a look to Rserve which allows to execute R scripts via the TCP/IP interface available in PHP for example if I'm not mistaken.
Its just asking for trouble to let people run arbitrary R code on your server. You could try running it in a chroot jail, but these things can be broken out of. Even in a chroot, the R process could delete or alter files, or spawn a long-running process, or download a file to your server, and all manner of nastiness.
You might look at Rweb, which has exactly this behavior: http://www.math.montana.edu/Rweb/
Since you can read and write files in R, it would not be safe to let people run arbitrary R code at your server. I would look if R has something like PHP's safe mode... If not, and if you are root, you can try to run R under user nobody in a chroot (you must also place there packages and libraries - for readonly access, and some temporary directory for RW access).