Managing multiple google cloud VM instances / compute engines at the same time - ssh

I have created a few servers on google cloud. I made them in VM instances. They run the same script everyday but each server runs with different arguments.
However, when changes need to be made to them or updates, I have to do them one by one, all the changes are the same, only different arguments. Meaning I would ssh into the server, run apt updates, download some files, upload some files, change some arguments and test. Then I repeat this process on all the servers.
I would like to be able to keep one copy of the server somewhere which would upload to the rest, or make changes that would apply automatically to each server.
Is there some way I can achieve this? Update all the servers (apt update, or download new files or make changes to scripts) all at once?

I would suggest creating a managed instance group that uses an instance template to create the VMs. Then, you can roll out updates to MIGs.

You can provide a startup script stored on Cloud Storage and apply it to the running instances.

Related

What is the convenient way to distribute configurations between hundreds of machines

we run a daemon in all of our machines, however we have a demand that we need to feed different machines with different configurations.
What we need is like this:
When some one reconfigure some thing in the front end, we need to generate new configuration and send these new configurations to the specified machine.
Besides, we should also need to execute commands, like restart after configuration distributed.
we should have a way to check whether the configuration in the specified machine is the newest one, i.e. whether the configuration distribution executed in the first phrase succeeds or not.
I'd keep separate the generation of the new configs from the actual deployment.
I'd have a centralized daemon keeping track of the frontend changes and updating the configs and the necessary machine/config mapping in a central, well/known location. In a simpler form it could also be an on-demand manually executed process.
Your existing daemon would be modified to periodically check if the particular config for its own machine is changed and, if so, apply the change, perform the necessary deployment cmds and maybe even report back into the central location its own progress and results for the centralized daemon's overall status reporting. This keep this daemon code simpler (free from the machine/config mapping logic) and thus more reliable.

What is a difference between vcenter's template and virtual machine?

As in the topic.
I wonder since I cannot find this information anywhere and currently I am using a virtual machine (linux) on my vcenter which is cloned and then a special shell script is run on this freshly cloned machine to setup up environment and IP adresses etc.
Maybe I would be able to benefit from templates this way.
I think this will be helpful
https://www.robertparten.com/virtualization/vmware-difference-between-clone-and-template/
Few Differences in my opinion:-
Virtual machine is the running instance while Template is compact copy of VM ( with baseline and factory settings), which can be stored anywhere.
one need to deploy template to make running VM.
one can create copy from both VM and template but in VM you need to clone it and in case of template you need to deploy it.
moving between different setup is easy with template.
Rest are already mentioned in link provided.
But first you need to search on your own and still have doubts than only ask, that's how we all learn.
Happy Learning!
Looking at these two scenarios:
Create a template from your active VM, then deploy from the template.
Deploy from the active VM directly.
As far as I know, there will be no difference in the end result if you run these scenarios in the near future. You'll still have to run a script in order to get your IPs setup, etc.
So what's the difference?
If you mess stuff up with your active VM, change things around or whatever, you lose the ability to deploy from the (good) setup you had.
Once you make a template from your active VM, that configuration is saved as a file on the ESX (or the storage, not 100% sure) and can be re-deployed in the future.

AWS EC2- Synching source code files with S3 - is it a proper approach?

On an app server in which a few source files change frequently, Is the following approach recommended?
Use a cron job with S3tools to sync the source files with S3 private bucket (every 15 mins for example).
On server start up - Use user data script to sync with the sources bucket to retrieve the latest sources.
Advantages:
1. No need to attach EBS for app server just to save a few files
2. Similar setup to all app servers
3. Sources automatically backed up.
4. As a byproduct, distributes code to multiple app servers automatically.
Disadvantages:
keeping source code on S3
other?
What do you think about this methodology? Is this the right way to use EC2 when source code change frequently (a few times a day) please recommend the best approach to run EC2 instances where sources change often.
I think you're better off using a proper source code repository, like Subversion or Git, rather than storing the source files on S3. That way you can have a central location for the source files while avoiding the update consistency problems that kdgregory mentioned.
You can put the source repository on one of your own servers outside of EC2, or host it on an EC2 instance (make sure the repository files are on an EBS volume in the latter case).
If you're going to be running a large number of EC2 instances, then it will be less effort to have them sync themselves from a central location (ie, you sync to private bucket, app-servers sync from that bucket).
HOWEVER, recognize that updates to an S3 bucket are atomic only at the object level, and more importantly, are not guaranteed to be immediately consistent (although I recall seeing a recent note that the us-west endpoint does offer read-after-write consistency).
This means that your app-servers may load a set of new files that are internally inconsistent -- some will be old, some will be new. If this is a problem for you, then you should implement a scheme that uploads directly to the app-servers, and ensures changeset consistency (perhaps by uploading to a temporary directory that is then renamed).

Fastest / best way copy data between S3 to EC2?

I have a fairly large amount of data (~30G, split into ~100 files) I'd like to transfer between S3 and EC2: when I fire up the EC2 instances I'd like to copy the data from S3 to EC2 local disks as quickly as I can, and when I'm done processing I'd like to copy the results back to S3.
I'm looking for a tool that'll do a fast / parallel copy of the data back and forth. I have several scripts hacked up, including one that does a decent job, so I'm not looking for pointers to basic libraries; I'm looking for something fast and reliable.
Unfortunately, Adam's suggestion won't work as his understanding of EBS is wrong (although I wish he was right and often thought myself it should work that way)... as EBS has nothing to do with S3, but it will only give you an "external drive" for EC2 instances that are separate, but connectable to the instances. You still have to do copying between S3 and EC2, even though there are no data transfer costs between the two.
You didn't mention an operating system of your instance, so I cannot give tailored information. A popular command line tool I use is http://s3tools.org/s3cmd ... it is based on Python and therefore, according to info on its website it should work on Win as well as Linux, although I use it ALL the time on Linux. You could easily whip up a quick script that uses its built in "sync" command that works similar to rsync, and have it triggered every time you're done processing your data. You could also use the recursive put and get commands to get and put data only when needed.
There are graphical tools like Cloudberry Pro that have some command line options for Windows too that you can setup schedule commands. http://s3tools.org/s3cmd is probably the easiest.
By now, there is a sync command in the AWS Command line tools, that should do the trick: http://docs.aws.amazon.com/cli/latest/reference/s3/sync.html
On startup:
aws s3 sync s3://mybucket /mylocalfolder
before shutdown:
aws s3 sync /mylocalfolder s3://mybucket
Of course, the details are always fun to work out eg. how can parallel it is (and can you make it more parallel and is that any faster goven the virtual nature of the whole setup)
Btw hope you're still working on this... or somebody is. ;)
I think you might be better off using an Elastic Block Store to store your files instead of S3. An EBS is akin to a 'drive' on S3 that can be mounted into your EC2 instance without having to copy the data each time, thereby allowing you to persist your data between EC2 instances without having to write to or read from S3 each time.
http://aws.amazon.com/ebs/
Install s3cmd Package as
yum install s3cmd
or
sudo apt-get install s3cmd
depending on your OS
then copy data with this
s3cmd get s3://tecadmin/file.txt
also ls can list the files.
for more detils see this
For me the best form is:
wget http://s3.amazonaws.com/my_bucket/my_folder/my_file.ext
from PuTTy

Joomla 1.5 Site Backup Strategy

I would like to make a complete backup of my whole joomla 1.5 based site from time to time. How would this ideally be done? Are there any common pitfalls? Not that I only have ftp access to the hosting server. Is there a step by step tutorial somewhere? I am using latest Joomgallery and Kunena 1.0.9 (Legacy mode).
Maybe there is a good way to automate this?
There's two parts of the backup you have to worry about, the database and the files.
The first part is the database. It can be backed up using something like phpMyAdmin. If you don't have this available on your server already, it's not too hard to upload and get it going yourself. From there, you can just Export the entire database to a gzip file.
The second part is the code and uploaded files. The code base shouldn't change too often, so you could probably just make one backup of this. There's a number of ways. The simplest is to just download the entire folder via FTP, though if you're Linux, I'm sure someone will know a single command line to get all the changed files (rsync?).
The database is the main thing you have to worry about though: everything else should be able to be rebuilt just by reinstalling.
I think this: http://www.joomlapack.net/ is what you need. I use it myself and it works like a charm. Both for backups and for moving my Joomla installations from developer sites and to the real site.
get an FTP synchronisation tool and keep an up-to-date copy of your site locally. Then you could run the batch script
mysqldump -hhost -uuser -p%1 schema > C:\backup.sql
to create a backup of your mysql tables at various points in time.
edit
you would have to have MySQL Server installed on your local machine and path to its bin directory in you PATH, in order to run the mysqldump command without much hassle. -p%1 would take the command-line provided password, as you wouldn't want to store passwords in your batch script.
If you only have FTP access you are in a bit of a problem, as beside all files you'll also have to backup the database. Without accessing the database, a full-backup won't do you any good.
Whatever backup strategy you choose - be sure it can handle UTF-8 correctly. Joomla 1.5 stores all content with UTF-8, even when the database charset is set on 'iso-5589-1' - so when the backup solution is detecting the database charset, some characters like € or é will result in "strange" ¬ / é - not really what you'll want.
I absolutely endorse using Joomlapack - it works great. The optional remote tools allow you to initiate the backup from a Windows desktop machine - it performs the backup and downloads it. The remote has a scheduler, and you can also set it off to backup and download a list of sites.
Joomlapack also provides a file "kickstart.php" which you copy to your empty server account along with the backup, which automates the restore procedure. You do have to create an empty database with PHPMyAdmin or similar, and you are given the opportunity to supply the database parameters (host, database, username, password) during the process.
One pitfall I did run into with this though is that some common components can have absolute URLs in their configuration - e.g. SOBI2, Virtuemart. It's then just a matter of finding the appropriate configuration file, editing it and re-uploading it.
Another problem was one archive file (either ZIP or their JPA format) got a filename with a "?" character in it (from a Linux server) and this caused a bit of a problem trying to install it locally on a Windows WAMP stack - the extract process on the ZIP file failed, and it stopped the process completing cleanly.
I suggest using automatic backup service by http://www.everlive.net
Update:
Ok, here is some more information. EverLive.net is a website where you can create a free account. Enter your website details and you are ready to take your backups withe just one click. Restore is also possible in the same way.
Further you can use automatic backup option to take automatic backups at defined intervals. Other than that, you can use the website health check service to inform you if your website is not available.