Some software we have developed, we have "encapsulated it" into a virtual machine, that we run with Virtualbox, in command line in a non interactive way (no graphical interface). We send some instructions to the virtual machine, and it outputs some resulting files. We have tested this locally in a Linux machine. Now we would like to send this to many people using Linux, but we realize they will have different distributions, system libraries versions, etc, and then our VM might fail. So my question, is, it is possible to have someething like a static binary version of Virtualbox (or any other similar system / VM / Container) that does not need to use the system libraries, so that it can be run like a static binary?
It would be important to know what are the 'special' requirements of your solution regarding system libraries and the kind.
If you are using a standard host configuration, a standard VirtualBox install should be able to run the VM on any host OS.
Since a VM runs its own kernel, for the most part, is not dependent on host libraries. The the exception to this is when accessing/controlling host resources (disk, net, etc.). This being said, VirtualBox provides ways to access the most common resources (disk, net, etc.) that are transparent for the VM. Meaning that the VM will be configured always in the same way, regardless of whether the host is Win, Linux or Mac, and you can export your VM on Linux and importing it in other platforms without having to tweak it.
A container (eg. dockers) is more complicated, since it shares the kernel of the host, and it depends on how the host kernel is configured.
Again, if your application doesn't depend on 'special' access to host resources, a Docker will run the same way on all host OSs (Linux provides a native kernel, while Win and Mac run a linux virtual machine and then dockers inside it)
If you feel this doesn't answer your question, please share more details about the 'special' needs/configurations of your application, so we can dive deeper into this.
Have you looked at providing portable instances of the VM that can run on different host systems?
This example show how to create one for a windows host, check it out here, but I'm sure it can be done for different host systems as well.
Related
I have a bare qemu or kvm virtual machine and would like to observe or wait for the event that the virtual machine has booted in a reliable way.
This is a generic question that may not have a generic answer. If it helps you may assume a subset of the following:
The VM is running Debian GNU/Linux.
The actual question is whether the contained ssh server is reachable. It is exported via user networking and a hostfwd.
Remarks:
reliable means that it is suitable for continous integration testing. It should fail in less than 0.1% of cases.
Running ssh -o ConnectionAttempts=30 sometimes produces a failure even though ssh would work afterwards.
I have been looking around to see if there is some simple, stand-alone(ish) agent/server setup that would allow a ping to be launched from a host with an agent on it. When I say "ping," I mean via icmp echo and/or tcp port check. I have Windows, Linux, and AIX systems that would get such an agent.
I would like to set up a central server with authentication that can issue pings from any device that has one of these agents. The primary use would be VPN testing, so that traffic can be initiated from a device that I don't necessarily have access to.
It seems that some monitoring software has this (e.g., Zabbix) but I don't want to go through the pain of installing a whole big piece of software like that just to get this functionality.
Almost all our AIX and Linux systems have perl installed, so that could be a nice option if I had to write my own. I would rather find something "tried-and-true" though...
I didn't realize that we already had SaltStack installed on almost all our servers (I'm a network guy, not a server guy). Once I talked to one of the server administrators, he showed me how this could be done using Salt.
From what I gather, the only way to use a MySQL database with Azure websites is to use Cleardb but can I install MySQL on VMs provided in Azure Cloud Services. And if so how?
This question might get closed and moved to ServerFault (where it really belongs). That said: ClearDB provides MySQL-as-a-Service in Azure. It has nothing to do with what you can install in your own Virtual Machines. You can absolutely do a VM-based MySQL install (or any other database engine that you can install on Linux or Windows). In fact, the Azure portal even has a tutorial for a MySQL installation on OpenSUSE.
If you're referring to installing in web/worker roles: This simply isn't a good fit for database engines, due to:
the need to completely script/automate the install with zero interaction (which might take a long time). This includes all necessary software being downloaded/installed to the vm images every time a new instance is spun up.
the likely inability for a database cluster to cope with arbitrary scale-out (the typical use case for web/worker roles). Database clusters may or may not work well when a scale-out occurs (adding an additional vm). Same thing when scaling in (removing a vm).
less-optimal attached-storage configuration
inability to use Linux VMs
So, assuming you're still ok with Virtual Machines (vs stateless Cloud Service vm's): You'll need to carefully plan your deployment, with decisions such as:
Distro (Ubuntu, CentOS, etc). Azure-supported Linux distro list here
Selecting proper VM size (the DS series provide SSD attached disk support; the G series scale to 448GB RAM)
Azure Storage attached disks being non-Premium or Premium (premium disks are SSD-backed, durable disks scaling to 1TB/5000 IOPS per disk, up to 32 disks per VM depending on VM size)
Virtual network configuration (for multi-node cluster)
Accessibility of database cluster (whether your app is in the vnet or accesses it through a public endpoint; and if the latter, setting up ACL's)
Backup / HA / DR planning
Someone else mentioned using a pre-built VM image from VM Depot. Just realize that, if you go that route, you're relying on someone else to configure the database engine install for you. This may or may not be optimal for what you're trying to achieve. And the images may or may not be up-to-date with the latest versions, patches, etc.
Of course, what I wrote applies to any database engine you install in your own virtual machines, where a service provider (such as ClearDB) tends to take care of most of these things for you.
If you are talking about standard VMs then you can use a pre-built images on VMDepot for that.
If you are talking about web or worker roles (PaaS) I wouldn't recommend it, but if you really want to you could. You would need to fully script the install of the solution on the host. The only downside (and it's a big one) you would have would be the that the host will be moved to a new host at some point which would mean your MySQL data files would be lost - if you backed up frequently and were happy to lose some data then this option may work for you.
I think, that the main question is "what You want to achieve?". As I see, You want to use PaaS solution with Web Apps or Cloud Service and You need a MySQL database. If Yes, You have two options (both technically as David Makogon said). First one is to deploy Your own (one) server with MySQL and connect to it from the outside (internet side). Second solution is to create one MySQL server or cluster and connect Your application internally in Azure virtual network. WIth Cloud Service it is simple but with Web App it is not. You must create VPN gateway in Azure VM and connect Your Web App to this gateway. In this way You will have internal connection wfrom Your application to Your own MySQL cluster.
Simple question can a Java service layer running on Tomcat7 on a host machine connect to persistent data store (mySQL) running inside a virtual box with portforwarding? I want to know if the hibernate or Jdbc connection strings from host machine work if mySQL server is installed inside a VirtualBox.
Also if it does work can I expect behavioral deviations in terms of speed and connection pooling if everything is packaged into one single system and deployed in a real world web server in a single enviroment?
The short answer is yes, it is possible and will work. You will likely have to play with the firewall settings on your virtual box instance. You don't specify OS, so it's hard to tell you what exactly you'll need to tweak.
As far as deploying this in a real-world environment, if you mean production, you probably should NOT do that. This is a great setup to build on, but not something I would run in production.
To be clear, there won't be any issues behaviorally speaking, it will act as MySQL always acts, but it will absolutely be slower than running it on 'bare metal' -- how much slower will vary based on hardware, workload, etc. and it is generally not a great design for a production deployment..
We're using OpenNebula to simulate a simple replicated JBoss application.
We've installed all opennebula packages, qemu and kvm and libvirt.
We have created a simple ethernet network ad hoc between my pc (a node) and the one of my friend (which is both node and front-end) by plugging an ethernet cable between me and him (10.0.0.1 and 10.0.0.2).
So we can ping each other correctly, we've set everything to that we can ssh without a password to each other with "oneadmin" user.
We've configured all files such as below:
/etc/libvirt/libvirtd.conf
/etc/default/libvirtd-bin
And so on...
kvm and kvm-intel are both enabled.
The daemon
libvirtd -d -l
seems to start correctly.
In fact, from the gui of opennebula in the front end, we can see both the hosts monitored.
Anyway there's a problem when we try to start the virtual machine on the node which is not the front-end. I mean when we try to do a deploy of a VM on the other node. The error is something like this
cannot stat `/var/lib/one/datastores/1/f5394317d377beaa09fc07697df9ff68
but if, from the front end which has virtual machine n°1 we perform,
cd /var/lib/one/datastores/1
then we can see that file, we've also given all the permissions to it...
Any idea? :(
This may be related with the datastore configuration. If you left the default values, OpenNebula expects a shared filesystem (ie NFS) between the front-end and the virtualization nodes.
More context on the error (which I believe can be found in /var/lib/one/oned.log) would help analysing this problem.