HashiCorp Terraform vs. Kernel-based Virtual Machine (KVM)

Anything that needs to be repeated en masse. Terraform is great at taking a template and have it be repeated across your estate. You can dynamically change the assets they're generating depending on certain variables. Which means though templated assets will all be similar, they're allowed to have unique properties about them. For example flattening JSON into tabular data and ensuring the flattening code is unique to the file's schema.

Incentivized

KVM is the best solution in the case you need to test and turn up any virtual environment with limited vCPU/RAM resources. The obvious area of its use is a network environment when we want to avoid being tied to one type of hardware/vendor and being able to swap from one instance to another with no downtimes. The use of a vSwitch (that supports VLAN tagging) is a significant bonus for network engineers that some other hypervisors do not provide.

Incentivized

• Terraform is cloud agnostic. Just select the suitable provider for the cloud and it will do the job.
• Templating is possible to make the Terraform templates reusable.
• Variables can be created to make the templates generic so that it can be reused for different environments or resources.

Incentivized

• KVM is really good at providing fast and reliable virtualization for Linux guests
• Since KVM is a kernel module, every VM is a Linux process which can be managed by Linux system tools
• KVM integrates very well with the management framework libvirt, which is why KVM can be integrated in automation tools as well

Incentivized

• The language itself is a bit unusual and this makes it hard for new users to get onboarded into the codebase. While it's improving with later releases, basic concepts like "map an array of options into a set of configurations" or "apply this logic if a variable is specified" are possible but unnecessarily cumbersome.
• The 'Terraform Plan' operation could be substantially more sophisticated. There are many situations where a Terraform file could never work but successfully passes the 'plan' phase only to fail during the 'apply' phase.
• Environment migrations could be smoother. Renaming/refactoring files is a challenge because of the need to use 'Terraform mv' commands, etc.

Incentivized

• KVM itself doesn't ship with a management interface
• KVM itself is a bit complicated to handle
• KVM needs Qemu to virtualize Windows guests

Incentivized

I love Terraform and I think it has done some great things for people that are working to automate their provisioning processes and also for those that are in the process of moving to the cloud or managing cloud resources. There are some quirks to HCL that take a little bit of getting used to and give picking up Terraform a little bit of a learning curve, thus the rating

Incentivized

It does the job and stays out of the way. The specifics of usability relies on the implementation, but with things like Icarus and libvirt, things are standardizing nicely.

Incentivized

Terraform's performance is quite amazing when it comes to deployment of resources in AWS. Of course, the deployment times depend on various parameters like the number of resources to deploy and different regions to deploy. Terraform cannot control that. The only minor drawback probably shows up when a terraform job is terminated mid way. Then in many cases, time-consuming manual cleanup is required.

Incentivized

I have yet to have an opportunity to reach out directly to HashiCorp for support on Terraform. However, I have spent a great deal of time considering their documentation as I use the tool. This opinion is based solely on that. I find the Terraform documentation to have great breadth but lacking in depth in many areas. I appreciate that all of the tool's resources have an entry in the docs but often the examples are lacking. Often, the examples provided are very basic and prompt additional exploration. Also, the links in the documentation often link back to the same page where one might expect to be linked to a different source with additional information.

Incentivized

Terraform is the solid leader in the space. It allows you to do more then just provisioning within a pre-existing servers. It is more extensible and has more providers available than it competitors. It is also open source and more adopted by the community then some of the other solutions that are available in the market place.

Incentivized

It is a very reliable solution that can be used for x86 architecture virtualization with low overhead. It is a free and open source software. Easy to use withOpenStack.

Incentivized

• we are able to deploy our infrastructure in a couple of ours in an automated and repeatable way, before this could take weeks if the work was done manually and was a lot of error prone.
• having the state file, you can see a diff of what things have changed manually out side of Terraform which is a huge plus
• if state file gets corrupted, it is very hard to debug or restore it without an impact or spending hours ..
• writing big scale code can be very challenging and hard to be efficient so it's usable by the whole team

• Fast provisioning of new servers.
• Huge drop of the cost of servers compared to bare metal.
• Easy upgrades of resources, sometimes now even requiring a server restart.

Incentivized