Using Terraform to configure vSphere vms, I'd like to be able to provide an IP address (and gateway and netmask) in the tfvars file, but have the vm default to using DHCP if the values are not provided. I know it will use DHCP if the 'vsphere_virtual_machine' resources' 'customize' block contains an empty 'network_interface' block. I was hoping that be giving a default value of "" to the settings in the variables.tf file I could set values if present and use DHCP if not, but I get an error stating:
Error: module.vm.vsphere_virtual_machine.node:
clone.0.customize.0.network_interface.0.ipv4_netmask: cannot parse ''
as int: strconv.ParseInt: parsing "": invalid syntax
So putting in a blank string won't parse, and it won't just leave the whole network_interface blank if the values are blank.
I can't use COUNT on a subresource, so the only thing I've come up with so far is to put two entire, nearly identical, 'vsphere_virtual_machine' resources into my module and then put COUNT statements on both so only one gets created, depending on whether the network settings are provided or not, but man, does that seem ugly...?
I think you are in luck. I've been waiting for this exact same problem to be solved since almost a year now.
Lo and behold, Terraform v0.12.0-alpha1:
They now support dynamic block definitions instead of just static ones
Enjoy, while I'm gonna throw away a couple of hundreds of lines worth of hacks just like the one you mentioned...
Related
I wanted to ask if there is a way to ignore whitespace changes when creating a terraform plan.
This question is related to this one, I created a new one because I wanted to give a new example of the issue.
Terraform shows unnecessary changes due to whitespace
For example, when running
terraform plan
I get the following change for a helm provider resource
# helm_release.cert-manager will be updated in-place
~ resource "helm_release" "cert-manager" {
id = "cert-manager"
name = "cert-manager"
~ values = [
- <<-EOT
installCRDs: true
EOT,
+ <<-EOT
installCRDs: true
EOT,
]
# (27 unchanged attributes hidden)
}
I found out that the change was due to line endings. Deployed was CRLF and my local source file had LF as line ending.
Is there an option to ignore whitespaces and/or line ending characters?
It's typically the responsibility of the provider itself to determine whether the prior value and the new value are equivalent despite not being exactly equal, and so making this work automatically would require a change to the provider itself to notice that this argument is defined as being YAML and YAML doesn't ascribe any meaning to the decision between CRLF and just LF. The provider would ideally perform this check itself and thus avoid you needing to worry about it, and I would suggest opening a feature request with the provider developer to see if they would be interested in handling that.
However, if a provider isn't performing that job correctly itself then you can potentially work around it by doing your own normalization of the value using Terraform language features, so that the value passed to the provider is always the same when the meaning is the same.
One straightforward way to achieve that in this case would be to round-trip the value through both yamldecode and yamlencode, thereby normalizing the input to be in the style that yamlencode produces:
values = [yamlencode(yamldecode(var.something))]
If you want to be more surgical about it and only normalize the line endings, you could use replace to remove the CR character from any CRLF pair:
values = [replace(var.something, "\r\n", "\n")]
The above solution assumes that the difference in whitespace is being caused by something in your module, such as if you're storing your Terraform configuration in a misconfigured Git repository that's rewriting LF to CRLF when you clone it on a Windows system. This config-based normalization can undo that sort of transformation so that the provider will always see the value in the same way.
This solution cannot address problems that are caused by the provider itself misbehaving. Unfortunately some providers have bugs where they will silently rewrite the stored values for some arguments during the "refresh" step, regardless of how you wrote it in the configuration. In that case the only recourse is to fix the provider, because that incorrect value is originating inside the provider itself and isn't under the control of the module author.
I was wondering if it's possible to grab different data dynamically based on variables like so
data.terraform_remote_state.vm.outputs.vm_***var.vmname***
Or something similar? i dont have the option to redesign the outputs currently, and this would greatly lower the chance of making failure upon creating new terraform deployments
thanks!
There are Input Variables available in Terraform. These variables allow you to define inputs expected at the time of terraform apply. The values may be entered via an interactive terminal or provided in a .tfvars file.
variable "vmname" {
type = string
description = "The name of the virtual machine."
}
Then you can use them by expansion:
"data.terraform_remote_state.vm.outputs.vm_${var.vmname}"
For additional reference, see https://www.terraform.io/docs/language/values/variables.html
I'd like to know what would be the best way to populate a Chef attribute in a cookbook with the last octet of the IP address.
Here is how I do it now. It seems to work; however,I'd like to know how I can improve it.
default['application']['host_ip'] = node['network']['interfaces']['eth0']['addresses'].keys[1]
default['application']['app_id'] = node['application']['host_ip'].split('.')[-1]
Thanks!
That looks fine. You might want some error handling since this will crash if there isn't an eth0, but that's up to you. You could also use node['ipaddress'] which is the IP on the default interface.
I want Puppet to create a different variable name depending on the hiera file associated with the environment. I want to do this because I want Puppet to use the ip address associated with a specific network interface. Ideally, the network interface will be in the hiera file. That way you could concatenate the ip_address variable name with the network interface defined in the hiera file, which would look something like.
::ipaddress_{$network_interface_from_hiera_file}
Is this possible?
Right now I have an the following, but I think there is a better implementation. If the network interfaces change I would have to add another case.
if $environment == 'production' {
$client_address = $::ipaddress_enp130s0f0
} else {
$client_address = $::ipaddress_eth2
}
It sounds like you're after an eval in Puppet, like you have in shell and Perl other languages, and as far as I know, there isn't one.
I would probably just use a custom fact that always returns the IP address I care about. Of course, then you need to solve the problem of how to get the custom facts out to your fleet.
Another solution might be to use Hiera's hierarchical lookup:
In hiera.yaml:
:hierarchy:
- %{::node_environment}
- common
In common.yaml:
---
myclass::client_address: "%{::ipaddress_eth2}"
In production.yaml:
---
myclass::client_address: "%{::ipaddress_enp130s0f0}"
Finally, be aware that you can look up values from within Hiera, see here. Possibly that could be helpful.
I'm trying to set up a template in ansible, for our tomcat servers, but we have two tomcat instances on each host, each of which needs a different value for certain variables, for instance:
Tomcat_1 needs a port set to 8105
Tomcat_2 needs a port set to 8205
Easy enough to do if it's only one value per node needed, but I'm having some trouble finding how to do this when you need multiple values per host in either the Ansible or jinja2 docs. Can anyone offer some assistance, or point me to an example?
What I'm thinking is something along the lines of if this filepath then this value, but I'm not sure how to make that happen with jinja2.
I would either use two roles or use the role syntax that allows you to pass in values...
- { role: tomecat, some_parameter: 3 }