OCI Resource Manager
OCI Resource manager is an automation tool for infrastructure.
It can be considered as Infrastructure as a code tool. It executes the
terraform code and provisions the resource. It’s a managed service for
Terraform in OCI.
We would have provisioned resources using OCI market place
image. Basically, terraform code was written behind for provisioning market
place image in OCI and that terraform code will be executed via Resource
manager. So knowingly or unknowingly we use Resource manager for provisioning
resources in OCI.
Stacks
OCI resource manager bundles the terraform code and required
attributes/variable in a package called Stacks. The stacks will be validated
through plan and apply phase which is similar to terraform plan and apply. The
variables can have default value or it can collected dynamically during
execution.
Resource manager can be invoked in OCI console through Developer Services -> Resource Manager.
Lets see how to execute a terraform code using Resource
manager.
In the Resource manager window choose Stacks -> Create
stack.
Stack can be created in 4 ways.
My configuration: Stack creation with our own terraform
code.
Template: A set of defined templates available like market place images and
stack can be created using that.
Source code control system: Terraform code stored at Bitbucket Cloud, Bitbucket
Server, DevOps, GitHub, or GitLab can be used to create stack. Based on chosen repository
platform, details will be collected to create stack.
Existing compartment: This is very useful and unique feature of Resource
manager. It can read the existing resources and generate terraform code of
that. It will be useful to redeploy the resources in other region or other
tenancy.
In this article lets examine first option – My configuration.
My configuration – We need to provide terraform code to
create stack. The terraform code can be uploaded as folder or object storage bucket
URL or Zip file.
It
has option to choose custom terraform provides, but that would require the
provider to be stored in the object storage bucket. Hashicorp is used here.
Stack
name and description fields are optional and stack creation requires
compartment to create. Also, it has option to specify the preferred terraform
versions to execute the stack.
In
this article we use terraform code of vcn creation and it has been uploaded as
zip file.
The
next page will have details of variables needed to execute the stack. In case variables are specified with default
value in the code, that will be displayed here. It can be modified and also values
can be specified to other variables.
After
confirming values, click next.
The
next page will display all the variable and its value.
It
has option to execute this stack along with creation. In case we want to perform
terraform plan to preview the changes, not to choose the ratio button Run apply.
The
stack has option to perform Plan and Apply.
Edit
option will allow to recreate the stack with same name. We can upload new
terraform code if required. Plan will perform terraform plan with a task name.
Logs
column will show if any warnings or errors are observed.
If
the plan succeeded, we could see the banner in green color with the status.
Logs
can be downloaded for future reference. Also Terraform configuration and
Terraform plan (as binary or json file) can be downloaded.
When
plan is succeeded, we can proceed with apply.
Apply
can proceed with automatic approval or specify the plan which had success.
Apply
with automatic approval will perform terraform plan and also execute the code. Logs
will show the details of execution. Also Terraform configuration and Terraform state
file can be downloaded.
1)
Its serverless, we don’t need resource to
execute terraform code.
2)
It has native terraform integration using
Hashicorp.
3)
State files are maintained internally and has
provision to download.
4)
GUI based execution.
5)
All stack executions are recorded and it can be
referred at any point of time.
