terraform-controller VS sops-secrets-operator

In addition to creating Kubernetes clusters, there is also an increasing number of opportunities to use various Infrastructure-as-Code (IaC) tools, such as Terraform, with GitOps. As was already mentioned, PipeCD offers support for Terraform. Terraform's vendor, HashiCorp, now also offers an official Terraform Kubernetes operator. However, it needs access to HashiCorp's Terraform Cloud. Alternatively, there are also third-party operators that can function without Terraform Cloud, such as the one developed by Rancher. However, it is still in alpha stage.

sops-secrets-operator (sops)

There is also a third-party sops-secrets operator available.

I have configured sops-secret-controller too, I'll be using that to manage my secrets. But my problem is that I don't know beforehand the value.

SOPS that was developed by Mozilla offers significantly more options, though at the expense of a more complex configuration. Here, the key material can come from the key management systems (KMS) of the major cloud providers, from your own HashiCorp Vault, or from configured PGP keys. SOPS itself does not contain an operator, but there are different ways to use it with GitOps. Flux v2 offers native support. There is also the helm-secrets plug-in, which can also be used in ArgoCD with the manual configuration. There is also a sops-secrets operator that has been developed by a third party.