cdktf deploy fails with "Failed to instantiate provider" and "unknown provider registry.terraform.io/-/docker"

TL;DR

Your generated config points Terraform at a nonsense provider address (registry.terraform.io/-/docker) because the provider source is missing. Re-run cdktf get, fix the provider source to the real namespace, remove stale .gen/cdktf.out, and re-synth.

The error

Failed to instantiate provider "registry.terraform.io/-/docker" to obtain
schema: unknown provider "registry.terraform.io/-/docker"

non-zero exit code 1

Fix it

1. Re-run cdktf get to regenerate provider bindings with current sources.
2. Check cdk.tf.json required_providers: the docker entry must have a real source (e.g. kreuzwerker/docker), never -.
3. Remove stale generated output: rm -rf .gen cdktf.out (and any compiled main.js/main.d.ts).
4. Re-run cdktf synth, verify the provider address is correct in the JSON, then cdktf deploy.

Expected result: deploy plans and applies instead of failing on provider instantiation.

When to use this

• cdktf deploy or cdktf destroy fails with unknown provider "registry.terraform.io/-/[name]"
• You switched provider namespaces or upgraded cdktf recently

When NOT to use this

• The provider address is correct but the download fails (registry/network issue)
• Synth itself fails (fix the synth error first)

Root cause

The - in the address is Terraform's placeholder for "no namespace given". It appears when the generated required_providers lacks a source, common after namespace moves (the docker provider moved from terraform-providers to kreuzwerker) combined with stale generated bindings that predate the move.

Edge cases

• cdktf destroy hits the same bug on old stacks; clean and re-synth before destroying.
• If you hand-edit cdk.tf.json, your edits are overwritten on the next synth; fix the source in code or config instead.