Pulumi "no resource plugin ... found in the workspace" in CI

Pulumi needs a provider plugin (aws, gcp, azure, kubernetes) to manage resources and could not find it on the runner. In CI this usually means the ~/.pulumi/plugins cache was not restored and the plugin was never installed.

What this error means

A pulumi up or pulumi preview step fails with "error: no resource plugin 'aws' found in the workspace or on your $PATH, install the plugin using pulumi plugin install resource aws".

pulumi

error: no resource plugin 'aws-v6.0.0' found in the workspace or on your $PATH,
install the plugin using `pulumi plugin install resource aws v6.0.0`

Common causes

The plugin cache was not restored

A fresh runner has an empty ~/.pulumi/plugins, and the workflow did not cache or reinstall the provider plugins your program needs.

Language dependencies not installed before Pulumi

Pulumi installs provider plugins on demand from the SDK, but if the SDK packages were not installed first, the plugin never gets provisioned.

How to fix it

Install the plugin explicitly

Install language dependencies so the provider SDKs are present.
Run pulumi plugin install for each provider and version your program uses.
Then run the update.

Terminal

pulumi plugin install resource aws v6.0.0

Cache the plugin directory across runs

Persist ~/.pulumi/plugins so plugins downloaded once are reused instead of missing on the next run.

.github/workflows/ci.yml

- uses: actions/cache@v4
  with:
    path: ~/.pulumi/plugins
    key: pulumi-plugins-${{ hashFiles('**/package-lock.json') }}

How to prevent it

Cache ~/.pulumi/plugins keyed on your lockfile.
Install language dependencies before any Pulumi command.
Pin provider versions so the cache key stays stable.