Improve handling of tf plugin cache in tests (#885)

* disable tf cache in CI

* re-enable cache

* try a different approach

.github/workflows/tests.yml

@@ -54,13 +54,11 @@ jobs:
           terraform_version: ${{ env.TF_VERSION }}
           terraform_wrapper: false
 
-      - name: Config Terraform plugin cache
+      - name: Config Terraform plugin cache and initialize providers
         run: |
           echo 'plugin_cache_dir="$HOME/.terraform.d/plugin-cache"' >~/.terraformrc
           mkdir --parents ~/.terraform.d/plugin-cache
-
-      - name: Initialize providers
-        run: |
+          sed -i -e '/# CI hook/e cat tests/test-versions.tf' default-versions.tf
           terraform init
 
       # avoid conflicts with user-installed providers on local machines
@@ -107,6 +105,13 @@ jobs:
         run: |
           terraform init
 
+      - name: Config Terraform plugin cache and initialize providers
+        run: |
+          echo 'plugin_cache_dir="$HOME/.terraform.d/plugin-cache"' >~/.terraformrc
+          mkdir --parents ~/.terraform.d/plugin-cache
+          sed -i -e '/# CI hook/e cat tests/test-versions.tf' default-versions.tf
+          terraform init
+
       # avoid conflicts with user-installed providers on local machines
       - name: Pin provider versions
         run: |
@@ -151,6 +156,13 @@ jobs:
         run: |
           terraform init
 
+      - name: Config Terraform plugin cache and initialize providers
+        run: |
+          echo 'plugin_cache_dir="$HOME/.terraform.d/plugin-cache"' >~/.terraformrc
+          mkdir --parents ~/.terraform.d/plugin-cache
+          sed -i -e '/# CI hook/e cat tests/test-versions.tf' default-versions.tf
+          terraform init
+
       # avoid conflicts with user-installed providers on local machines
       - name: Pin provider versions
         run: |
@@ -195,6 +207,13 @@ jobs:
         run: |
           terraform init
 
+      - name: Config Terraform plugin cache and initialize providers
+        run: |
+          echo 'plugin_cache_dir="$HOME/.terraform.d/plugin-cache"' >~/.terraformrc
+          mkdir --parents ~/.terraform.d/plugin-cache
+          sed -i -e '/# CI hook/e cat tests/test-versions.tf' default-versions.tf
+          terraform init
+
       # avoid conflicts with user-installed providers on local machines
       - name: Pin provider versions
         run: |

default-versions.tf

@@ -23,14 +23,7 @@ terraform {
       source  = "hashicorp/google-beta"
       version = ">= 4.36.0" # tftest
     }
-    # used in modules
-    archive = {
-      source = "hashicorp/archive"
-    }
-    # used in fast
-    local = {
-      source = "hashicorp/local"
-    }
+    # CI hook
   }
 }
 

tests/test-versions.tf

@@ -0,0 +1,4 @@
+# skip boilerplate check
+archive = { source = "hashicorp/archive" }
+local   = { source = "hashicorp/local" }
+random  = { source = "hashicorp/random" }