Add OpenTofu to test matrix

OpenTofu, a community fork of Terraform, has yet to be released as
stable, but an alpha version is available. Let's add it to the test
matrix.

You also need to set the environment variable TFMIGRATE_EXEC_PATH to
tofu.

.github/workflows/test.yaml

@@ -32,14 +32,14 @@ jobs:
         go-version-file: '.go-version'
     - name: test
       run: make test
-  testacc:
+  testacc_terraform:
     runs-on: ubuntu-latest
     timeout-minutes: 20
     strategy:
       fail-fast: false
       matrix:
         terraform:
-        - 1.6.0
+        - 1.6.2
         - 1.5.7
         - 1.4.7
         - 0.12.31
@@ -58,3 +58,27 @@ jobs:
       run: docker-compose run --rm tfmigrate terraform --version
     - name: testacc
       run: docker-compose run --rm tfmigrate make testacc
+  testacc_opentofu:
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+    strategy:
+      fail-fast: false
+      matrix:
+        opentofu:
+        - 1.6.0-alpha3
+    env:
+      OPENTOFU_VERSION: ${{ matrix.opentofu }}
+      TFMIGRATE_EXEC_PATH: tofu
+    steps:
+    - uses: actions/checkout@v4
+    - name: docker build
+      run: docker-compose build
+    - name: start localstack
+      run: |
+        docker-compose up -d localstack
+        docker-compose run --rm dockerize -wait tcp://localstack:4566 -timeout 60s
+        docker-compose exec -T localstack /etc/localstack/init/wait_s3_bucket_exists.sh
+    - name: tofu --version
+      run: docker-compose run --rm tfmigrate tofu --version
+    - name: testacc
+      run: docker-compose run --rm tfmigrate make testacc

Dockerfile

@@ -1,9 +1,13 @@
 ARG TERRAFORM_VERSION=latest
+ARG OPENTOFU_VERSION=latest
+
 FROM hashicorp/terraform:$TERRAFORM_VERSION AS terraform
+FROM ghcr.io/opentofu/opentofu:$OPENTOFU_VERSION AS opentofu
 
 FROM golang:1.21-alpine3.18
 RUN apk --no-cache add make git bash
 COPY --from=terraform /bin/terraform /usr/local/bin/
+COPY --from=opentofu /usr/local/bin/tofu /usr/local/bin/
 WORKDIR /work
 
 COPY go.mod go.sum ./

docker-compose.yml

@@ -5,6 +5,7 @@ services:
       context: .
       args:
         TERRAFORM_VERSION: ${TERRAFORM_VERSION:-latest}
+        OPENTOFU_VERSION: ${OPENTOFU_VERSION:-latest}
     volumes:
       - ".:/work"
     environment:
@@ -19,6 +20,8 @@ services:
       # it appears that localstack sometimes misses API requests when run in parallel.
       TF_CLI_ARGS_apply: "--parallelism=1"
       TERRAFORM_VERSION: ${TERRAFORM_VERSION:-latest}
+      OPENTOFU_VERSION: ${OPENTOFU_VERSION:-latest}
+      TFMIGRATE_EXEC_PATH:
     depends_on:
       - localstack
       - fake-gcs-server