Add support for multiple terraform versions

that may be overridden by individual infrastructures, with versions
installed to a private cache directory.

Author: meatballhat

.example.env

@@ -8,3 +8,5 @@ export GITHUB_USERNAME=yourname
 export GITHUB_TOKEN=AFAFAFAFAFAFAFAFAFAFAFAFAFAF
 
 export TF_VAR_ssh_user=yourusername
+
+export TF_INSTALLATION_PREFIX=$HOME/.cache/travis-terraform-config

.travis.yml

@@ -5,14 +5,18 @@ sudo: required
 cache:
   directories:
   - "${HOME}/bin"
+  - "${HOME}/.cache/travis-terraform-config"
 env:
   global:
   - PATH="${HOME}/bin:${PATH}"
   - SHELLCHECK_URL="https://s3.amazonaws.com/travis-blue-public/binaries/ubuntu/14.04/x86_64/shellcheck-0.4.4.tar.bz2"
   - SHFMT_URL="mvdan.cc/sh/cmd/shfmt"
   - TMPDIR="${TMPDIR:-/tmp}"
 before_install:
-- ./bin/ensure-terraform "$(make -f terraform-common.mk .echo-tf-version)"
+- git ls-files '*/Makefile' | xargs -n 1 make .echo-tf-version -f 2>/dev/null | sort | uniq |
+  while read -r tf_version;
+    do ./bin/ensure-terraform "${tf_version}";
+  done
 - if [[ ! -x "${HOME}/bin/shellcheck" ]]; then
     curl -sSL "${SHELLCHECK_URL}" | tar -C "${HOME}/bin" -xjf -;
   fi

bin/ensure-terraform

@@ -11,24 +11,18 @@ main() {
   fi
 
   : "${TF_INSTALL_MISSING:=1}"
-  : "${TF_INSTALLATION_PREFIX:=${HOME}/bin}"
+  : "${TF_INSTALLATION_PREFIX:=${HOME}/.cache/travis-terraform-config}"
   : "${TF_DOWNLOAD_SERVER:=https://releases.hashicorp.com}"
   : "${TMPDIR:=/tmp}"
 
-  local tf_current='???'
-  local tf="${TF_INSTALLATION_PREFIX}/terraform"
+  mkdir -p "${TF_INSTALLATION_PREFIX}"
+  local tf="${TF_INSTALLATION_PREFIX}/terraform-${tf_version}"
 
-  if [[ -x "${tf}" ]]; then
-    local tf_current
-    tf_current="$( ("${tf}" version || true) | head -n1 | cut -d ' ' -f 2)"
-  fi
-
-  if [[ "${tf_current}" == "${tf_version}" ]]; then
-    exit 0
-  fi
-
-  if [[ "${TF_INSTALL_MISSING}" == 0 ]]; then
-    echo "Terraform ${tf_version} required (current=${tf_current})" >&2
+  if [[ ! -x "${tf}" && "${TF_INSTALL_MISSING}" == 0 ]]; then
+    echo "===> Terraform ${tf_version} required."
+    echo "     Run this:"
+    echo "     ${0} ${tf_version}"
+    echo
     exit 1
   fi
 
@@ -43,7 +37,7 @@ main() {
   mv -v terraform "${tf}"
   chmod +x "${tf}"
   popd &>/dev/null
-  terraform version
+  "${tf}" version
 }
 
 main "$@"

macstadium-shared-1/.terraform-validate-flags

@@ -0,0 +1 @@
+

macstadium-shared-1/Makefile

@@ -1,5 +1,8 @@
 include $(shell git rev-parse --show-toplevel)/terraform.mk
 
+PROD_TF_VERSION := v0.9.11
+TERRAFORM := $(HOME)/.cache/travis-terraform-config/terraform-$(PROD_TF_VERSION)
+
 .PHONY: default
 default: hello
 

macstadium-shared-2/.terraform-validate-flags

@@ -1,5 +1,8 @@
 include $(shell git rev-parse --show-toplevel)/terraform.mk
 
+PROD_TF_VERSION := v0.9.11
+TERRAFORM := $(HOME)/.cache/travis-terraform-config/terraform-$(PROD_TF_VERSION)
+
 .PHONY: default
 default: hello
 

macstadium-shared-2/Makefile

@@ -10,6 +10,9 @@ main() {
     git diff-index --quiet HEAD -- || (echo "$msg" && exit 1)
   fi
 
+  local terraform
+  terraform="$(make -f terraform-common.mk .echo-tf)"
+
   if [[ $# -gt 1 && $1 == --env ]]; then
     echo "Running isolated with env ${2}"
     exec env -i \
@@ -46,12 +49,22 @@ main() {
 
   for d in $(git ls-files '*.tf' | xargs -n1 dirname | LC_ALL=C sort | uniq); do
     echo -en "${d} "
-    terraform validate "${d}"
+    if [[ -f "${d}/Makefile" ]]; then
+      terraform="$(make -f "${d}/Makefile" .echo-tf)"
+    else
+      terraform="$(make -f terraform-common.mk .echo-tf)"
+    fi
+    if [[ -f "${d}/.terraform-validate-flags" ]]; then
+      # shellcheck disable=SC2046
+      "${terraform}" validate $(cat "${d}/.terraform-validate-flags") "${d}"
+    else
+      "${terraform}" validate -check-variables=false "${d}"
+    fi
     echo "✓"
   done
 
   echo 'Running terraform fmt'
-  terraform fmt
+  "${terraform}" fmt
 }
 
 main "$@"

runtests

@@ -10,7 +10,9 @@ TRAVIS_BUILD_ORG_HOST ?= build.travis-ci.org
 JOB_BOARD_HOST ?= job-board.travis-ci.com
 AMQP_URL_VARNAME ?= AMQP_URL
 TOP := $(shell git rev-parse --show-toplevel)
-PROD_TF_VERSION := v0.9.11
+
+PROD_TF_VERSION := v0.11.0
+TERRAFORM := $(HOME)/.cache/travis-terraform-config/terraform-$(PROD_TF_VERSION)
 
 .PHONY: hello
 hello: announce
@@ -27,6 +29,10 @@ hello: announce
 .echo-tf-version:
 	@echo $(PROD_TF_VERSION)
 
+.PHONY: .echo-tf
+.echo-tf:
+	@echo $(TERRAFORM)
+
 .PHONY: .assert-tf-version
 .assert-tf-version:
 	@TF_INSTALL_MISSING=0 $(TOP)/bin/ensure-terraform $(PROD_TF_VERSION)
@@ -37,20 +43,20 @@ announce: .assert-ruby .assert-tf-version
 
 .PHONY: apply
 apply: announce .config $(TFVARS) $(TFSTATE)
-	terraform apply $(TFPLAN)
+	$(TERRAFORM) apply $(TFPLAN)
 	$(TOP)/bin/post-flight $(TOP)
 
 .PHONY: plan
 plan: announce .config $(TFVARS) $(TFSTATE)
-	terraform plan \
+	$(TERRAFORM) plan \
 		-var-file=$(ENV_NAME).tfvars \
 		-var-file=$(TFVARS) \
 		-module-depth=-1 \
 		-out=$(TFPLAN)
 
 .PHONY: destroy
 destroy: announce .config $(TFVARS) $(TFSTATE)
-	terraform plan \
+	$(TERRAFORM) plan \
 		-var-file=$(ENV_NAME).tfvars \
 		-var-file=$(TFVARS) \
 		-module-depth=-1 \
@@ -59,7 +65,7 @@ destroy: announce .config $(TFVARS) $(TFSTATE)
 	$(TOP)/bin/post-flight $(TOP)
 
 $(TFSTATE):
-	terraform init
+	$(TERRAFORM) init
 
 .PHONY: clean
 clean: announce
@@ -71,7 +77,7 @@ distclean: clean
 
 .PHONY: graph
 graph:
-	terraform graph -draw-cycles | dot -Tpng > graph.png
+	$(TERRAFORM) graph -draw-cycles | dot -Tpng > graph.png
 
 $(ENV_NAME).tfvars:
 	$(TOP)/bin/generate-tfvars $@