shellcheck and expect TK_HOME to be set already

README.md

@@ -11,6 +11,11 @@ serialised in a manner that permits them to be loaded as inputs to Inspec.
 
 ## Usage
 
+Ensure that the `TK_HOME` environment variable is set to the directory that
+contains the Test Kitchen config.
+
+## Configuration
+
 The tool expects the following directory structure:
 
 ```none

tg-wrapper

@@ -2,12 +2,17 @@
 set -e
 # export TERRAGRUNT_SOURCE_UPDATE=true to track a branch rather than a tag
 export TF_INPUT=false
-TK_HOME="$(dirname $(readlink -f $0))"
-trap "mv $TK_HOME/environments/root.yaml.bak $TK_HOME/environments/root.yaml" EXIT
+# expect TK_HOME to be set
+if [ -z ${TK_HOME+x} ]; then
+  echo "TK_HOME is unset"
+  exit 1
+fi
+trap 'mv $TK_HOME/environments/root.yaml.bak $TK_HOME/environments/root.yaml' EXIT
 
-export GOOGLE_OAUTH_ACCESS_TOKEN=$(create-token -d $TK_HOME/test/integration)
-mv $TK_HOME/environments/root.yaml $TK_HOME/environments/root.yaml.bak
-cp $TK_HOME/test/integration/root.yaml $TK_HOME/environments/root.yaml
+GOOGLE_OAUTH_ACCESS_TOKEN=$(create-token -d "$TK_HOME/test/integration")
+export GOOGLE_OAUTH_ACCESS_TOKEN
+mv "$TK_HOME/environments/root.yaml" "$TK_HOME/environments/root.yaml.bak"
+cp "$TK_HOME/test/integration/root.yaml" "$TK_HOME/environments/root.yaml"
 
 case $1 in
 "apply")