Handle non-success error codes in healthcheck (#1651)

* Handle non-success error codes in healthcheck

Only attempt to parse response as JSON for 200 success responses
Avoids attempting to parse HTML from 502 Bad Gateway responses

* Update healthcheck script to use tmp output folder

Set .gitignore in tmp folder (and remove from main gitignore)
Tidy handling of showing output

devops/scripts/api_healthcheck.sh

@@ -1,19 +1,33 @@
 #!/bin/bash
 set -e
 
-response=$(curl -k "https://${TRE_ID}.${LOCATION}.cloudapp.azure.com/api/health")
+# Get the directory that this script is in
+DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
+# Create a .gitignore'd  directory for temp output
+mkdir -p "$DIR/script_tmp"
+echo '*' > "$DIR/script_tmp/.gitignore"
+api_response_file="$DIR/script_tmp/api_response.txt"
+
+echo "Calling /health endpoint..."
+response_code=$(curl --insecure --silent --output "$api_response_file" --write-out "%{http_code}" "https://${TRE_ID}.${LOCATION}.cloudapp.azure.com/api/health")
 
-echo "Got response from https://${TRE_ID}.${LOCATION}.cloudapp.azure.com/api/health:"
-echo "$response"
 echo
 
-not_ok_count=$(echo "${response}"  | jq -r '[.services | .[] | select(.status!="OK")] | length')
+if [[ "$response_code" != "200" ]]; then
+  echo "*** ⚠️ API _not_ healthy ***"
+  echo "Non-success code returned: $response_code"
+  echo "Response:"
+  cat "$api_response_file"
+  exit 1
+fi
+
+not_ok_count=$(jq -r '[.services | .[] | select(.status!="OK")] | length' < "$api_response_file")
 
 if [[ "$not_ok_count" == "0" ]]; then
   echo "*** ✅ API healthy ***"
 else
   echo "*** ⚠️ API _not_ healthy ***"
   echo "Unhealthy services:"
-  echo "${response}"  | jq -r '[.services | .[] | select(.status!="OK")]'
+  jq -r '[.services | .[] | select(.status!="OK")]' < "$api_response_file"
   exit 1
 fi