Fail if unsupported environment variables are set

This commit adds a hard failure on startup if any unsupported
environment variables from older versions of Elasticsearch are still
set.

distribution/src/main/resources/bin/elasticsearch

@@ -54,6 +54,33 @@ EOF
     exit 1
 fi
 
+# TODO: remove for Elasticsearch 6.x
+unsupported_environment_variable() {
+    if [ ! -z "$1" ]; then
+        echo "$2=$1"
+    fi
+}
+
+if [[ !(-z "$ES_MIN_MEM" &&
+        -z "$ES_MAX_MEM" &&
+        -z "$ES_HEAP_SIZE" &&
+        -z "$ES_HEAP_NEWSIZE" &&
+        -z "$ES_DIRECT_SIZE" &&
+        -z "$ES_USE_IPV4" &&
+        -z "$ES_GC_OPTS") ]]; then
+    echo "Error: encountered environment variables that are no longer supported"
+    echo "Use jvm.options or ES_JAVA_OPTS to configure the JVM"
+    unsupported_environment_variable "$ES_MIN_MEM" ES_MIN_MEM
+    unsupported_environment_variable "$ES_MAX_MEM" ES_MAX_MEM
+    unsupported_environment_variable "$ES_HEAP_SIZE" ES_HEAP_SIZE
+    unsupported_environment_variable "$ES_HEAP_NEWSIZE" ES_HEAP_NEWSIZE
+    unsupported_environment_variable "$ES_DIRECT_SIZE" ES_DIRECT_SIZE
+    unsupported_environment_variable "$ES_USE_IPV4" ES_USE_IPV4
+    unsupported_environment_variable "$ES_GC_OPTS" ES_GC_OPTS
+    exit 1
+fi
+# end TODO: remove for Elasticsearch 6.x
+
 parse_jvm_options() {
   if [ -f "$1" ]; then
     echo "$(grep "^-" "$1" | tr '\n' ' ')"

distribution/src/main/resources/bin/elasticsearch.bat

@@ -5,6 +5,28 @@ TITLE Elasticsearch ${project.version}
 
 SET params='%*'
 
+rem TODO: remove for Elasticsearch 6.x
+if not "%ES_MIN_MEM%" == "" set bad_env_var=1
+if not "%ES_MAX_MEM%" == "" set bad_env_var=1
+if not "%ES_HEAP_SIZE%" == "" set bad_env_var=1
+if not "%ES_HEAP_NEWSIZE%" == "" set bad_env_var=1
+if not "%ES_DIRECT_SIZE%" == "" set bad_env_var=1
+if not "%ES_USE_IPV4%" == "" set bad_env_var=1
+if not "%ES_GC_OPTS%" == "" set bad_env_var=1
+if %bad_env_var% == 1 (
+    echo Error: encountered environment variables that are no longer supported
+    echo Use jvm.options or ES_JAVA_OPTS to configure the JVM
+    if not "%ES_MIN_MEM%" == "" echo ES_MIN_MEM=%ES_MIN_MEM%
+    if not "%ES_MAX_MEM%" == "" echo ES_MAX_MEM=%ES_MAX_MEM%
+    if not "%ES_HEAP_SIZE%" == "" echo ES_HEAP_SIZE=%ES_HEAP_SIZE%
+    if not "%ES_HEAP_NEWSIZE%" == "" echo ES_HEAP_NEWSIZE=%ES_HEAP_NEWSIZE%
+    if not "%ES_DIRECT_SIZE%" == "" echo ES_DIRECT_SIZE=%ES_DIRECT_SIZE%
+    if not "%ES_USE_IPV4%" == "" echo ES_USE_IPV4=%ES_USE_IPV4%
+    if not "%ES_GC_OPTS%" == "" echo ES_GC_OPTS=%ES_GC_OPTS%
+    exit /b 1
+)
+rem end TODO: remove for Elasticsearch 6.x
+
 :loop
 FOR /F "usebackq tokens=1* delims= " %%A IN (!params!) DO (
     SET current=%%A

distribution/src/main/resources/bin/service.bat

@@ -3,6 +3,28 @@ SETLOCAL enabledelayedexpansion
 
 TITLE Elasticsearch Service ${project.version}
 
+rem TODO: remove for Elasticsearch 6.x
+if not "%ES_MIN_MEM%" == "" set bad_env_var=1
+if not "%ES_MAX_MEM%" == "" set bad_env_var=1
+if not "%ES_HEAP_SIZE%" == "" set bad_env_var=1
+if not "%ES_HEAP_NEWSIZE%" == "" set bad_env_var=1
+if not "%ES_DIRECT_SIZE%" == "" set bad_env_var=1
+if not "%ES_USE_IPV4%" == "" set bad_env_var=1
+if not "%ES_GC_OPTS%" == "" set bad_env_var=1
+if %bad_env_var% == 1 (
+    echo Error: encountered environment variables that are no longer supported
+    echo Use jvm.options or ES_JAVA_OPTS to configure the JVM
+    if not "%ES_MIN_MEM%" == "" echo ES_MIN_MEM=%ES_MIN_MEM%
+    if not "%ES_MAX_MEM%" == "" echo ES_MAX_MEM=%ES_MAX_MEM%
+    if not "%ES_HEAP_SIZE%" == "" echo ES_HEAP_SIZE=%ES_HEAP_SIZE%
+    if not "%ES_HEAP_NEWSIZE%" == "" echo ES_HEAP_NEWSIZE=%ES_HEAP_NEWSIZE%
+    if not "%ES_DIRECT_SIZE%" == "" echo ES_DIRECT_SIZE=%ES_DIRECT_SIZE%
+    if not "%ES_USE_IPV4%" == "" echo ES_USE_IPV4=%ES_USE_IPV4%
+    if not "%ES_GC_OPTS%" == "" echo ES_GC_OPTS=%ES_GC_OPTS%
+    exit /b 1
+)
+rem end TODO: remove for Elasticsearch 6.x
+
 if NOT DEFINED JAVA_HOME goto err
 
 if not "%CONF_FILE%" == "" goto conffileset