Fix replace os vars functionality

The first run would correctly replace the environment
variables, however it would also overwrite the original
vm.args and sys.config thus preventing any further
substitution in subsequent runs.
Dev mode runs were also broken, all runs after the
first were required to also define the
RELX_REPLACE_OS_VARS variable in order not to
overwrite the current vm.args with the original one,
this prevented simply attaching to an already running
node that was started this way.

Add tests to exercise this functionality.

1 files changed, 34 insertions, 32 deletions

diff --git a/priv/templates/extended_bin b/priv/templates/extended_bin
index 7a9f0c7..e844e46 100755
--- a/priv/templates/extended_bin
+++ b/priv/templates/extended_bin
@@ -98,28 +98,6 @@ if [ -z "$VMARGS_PATH" ]; then
     fi
 fi
 
-orig_vmargs_path="$VMARGS_PATH.orig"
-if [ $RELX_REPLACE_OS_VARS ]; then
-    #Make sure we don't break dev mode by keeping the symbolic link to 
-    #the user's vm.args
-    if [ ! -L "$orig_vmargs_path" ]; then
-       #we're in copy mode, rename the vm.args file to vm.args.orig
-       mv "$VMARGS_PATH" "$orig_vmargs_path"
-    fi
-
-    awk '{while(match($0,"[$]{[^}]*}")) {var=substr($0,RSTART+2,RLENGTH -3);gsub("[$]{"var"}",ENVIRON[var])}}1' < "$orig_vmargs_path" > "$VMARGS_PATH"
- else
-    #We don't need to replace env. vars, just rename the
-    #symlink vm.args.orig to vm.args, and keep it as a
-    #symlink.
-    if [ -L "$orig_vmargs_path" ]; then
-       mv "$orig_vmargs_path" "$VMARGS_PATH" 
-    fi
-fi
-
-# Make sure log directory exists
-mkdir -p "$RUNNER_LOG_DIR"
-
 # Use $CWD/sys.config if exists, otherwise releases/VSN/sys.config
 if [ -z "$RELX_CONFIG_PATH" ]; then
     if [ -f "$RELEASE_ROOT_DIR/sys.config" ]; then
@@ -129,25 +107,49 @@ if [ -z "$RELX_CONFIG_PATH" ]; then
     fi
 fi
 
+orig_vmargs_path="$VMARGS_PATH.orig"
+if [ $RELX_REPLACE_OS_VARS ]; then
+    # if there is no vm.args.orig then make a copy of the
+    # the original vm.args
+    if [ ! -f "$orig_vmargs_path" ]; then
+       mv "$VMARGS_PATH" "$orig_vmargs_path"
+    fi
+
+    # apply the environment variable substitution to vm.args.orig
+    # the result is saved to vm.args
+    awk '{while(match($0,"[$]{[^}]*}")) {var=substr($0,RSTART+2,RLENGTH -3);gsub("[$]{"var"}",ENVIRON[var])}}1' < "$orig_vmargs_path" > "$VMARGS_PATH"
+else
+    # if a vm.args.orig is present this means that
+    # env variable substitution has occurred before
+    # so use the original
+    if [ -f "$orig_vmargs_path" ]; then
+       mv "$orig_vmargs_path" "$VMARGS_PATH"
+    fi
+fi
+
 orig_relx_config_path="$RELX_CONFIG_PATH.orig"
 if [ $RELX_REPLACE_OS_VARS ]; then
-    #Make sure we don't break dev mode by keeping the symbolic link to 
-    #the user's sys.config
-    if [ ! -L "$orig_relx_config_path" ]; then
-       #We're in copy mode, rename sys.config to sys.config.orig
+    # if there is no sys.config.orig then make a copy of the
+    # the original sys.config
+    if [ ! -f "$orig_relx_config_path" ]; then
        mv "$RELX_CONFIG_PATH" "$orig_relx_config_path"
     fi
 
+    # apply the environment variable substitution to sys.config.orig
+    # the result is saved to sys.config
     awk '{while(match($0,"[$]{[^}]*}")) {var=substr($0,RSTART+2,RLENGTH -3);gsub("[$]{"var"}",ENVIRON[var])}}1' < "$orig_relx_config_path" > "$RELX_CONFIG_PATH"
- else
-    #We don't need to replace env. vars, just rename the
-    #symlink sys.config.orig to sys.config. Keep it as 
-    #a symlink.
-    if [ -L "$orig_relx_config_path" ]; then
-       mv "$orig_relx_config_path"  "$RELX_CONFIG_PATH"
+else
+    # if a sys.config.orig is present this means that
+    # env variable substitution has occurred before
+    # so use the original
+    if [ -f "$orig_relx_config_path" ]; then
+       mv "$orig_relx_config_path" "$RELX_CONFIG_PATH"
     fi
 fi
 
+# Make sure log directory exists
+mkdir -p "$RUNNER_LOG_DIR"
+
 # Extract the target node name from node.args
 NAME_ARG=$(egrep '^-s?name' "$VMARGS_PATH" || true)
 if [ -z "$NAME_ARG" ]; then