From 4ebfe9a6464d981b77008e083d258b4b720c6838 Mon Sep 17 00:00:00 2001
From: Paul Schoenfelder <paulschoenfelder@gmail.com>
Date: Mon, 20 May 2019 15:22:27 -0400
Subject: [PATCH] Address #670 - Improvements to read-only support

---
 priv/libexec/erts.sh                       |  3 +++
 priv/templates/release_rc_exec.eex         | 12 +++++++++++-
 priv/templates/release_rc_main.eex         | 12 ------------
 priv/templates/release_rc_win_main.ps1.eex |  5 ++++-
 4 files changed, 18 insertions(+), 14 deletions(-)

diff --git a/priv/libexec/erts.sh b/priv/libexec/erts.sh
index 19c2cd16..651692e3 100755
--- a/priv/libexec/erts.sh
+++ b/priv/libexec/erts.sh
@@ -307,6 +307,9 @@ if __info="$(erl -noshell -eval 'io:format("~s~n~s~n", [code:root_dir(), erlang:
     ROOTDIR="$(echo "$__info" | head -n1)"
     export ERTS_VSN
     if [ -z "$ERTS_VSN" ]; then
+        if [ ! -f "${START_ERL_DATA}" ]; then
+            fail "Unable to boot release, missing start_erl.data at '"${START_ERL_DATA}"'"
+        fi
         # Update start_erl.data
         ERTS_VSN="$(echo "$__info" | tail -n1)"
         echo "$ERTS_VSN $REL_VSN" > "$START_ERL_DATA"
diff --git a/priv/templates/release_rc_exec.eex b/priv/templates/release_rc_exec.eex
index e643ec70..5573c7d5 100644
--- a/priv/templates/release_rc_exec.eex
+++ b/priv/templates/release_rc_exec.eex
@@ -7,13 +7,23 @@ unset CDPATH
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
 RELEASE_ROOT_DIR="$(cd "$SCRIPT_DIR/.." && pwd)"
 RELEASES_DIR="${RELEASE_ROOT_DIR}/releases"
+RELEASE_MUTABLE_DIR="${RELEASE_MUTABLE_DIR:-"${RELEASE_ROOT_DIR}/var"}"
+START_ERL_DATA="${RELEASE_MUTABLE_DIR}/start_erl.data"
 REL_NAME="${REL_NAME:-<%= release_name %>}"
-REL_VSN="${REL_VSN:-$(cut -d' ' -f2 "${RELEASES_DIR}"/start_erl.data)}"
+if [ ! -f "${START_ERL_DATA}" ]; then
+    cp "${RELEASES_DIR}/start_erl.data" "${START_ERL_DATA}"
+fi
+REL_VSN="${REL_VSN:-$(cut -d' ' -f2 "${START_ERL_DATA}")}"
+ERTS_VSN="${ERTS_VSN:-$(cut -d' ' -f1 "${START_ERL_DATA}")}"
+<%= if (include_erts == false or is_nil(erts_vsn)) do %>USE_HOST_ERTS=true<% end %>
 
 export RELEASE_ROOT_DIR
 export RELEASES_DIR
+export RELEASE_MUTABLE_DIR
+export START_ERL_DATA
 export REL_NAME
 export REL_VSN
+export ERTS_VSN
 export DEBUG_BOOT
 
 # Set DEBUG_BOOT to output verbose debugging info during execution
diff --git a/priv/templates/release_rc_main.eex b/priv/templates/release_rc_main.eex
index 917ac52b..b56d4d63 100644
--- a/priv/templates/release_rc_main.eex
+++ b/priv/templates/release_rc_main.eex
@@ -10,25 +10,13 @@ fi
 
 unset CDPATH
 
-# Name of the release
-REL_NAME="${REL_NAME:-<%= release_name %>}"
-# Current version of the release
-REL_VSN="${REL_VSN:-<%= release_version %>}"
 # Options passed to erl
 ERL_OPTS="${ERL_OPTS:-<%= release.profile.erl_opts %>}"
 # Environment variables for run_erl
 RUN_ERL_ENV="${RUN_ERL_ENV:-<%= release.profile.run_erl_env %>}"
-# Current version of ERTS being used
-<%= if (include_erts == false or is_nil(erts_vsn)) do %>USE_HOST_ERTS=true<% end %>
-# If this is not present/unset, it will be detected
-<%= if ((is_binary(include_erts) or include_erts) and not is_nil(erts_vsn)) do %>ERTS_VSN="${ERTS_VSN:-<%= erts_vsn %>}"<% end %>
 DISTILLERY_VSN="<%= Application.spec(:distillery, :vsn) %>"
-export REL_NAME
-export REL_VSN
 export ERL_OPTS
 export RUN_ERL_ENV
-export USE_HOST_ERTS
-export ERTS_VSN
 export DISTILLERY_VSN
 
 # If readlink has no -f option, or greadlink is not available,
diff --git a/priv/templates/release_rc_win_main.ps1.eex b/priv/templates/release_rc_win_main.ps1.eex
index 518b145f..5fd5ce08 100644
--- a/priv/templates/release_rc_win_main.ps1.eex
+++ b/priv/templates/release_rc_win_main.ps1.eex
@@ -87,7 +87,10 @@ if ($Env:RELEASE_MUTABLE_DIR -eq $null) {
 # be stored in. defaults to /log in the release root directory
 $Env:RUNNER_LOG_DIR = (join-path $Env:RELEASE_MUTABLE_DIR "log")
 # Path to start_erl.data
-$Env:START_ERL_DATA = (join-path $release_root_dir (join-path "releases" "start_erl.data"))
+$Env:START_ERL_DATA = (join-path $Env:RELEASE_MUTABLE_DIR "start_erl.data")
+if (-not (test-path $Env:START_ERL_DATA)) {
+    copy-item -Path (join-path $releases_dir "start_erl.data") -Destination $Env:START_ERL_DATA -Force
+}
 # Directory containing lifecycle hook scripts
 $Env:HOOKS_DIR = (join-path $Env:REL_DIR "hooks")
 # Allow override of where to read configuration from