From c1125dc9b890ba118abc5db20ef4a879dcd04a29 Mon Sep 17 00:00:00 2001
From: Christian Kotte <christian.kotte@gmx.de>
Date: Mon, 13 Jul 2020 13:03:01 +0200
Subject: [PATCH] Add variable/option to control if zeros are written to the
 disk

It takes some time to write zeros to the disk and it aborts later if
less than 20GB are available.

Add variable to the template, cleanup script and add a new option to
wrapacker.
---
 arch-template.json |  3 ++-
 scripts/cleanup.sh | 12 +++++++-----
 wrapacker          | 19 ++++++++++++++++++-
 3 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/arch-template.json b/arch-template.json
index a34799a..ff74f8b 100644
--- a/arch-template.json
+++ b/arch-template.json
@@ -4,6 +4,7 @@
         "iso_checksum_url": "https://mirrors.kernel.org/archlinux/iso/{{isotime \"2006.01\"}}.01/sha1sums.txt",
         "ssh_timeout": "20m",
         "country": "US",
+        "write_zeros": "true",
         "headless": "false"
     },
     "builders": [
@@ -124,7 +125,7 @@
         },
         {
             "type": "shell",
-            "execute_command": "{{ .Vars }} sudo -E -S bash '{{ .Path }}'",
+            "execute_command": "{{ .Vars }} WRITE_ZEROS={{ user `write_zeros` }} sudo -E -S bash '{{ .Path }}'",
             "script": "scripts/cleanup.sh"
         }
     ],
diff --git a/scripts/cleanup.sh b/scripts/cleanup.sh
index 7227397..967c505 100755
--- a/scripts/cleanup.sh
+++ b/scripts/cleanup.sh
@@ -5,8 +5,10 @@ echo ">>>> cleanup.sh: Cleaning pacman cache.."
 /usr/bin/pacman -Scc --noconfirm
 
 # Write zeros to improve virtual disk compaction.
-echo ">>>> cleanup.sh: Writing zeros to improve virtual disk compaction.."
-zerofile=$(/usr/bin/mktemp /zerofile.XXXXX)
-/usr/bin/dd if=/dev/zero of="$zerofile" bs=1M
-/usr/bin/rm -f "$zerofile"
-/usr/bin/sync
+if [[ $WRITE_ZEROS == "true" ]]; then
+  echo ">>>> cleanup.sh: Writing zeros to improve virtual disk compaction.."
+  zerofile=$(/usr/bin/mktemp /zerofile.XXXXX)
+  /usr/bin/dd if=/dev/zero of="$zerofile" bs=1M
+  /usr/bin/rm -f "$zerofile"
+  /usr/bin/sync
+fi
diff --git a/wrapacker b/wrapacker
index 23e50f2..6ae77a5 100755
--- a/wrapacker
+++ b/wrapacker
@@ -64,7 +64,7 @@ validate_country() {
 # print this script's usage message to stderr
 usage() {
   cat <<-EOF >&2
-  usage: wrapacker [-c COUNTRY] [-p PROVIDER] [-t TIMEOUT] [-o ON-ERROR ACTION] [-f] [-d] [-h]
+  usage: wrapacker [-c COUNTRY] [-p PROVIDER] [-t TIMEOUT] [-w] [-o ON-ERROR ACTION] [-f] [-d] [-h]
 EOF
 }
 
@@ -129,6 +129,9 @@ help() {
               sets the amount of time packer will wait for trying ssh login;
               defaults to 20m
 
+       -w, --skip-write-zeros
+              don't inflate the disk to improve virtual disk compaction
+
        -o, --on-error=ACTION
               error handling if the build fails;
               defaults to cleanup
@@ -165,6 +168,7 @@ country=''
 provider=''
 dry_run=false
 timeout=''
+skip_write_zeros=false
 on_error=''
 force=false
 headless=false
@@ -193,6 +197,9 @@ while [[ $1 != '' ]]; do
     --timeout=*)
       timeout=${1#*=}
       ;;
+    -w | --skip-write-zeros)
+      skip_write_zeros=true
+      ;;
     -o | --on-error)
       on_error=$2
       shift
@@ -288,6 +295,12 @@ else
   SSH_TIMEOUT='20m'
 fi
 
+if [[ $skip_write_zeros = true ]]; then
+  WRITE_ZEROS="false"
+else
+  WRITE_ZEROS="true"
+fi
+
 if [[ $on_error ]]; then
   case $(echo "$on_error" | tr '[:upper:]' '[:lower:]') in
     cleanup)
@@ -320,6 +333,7 @@ cat <<-EOF
     -var "ssh_timeout=$SSH_TIMEOUT" \\
     -var "country=$country" \\
     -var "headless=$headless" \\
+    -var "write_zeros=$WRITE_ZEROS" \\
     -on-error=$ON_ERROR \\
     -force \\
     arch-template.json
@@ -333,6 +347,7 @@ cat <<-EOF
     -var "ssh_timeout=$SSH_TIMEOUT" \\
     -var "country=$country" \\
     -var "headless=$headless" \\
+    -var "write_zeros=$WRITE_ZEROS" \\
     -on-error=$ON_ERROR \\
     arch-template.json
 EOF
@@ -346,6 +361,7 @@ else
       -var "ssh_timeout=$SSH_TIMEOUT" \
       -var "country=$country" \
       -var "headless=$headless" \
+      -var "write_zeros=$WRITE_ZEROS" \
       -on-error=$ON_ERROR \
       -force \
       arch-template.json
@@ -357,6 +373,7 @@ else
       -var "ssh_timeout=$SSH_TIMEOUT" \
       -var "country=$country" \
       -var "headless=$headless" \
+      -var "write_zeros=$WRITE_ZEROS" \
       -on-error=$ON_ERROR \
       arch-template.json
   fi