From d94ff9a8d1b05800c6a92ad790b95aab7379c728 Mon Sep 17 00:00:00 2001
From: Jason Wallace <jdeanwallace@gmail.com>
Date: Fri, 23 Jun 2023 19:27:47 +0200
Subject: [PATCH] Place temporary install files within RAMdisk (#1464)

Resolves https://github.com/tiny-pilot/tinypilot/issues/1462

You can test this PR's install script and bundle via:
```bash
curl \
  --silent \
  --show-error \
  https://raw.githubusercontent.com/tiny-pilot/tinypilot/aca37b26108c7fc7fc24fad48890734859fe9221/get-tinypilot.sh | \
    bash -
```


<a data-ca-tag
href="https://codeapprove.com/pr/tiny-pilot/tinypilot/1464"><img
src="https://codeapprove.com/external/github-tag-allbg.png" alt="Review
on CodeApprove" /></a>

---------

Co-authored-by: Michael Lynch <git@mtlynch.io>
---
 bundler/bundle/install |  7 +------
 get-tinypilot.sh       | 20 +++++++++++++++++---
 scripts/install-bundle | 16 ++++++++++++++--
 3 files changed, 32 insertions(+), 11 deletions(-)

diff --git a/bundler/bundle/install b/bundler/bundle/install
index cf268db83..618855700 100755
--- a/bundler/bundle/install
+++ b/bundler/bundle/install
@@ -14,13 +14,8 @@ set -x
 # shellcheck disable=SC1091 # Don’t follow sourced script.
 . lib.sh
 
-# HACK: If we let mktemp use the default /tmp directory, the system purges the
-# file before the end of the script for some reason. We use /var/tmp as a
-# workaround.
-readonly TEMP_DIR='/var/tmp'
-
 # Temporary file for installation settings.
-INSTALL_SETTINGS_FILE="$(mktemp --tmpdir="${TEMP_DIR}" --suffix .yml)"
+INSTALL_SETTINGS_FILE="$(mktemp --suffix .yml)"
 readonly INSTALL_SETTINGS_FILE
 
 # The eventual, permanent settings files. Note, that these might not exist
diff --git a/get-tinypilot.sh b/get-tinypilot.sh
index 58db4d47d..b1a2d7671 100755
--- a/get-tinypilot.sh
+++ b/get-tinypilot.sh
@@ -66,10 +66,11 @@ readonly LEGACY_INSTALLER_DIR='/opt/tinypilot-updater'
 # - The TinyPilot bundle archive
 # - The unpacked TinyPilot bundle archive, after running the bundle's `install`
 #     script
+# - About 50 MiB of temporary files
 # - At least a 20% safety margin
 # Use the following command to help you estimate a sensible size allocation:
 #   du --summarize --total --bytes "${INSTALLER_DIR}" "${BUNDLE_FILE}"
-readonly RAMDISK_SIZE_MIB=500
+readonly RAMDISK_SIZE_MIB=560
 
 AVAILABLE_MEMORY_MIB="$(free --mebi |
   grep --fixed-strings 'Mem:' |
@@ -111,10 +112,21 @@ if (( "${AVAILABLE_MEMORY_MIB}" >= "${RAMDISK_SIZE_MIB}" )); then
     --verbose
 else
   # Fall back to installing from disk.
-  INSTALLER_DIR="$(mktemp --directory)"
+  # HACK: If we let mktemp use the default /tmp directory, the system begins
+  # purging files before the end of the script for some reason. We use /var/tmp
+  # as a workaround.
+  INSTALLER_DIR="$(mktemp \
+    --tmpdir='/var/tmp' \
+    --directory)"
 fi
 readonly INSTALLER_DIR
 
+# Use a temporary directory within the installer directory so that we take
+# advantage of RAMdisk if we're using one.
+readonly TMPDIR="${INSTALLER_DIR}/tmp"
+export TMPDIR
+sudo mkdir "${TMPDIR}"
+
 readonly BUNDLE_FILE="${INSTALLER_DIR}/bundle.tgz"
 
 # Download tarball to RAMdisk.
@@ -147,6 +159,8 @@ fi
 
 # Run install.
 pushd "${INSTALLER_DIR}"
-sudo ./install
+sudo \
+  TMPDIR="${TMPDIR}" \
+  ./install
 
 } # Prevent the script from executing until the client downloads the full file.
diff --git a/scripts/install-bundle b/scripts/install-bundle
index e38d239f8..cd8a7561a 100755
--- a/scripts/install-bundle
+++ b/scripts/install-bundle
@@ -81,10 +81,11 @@ readonly LEGACY_INSTALLER_DIR='/opt/tinypilot-updater'
 # - The TinyPilot bundle archive
 # - The unpacked TinyPilot bundle archive, after running the bundle's `install`
 #     script
+# - About 50 MiB of temporary files
 # - At least a 20% safety margin
 # Use the following command to help you estimate a sensible size allocation:
 #   du --summarize --total --bytes "${INSTALLER_DIR}" "${BUNDLE_FILE}"
-readonly RAMDISK_SIZE_MIB=500
+readonly RAMDISK_SIZE_MIB=560
 
 AVAILABLE_MEMORY_MIB="$(free --mebi |
   grep --fixed-strings 'Mem:' |
@@ -126,10 +127,21 @@ if (( "${AVAILABLE_MEMORY_MIB}" >= "${RAMDISK_SIZE_MIB}" )); then
     --verbose
 else
   # Fall back to installing from disk.
-  INSTALLER_DIR="$(mktemp --directory)"
+  # HACK: If we let mktemp use the default /tmp directory, the system begins
+  # purging files before the end of the script for some reason. We use /var/tmp
+  # as a workaround.
+  INSTALLER_DIR="$(mktemp \
+    --tmpdir='/var/tmp' \
+    --directory)"
 fi
 readonly INSTALLER_DIR
 
+# Use a temporary directory within the installer directory so that we take
+# advantage of RAMdisk if we're using one.
+readonly TMPDIR="${INSTALLER_DIR}/tmp"
+export TMPDIR
+mkdir "${TMPDIR}"
+
 # Extract tarball to installer directory.
 tar \
   --gunzip \