Fix `contrib/upgrade.sh` (#19222)

* fix idempotency of script (eg when aborting the downloads)
* improve readability (user facing variables first, definitions next, statements last)
* improve dependency checks
* fix ignored $giteaversion variable
* more logging
* print usage string on incorrect usage

contrib/upgrade.sh

@@ -3,26 +3,32 @@
 # from dl.gitea.io on linux as systemd service. It performs a backup and updates
 # Gitea in place.
 # NOTE: This adds the GPG Signing Key of the Gitea maintainers to the keyring.
-# Depends on: bash, curl, xz, sha256sum, gpg. optionally jq.
-# Usage:      [environment vars] upgrade.sh [version]
+# Depends on: bash, curl, xz, sha256sum. optionally jq, gpg
 #   See section below for available environment vars.
 #   When no version is specified, updates to the latest release.
 # Examples:
 #   upgrade.sh 1.15.10
 #   giteahome=/opt/gitea giteaconf=$giteahome/app.ini upgrade.sh
 
-while true; do
-  case "$1" in
-    -v | --version ) ver="$2"; shift 2 ;;
-    -y | --yes ) no_confirm="yes"; shift ;;
-    --ignore-gpg) ignore_gpg="yes"; shift ;;
-    -- ) shift; break ;;
-    * ) break ;;
-  esac
-done
-
-set -euo pipefail
+# apply variables from environment
+: "${giteabin:="/usr/local/bin/gitea"}"
+: "${giteahome:="/var/lib/gitea"}"
+: "${giteaconf:="/etc/gitea/app.ini"}"
+: "${giteauser:="git"}"
+: "${sudocmd:="sudo"}"
+: "${arch:="linux-amd64"}"
+: "${service_start:="$sudocmd systemctl start gitea"}"
+: "${service_stop:="$sudocmd systemctl stop gitea"}"
+: "${service_status:="$sudocmd systemctl status gitea"}"
+: "${backupopts:=""}" # see `gitea dump --help` for available options
 
+function giteacmd {
+  if [[ $sudocmd = "su" ]]; then
+    "$sudocmd" - "$giteauser" -c "$giteabin" --config "$giteaconf" --work-path "$giteahome" "$@"
+  else
+    "$sudocmd" --user "$giteauser" "$giteabin" --config "$giteaconf" --work-path "$giteahome" "$@"
+  fi
+}
 
 function require {
   for exe in "$@"; do
@@ -30,8 +36,19 @@ function require {
   done
 }
 
+# parse command line arguments
+while true; do
+  case "$1" in
+    -v | --version ) giteaversion="$2"; shift 2 ;;
+    -y | --yes ) no_confirm="yes"; shift ;;
+    --ignore-gpg) ignore_gpg="yes"; shift ;;
+    "" | -- ) shift; break ;;
+    * ) echo "Usage:  [<environment vars>] upgrade.sh [-v <version>] [-y] [--ignore-gpg]"; exit 1;; 
+  esac
+done
 
-require curl xz sha256sum gpg
+# exit once any command fails. this means that each step should be idempotent!
+set -euo pipefail
 
 if [[ -f /etc/os-release ]]; then
   os_release=$(cat /etc/os-release)
@@ -46,38 +63,17 @@ if [[ -f /etc/os-release ]]; then
   fi
 fi
 
-
-# apply variables from environment
-: "${giteabin:="/usr/local/bin/gitea"}"
-: "${giteahome:="/var/lib/gitea"}"
-: "${giteaconf:="/etc/gitea/app.ini"}"
-: "${giteauser:="git"}"
-: "${sudocmd:="sudo"}"
-: "${arch:="linux-amd64"}"
-: "${service_start:="$sudocmd systemctl start gitea"}"
-: "${service_stop:="$sudocmd systemctl stop gitea"}"
-: "${service_status:="$sudocmd systemctl status gitea"}"
-: "${backupopts:=""}" # see `gitea dump --help` for available options
-
-
-function giteacmd {
-  if [[ $sudocmd = "su" ]]; then
-    "$sudocmd" - "$giteauser" -c "$giteabin" --config "$giteaconf" --work-path "$giteahome" "$@"
-  else
-    "$sudocmd" --user "$giteauser" "$giteabin" --config "$giteaconf" --work-path "$giteahome" "$@"
-  fi
-}
+require curl xz sha256sum "$sudocmd"
 
 # select version to install
-if [[ -z "${ver:-}" ]]; then
+if [[ -z "${giteaversion:-}" ]]; then
   require jq
   giteaversion=$(curl --connect-timeout 10 -sL https://dl.gitea.io/gitea/version.json | jq -r .latest.version)
-else
-  giteaversion="$ver"
+  echo "Latest available version is $giteaversion"
 fi
 
-
 # confirm update
+echo "Checking currently installed version..."
 current=$(giteacmd --version | cut -d ' ' -f 3)
 [[ "$current" == "$giteaversion" ]] && echo "$current is already installed, stopping." && exit 1
 if [[ -z "${no_confirm:-}"  ]]; then
@@ -98,22 +94,24 @@ binurl="https://dl.gitea.io/gitea/${giteaversion}/${binname}.xz"
 echo "Downloading $binurl..."
 curl --connect-timeout 10 --silent --show-error --fail --location -O "$binurl{,.sha256,.asc}"
 
-# validate checksum & gpg signature (exit script if error)
+# validate checksum & gpg signature
 sha256sum -c "${binname}.xz.sha256"
 if [[ -z "${ignore_gpg:-}" ]]; then
+  require gpg
   gpg --keyserver keys.openpgp.org --recv 7C9E68152594688862D62AF62D9AE806EC1592E2
   gpg --verify "${binname}.xz.asc" "${binname}.xz" || { echo 'Signature does not match'; exit 1; }
 fi
 rm "${binname}".xz.{sha256,asc}
 
 # unpack binary + make executable
-xz --decompress "${binname}.xz"
+xz --decompress --force "${binname}.xz"
 chown "$giteauser" "$binname"
 chmod +x "$binname"
 
 # stop gitea, create backup, replace binary, restart gitea
-echo "Stopping gitea at $(date)"
+echo "Flushing gitea queues at $(date)"
 giteacmd manager flush-queues
+echo "Stopping gitea at $(date)"
 $service_stop
 echo "Creating backup in $giteahome"
 giteacmd dump $backupopts