Add `contrib/upgrade.sh` (#18286)

Adds an upgrade script that automates upgrading installations on Linux from binary releases, so people don't need to reinvent the wheel. Hopefully this leads to less questions about how to upgrade, and consequently less Gitea instances running unmaintained versions in the wild.

Co-authored-by: delvh <dev.lh@web.de>
Co-authored-by: Gusted <williamzijl7@hotmail.com>
Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: 6543 <6543@obermui.de>

contrib/upgrade.sh

@@ -0,0 +1,83 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# This is an update script for gitea installed via the binary distribution
+# 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]
+#   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=$giteahome/app.ini upgrade.sh
+
+# apply variables from environment
+: "${giteabin:="/usr/local/bin/gitea"}"
+: "${giteahome:="/var/lib/gitea"}"
+: "${giteaconf:="/etc/gitea/app.ini"}"
+: "${giteauser:="git"}"
+: "${sudocmd:="sudo"}"
+: "${arch:="linux-amd64"}"
+: "${backupopts:=""}" # see `gitea dump --help` for available options
+
+function giteacmd {
+  "$sudocmd" --user "$giteauser" "$giteabin" --config "$giteaconf" --work-path "$giteahome" "$@"
+}
+
+function require {
+  for exe in "$@"; do
+    command -v "$exe" &>/dev/null || (echo "missing dependency '$exe'"; exit 1)
+  done
+}
+require systemctl curl xz sha256sum gpg "$sudocmd"
+
+# select version to install
+if [[ -z "${1:-}" ]]; then
+  require jq
+  giteaversion=$(curl --connect-timeout 10 -sL https://dl.gitea.io/gitea/version.json | jq -r .latest.version)
+else
+  giteaversion="$1"
+fi
+
+# confirm update
+current=$(giteacmd --version | cut --delimiter=' ' --fields=3)
+[[ "$current" == "$giteaversion" ]] && echo "$current is already installed, stopping." && exit 1
+echo "Make sure to read the changelog first: https://github.com/go-gitea/gitea/blob/main/CHANGELOG.md"
+echo "Are you ready to update Gitea from ${current} to ${giteaversion}? (y/N)"
+read -r confirm
+[[ "$confirm" == "y" ]] || [[ "$confirm" == "Y" ]] || exit 1
+
+pushd "$(pwd)" &>/dev/null
+cd "$giteahome" # needed for gitea dump later
+
+# download new binary
+binname="gitea-${giteaversion}-${arch}"
+binurl="https://dl.gitea.io/gitea/${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)
+sha256sum --check "${binname}.xz.sha256"
+gpg --keyserver keys.openpgp.org --recv 7C9E68152594688862D62AF62D9AE806EC1592E2
+gpg --verify "${binname}.xz.asc" "${binname}.xz" || { echo 'Signature does not match'; exit 1; }
+rm "${binname}".xz.{sha256,asc}
+
+# unpack binary + make executable
+xz --decompress "${binname}.xz"
+chown "$giteauser" "$binname"
+chmod +x "$binname"
+
+# stop gitea, create backup, replace binary, restart gitea
+echo "Stopping gitea at $(date)"
+giteacmd manager flush-queues
+$sudocmd systemctl stop gitea
+echo "Creating backup in $giteahome"
+giteacmd dump $backupopts
+echo "Updating binary at $giteabin"
+mv --force --backup "$binname" "$giteabin"
+$sudocmd systemctl start gitea
+$sudocmd systemctl status gitea
+
+popd

docs/content/doc/upgrade/from-gitea.en-us.md

@@ -76,6 +76,8 @@ a snapshot for the Gitea data volume and related object storage is more convenie
 * Replace the installed Gitea binary with the downloaded one. 
 * Start the Gitea instance.
 
+A script automating these steps for a deployment on Linux can be found at [`contrib/upgrade.sh` in Gitea's source tree](https://github.com/go-gitea/gitea/blob/main/contrib/upgrade.sh).
+
 ## Take care about customized templates
 
 Gitea's template structure and variables may change between releases, if you are using customized templates,