From 6618a6baf4c9d7eb1c6c3157febc56cf89263a95 Mon Sep 17 00:00:00 2001
From: Hampus <hampus@fluxer.com>
Date: Mon, 5 Oct 2026 21:50:16 +0200
Subject: [PATCH] fix(installer): replace a stale installer before upgrading
 (#3235)

---
 fluxer_docs/scripts/VerifyDocsCoverage.ts     |  1 +
 .../src/content/docs/operator/upgrading.mdx   |  2 +
 fluxer_docs/src/installer/install.ps1         | 75 ++++++++++++++++
 fluxer_docs/src/installer/install.sh          | 85 +++++++++++++++++++
 4 files changed, 163 insertions(+)

diff --git a/fluxer_docs/scripts/VerifyDocsCoverage.ts b/fluxer_docs/scripts/VerifyDocsCoverage.ts
index 0c11b0247..7ab185239 100644
--- a/fluxer_docs/scripts/VerifyDocsCoverage.ts
+++ b/fluxer_docs/scripts/VerifyDocsCoverage.ts
@@ -2198,6 +2198,7 @@ async function verifyInstallerExecution(installerRoot: string): Promise<Array<st
 				env: {
 					...process.env,
 					PATH: `${stubBin}${path.delimiter}${process.env.PATH ?? ''}`,
+					FLUXER_INSTALLER_REFRESHED: '1',
 					...(cwd == null ? {} : {PWD: cwd}),
 				},
 			});
diff --git a/fluxer_docs/src/content/docs/operator/upgrading.mdx b/fluxer_docs/src/content/docs/operator/upgrading.mdx
index 1984b331f..494163ce4 100644
--- a/fluxer_docs/src/content/docs/operator/upgrading.mdx
+++ b/fluxer_docs/src/content/docs/operator/upgrading.mdx
@@ -128,6 +128,8 @@ Removing the line from `.env` also lets the upgrade run, and it is the wrong fix
 
 Keep the installer beside the stack files. [Get started](/operator/get-started/#step-4-bring-up-the-instance) has the download and the checksum check for a fresh copy.
 
+`--update` first compares the installer against the digest at `https://fluxer.dev/install.sh.sha256`. When the copy differs, it downloads the current one, checks it against that digest, and asks before it replaces the copy and runs it with the same options. Answering no, `--non-interactive`, or a run without a terminal stops before anything changes. On Windows the same check reads `https://fluxer.dev/install.ps1.sha256`.
+
 See the plan first:
 
 ```bash
diff --git a/fluxer_docs/src/installer/install.ps1 b/fluxer_docs/src/installer/install.ps1
index 262dd7a70..35197e8b5 100644
--- a/fluxer_docs/src/installer/install.ps1
+++ b/fluxer_docs/src/installer/install.ps1
@@ -59,11 +59,17 @@ param(
 	[string[]]$Rest = @()
 )
 
+$FluxerScriptArguments = @{}
+foreach ($entry in $PSBoundParameters.GetEnumerator()) {
+	$FluxerScriptArguments[$entry.Key] = $entry.Value
+}
+
 Set-StrictMode -Version Latest
 $ErrorActionPreference = 'Stop'
 $ProgressPreference = 'SilentlyContinue'
 
 $FluxerRawBase = 'https://raw.githubusercontent.com/fluxerapp/fluxer'
+$FluxerInstallerUrl = 'https://fluxer.dev/install.ps1'
 $FluxerStackPath = 'deploy/self-hosting'
 $FluxerHealthPath = '/_health'
 $FluxerInitService = 'seaweedfs-init'
@@ -1980,6 +1986,71 @@ function Assert-FluxerComposeFiles([string]$TargetDir, [string]$EnvPath) {
 	}
 }
 
+function Get-FluxerSha256([string]$Path) {
+	return (Get-FileHash -LiteralPath $Path -Algorithm SHA256).Hash.ToLowerInvariant()
+}
+
+function Update-FluxerInstaller {
+	if ($env:FLUXER_INSTALLER_REFRESHED) {
+		return
+	}
+	$self = $PSCommandPath
+	if (-not $self) {
+		return
+	}
+	$selfDir = Split-Path -Parent $self
+	if ($DryRun) {
+		$staging = New-FluxerStagingDirectory ([System.IO.Path]::GetTempPath())
+	} else {
+		$staging = New-FluxerStagingDirectory $selfDir
+	}
+	try {
+		$digestPath = Join-Path $staging 'install.ps1.sha256'
+		try {
+			Invoke-WebRequest -Uri "$FluxerInstallerUrl.sha256" -OutFile $digestPath -UseBasicParsing -MaximumRedirection 5 -TimeoutSec 60
+		} catch {
+			Write-FluxerLine "Could not reach $FluxerInstallerUrl.sha256, so this run goes on with $self."
+			return
+		}
+		$published = ([System.IO.File]::ReadAllText($digestPath).Trim() -split '\s+')[0].ToLowerInvariant()
+		if ($published -notmatch '^[0-9a-f]{64}$') {
+			Stop-Fluxer "$FluxerInstallerUrl.sha256 holds no sha256 digest. Nothing was changed." $FluxerExitDownload
+		}
+		if ((Get-FluxerSha256 $self) -eq $published) {
+			return
+		}
+		$fresh = Join-Path $staging 'install.ps1'
+		try {
+			Invoke-WebRequest -Uri $FluxerInstallerUrl -OutFile $fresh -UseBasicParsing -MaximumRedirection 5 -TimeoutSec 120
+		} catch {
+			Stop-Fluxer "Download failed for $FluxerInstallerUrl. Nothing was changed." $FluxerExitDownload
+		}
+		if ((Get-FluxerSha256 $fresh) -ne $published) {
+			Stop-Fluxer "$FluxerInstallerUrl does not match the digest in $FluxerInstallerUrl.sha256. Nothing was changed." $FluxerExitDownload
+		}
+		Write-FluxerLine "$self differs from the installer $FluxerInstallerUrl serves. The stack files an upgrade downloads can require .env keys that only the current installer writes."
+		if ($DryRun) {
+			Write-FluxerLine 'The run asks to replace it with the current installer before it changes anything. The plan below is the one this copy would follow.'
+			return
+		}
+		if ($NonInteractive -or [Console]::IsInputRedirected) {
+			Stop-Fluxer "Nothing was changed. Download the current installer and run it:`n  Invoke-WebRequest -Uri $FluxerInstallerUrl -OutFile install.ps1 -UseBasicParsing" $FluxerExitRefused
+		}
+		$answer = Read-Host -Prompt "Replace $self with the current installer and run that? [y/N]"
+		if ($null -eq $answer -or $answer.Trim() -notmatch '^(y|yes)$') {
+			Stop-Fluxer "Kept $self. Nothing was changed. Read the current installer at $FluxerInstallerUrl and run it once it is in place." $FluxerExitRefused
+		}
+		Move-Item -LiteralPath $fresh -Destination $self -Force
+	} finally {
+		Remove-FluxerStagingDirectory $staging
+	}
+	Write-FluxerLine "Replaced $self. Running it."
+	$env:FLUXER_INSTALLER_REFRESHED = '1'
+	$global:LASTEXITCODE = 0
+	& $self @FluxerScriptArguments
+	exit $LASTEXITCODE
+}
+
 function Invoke-FluxerInstall {
 	if ($Help) {
 		Show-FluxerUsage
@@ -2022,6 +2093,10 @@ function Invoke-FluxerInstall {
 
 	Invoke-FluxerPreflight
 
+	if ($Update) {
+		Update-FluxerInstaller
+	}
+
 	$targetPath = $Dir
 	$adoptedCwd = $false
 	$fellBack = $false
diff --git a/fluxer_docs/src/installer/install.sh b/fluxer_docs/src/installer/install.sh
index 74ab1a5b5..32d53feaf 100644
--- a/fluxer_docs/src/installer/install.sh
+++ b/fluxer_docs/src/installer/install.sh
@@ -51,6 +51,7 @@ LC_ALL=C
 export LC_ALL
 
 FLUXER_RAW_BASE='https://raw.githubusercontent.com/fluxerapp/fluxer'
+FLUXER_INSTALLER_URL='https://fluxer.dev/install.sh'
 FLUXER_STACK_PATH='deploy/self-hosting'
 FLUXER_MIN_ENGINE='24.0.0'
 # Podman numbers its releases on its own scale, so the Docker Engine floor says
@@ -305,6 +306,18 @@ opt_no_volume_compression=0
 opt_skip_backup=0
 opt_allow_root=0
 
+fluxer_self=''
+if [ -f "$0" ]; then
+	case $0 in
+		/*) fluxer_self=$0 ;;
+		*) fluxer_self="$(pwd)/$0" ;;
+	esac
+fi
+fluxer_self_args=''
+for fluxer_arg in "$@"; do
+	fluxer_self_args="$fluxer_self_args '$(printf '%s' "$fluxer_arg" | sed "s/'/'\\\\''/g")'"
+done
+
 while [ $# -gt 0 ]; do
 	case $1 in
 		--domain)
@@ -651,6 +664,74 @@ fluxer_prompt() {
 	return 1
 }
 
+fluxer_sha256() {
+	openssl dgst -sha256 < "$1" | awk '{print $NF}'
+}
+
+fluxer_drop_scratch() {
+	fluxer_cleanup
+	fluxer_scratch=''
+}
+
+fluxer_refresh_installer() {
+	[ -z "${FLUXER_INSTALLER_REFRESHED:-}" ] || return 0
+	[ -n "$fluxer_self" ] || return 0
+	fluxer_self_dir=$(dirname "$fluxer_self")
+	if [ "$opt_dry_run" -eq 1 ]; then
+		fluxer_open_scratch "${TMPDIR:-/tmp}"
+	elif [ -w "$fluxer_self_dir" ]; then
+		fluxer_open_scratch "$fluxer_self_dir"
+	else
+		fluxer_say "$fluxer_self_dir is not writable, so this run cannot check $fluxer_self against $FLUXER_INSTALLER_URL and goes on with it."
+		return 0
+	fi
+	if ! curl -fsSL --proto '=https' --tlsv1.2 -o "$fluxer_scratch/install.sh.sha256" "$FLUXER_INSTALLER_URL.sha256"; then
+		fluxer_say "Could not reach $FLUXER_INSTALLER_URL.sha256, so this run goes on with $fluxer_self."
+		fluxer_drop_scratch
+		return 0
+	fi
+	fluxer_published=$(awk 'NR == 1 {print $1}' "$fluxer_scratch/install.sh.sha256")
+	case $fluxer_published in
+		''|*[!0-9a-f]*) fluxer_fail 4 "$FLUXER_INSTALLER_URL.sha256 holds no sha256 digest. Nothing was changed." ;;
+	esac
+	if [ "$(fluxer_sha256 "$fluxer_self")" = "$fluxer_published" ]; then
+		fluxer_drop_scratch
+		return 0
+	fi
+	if ! curl -fsSL --proto '=https' --tlsv1.2 -o "$fluxer_scratch/install.sh" "$FLUXER_INSTALLER_URL"; then
+		fluxer_fail 4 "Download failed for $FLUXER_INSTALLER_URL. Nothing was changed."
+	fi
+	if [ "$(fluxer_sha256 "$fluxer_scratch/install.sh")" != "$fluxer_published" ]; then
+		fluxer_fail 4 "$FLUXER_INSTALLER_URL does not match the digest in $FLUXER_INSTALLER_URL.sha256. Nothing was changed."
+	fi
+	fluxer_say "$fluxer_self differs from the installer $FLUXER_INSTALLER_URL serves. The stack files an upgrade downloads can require .env keys that only the current installer writes."
+	if [ "$opt_dry_run" -eq 1 ]; then
+		fluxer_say 'The run asks to replace it with the current installer before it changes anything. The plan below is the one this copy would follow.'
+		fluxer_drop_scratch
+		return 0
+	fi
+	if [ "$opt_non_interactive" -eq 1 ] || [ ! -t 0 ]; then
+		fluxer_fail 3 "Nothing was changed. Download the current installer and run it:
+  curl -fsSLO $FLUXER_INSTALLER_URL"
+	fi
+	printf 'Replace %s with the current installer and run that? [y/N] ' "$fluxer_self" >&2
+	fluxer_answer=''
+	read -r fluxer_answer || true
+	case $fluxer_answer in
+		y|Y|yes|Yes|YES) ;;
+		*) fluxer_fail 3 "Kept $fluxer_self. Nothing was changed. Read the current installer at $FLUXER_INSTALLER_URL and run it once it is in place." ;;
+	esac
+	if [ -x "$fluxer_self" ]; then
+		chmod +x "$fluxer_scratch/install.sh"
+	fi
+	mv "$fluxer_scratch/install.sh" "$fluxer_self"
+	fluxer_drop_scratch
+	fluxer_say "Replaced $fluxer_self. Running it."
+	FLUXER_INSTALLER_REFRESHED=1
+	export FLUXER_INSTALLER_REFRESHED
+	eval "exec sh \"\$fluxer_self\" $fluxer_self_args"
+}
+
 fluxer_resolve_values() {
 	if [ "$opt_update" -eq 1 ] || [ "$opt_rollback" -eq 1 ]; then
 		return 0
@@ -2100,6 +2181,10 @@ fluxer_preflight
 fluxer_validate_options
 fluxer_resolve_values
 
+if [ "$opt_update" -eq 1 ]; then
+	fluxer_refresh_installer
+fi
+
 if [ "$opt_update" -eq 1 ] || [ "$opt_rollback" -eq 1 ]; then
 	fluxer_require_instance
 	fluxer_resolve_ref