Make installer work on any os/arch

Author: code-asher

install.sh

@@ -2,7 +2,7 @@
 set -eu
 
 # code-server's automatic install script.
-# See https://github.com/cdr/code-server/blob/main/docs/install
+# See https://coder.com/docs/code-server/v3.10.2/install
 
 usage() {
   arg0="$0"
@@ -48,24 +48,23 @@ Usage:
   --rsh <bin>
       Specifies the remote shell for remote installation. Defaults to ssh.
 
-- For Debian, Ubuntu and Raspbian it will install the latest deb package.
-- For Fedora, CentOS, RHEL and openSUSE it will install the latest rpm package.
-- For Arch Linux it will install the AUR package.
-- For any unrecognized Linux operating system it will install the latest standalone
-  release into ~/.local
+The detection method works as follows:
+  - Debian, Ubuntu, Raspbian: install the deb package from GitHub.
+  - Fedora, CentOS, RHEL, openSUSE: install the rpm package from GitHub.
+  - Arch Linux: install from the AUR (which pulls releases from GitHub).
+  - FreeBSD, Alpine: install from yarn/npm.
+  - macOS: install using Homebrew if installed otherwise install from GitHub.
+  - All others: install the release from GitHub.
 
-- For macOS it will install the Homebrew package.
-  - If Homebrew is not installed it will install the latest standalone release
-    into ~/.local
+We only build releases on GitHub for amd64 and arm64 on Linux and amd64 for
+macOS. When the detection method tries to pull a release from GitHub it will
+fall back to installing from npm when there is no matching release for the
+system's operating system and architecture.
 
-- For FreeBSD or Alpine, it will install the npm package with yarn or npm.
+The standalone method will force installion using GitHub releases. It will not
+fall back to npm so on architectures without pre-built releases this will error.
 
-- If ran on an architecture with no releases, it will install the
-  npm package with yarn or npm.
-  - We only have releases for amd64 and arm64 presently.
-  - The npm package builds the native modules on postinstall.
-
-It will cache all downloaded assets into ~/.cache/code-server
+The installer will cache all downloaded assets into ~/.cache/code-server
 
 More installation docs are at https://coder.com/docs/code-server/v3.10.2/install
 EOF
@@ -198,80 +197,63 @@ main() {
     return
   fi
 
-  VERSION="${VERSION-$(echo_latest_version)}"
   METHOD="${METHOD-detect}"
   if [ "$METHOD" != detect ] && [ "$METHOD" != standalone ]; then
     echoerr "Unknown install method \"$METHOD\""
     echoerr "Run with --help to see usage."
     exit 1
   fi
-  STANDALONE_INSTALL_PREFIX="${STANDALONE_INSTALL_PREFIX-$HOME/.local}"
 
-  OS="$(os)"
-  if [ ! "$OS" ]; then
-    echoerr "Unsupported OS $(uname)."
-    exit 1
-  fi
+  # These are used by the various install_* functions that make use of GitHub
+  # releases in order to download and unpack the right release.
+  CACHE_DIR=$(echo_cache_dir)
+  STANDALONE_INSTALL_PREFIX=${STANDALONE_INSTALL_PREFIX:-$HOME/.local}
+  VERSION=${VERSION:-$(echo_latest_version)}
+  OS=$(os)
+  ARCH=$(arch)
 
   distro_name
 
-  ARCH="$(arch)"
-  if [ ! "$ARCH" ]; then
-    if [ "$METHOD" = standalone ]; then
-      echoerr "No precompiled releases for $(uname -m)."
-      echoerr 'Please rerun without the "--method standalone" flag to install from npm.'
-      exit 1
-    fi
-    echoh "No precompiled releases for $(uname -m)."
-    install_npm
-    return
-  fi
-
-  if [ "$OS" = "freebsd" ]; then
-    if [ "$METHOD" = standalone ]; then
-      echoerr "No precompiled releases available for $OS."
-      echoerr 'Please rerun without the "--method standalone" flag to install from npm.'
-      exit 1
-    fi
-    echoh "No precompiled releases available for $OS."
-    install_npm
-    return
-  fi
-
-  if [ "$OS" = "linux" ] && [ "$(distro)" = "alpine" ]; then
-    if [ "$METHOD" = standalone ]; then
-      echoerr "No precompiled releases available for alpine."
-      echoerr 'Please rerun without the "--method standalone" flag to install from npm.'
+  # Standalone installs by pulling pre-built releases from GitHub.
+  if [ "$METHOD" = standalone ]; then
+    if has_standalone; then
+      install_standalone
+    else
+      echoerr "There are no standalone releases for $(arch)"
+      echoerr "Please try again without '--method standalone'"
       exit 1
     fi
-    echoh "No precompiled releases available for alpine."
-    install_npm
-    return
-  fi
-
-  CACHE_DIR="$(echo_cache_dir)"
-
-  if [ "$METHOD" = standalone ]; then
-    install_standalone
-    return
   fi
 
+  # Otherwise try using the system's package manager where possible.
   case "$(distro)" in
+    # macOS uses brew which should work for any architecture. Fall back to
+    # standalone/npm if brew is not installed.
     macos)
-      install_macos
-      ;;
-    debian)
-      install_deb
-      ;;
-    fedora | opensuse)
-      install_rpm
-      ;;
-    arch)
-      install_aur
+      if command_exists brew; then
+        install_brew
+      else
+        echoh "Homebrew not installed."
+        echoh "Falling back to standalone installation."
+        npm_fallback install_standalone
+      fi
       ;;
+    # The .deb and .rpm files are pulled from GitHub and we only have amd64 and
+    # arm64 there and need to fall back to npm otherwise.
+    debian) npm_fallback install_deb ;;
+    fedora | opensuse) npm_fallback install_rpm ;;
+    # Arch uses the AUR package which only supports amd64 and arm64 since it
+    # pulls releases from GitHub so we need to fall back to npm.
+    arch) npm_fallback install_aur ;;
+    # We don't have GitHub releases that work on Alpine or FreeBSD so we have no
+    # choice but to use npm here.
+    alpine | freebsd) install_npm ;;
+    # For anything else we'll try to install standalone but fall back to npm if
+    # we don't have releases for the architecture.
     *)
       echoh "Unsupported package manager."
-      install_standalone
+      echoh "Falling back to standalone installation."
+      npm_install install_standalone
       ;;
   esac
 }
@@ -326,19 +308,11 @@ fetch() {
   sh_c mv "$FILE.incomplete" "$FILE"
 }
 
-install_macos() {
-  if command_exists brew; then
-    echoh "Installing from Homebrew."
-    echoh
-
-    sh_c brew install code-server
-
-    return
-  fi
-
-  echoh "Homebrew not installed."
+install_brew() {
+  echoh "Installing from Homebrew."
+  echoh
 
-  install_standalone
+  sh_c brew install code-server
 }
 
 install_deb() {
@@ -434,22 +408,41 @@ install_npm() {
   exit 1
 }
 
-os() {
-  case "$(uname)" in
-    Linux)
-      echo linux
-      ;;
-    Darwin)
-      echo macos
-      ;;
-    FreeBSD)
-      echo freebsd
+# Run $1 if we have a standalone otherwise run install_npm.
+npm_fallback() {
+  if has_standalone; then
+    $1
+  else
+    echoh "No standalone releases for $(arch)."
+    echoh "Falling back to installation from npm."
+    install_npm
+  fi
+}
+
+# Determine if we have standalone releases on GitHub for the system's arch.
+has_standalone() {
+  case $(arch) in
+    amd64) return 0 ;;
+    # We only have amd64 for macOS.
+    arm64)
+      [ "$(distro)" != macos ]
+      return
       ;;
+    *) return 1 ;;
   esac
 }
 
-# distro prints the detected operating system including linux distros.
-# Also parses ID_LIKE for common distro bases.
+os() {
+  uname="$(uname)"
+  case $uname in
+    Linux) echo linux ;;
+    Darwin) echo macos ;;
+    FreeBSD) echo freebsd ;;
+    *) echo "$uname" ;;
+  esac
+}
+
+# Print the detected Linux distro, otherwise print the OS name.
 #
 # Example outputs:
 # - macos -> macos
@@ -486,7 +479,7 @@ distro() {
   fi
 }
 
-# os_name prints a pretty human readable name for the OS/Distro.
+# Print a human-readable name for the OS/distro.
 distro_name() {
   if [ "$(uname)" = "Darwin" ]; then
     echo "macOS v$(sw_vers -productVersion)"
@@ -506,16 +499,11 @@ distro_name() {
 }
 
 arch() {
-  case "$(uname -m)" in
-    aarch64)
-      echo arm64
-      ;;
-    x86_64)
-      echo amd64
-      ;;
-    amd64) # FreeBSD.
-      echo amd64
-      ;;
+  uname_m=$(uname -m)
+  case $uname_m in
+    aarch64) echo arm64 ;;
+    x86_64) echo amd64 ;;
+    *) echo "$uname_m" ;;
   esac
 }