feat: Extend release targets and add install.bash script (#288)

## Motivation

Currently we're only building binaries for amd64 architecture, it would
be good to support arm64 as well.
In addition, many tools often provide an install script which automates
the process of installing/upgrading these tools.

## Testing

Run install script:

```bash
./install.bash -v v0.11.0-rc1 -d <YOUR_PATH>
```

You can also test the commands for installment from README, for
instance:

```bash
curl -fsSL -o install.bash https://raw.githubusercontent.com/nobl9/sloctl/extend-release-targets-and-add-install-script/install.bash
```

## Release Notes

Sloctl pre-built binaries are now also built for arm64 architecture.
In addition there's now a now method of installing sloctl, via an
install script.
For more details refer to the
[README](https://github.com/nobl9/sloctl/tree/main?tab=readme-ov-file#script).

## Breaking Changes

Sloctl released binaries are no longer of a form
_sloctl-${OS}-${VERSION}_ (e.g. `sloctl-linux-0.10.1`), instead they now
follow this pattern: _sloctl-${VERSION}-${OS}-${ARCH} (e.g.
`sloctl-0.11.0-linux-adm64`).
In addition, the checksum for each release is changing it's name from
_sloctl-${VERSION}-SHA256SUMS to _sloctl-${VERSION}.sha256_.

.goreleaser.yml

@@ -16,14 +16,16 @@ builds:
     - darwin
   goarch:
     - amd64
+    - arm64
   binary: '{{ .ProjectName }}'
 
 archives:
-- format: binary
-  name_template: '{{ .ProjectName }}-{{ if eq .Os "darwin" }}macos{{ else }}{{ .Os }}{{ end }}-{{ .Version }}'
+- formats:
+    - binary
+  name_template: '{{ .ProjectName }}-{{ .Version }}-{{ .Os }}-{{ .Arch }}'
 
 checksum:
-  name_template: '{{ .ProjectName }}-{{ .Version }}-SHA256SUMS'
+  name_template: '{{ .ProjectName }}-{{ .Version }}.sha256'
   algorithm: sha256
 
 release:

README.md

@@ -52,6 +52,30 @@ If you want to learn how to fully tame the sloctl's potential, see
 
 ## Install
 
+### Script
+
+The script requires bash and a minimal set of GNU utilities.
+On Windows it will work with either MinGW or Cygwin.
+You can either pipe it directly into bash or download the file and run it manually.
+
+```bash
+# Using curl:
+curl -fsSL https://raw.githubusercontent.com/nobl9/sloctl/main/install.bash | bash
+
+# On systems where curl is not available:
+wget -O - -q https://raw.githubusercontent.com/nobl9/sloctl/main/install.bash | bash
+
+# If you prefer to first download the script, inspect it and then run it:
+curl -fsSL -o install.bash https://raw.githubusercontent.com/nobl9/sloctl/main/install.bash
+# Or with wget:
+wget -O install.bash -q https://raw.githubusercontent.com/nobl9/sloctl/main/install.bash
+# Once downloaded, set execution permissions:
+chmod 700 install.bash
+# The script is well documented and comes with additional options.
+# You can display the help message by running:
+./install.bash --help
+```
+
 ### Prebuilt Binaries
 
 The binaries are available at

cspell.yaml

@@ -28,6 +28,7 @@ ignorePaths:
   - "**/test_data/**"
   - dist/**
 words:
+  - armv
   - distroless
   - dynatrace
   - endef

install.bash

@@ -0,0 +1,329 @@
+#!/usr/bin/env bash
+
+# The install script is based on the Apache 2.0 licensed script from Helm,
+# the Kubernetes resource manager: https://github.com/helm/helm.
+# Original script from Helm:
+#   https://raw.githubusercontent.com/helm/helm/main/scripts/get-helm-3
+
+PROGRAM_NAME="sloctl"
+GITHUB_REPOSITORY="nobl9/$PROGRAM_NAME"
+VERSION_CMD="version"
+
+DESIRED_VERSION=""
+USE_SUDO="true"
+DEBUG="false"
+VERIFY_CHECKSUM="true"
+PROGRAM_INSTALL_DIR="/usr/local/bin"
+PROGRAM_EXTENSION=""
+
+HAS_CURL="$(type "curl" &>/dev/null && echo true || echo false)"
+HAS_WGET="$(type "wget" &>/dev/null && echo true || echo false)"
+HAS_OPENSSL="$(type "openssl" &>/dev/null && echo true || echo false)"
+
+initVersion() {
+  if [[ "$DESIRED_VERSION" != "" ]] && [[ "$DESIRED_VERSION" != "v"* ]]; then
+    echo "Expected version arg ('${DESIRED_VERSION}') to begin with 'v', fixing..."
+    export DESIRED_VERSION="v${DESIRED_VERSION}"
+  fi
+}
+
+# initArch discovers the architecture for this system.
+initArch() {
+  ARCH=$(uname -m)
+  case $ARCH in
+  armv5*) ARCH="armv5" ;;
+  armv6*) ARCH="armv6" ;;
+  armv7*) ARCH="arm" ;;
+  aarch64) ARCH="arm64" ;;
+  x86) ARCH="386" ;;
+  x86_64) ARCH="amd64" ;;
+  i686) ARCH="386" ;;
+  i386) ARCH="386" ;;
+  esac
+}
+
+# initOS discovers the operating system for this system.
+initOS() {
+  OS=$(uname | tr '[:upper:]' '[:lower:]')
+
+  case "$OS" in
+  # Minimalist GNU for Windows
+  mingw* | cygwin*) OS='windows' ;;
+  esac
+
+  if [[ "$OS" == "windows" ]]; then
+    PROGRAM_EXTENSION=".exe"
+  fi
+}
+
+# runs the given command as root (detects if we are root already)
+runAsRoot() {
+  if [ $EUID -ne 0 ] && [ "$USE_SUDO" = "true" ]; then
+    sudo "${@}"
+  else
+    "${@}"
+  fi
+}
+
+# verifySupported checks that the os/arch combination is supported for
+# binary builds, as well whether or not necessary tools are present.
+verifySupported() {
+  local supported="darwin-amd64\ndarwin-arm64\nlinux-amd64\nlinux-arm64\nwindows-amd64\nwindows-arm64"
+  if ! echo "$supported" | grep -q "${OS}-${ARCH}"; then
+    echo "No prebuilt binary for ${OS}-${ARCH}."
+    echo "To build from source, go to https://github.com/${GITHUB_REPOSITORY}"
+    exit 1
+  fi
+
+  if [ "${HAS_CURL}" != "true" ] && [ "${HAS_WGET}" != "true" ]; then
+    echo "Either curl or wget is required"
+    exit 1
+  fi
+
+  if [ "${VERIFY_CHECKSUM}" == "true" ] && [ "${HAS_OPENSSL}" != "true" ]; then
+    echo "In order to verify checksum, openssl must first be installed."
+    echo "Please install openssl or set --no-verify-checksum flag."
+    exit 1
+  fi
+}
+
+# checkLatestVersion checks if the desired version is available.
+checkLatestVersion() {
+  if [ "$DESIRED_VERSION" != "" ]; then
+    TAG=$DESIRED_VERSION
+    return 0
+  fi
+  # Get tag from release URL
+  local latest_release_url="https://api.github.com/repos/${GITHUB_REPOSITORY}/releases/latest"
+  local response=""
+  if [ "${HAS_CURL}" == "true" ]; then
+    response=$(curl -L --silent --show-error --fail "$latest_release_url" 2>&1 || true)
+  elif [ "${HAS_WGET}" == "true" ]; then
+    response=$(wget "$latest_release_url" -q -O - 2>&1 || true)
+  fi
+  if [[ $response =~ \"tag_name\":\ \"([^\"]+)\" ]]; then
+    TAG="${BASH_REMATCH[1]}"
+  fi
+  if [ "$TAG" == "" ]; then
+    printf "Could not retrieve the latest release tag information from %s: %s\n" "${latest_release_url}" "${response}"
+    exit 1
+  fi
+}
+
+# checkInstalledVersion checks which version of program is installed and
+# if it needs to be changed.
+checkInstalledVersion() {
+  if ! [[ -f "${PROGRAM_INSTALL_DIR}/${PROGRAM_NAME}" ]]; then
+    return 1
+  fi
+  local version
+  version=$("${PROGRAM_INSTALL_DIR}/${PROGRAM_NAME}" "$VERSION_CMD")
+  # Remove the program name before the first '/'.
+  version="${version#*/}"
+  # Remove the segment after the last '-' (git revision).
+  version="${version%-*}"
+  # Remove the segment after the second last '-' (git branch).
+  version="${version%-*}"
+  if [[ "v${version}" == "$TAG" ]]; then
+    echo "${PROGRAM_NAME} ${version} is already installed, skipping installation"
+    return 0
+  else
+    echo "${PROGRAM_NAME} ${TAG} is available. Changing from version ${version}."
+    return 1
+  fi
+}
+
+# downloadFile downloads the latest program package and also the checksum
+# for that binary.
+downloadFile() {
+  VERSION="${TAG#v}"
+
+  PROGRAM_DIST="${PROGRAM_NAME}-${VERSION}-${OS}-${ARCH}${PROGRAM_EXTENSION}"
+  DOWNLOAD_BASE_URL="https://github.com/${GITHUB_REPOSITORY}/releases/download/$TAG"
+
+  DOWNLOAD_URL="${DOWNLOAD_BASE_URL}/${PROGRAM_DIST}"
+  CHECKSUM_URL="${DOWNLOAD_BASE_URL}/${PROGRAM_NAME}-${VERSION}.sha256"
+
+  PROGRAM_TMP_ROOT="$(mktemp -dt "${PROGRAM_NAME}-installer-XXXXXX")"
+  PROGRAM_TMP_BIN="${PROGRAM_TMP_ROOT}/${PROGRAM_NAME}${PROGRAM_EXTENSION}"
+  PROGRAM_SUM_FILE="${PROGRAM_TMP_ROOT}/${PROGRAM_NAME}-${VERSION}.sha256"
+
+  echo "Downloading ${DOWNLOAD_URL}"
+  if [ "$HAS_CURL" == "true" ]; then
+    curl -SsL --fail "$DOWNLOAD_URL" -o - > "$PROGRAM_TMP_BIN"
+  elif [ "$HAS_WGET" == "true" ]; then
+    wget -q -O - "$DOWNLOAD_URL" > "$PROGRAM_TMP_BIN"
+  fi
+
+  echo "Downloading checksum $CHECKSUM_URL"
+  if [ "$HAS_CURL" == "true" ]; then
+    curl -SsL --fail "$CHECKSUM_URL" -o - > "$PROGRAM_SUM_FILE"
+  elif [ "$HAS_WGET" == "true" ]; then
+    wget -q -O - "$CHECKSUM_URL" > "$PROGRAM_SUM_FILE"
+  fi
+}
+
+# installFile installs the program binary.
+installFile() {
+  local destination="${PROGRAM_INSTALL_DIR}/${PROGRAM_NAME}${PROGRAM_EXTENSION}"
+  echo "Preparing to install ${PROGRAM_NAME} into ${PROGRAM_INSTALL_DIR}"
+  runAsRoot cp "$PROGRAM_TMP_BIN" "$destination"
+  runAsRoot chmod +x "$destination"
+  echo "${PROGRAM_NAME} installed into ${destination}"
+}
+
+# verifyChecksum verifies the SHA256 checksum of the binary package.
+verifyChecksum() {
+  printf "Verifying checksum... "
+  local actual_sum
+  local expected_sum
+  actual_sum=$(openssl sha1 -sha256 "$PROGRAM_TMP_BIN" | awk '{print $2}')
+  expected_sum=$(awk "/${PROGRAM_DIST}/ {print \$1}" "$PROGRAM_SUM_FILE")
+  if [ "$actual_sum" != "$expected_sum" ]; then
+    echo "SHA sum of ${PROGRAM_TMP_BIN} does not match. Aborting."
+    exit 1
+  fi
+  echo "Done."
+}
+
+# fail_trap is executed if an error occurs.
+fail_trap() {
+  result=$?
+  if [ "$result" != "0" ]; then
+    if [[ -n "$INPUT_ARGUMENTS" ]]; then
+      echo -e "Failed to install ${PROGRAM_NAME} with the arguments provided: ${INPUT_ARGUMENTS}\n"
+      help
+    else
+      echo "Failed to install ${PROGRAM_NAME}"
+    fi
+    echo -e "\nFor support, go to https://github.com/${GITHUB_REPOSITORY}."
+  fi
+  cleanup
+  exit $result
+}
+
+# testVersion tests the installed client to make sure it is working.
+testVersion() {
+  if ! command -v "$PROGRAM_NAME" &>/dev/null; then
+    echo "${PROGRAM_NAME} not found. Is ${PROGRAM_INSTALL_DIR} on your '\$PATH?'"
+    exit 1
+  fi
+}
+
+# help provides possible cli installation arguments.
+help() {
+  local script_name
+  script_name=$(basename "$0")
+  cat >&2 <<EOF
+Usage: ${script_name} [OPTS]
+
+An installer script for ${PROGRAM_NAME}!
+It can be used to both install ${PROGRAM_NAME} for the first time and upgrade an existing version.
+
+OPTS:
+  -h, --help            Print this message
+  -v, --version         ${PROGRAM_NAME} version, when not defined it fetches the latest release from GitHub
+  -d, --dir             Install directory, defaults to /usr/local/bin
+  --no-sudo             Do not use sudo for installation
+  --no-verify-checksum  Do not verify the checksum of the binary
+  --debug               Print additional debug information
+Examples:
+  ${script_name} --no-sudo --version=v0.10.0 -d /home/me/go/bin
+EOF
+}
+
+# cleanup temporary files.
+cleanup() {
+  if [[ -d "${PROGRAM_TMP_ROOT:-}" ]]; then
+    rm -rf "$PROGRAM_TMP_ROOT"
+  fi
+}
+
+# Execution.
+
+# Stop execution on any error.
+trap "fail_trap" EXIT
+set -e
+
+# Set debug if desired.
+if [ "$DEBUG" == "true" ]; then
+  set -x
+fi
+
+# Normalize args.
+# Step 1: Preprocess arguments to split any --option=value pairs.
+normalized_args=()
+for arg in "$@"; do
+  if [[ $arg == --*=* ]]; then
+    # Split at the first '=': key gets the part before, value gets the part after.
+    normalized_args+=("${arg%%=*}" "${arg#*=}")
+  else
+    normalized_args+=("$arg")
+  fi
+done
+# Step 2: Reset the positional parameters with our normalized arguments.
+set -- "${normalized_args[@]}"
+
+# Parsing input arguments (if any).
+export INPUT_ARGUMENTS="${*}"
+set -u
+while (("$#")); do
+  case "$1" in
+  --version | -v)
+    shift
+    if [[ $# -ne 0 ]]; then
+      DESIRED_VERSION="$1"
+      if [[ "$1" != "v"* ]]; then
+        echo "Expected version arg ('${DESIRED_VERSION}') to begin with 'v', fixing..."
+        DESIRED_VERSION="v${1}"
+      fi
+      shift # Shift again to remove the version argument.
+    else
+      echo "Please provide the desired version. e.g. --version v0.10.0"
+      exit 0
+    fi
+    ;;
+  --dir | -d)
+    shift
+    PROGRAM_INSTALL_DIR="${1%/}" # Remove extra slash from the path if present.
+    shift # Shift again to remove the directory argument.
+    ;;
+  '--no-sudo')
+    shift
+    USE_SUDO="false"
+    ;;
+  '--no-verify-checksum')
+    shift
+    VERIFY_CHECKSUM="false"
+    ;;
+  '--debug')
+    shift
+    DEBUG="false"
+    ;;
+  '--help' | -h)
+    help
+    exit 0
+    ;;
+  *)
+    echo "Invalid option: $1"
+    exit 1
+    ;;
+  esac
+done
+set +u
+
+# Run.
+initVersion
+initArch
+initOS
+verifySupported
+checkLatestVersion
+if ! checkInstalledVersion; then
+  downloadFile
+  if [ "$VERIFY_CHECKSUM" == "true" ]; then
+    verifyChecksum
+  fi
+  installFile
+fi
+testVersion
+cleanup