Add install script for easy CLI installation via curl

Provides a POSIX-compatible installer that detects OS/arch, downloads
the correct binary from GitHub Releases, verifies SHA256 checksums,
and installs to /usr/local/bin (with ~/.local/bin fallback).

Usage: curl -fsSL https://raw.githubusercontent.com/helmcode/finops-cli/main/install.sh | sh

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: barckcode

install.sh

@@ -0,0 +1,167 @@
+#!/bin/sh
+# install.sh — Install the finops CLI from GitHub Releases.
+#
+# Usage:
+#   curl -fsSL https://raw.githubusercontent.com/helmcode/finops-cli/main/install.sh | sh
+#
+# The script detects your OS and architecture, downloads the latest release,
+# and installs the binary to /usr/local/bin (or ~/.local/bin as fallback).
+
+set -e
+
+REPO="helmcode/finops-cli"
+BINARY_NAME="finops"
+
+# --- Helpers ---
+
+info() {
+    printf '[info] %s\n' "$1"
+}
+
+error() {
+    printf '[error] %s\n' "$1" >&2
+    exit 1
+}
+
+# --- Detect OS ---
+
+detect_os() {
+    os="$(uname -s)"
+    case "$os" in
+        Linux*)  echo "linux" ;;
+        Darwin*) echo "darwin" ;;
+        CYGWIN*|MINGW*|MSYS*|Windows*)
+            printf '[error] Windows is not supported by this installer.\n' >&2
+            printf '        Please download the binary manually from:\n' >&2
+            printf '        https://github.com/%s/releases/latest\n' "$REPO" >&2
+            exit 1
+            ;;
+        *)
+            error "Unsupported operating system: $os"
+            ;;
+    esac
+}
+
+# --- Detect Architecture ---
+
+detect_arch() {
+    arch="$(uname -m)"
+    case "$arch" in
+        x86_64|amd64)  echo "amd64" ;;
+        aarch64|arm64) echo "arm64" ;;
+        *)
+            error "Unsupported architecture: $arch"
+            ;;
+    esac
+}
+
+# --- Fetch latest version ---
+
+get_latest_version() {
+    url="https://api.github.com/repos/${REPO}/releases/latest"
+
+    if command -v curl >/dev/null 2>&1; then
+        response="$(curl -fsSL "$url")" || error "Failed to fetch latest release from GitHub API."
+    elif command -v wget >/dev/null 2>&1; then
+        response="$(wget -qO- "$url")" || error "Failed to fetch latest release from GitHub API."
+    else
+        error "Neither curl nor wget found. Please install one and try again."
+    fi
+
+    # Extract tag_name from JSON without requiring jq.
+    version="$(printf '%s' "$response" | grep '"tag_name"' | head -1 | sed 's/.*"tag_name"[[:space:]]*:[[:space:]]*"\([^"]*\)".*/\1/')"
+
+    if [ -z "$version" ]; then
+        error "Could not determine latest version. GitHub API response may have changed or rate limit reached."
+    fi
+
+    # Strip leading 'v' if present (goreleaser uses the version without it in archive names).
+    echo "$version" | sed 's/^v//'
+}
+
+# --- Determine install directory ---
+
+get_install_dir() {
+    if [ -d "/usr/local/bin" ] && [ -w "/usr/local/bin" ]; then
+        echo "/usr/local/bin"
+    elif [ -d "$HOME/.local/bin" ] && [ -w "$HOME/.local/bin" ]; then
+        echo "$HOME/.local/bin"
+    else
+        mkdir -p "$HOME/.local/bin" 2>/dev/null || error "Cannot create $HOME/.local/bin. Please create it manually."
+        echo "$HOME/.local/bin"
+    fi
+}
+
+# --- Main ---
+
+main() {
+    info "Detecting platform..."
+    os="$(detect_os)"
+    arch="$(detect_arch)"
+    info "Platform: ${os}/${arch}"
+
+    info "Fetching latest release version..."
+    version="$(get_latest_version)"
+    info "Latest version: ${version}"
+
+    archive="finops-cli_${version}_${os}_${arch}.tar.gz"
+    download_url="https://github.com/${REPO}/releases/download/v${version}/${archive}"
+
+    tmpdir="$(mktemp -d)" || error "Failed to create temporary directory."
+    trap 'rm -rf "$tmpdir"' EXIT
+
+    checksums_file="finops-cli_${version}_checksums.txt"
+    checksums_url="https://github.com/${REPO}/releases/download/v${version}/${checksums_file}"
+
+    info "Downloading ${archive}..."
+    if command -v curl >/dev/null 2>&1; then
+        curl -fsSL -o "${tmpdir}/${archive}" "$download_url" || error "Download failed. Check that version v${version} exists at: ${download_url}"
+        curl -fsSL -o "${tmpdir}/${checksums_file}" "$checksums_url" || error "Failed to download checksums file."
+    elif command -v wget >/dev/null 2>&1; then
+        wget -qO "${tmpdir}/${archive}" "$download_url" || error "Download failed. Check that version v${version} exists at: ${download_url}"
+        wget -qO "${tmpdir}/${checksums_file}" "$checksums_url" || error "Failed to download checksums file."
+    fi
+
+    info "Verifying checksum..."
+    expected_checksum="$(grep "${archive}" "${tmpdir}/${checksums_file}" | cut -d ' ' -f 1)"
+    if [ -z "$expected_checksum" ]; then
+        error "Checksum for ${archive} not found in checksums file."
+    fi
+    if command -v sha256sum >/dev/null 2>&1; then
+        actual_checksum="$(sha256sum "${tmpdir}/${archive}" | cut -d ' ' -f 1)"
+    elif command -v shasum >/dev/null 2>&1; then
+        actual_checksum="$(shasum -a 256 "${tmpdir}/${archive}" | cut -d ' ' -f 1)"
+    else
+        error "No SHA256 tool found. Cannot verify download integrity."
+    fi
+    if [ "$expected_checksum" != "$actual_checksum" ]; then
+        error "Checksum verification failed. Expected: ${expected_checksum}, Got: ${actual_checksum}"
+    fi
+    info "Checksum verified."
+
+    info "Extracting binary..."
+    tar --no-same-owner -xzf "${tmpdir}/${archive}" -C "$tmpdir" || error "Failed to extract archive."
+
+    if [ ! -f "${tmpdir}/${BINARY_NAME}" ]; then
+        error "Binary '${BINARY_NAME}' not found in archive. The release archive may have an unexpected structure."
+    fi
+
+    install_dir="$(get_install_dir)"
+    info "Installing to ${install_dir}/${BINARY_NAME}..."
+
+    mv "${tmpdir}/${BINARY_NAME}" "${install_dir}/${BINARY_NAME}" || error "Failed to install binary to ${install_dir}. Try running with sudo."
+    chmod 755 "${install_dir}/${BINARY_NAME}"
+
+    info "Successfully installed finops v${version} to ${install_dir}/${BINARY_NAME}"
+
+    # Check if the install directory is in PATH.
+    case ":${PATH}:" in
+        *":${install_dir}:"*) ;;
+        *)
+            printf '\n[warn] %s is not in your PATH.\n' "$install_dir"
+            printf '       Add it with:  export PATH="%s:$PATH"\n' "$install_dir"
+            ;;
+    esac
+}
+
+main