Implement Sqldef

Author: k0kubun

lib/sqldef.rb

@@ -1,8 +1,128 @@
 # frozen_string_literal: true
 
-require_relative "sqldef/version"
+require 'etc'
+require 'fileutils'
+require 'net/http'
+require 'rubygems/package'
+require 'stringio'
+require 'uri'
+require 'zlib'
+require_relative 'sqldef/version'
 
 module Sqldef
-  class Error < StandardError; end
-  # Your code goes here...
+  GOARCH = {
+    'x86_64'  => 'amd64',
+    'aarch64' => 'arm64',
+    # TODO: add arm and 386
+  }
+  private_constant :GOARCH
+
+  COMMANDS = %w[
+    mysqldef
+    psqldef
+    sqlite3def
+  ]
+  private_constant :COMMANDS
+
+  @bin = Dir.pwd
+
+  class << self
+    attr_accessor :bin
+
+    # @param [String,Symbol] command - mysqldef, psqldef, sqllite3def
+    # @param [String] path - Schema export path
+    def export(command:, path:, host:, port: nil, user:, password: nil, database:)
+      sqldef = download(command)
+      schema = IO.popen(
+        [
+          sqldef,
+          "--user=#{user}", *(["--password=#{password}"] if password),
+          "--host=#{host}", *(["--port=#{port}"] if port),
+          '--export', database,
+        ],
+        &:read
+      )
+      raise "Failed to execute '#{sqldef}'" unless $?.success?
+      File.write(path, schema)
+    end
+
+    # @param [String,Symbol] command - mysqldef, psqldef, sqllite3def
+    # @param [String] path - Schema file path
+    def dry_run(command:, path:, host:, port: nil, user:, password: nil, database:)
+      sqldef = download(command)
+      execute(
+        sqldef,
+        "--user=#{user}", *(["--password=#{password}"] if password),
+        "--host=#{host}", *(["--port=#{port}"] if port),
+        '--dry-run', database,
+        in: path,
+      )
+    end
+
+    # @param [String,Symbol] command - mysqldef, psqldef, sqllite3def
+    # @param [String] path - Schema file path
+    def apply(command:, path:, host:, port: nil, user:, password: nil, database:)
+      sqldef = download(command)
+      execute(
+        sqldef,
+        "--user=#{user}", *(["--password=#{password}"] if password),
+        "--host=#{host}", *(["--port=#{port}"] if port),
+        database,
+        in: path,
+      )
+    end
+
+    # @param [String,Symbol] command - mysqldef, psqldef, sqllite3def
+    # @return String - command path
+    def download(command)
+      path = File.join(bin, command = command.to_s)
+      return path if File.executable?(path)
+
+      print("Downloading '#{command}' under '#{bin}'... ")
+      resp = get(build_url(command), code: 302) # Latest
+      resp = get(resp['location'],   code: 302) # vX.Y.Z
+      resp = get(resp['location'],   code: 200) # Binary
+
+      gzip = Zlib::GzipReader.new(StringIO.new(resp.body))
+      Gem::Package::TarReader.new(gzip) do |tar|
+        unless file = tar.find { |f| f.full_name == command }
+          raise "'#{command}' was not found in the archive"
+        end
+        File.binwrite(path, file.read)
+      end
+
+      FileUtils.chmod('+x', path)
+      puts 'done.'
+      path
+    end
+
+    private
+
+    def execute(*cmd, **opts)
+      unless system(*cmd, **opts)
+        raise "Failed to execute '#{cmd.first}'"
+      end
+    end
+
+    def build_url(command)
+      unless COMMANDS.include?(command)
+        raise "Unexpected sqldef command: #{command}" 
+      end
+      os = Etc.uname.fetch(:sysname).downcase
+      arch = GOARCH.fetch(Etc.uname.fetch(:machine))
+      "https://github.com/k0kubun/sqldef/releases/latest/download/#{command}_#{os}_#{arch}.tar.gz"
+    end
+
+    # TODO: Retry transient errors
+    def get(url, code: nil)
+      uri = URI.parse(url)
+      Net::HTTP.start(uri.host, uri.port, use_ssl: uri.scheme == 'https') do |http|
+        http.get("#{uri.path}?#{uri.query}")
+      end.tap do |resp|
+        if code && resp.code != code.to_s
+          raise "Expected '#{url}' to return #{code}, but got #{resp.code}: #{resp.body}"
+        end
+      end
+    end
+  end
 end

lib/sqldef/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module Sqldef
-  VERSION = "0.1.0"
+  VERSION = '0.1.0'
 end