Class: Boxd::CLIBackend

Inherits:
Object
  • Object
show all
Defined in:
lib/boxd/cli_backend.rb

Overview

CLIBackend shells out to the ‘boxd` CLI for every operation. v0 of this gem is built on this; v1 will speak gRPC directly. The public API does not change between the two — only this file does.

Constant Summary collapse

DEFAULT_BIN = 
"boxd"

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(api_key: nil, bin: nil, environment: nil) ⇒ CLIBackend

Returns a new instance of CLIBackend.



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# File 'lib/boxd/cli_backend.rb', line 17

def initialize(api_key: nil, bin: nil, environment: nil)
  @bin = bin || ENV["BOXD_BIN"] || DEFAULT_BIN
  @env = {}
  @env["BOXD_TOKEN"]       = api_key     if api_key
  @env["BOXD_ENVIRONMENT"] = environment if environment

  assert_cli_present!
end

Instance Attribute Details

#bin ⇒ Object (readonly)

Returns the value of attribute bin.



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# File 'lib/boxd/cli_backend.rb', line 15

def bin
  @bin
end

#env ⇒ Object (readonly)

Returns the value of attribute env.



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# File 'lib/boxd/cli_backend.rb', line 15

def env
  @env
end

Instance Method Details

#call_json(*args) ⇒ Object

Run ‘boxd <args>` and parse `–json` output. Raises on non-zero exit with a typed Boxd::Error subclass when we recognise the failure.



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# File 'lib/boxd/cli_backend.rb', line 28

def call_json(*args)
  out, err, status = Open3.capture3(env, bin, "--json", *args.map(&:to_s))
  unless status.success?
    raise classify_error(err.empty? ? out : err, args)
  end

  return nil if out.strip.empty?

  JSON.parse(out, symbolize_names: true)
rescue JSON::ParserError => e
  raise InternalError, "boxd CLI returned non-JSON output for `#{args.join(' ')}`: #{e.message}\n#{out}"
end

#call_raw(*args) ⇒ Object

Run ‘boxd <args>` and return [stdout, stderr] as strings. Used for commands without –json support.



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# File 'lib/boxd/cli_backend.rb', line 43

def call_raw(*args)
  out, err, status = Open3.capture3(env, bin, *args.map(&:to_s))
  raise classify_error(err.empty? ? out : err, args) unless status.success?

  [out, err]
end

#exec_stream(vm, cmd, env: nil, tty: false, &block) ⇒ Object

Stream ‘boxd exec` for a single command, yielding chunks. Returns the exit code captured from CLI exit status.

The CLI does not stream stdout/stderr separately by default; we capture both via pipes and yield each line as it arrives, tagging the stream.



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# File 'lib/boxd/cli_backend.rb', line 56

def exec_stream(vm, cmd, env: nil, tty: false, &block)
  cli_args = ["exec"]
  cli_args << "--tty" if tty
  Array(env).each do |k, v|
    cli_args.push("-e", "#{k}=#{v}")
  end
  cli_args << vm.to_s
  cli_args << "--"
  cli_args.concat(Array(cmd).map(&:to_s))

  stdout_buf = +""
  stderr_buf = +""
  exit_code  = nil

  Open3.popen3(self.env, bin, *cli_args) do |_stdin, stdout, stderr, wait_thr|
    threads = []
    threads << Thread.new do
      stdout.each_line do |line|
        stdout_buf << line
        block&.call(:stdout, line)
      end
    end
    threads << Thread.new do
      stderr.each_line do |line|
        stderr_buf << line
        block&.call(:stderr, line)
      end
    end
    threads.each(&:join)
    exit_code = wait_thr.value.exitstatus
  end

  { stdout: stdout_buf, stderr: stderr_buf, exit_code: exit_code }
end