feat: Adding a sam --info command (aws#776)

This command currently prints version information in JSON format.
In future we will expand this to print everything from versions of
dependencies, list of commands available, capabilities exposed by
the commands, etc. Hopefully eventually this will provide a nice
list of machine readable instructions for other tools to integrate
with SAM CLI

requirements/base.txt

@@ -11,4 +11,4 @@ docker>=3.3.0
 dateparser~=0.7
 python-dateutil~=2.6
 pathlib2~=2.3.2; python_version<"3.4"
-aws_lambda_builders==0.0.2-dev
+aws_lambda_builders==0.0.2

samcli/cli/main.py

@@ -3,6 +3,7 @@
 """
 
 import logging
+import json
 import click
 
 from samcli import __version__
@@ -36,9 +37,21 @@ def aws_creds_options(f):
     return f
 
 
+def print_info(ctx, param, value):
+    if not value or ctx.resilient_parsing:
+        return
+
+    click.echo(json.dumps({
+        "version": __version__
+    }, indent=2))
+
+    ctx.exit()
+
+
 @click.command(cls=BaseCommand)
 @common_options
 @click.version_option(version=__version__, prog_name="SAM CLI")
+@click.option("--info", is_flag=True, is_eager=True, callback=print_info, expose_value=False)
 @pass_context
 def cli(ctx):
     """

samcli/commands/build/command.py

@@ -17,9 +17,11 @@
 
 LOG = logging.getLogger(__name__)
 
+DEFAULT_BUILD_DIR = os.path.join(".aws-sam", "build")
 
 HELP_TEXT = """
-Use this command to build your AWS Lambda Functions source code to generate artifacts that can run on AWS Lambda.\n
+Use this command to build your AWS Lambda Functions source code to generate artifacts that target AWS Lambda's
+execution environment.\n
 \b
 Supported Resource Types
 ------------------------
@@ -31,10 +33,10 @@
 1. Python2.7\n
 2. Python3.6\n
 \b
-Usage
------
-In your SAM template, specify the path to your function's source code
-in the resource's Code or CodeUri property.
+Examples
+--------
+To use this command, update your SAM template to specify the path
+to your function's source code in the resource's Code or CodeUri property.
 \b
 To build on your workstation, run this command in folder containing
 SAM template. Built artifacts will be written to .aws-sam/build folder
@@ -47,24 +49,25 @@
 $ sam build && sam local invoke
 \b
 To build and package for deployment
-$ sam build && sam package
+$ sam build && sam package --s3-bucket <bucketname>
 """
 
 
 @click.command("build", help=HELP_TEXT, short_help="Build your Lambda function code")
 @click.option('--build-dir', '-b',
-              default=os.path.join(".aws-sam", "build"),
+              default=DEFAULT_BUILD_DIR,
               type=click.Path(file_okay=False, dir_okay=True, writable=True),  # Must be a directory
               help="Path to a folder where the built artifacts will be stored")
 @click.option("--base-dir", "-s",
               default=None,
               type=click.Path(dir_okay=True, file_okay=False),  # Must be a directory
               help="Resolve relative paths to function's source code with respect to this folder. Use this if "
-                   "SAM template and your source code are not in same enclosing folder. By default, relative paths to"
+                   "SAM template and your source code are not in same enclosing folder. By default, relative paths "
                    "are resolved with respect to the SAM template's location")
-@click.option("--use-container",
+@click.option("--use-container", "-u",
               is_flag=True,
-              help="Run the builds inside a Docker container that simulates an AWS Lambda like environment")
+              help="If your functions depend on packages that have natively compiled dependencies, use this flag "
+                   "to build your function inside an AWS Lambda-like Docker container")
 @click.option("--manifest", "-m",
               default=None,
               type=click.Path(),
@@ -133,19 +136,39 @@ def do_cli(template,  # pylint: disable=too-many-locals
             with open(ctx.output_template_path, "w") as fp:
                 fp.write(yaml_dump(modified_template))
 
-            msg = """\nBuild Artifacts Available At: {artifacts_dir}
-
-Next Steps
-==========
-[*] Invoke Function: sam local invoke -t {template}
-[*] Package: sam package --template-file {template}
-            """.format(artifacts_dir=os.path.relpath(ctx.build_dir),
-                       template=os.path.relpath(ctx.output_template_path))
-
             click.secho("\nBuild Succeeded", fg="green")
 
+            msg = gen_success_msg(os.path.relpath(ctx.build_dir),
+                                  os.path.relpath(ctx.output_template_path),
+                                  os.path.abspath(ctx.build_dir) == os.path.abspath(DEFAULT_BUILD_DIR))
+
             click.secho(msg, fg="yellow")
 
         except (UnsupportedRuntimeException, BuildError, UnsupportedBuilderLibraryVersionError) as ex:
             click.secho("Build Failed", fg="red")
             raise UserException(str(ex))
+
+
+def gen_success_msg(artifacts_dir, output_template_path, is_default_build_dir):
+
+    invoke_cmd = "sam local invoke"
+    if not is_default_build_dir:
+        invoke_cmd += " -t {}".format(output_template_path)
+
+    package_cmd = "sam package --s3-bucket <yourbucket>"
+    if not is_default_build_dir:
+        package_cmd += " --template-file {}".format(output_template_path)
+
+    msg = """\nBuilt Artifacts  : {artifacts_dir}
+Built Template   : {template}
+
+Commands you can use next
+=========================
+[*] Invoke Function: {invokecmd}
+[*] Package: {packagecmd}
+    """.format(invokecmd=invoke_cmd,
+               packagecmd=package_cmd,
+               artifacts_dir=artifacts_dir,
+               template=output_template_path)
+
+    return msg

tests/integration/buildcmd/test_build_cmd.py

@@ -16,18 +16,18 @@
 class TestBuildCommand_PythonFunctions(BuildIntegBase):
 
     EXPECTED_FILES_GLOBAL_MANIFEST = set()
-    EXPECTED_FILES_PROJECT_MANIFEST = {'__init__.py', 'main.py', 'numpy', 'cryptography', "jinja2",
+    EXPECTED_FILES_PROJECT_MANIFEST = {'__init__.py', 'main.py', 'numpy',
+                                       # 'cryptography',
+                                       "jinja2",
                                        'requirements.txt'}
 
     FUNCTION_LOGICAL_ID = "PythonFunction"
 
     @parameterized.expand([
         ("python2.7", False),
-        ("python3.6", False)
-
-        # FIXME: Turning off Container build tests until official Docker Container is published
-        # ("python2.7", "use_container"),
-        # ("python3.6", "use_container"),
+        ("python3.6", False),
+        ("python2.7", "use_container"),
+        ("python3.6", "use_container"),
     ])
     def test_with_default_requirements(self, runtime, use_container):
 

tests/integration/testdata/buildcmd/Python/main.py

@@ -1,12 +1,12 @@
 import numpy
-from cryptography.fernet import Fernet
+# from cryptography.fernet import Fernet
 from jinja2 import Template
 
 
 def handler(event, context):
 
     # Try using some of the modules to make sure they work & don't crash the process
-    print(Fernet.generate_key())
+    # print(Fernet.generate_key())
 
     template = Template('Hello {{ name }}')
 

tests/integration/testdata/buildcmd/Python/requirements.txt

@@ -1,5 +1,7 @@
 # These are some hard packages to build. Using them here helps us verify that building works on various platforms
 
 numpy~=1.15
-cryptography~=2.4
+# `cryptography` has a dependency on `pycparser` which, for some reason doesn't build inside a Docker container.
+# Turning this off until we resolve this issue: https://github.com/awslabs/aws-lambda-builders/issues/29
+# cryptography~=2.4
 Jinja2~=2.10