Add --name option to 'chalice logs' command

[jamesls]

Issue #, if available:

#841.

Description of changes:

Adds a --name option to chalice logs command. The original logs command was written in when there was only a single lambda function. This now adds support for all lambda functions.

Example

Given this app:

from chalice import Chalice

app = Chalice(app_name='multilog')
app.debug = True

i = 0

def incr_counter():
    global i
    i += 1


@app.lambda_function()
def foo(event, context):
    incr_counter()
    app.log.debug("Invoking from function foo: %s", i)
    return {'hello': 'world'}


@app.lambda_function()
def bar(event, context):
    incr_counter()
    app.log.debug("Invoking from function bar: %s", i)
    return {'hello': 'world'}


@app.route('/')
def index():
    incr_counter()
    app.log.info("Invoking from '/' route: %s", i)
    return {'hello': 'world'}

After invoking the functions a few times:

$ http https://abcd.execute-api.us-west-2.amazonaws.com/api/
$ aws lambda invoke --function-name multilog-dev-foo /dev/stdout
$ aws lambda invoke --function-name multilog-dev-bar /dev/stdout

The default is still for the API handler lambda so there's no change in behavior:

2018-05-19 09:59:44.454000 59fc08 multilog - INFO - Invoking from '/' route: 1
2018-05-19 09:59:44.977000 59fc08 multilog - INFO - Invoking from '/' route: 2
2018-05-19 09:59:45.496000 59fc08 multilog - INFO - Invoking from '/' route: 3
2018-05-19 09:59:46.076000 59fc08 multilog - INFO - Invoking from '/' route: 4
2018-05-19 09:59:46.637000 59fc08 multilog - INFO - Invoking from '/' route: 5
2018-05-19 09:59:47.192000 59fc08 multilog - INFO - Invoking from '/' route: 6
2018-05-19 09:59:47.775000 59fc08 multilog - INFO - Invoking from '/' route: 7

But you can now retrieve logs for your other lambda functions as well:

$ chalice logs -n foo
2018-05-19 10:01:16.966000 d47fc8 multilog - DEBUG - Invoking from function foo: 1
2018-05-19 10:01:21.994000 d47fc8 multilog - DEBUG - Invoking from function foo: 2
2018-05-19 10:01:22.615000 d47fc8 multilog - DEBUG - Invoking from function foo: 3
2018-05-19 10:01:23.204000 d47fc8 multilog - DEBUG - Invoking from function foo: 4
...

$ chalice logs -n bar
2018-05-19 10:01:39.631000 577e3a multilog - DEBUG - Invoking from function bar: 1
2018-05-19 10:01:40.340000 577e3a multilog - DEBUG - Invoking from function bar: 2
2018-05-19 10:01:41.008000 577e3a multilog - DEBUG - Invoking from function bar: 3
2018-05-19 10:01:41.644000 577e3a multilog - DEBUG - Invoking from function bar: 4
2018-05-19 10:01:42.245000 577e3a multilog - DEBUG - Invoking from function bar: 5

Note that the argument of -n/--name is the logical resource name, that is foo and bar, which match the def foo(): ..., def bar(): ... in the app.py file.

[codecov-io]

Codecov Report

Merging #848 into master will increase coverage by 0.21%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #848      +/-   ##
==========================================
+ Coverage   94.81%   95.03%   +0.21%     
==========================================
  Files          21       21              
  Lines        3741     3743       +2     
  Branches      487      487              
==========================================
+ Hits         3547     3557      +10     
+ Misses        130      123       -7     
+ Partials       64       63       -1

Impacted Files	Coverage Δ
chalice/logs.py	100% <ø> (ø)	⬆️
chalice/cli/__init__.py	81.5% <100%> (+2.71%)	⬆️
chalice/cli/factory.py	93.22% <100%> (+2.54%)	⬆️

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[kyleknap]

Looks good. Just had a small comment/question. Otherwise 🚢

[kyleknap]

What are your thoughts on using chalice.constants.DEFAULT_HANDLER_NAME instead of the hard coded string here?

[jamesls]

Yeah, good catch. I'll update before merging.

[stealthycoin]

Might be nice to update the docs as well in logging.rst and mention that --name will refer to either the actual python function name or whatever is provided by the name kwarg.

[jamesls]

Merged via 3ce3f79