This image contains everything you need to have a working development environment for claudia.js projects. The container's working dir is /myapp so that you can setup a volume mapping your laptop's project dir to /myapp in the container.

Supported tags and respective Dockerfile links

• 2.13.0,latest (2.13.0/Dockerfile)
• 2.12.1 (2.12.1/Dockerfile)
• 2.11.0 (2.11.0/Dockerfile)
• 2.9.0 (2.9.0/Dockerfile)

claudia 2.13.0 + node 6.11.0 + npm 3.10.10 + aws-cli 1.11.75 + python 2.7.9 + smoketail 0.1.0

How to use

Basically, there is an install-claudia-app-template command in the container which will add some basic config and shortcut scripts to your lambda project's directory. You will be using the added bash shortcut to launch a shell in which you can execute all your Claudia.js related commands. You will basically leave this bash shell open during development. It has your project directory from you laptop mapped to /myapp in the container allowing you do to all your development with your normal editor and tools then you can use the bash shell for Claudia.js related commands. There is also a helpful logs shortcut that will actively tail the lambda logs.

hello-world tutorial

1. Initialize the project

Assuming that you already have Docker installed on your laptop, you can setup a new claudia project using this docker container by simply executing the following commands:

$ mkdir hello-world
$ cd hello-world
$ docker run -ti -v "$(pwd):/myapp" danlynn/claudia:latest install-claudia-app-template

This will add the following structure in your laptop's current directory:

.aws
    config
    credentials
.claudia-version
.gitignore
TEMPLATE-README.md
bash
logs
synctime

This gives you some aws config files that will be specific to only this project. It also gives you the bash and logs commands. Note that you can alternatively provide a specific claudia version by replacing latest in the command above with a Claudia.js version like 2.9.0. If any of these files already exist in the current directory (like .gitignore or .aws/credentials) then they will NOT be overwritten by the template files.

2. Configure aws credentials and region

Next modify the .aws/credentials file adding your own aws_access_key_id and aws_secret_access_key.

[claudia]
aws_access_key_id = YOUR_ACCESS_KEY
aws_secret_access_key = YOUR_ACCESS_SECRET

By default, the .aws/config file sets the aws region to 'us-east-1'. However, you can feel free to make whatever changes you desire.

3. Create hello-world lambda

You are now ready to create a claudia.js lambda function. This is adapted from the Hello World AWS Lambda function tutorial on the Claudia.js website.

1. Create a new file named hello-world.js in your laptop's project folder to hold your lambda function.

2. Copy the following into the JS file:

   exports.handler = function (event, context) {
      context.succeed('hello world');
   };
   

3. Launch the claudia container bash shell:

   $ ./bash
   

   Don't forget the preceding ./ so that you execute the shortcut instead of launching a local bash shell.

4. Create a package.json file with the npm init command. You can simply enter "hello-world" at the 'name' prompt then hit enter accepting the defaults for all subsequent fields:

   root@3aeafad121e8:/myapp# npm init
   
   name: (myapp) hello-world
   version: (1.0.0) 
   description: 
   entry point: (hello-world.js) 
   test command: 
   git repository: 
   keywords: 
   author: 
   license: (ISC) 
   About to write to /myapp/package.json:
   
   {
     "name": "hello-world",
     "version": "1.0.0",
     "description": "",
     "main": "hello-world.js",
     "scripts": {
       "test": "echo \"Error: no test specified\" && exit 1"
     },
     "author": "",
     "license": "ISC"
   }
   
   Is this ok? (yes) 
   npm info init written successfully
   npm info ok 
   

5. Deploy the lambda function to aws using claudia in the container shell:

   root@3aeafad121e8:/myapp# claudia create --region us-east-1 --handler hello-world.handler
   
   {
     "lambda": {
       "role": "hello-world-executor",
       "name": "hello-world",
       "region": "us-east-1"
     }
   }
   

   This command will iterate through a series of steps then output a json response as shown above.

   Note that even though we have specified the region in our project's .aws/config file, the claudia create command requires it to be explicitly specified in the command params.

   The --handler value is made up of our main lambda function's filename and the name of the exported function. In our case the "hello-world.handler" value gets "hello-world" from hello-world.js and "handler" from exports.handler = function in that file's source.

4. Test hello-world lambda

The lambda function can now be tested from the container bash shell using:

root@3aeafad121e8:/myapp# claudia test-lambda

{
  "StatusCode": 200,
  "Payload": "\"hello world\""
}

This command will output the response from running the lambda function.

Note that the claudia test-lambda command does not need you to specify which lambda function to execute because claudia stored that information into claudia.json when you deployed it.

Making a change and redeploying

Modify the contents of your hello-world.js file as follows (add the word "again"):

exports.handler = function (event, context) {
  context.succeed('hello again world');
};

Then redeploy the code changes to aws with:

root@3aeafad121e8:/myapp# claudia update

updating Lambda	lambda.updateFunctionCode	FunctionName=hello-world
{
  "FunctionName": "hello-world",
  "FunctionArn": "arn:aws:lambda:us-east-1:018867421119:function:hello-world:2",
  "Runtime": "nodejs4.3",
  "Role": "arn:aws:iam::018867421119:role/hello-world-executor",
  "Handler": "hello-world.handler",
  "CodeSize": 1928,
  "Description": "",
  "Timeout": 3,
  "MemorySize": 128,
  "LastModified": "2017-04-12T03:18:41.060+0000",
  "CodeSha256": "XzMlQlas26zQep/9A3faz9DTBkctIsOdev5kppZNpBQ=",
  "Version": "2",
  "KMSKeyArn": null
}

And test again with:

root@3aeafad121e8:/myapp# claudia test-lambda
{
  "StatusCode": 200,
  "Payload": "\"hello again world\""
}

Tailing the lambda logs

The logs shortcut script that was installed when you ran install-claudia-app-template can be used to tail the lambda logs for your lambda function directly on the command line.

When in a terminal window on your laptop, from your project's directory, simply type ./logs to start tailing your lambda function's logs:

$ ./logs

2017-06-20T21:39:14.156Z START RequestId: e7732057-5600-11e7-ad11-3308ceab63aa Version: $LATEST
2017-06-20T21:39:14.393Z	e7732057-5600-11e7-ad11-3308ceab63aa	====== coalescingImageHandler: begin: url = /image/100/0/image.jpg?card_number=0000000220&retailer_id=767
2017-06-20T21:39:14.393Z	e7732057-5600-11e7-ad11-3308ceab63aa	coalescingImageHandler: invoke getRenderRoute: before
2017-06-20T21:39:14.454Z	e7732057-5600-11e7-ad11-3308ceab63aa	coalescingImageHandler: invoke getRenderRoute: after
2017-06-20T21:39:14.454Z	e7732057-5600-11e7-ad11-3308ceab63aa	coalescingImageHandler: invoke render: before
2017-06-20T21:39:14.454Z	e7732057-5600-11e7-ad11-3308ceab63aa	render: start
2017-06-20T21:39:14.454Z	e7732057-5600-11e7-ad11-3308ceab63aa	render: invoke redis.get(redisKey): before
2017-06-20T21:39:14.473Z	e7732057-5600-11e7-ad11-3308ceab63aa	render: invoke redis.get(redisKey): after
2017-06-20T21:39:14.473Z	e7732057-5600-11e7-ad11-3308ceab63aa	render: invoke removeRedisKeyIfExists: before
2017-06-20T21:39:14.473Z	e7732057-5600-11e7-ad11-3308ceab63aa	removeRedisKeyIfExists: start
2017-06-20T21:39:14.473Z	e7732057-5600-11e7-ad11-3308ceab63aa	removeRedisKeyIfExists: end
2017-06-20T21:39:14.473Z	e7732057-5600-11e7-ad11-3308ceab63aa	render: invoke removeRedisKeyIfExists: after
2017-06-20T21:39:14.473Z	e7732057-5600-11e7-ad11-3308ceab63aa	render: invoke removeS3IfExists: before
2017-06-20T21:39:14.473Z	e7732057-5600-11e7-ad11-3308ceab63aa	removeS3IfExists: start
2017-06-20T21:39:14.473Z	e7732057-5600-11e7-ad11-3308ceab63aa	removeS3IfExists: end
2017-06-20T21:39:14.473Z	e7732057-5600-11e7-ad11-3308ceab63aa	render: invoke removeS3IfExists: after
2017-06-20T21:39:14.473Z	e7732057-5600-11e7-ad11-3308ceab63aa	render: invoke renderImageUnlessAlreadyRendered: before
2017-06-20T21:39:14.473Z	e7732057-5600-11e7-ad11-3308ceab63aa	renderImageUnlessAlreadyRendered: start
2017-06-20T21:39:14.473Z	e7732057-5600-11e7-ad11-3308ceab63aa	renderImageUnlessAlreadyRendered: end
2017-06-20T21:39:14.473Z	e7732057-5600-11e7-ad11-3308ceab63aa	render: invoke renderImageUnlessAlreadyRendered: after
2017-06-20T21:39:14.473Z	e7732057-5600-11e7-ad11-3308ceab63aa	render: end
2017-06-20T21:39:14.473Z	e7732057-5600-11e7-ad11-3308ceab63aa	coalescingImageHandler: invoke render: after
2017-06-20T21:39:14.473Z	e7732057-5600-11e7-ad11-3308ceab63aa	====== coalescingImageHandler: end
2017-06-20T21:39:14.473Z END RequestId: e7732057-5600-11e7-ad11-3308ceab63aa
2017-06-20T21:39:14.473Z REPORT RequestId: e7732057-5600-11e7-ad11-3308ceab63aa	Duration: 313.01 ms	Billed Duration: 400 ms 	Memory Size: 128 MB	Max Memory Used: 45 MB	

Type ctrl-C to stop tailing the logs. The output will be updated about every 5 seconds as new log entries appear.

You can also start tailing the logs while in the docker container's bash session by simply typing logs from any directory:

root@ea36c452ab85:/myapp# logs

2017-06-20T21:39:14.156Z START RequestId: e7732057-5600-11e7-ad11-3308ceab63aa Version: $LATEST
2017-06-20T21:39:14.393Z	e7732057-5600-11e7-ad11-3308ceab63aa	====== coalescingImageHandler: begin: url = /image/100/0/image.jpg?card_number=0000000220&retailer_id=767
2017-06-20T21:39:14.393Z	e7732057-5600-11e7-ad11-3308ceab63aa	coalescingImageHandler: invoke getRenderRoute: before
...
2017-06-20T21:39:14.473Z	e7732057-5600-11e7-ad11-3308ceab63aa	coalescingImageHandler: invoke render: after
2017-06-20T21:39:14.473Z	e7732057-5600-11e7-ad11-3308ceab63aa	====== coalescingImageHandler: end
2017-06-20T21:39:14.473Z END RequestId: e7732057-5600-11e7-ad11-3308ceab63aa
2017-06-20T21:39:14.473Z REPORT RequestId: e7732057-5600-11e7-ad11-3308ceab63aa	Duration: 313.01 ms	Billed Duration: 400 ms 	Memory Size: 128 MB	Max Memory Used: 45 MB	

The ./logs command uses smoketail to actively tail all the streams in the CloudWatch log group associated with your lambda function. However, if you need to tail just a single stream or apply a filter then you can use the smoketail command directly in the container's bash session via something like:

root@ea36c452ab85:/myapp# smoketail -f /aws/lambda/<lambda-name>

See: https://github.com/cinema6/smoketail more additional smoketail cli usage examples.

Troubleshooting

Sometimes, you will receive a message like this when executing commands that interact with aws:

An error occurred (InvalidSignatureException) when calling the FilterLogEvents operation: Signature expired: 20170406T184748Z is now earlier than 20170406T190807Z (20170406T191307Z - 5 min.)

When this occurs, you can correct the situation by simply synchronizing the clock of the container with the synctime shortcut:

$ ./synctime

Note that both the bash and logs shortcut scripts call synctime before launching the docker container. So, chances are that you won't need to be calling synctime yourself.

Another way to avoid sync issues when executing commands that interact with aws is to add the following at the top of your lambda function before the export:

// Fix: InvalidSignatureException: Signature expired: 20170223T053320Z is now earlier than 20170223T150109Z (20170223T150609Z - 5 min.)
const AWS = require('aws-sdk');
AWS.config.update({
  region: 'us-east-1',
  correctClockSkew: true
});