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* fn: improve UX and publish/deploy command * fn: remove wrong use cases for deploy * fn: fix regression introduced by merge
128 lines
4.5 KiB
Markdown
128 lines
4.5 KiB
Markdown
# Introduction
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This guide will walk you through creating and testing a simple Lambda function.
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We need the the `fn` tool for the rest of this guide. You can install it
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by following [these instructions](https://github.com/iron-io/function/fn).
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*For this getting started we are assuming you already have working lambda function code available, if not head to the [import instructions] (import.md) and skip the next section.*
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## Creating the function
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Let's convert the `hello_world` AWS Lambda example to Docker.
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```python
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def my_handler(event, context):
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message = 'Hello {} {}!'.format(event['first_name'],
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event['last_name'])
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return {
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'message' : message
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}
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```
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Create an empty directory for your project and save this code in a file called
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`hello_world.py`.
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Now let's use `fn`'s Lambda functionality to create a Docker image. We can
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then run the Docker image with a payload to execute the Lambda function.
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```sh
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$ fn lambda create-function irontest/hello_world:1 python2.7 hello_world.my_handler hello_world.py
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Creating directory: irontest/hello_world:1 ... OK
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Creating Dockerfile: irontest/hello_world:1/Dockerfile ... OK
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Copying file: irontest/hello_world/hello_world:1.py ... OK
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Creating function.yaml ... OK
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```
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As you can see, this is very similar to creating a Lambda function using the
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`aws` CLI tool. We name the function as we would name other Docker images. The
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`1` indicates the version. You can use any string. This way you can configure
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your deployment environment to use different versions. The handler is
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the name of the function to run, in the form that python expects
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(`module.function`). Where you would package the files into a `.zip` to upload
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to Lambda, we just pass the list of files to `fn`.
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## Deploying the function to IronFunctions
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Next we want to deploy the function to our IronFunctions
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```sh
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$ fn deploy -v -d ./irontest irontest
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deploying irontest/hello_world:1/function.yaml
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Sending build context to Docker daemon 4.096 kB
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Step 1 : FROM iron/lambda-python2.7
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latest: Pulling from iron/lambda-python2.7
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c52e3ed763ff: Pull complete
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789cf808491a: Pull complete
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d1b635efed57: Pull complete
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fe23c3dbcfa8: Pull complete
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63c874a9687e: Pull complete
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a6d462dae1df: Pull complete
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Digest: sha256:c5dde3bf3be776c0f6b909d4ad87255a0af9b6696831fbe17c5f659655a0494a
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Status: Downloaded newer image for iron/lambda-python2.7:latest
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---> 66d3adf47835
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Step 2 : ADD hello_world.py ./hello_world:1.py
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---> 91a592e0dfa9
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Removing intermediate container 1a1ef40ff0dd
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Step 3 : CMD hello_world.my_handler
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---> Running in 318da1bba060
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---> db9b9644168e
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Removing intermediate container 318da1bba060
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Successfully built db9b9644168e
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The push refers to a repository [docker.io/irontest/hello_world:1]
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5d9d142e21b2: Pushed
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11d8145d6038: Layer already exists
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23885f85dbd0: Layer already exists
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6a350a8d14ee: Layer already exists
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e67f7ef625c5: Layer already exists
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321db514ef85: Layer already exists
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6102f0d2ad33: Layer already exists
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latest: digest: sha256:5926ff413f134fa353e4b42f2d4a0d2d4f5b3a39489cfdf6dd5b4a63c4e40dee size: 1784
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updating API with appName: irontest route: /hello_world:1 image: irontest/hello_world:1
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path result
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irontest/hello_world:1/function.yaml done
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```
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This will deploy the generated function under the app `irontest` with `hello_world` as a route, e.g:
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`http://<hostname>/r/irontest/hello_world:1`,
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You should also now see the generated Docker image.
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```sh
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$ docker images
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REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
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irontest/hello_world:1 latest db9b9644168e About a minute ago 108.4 MB
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...
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```
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## Testing the function
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The `test-function` subcommand can launch the Dockerized function with the
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right parameters.
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```sh
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$ fn lambda test-function irontest/hello_world:1 --payload '{ "first_name": "Jon", "last_name": "Snow" }'
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{"message": "Hello Jon Snow!"}
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```
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You should see the output.
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## Calling the function from IronFunctions
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The `fn call` command can call the deployed version with a given payload.
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```sh
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$ echo '{ "first_name": "Jon", "last_name": "Snow" }' | ./fn call irontest /hello_world:1
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{"message": "Hello Jon Snow!"}
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```
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You should see the output.
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## Commands documentation
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* [create-function](create.md)
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* [test-function](test.md)
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* [aws-import](import.md)
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## More documentation
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* [env](environment.md)
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* [aws](aws.md) |