Minor edits in the READMEs along with updated CMake commands

- In the AWS C++ SDK `ENABLE_UNITY_BUILD` now defaults to `ON`
- Expose the CMake `BUILD_SHARED_LIBS` flag as a configurable option

Author: specious

CMakeLists.txt

@@ -6,6 +6,7 @@ project(aws-lambda-runtime
 
 option(ENABLE_LTO "Enables link-time optimization, requires compiler support." ON)
 option(ENABLE_TESTS "Enables building the test project, requires AWS C++ SDK." OFF)
+option(BUILD_SHARED_LIBS "Enables building using shared libraries" OFF)
 
 add_library(${PROJECT_NAME}
     "src/logging.cpp"

README.md

@@ -1,6 +1,7 @@
 [![GitHub](https://img.shields.io/github/license/awslabs/aws-lambda-cpp.svg)](https://github.com/awslabs/aws-lambda-cpp/blob/master/LICENSE)
 ![CodeBuild](https://codebuild.us-west-2.amazonaws.com/badges?uuid=eyJlbmNyeXB0ZWREYXRhIjoiQkN1b0srbWtnUjNibFVyL2psNmdaM0l4RnVQNzVBeG84QnQvUjRmOEJVdXdHUXMxZ25iWnFZQUtGTkUxVGJhcGZaVEhXY2JOSTFHTlkvaGF2RDRIZlpVPSIsIml2UGFyYW1ldGVyU3BlYyI6IjRiS3hlRjFxVFZHSWViQmQiLCJtYXRlcmlhbFNldFNlcmlhbCI6MX0%3D&branch=master)
 [![Language grade: C/C++](https://img.shields.io/lgtm/grade/cpp/g/awslabs/aws-lambda-cpp.svg?logo=lgtm&logoWidth=18)](https://lgtm.com/projects/g/awslabs/aws-lambda-cpp/context:cpp)
+
 ## AWS Lambda C++ Runtime
 
 C++ implementation of the lambda runtime API
@@ -14,13 +15,15 @@ Since AWS Lambda runs on GNU/Linux, you should build this runtime library and yo
 
 ### Prerequisites
 Make sure you have the following packages installed first:
+
 1. CMake (version 3.9 or later)
 1. git
 1. Make or Ninja
 1. zip
 1. libcurl-devel (on Debian-basded distros it's libcurl4-openssl-dev)
 
 In a terminal, run the following commands:
+
 ```bash
 $ git clone https://github.com/awslabs/aws-lambda-cpp.git
 $ cd aws-lambda-cpp
@@ -42,11 +45,15 @@ target_link_libraries(${PROJECT_NAME} PRIVATE AWS::aws-lambda-runtime)
 target_compile_features(${PROJECT_NAME} PRIVATE "cxx_std_11")
 target_compile_options(${PROJECT_NAME} PRIVATE "-Wall" "-Wextra")
 
-# this line creates a target that packages your binary and zips it up
+#
+# This line creates a target that packages your binary along with its shared dependencies
+# as a zip file ready for deployment
+#
 aws_lambda_package_target(${PROJECT_NAME})
 ```
 
 And here is how a sample `main.cpp` would look like:
+
 ```cpp
 #include <aws/lambda-runtime/runtime.h>
 
@@ -78,6 +85,7 @@ $ cd build
 $ cmake .. -DCMAKE_BUILD_TYPE=Debug -DCMAKE_INSTALL_PREFIX=~/lambda-install
 $ make
 $ make aws-lambda-package-demo
+
 ```
 The last command above `make aws-lambda-package-demo` will create a zip file called `demo.zip` in the current directory.
 
@@ -101,6 +109,7 @@ $ cat trust-policy.json
 }
 
 ```
+
 Then create the IAM role:
 
 ```bash
@@ -110,6 +119,7 @@ $ aws iam create-role --role-name lambda-demo --assume-role-policy-document file
 Note down the role Arn returned to you after running that command. We'll need it in the next steps:
 
 Attach the following policy to allow Lambda to write logs in CloudWatch:
+
 ```bash
 $ aws iam attach-role-policy --role-name lambda-demo --policy-arn arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole
 ```
@@ -118,14 +128,15 @@ Make sure you attach the appropriate policies and/or permissions for any other A
 
 And finally, create the Lambda function:
 
-```
+```bash
 $ aws lambda create-function --function-name demo \
---role <specify role arn from previous step here> \
---runtime provided --timeout 15 --memory-size 128 \
---handler demo --zip-file fileb://demo.zip
+  --role <specify role arn from previous step here> \
+  --runtime provided --timeout 15 --memory-size 128 \
+  --handler demo --zip-file fileb://demo.zip
 ```
 
 And to invoke the function:
+
 ```bash
 $ aws lambda invoke --function-name demo --payload '{"answer":42}' output.txt
 ```
@@ -152,6 +163,7 @@ This can be done by passing the `NO_LIBC` flag in CMake as follows:
 ```cmake
 aws_lambda_package_target(${PROJECT_NAME} NO_LIBC)
 ```
+
 ### Common Pitfalls with Packaging
 
 * Any library dependency your Lambda function has that is dynamically loaded via `dlopen` will NOT be automatically packaged. You **must** add those dependencies manually to the zip file.
@@ -164,12 +176,15 @@ For example, if you are using the AWS C++ SDK, it's best to set the following co
 Aws::Client::ClientConfiguration config;
 config.caFile = "/etc/pki/tls/certs/ca-bundle.crt";
 ```
+
 If you are not using the AWS C++ SDK, but happen to be using libcurl directly, you can set the CA bundle location by doing:
+
 ```c
 curl_easy_setopt(curl_handle, CURLOPT_CAINFO, "/etc/pki/tls/certs/ca-bundle.crt");
 ```
 
 ## FAQ & Troubleshooting
+
 1. **Why is the zip file so large? what are all those files?**
    Typically, the zip file is large because we have to package the entire C standard library.
    You can reduce the size by doing some or all of the following:

ci/codebuild/build-cpp-sdk.sh

@@ -6,9 +6,9 @@ set -euo pipefail
 cd /aws-sdk-cpp
 mkdir build
 cd build
-cmake .. -GNinja -DBUILD_ONLY="lambda" \
+cmake .. -GNinja \
+    -DBUILD_ONLY="lambda" \
     -DCMAKE_BUILD_TYPE=Release \
-    -DENABLE_UNITY_BUILD=ON \
     -DBUILD_SHARED_LIBS=ON \
     -DENABLE_TESTING=OFF \
     -DCMAKE_INSTALL_PREFIX=/install $@

examples/api-gateway/README.md

@@ -1,9 +1,9 @@
 # Example using the AWS C++ Lambda runtime and Amazon API Gateway
 
-In this example, we'll build a simple "Hello, World" lambda function that can be invoked using an api endpoint created using Amazon API gateway. This example can be viewed as the C++ counterpart to the NodeJS "Hello, World" API example as viewed [here](https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-create-api-as-simple-proxy-for-lambda.html). At the end of this example, you should be able to invoke your lambda via an api endpoint and receive a raw JSON response. This example employs the use of the AWS C++ SDK to parse the request and write the necessary response. 
- 
+In this example, we'll build a simple "Hello, World" lambda function that can be invoked using an api endpoint created using Amazon API gateway. This example can be viewed as the C++ counterpart to the NodeJS "Hello, World" API example as viewed [here](https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-create-api-as-simple-proxy-for-lambda.html). At the end of this example, you should be able to invoke your lambda via an api endpoint and receive a raw JSON response. This example employs the use of the AWS C++ SDK to parse the request and write the necessary response.
+
 ## Build the AWS C++ SDK
-Start by building the SDK from source.
+Start by building the AWS C++ SDK from source:
 
 ```bash
 $ mkdir ~/install
@@ -15,29 +15,28 @@ $ cmake .. -DBUILD_ONLY="core" \
   -DCMAKE_BUILD_TYPE=Release \
   -DBUILD_SHARED_LIBS=OFF \
   -DCUSTOM_MEMORY_MANAGEMENT=OFF \
-  -DCMAKE_INSTALL_PREFIX=~/install \
-  -DENABLE_UNITY_BUILD=ON
+  -DCMAKE_INSTALL_PREFIX=~/install
 $ make
 $ make install
 ```
 
 ## Build the Runtime
-We need to build the C++ Lambda runtime as outlined in the other examples.
+We need to build the C++ Lambda runtime as outlined in the other examples:
 
 ```bash
 $ git clone https://github.com/awslabs/aws-lambda-cpp-runtime.git
 $ cd aws-lambda-cpp-runtime
 $ mkdir build
 $ cd build
-$ cmake .. -DCMAKE_BUILD_TYPE=Release \
-  -DBUILD_SHARED_LIBS=OFF \
-  -DCMAKE_INSTALL_PREFIX=~/install \
+$ cmake .. \
+  -DCMAKE_BUILD_TYPE=Release \
+  -DCMAKE_INSTALL_PREFIX=~/install
 $ make
 $ make install
 ```
 
 ## Build the application
-The next step is to build the Lambda function in `main.cpp` and run the packaging command as follows:
+The next step is to build the Lambda function in `main.cpp` and run the packaging script as follows:
 
 ```bash
 $ mkdir build
@@ -62,18 +61,19 @@ For the rest of this example, we will use the AWS Management Console to create t
 1. Once you have added the API gateway, locate the newly created endpoint. View how to test the endpoint below.
 
 ## Test the endpoint
-Feel free to test the endpoint any way you desire. Below is a way to test using cURL: 
+Test the endpoint:
 
-```
+```bash
 curl -v -X POST \
   '<YOUR-API-ENDPOINT>?name=Bradley&city=Chicago' \
   -H 'content-type: application/json' \
   -H 'day: Sunday' \
   -d '{ "time": "evening" }'
 ```
 
-With the expected response being: 
-```
+With the expected response being:
+
+```json
 {
   "message": "Good evening, Bradley of Chicago. Happy Sunday!"
 }

examples/dynamodb/README.md

@@ -6,20 +6,20 @@ To also show case how this can be done on a Linux distro other than Amazon Linux
 That being said, the instructions below should work on any Linux distribution.
 
 ## Build the AWS C++ SDK
-Start by building the SDK from source.
+Start by building the AWS C++ SDK from source:
+
 ```bash
 $ mkdir ~/install
 $ git clone https://github.com/aws/aws-sdk-cpp.git
 $ cd aws-sdk-cpp
 $ mkdir build
 $ cd build
-$ cmake .. -DBUILD_ONLY="dynamodb" \
+$ cmake .. \
+  -DBUILD_ONLY="dynamodb" \
   -DCMAKE_BUILD_TYPE=Release \
   -DBUILD_SHARED_LIBS=OFF \
   -DCUSTOM_MEMORY_MANAGEMENT=OFF \
-  -DCMAKE_INSTALL_PREFIX=~/install \
-  -DENABLE_UNITY_BUILD=ON
-
+  -DCMAKE_INSTALL_PREFIX=~/install
 $ make -j 4
 $ make install
 ```
@@ -32,15 +32,15 @@ $ git clone https://github.com/awslabs/aws-lambda-cpp-runtime.git
 $ cd aws-lambda-cpp-runtime
 $ mkdir build
 $ cd build
-$ cmake .. -DCMAKE_BUILD_TYPE=Release \
-  -DBUILD_SHARED_LIBS=OFF \
+$ cmake .. \
+  -DCMAKE_BUILD_TYPE=Release \
   -DCMAKE_INSTALL_PREFIX=~/install \
 $ make
 $ make install
 ```
 
 ## Build the application
-The last step is to build the Lambda function in `main.cpp` and run the packaging command as follows:
+The last step is to build the Lambda function in `main.cpp` and run the packaging script as follows:
 
 ```bash
 $ cmake .. -DCMAKE_BUILD_TYPE=Release -DCMAKE_PREFIX_PATH=~/install

examples/s3/README.md

@@ -6,20 +6,20 @@ To also show case how this can be done on a Linux distro other than Amazon Linux
 That being said, the instructions below should work on any Linux distribution.
 
 ## Build the AWS C++ SDK
-Start by building the SDK from source.
+Start by building the AWS C++ SDK from source:
+
 ```bash
 $ mkdir ~/install
 $ git clone https://github.com/aws/aws-sdk-cpp.git
 $ cd aws-sdk-cpp
 $ mkdir build
 $ cd build
-$ cmake .. -DBUILD_ONLY="s3" \
+$ cmake .. \
+  -DBUILD_ONLY="s3" \
   -DCMAKE_BUILD_TYPE=Release \
   -DBUILD_SHARED_LIBS=OFF \
   -DCUSTOM_MEMORY_MANAGEMENT=OFF \
-  -DCMAKE_INSTALL_PREFIX=~/install \
-  -DENABLE_UNITY_BUILD=ON
-
+  -DCMAKE_INSTALL_PREFIX=~/install
 $ make
 $ make install
 ```
@@ -32,15 +32,15 @@ $ git clone https://github.com/awslabs/aws-lambda-cpp-runtime.git
 $ cd aws-lambda-cpp-runtime
 $ mkdir build
 $ cd build
-$ cmake .. -DCMAKE_BUILD_TYPE=Release \
-  -DBUILD_SHARED_LIBS=OFF \
+$ cmake .. \
+  -DCMAKE_BUILD_TYPE=Release \
   -DCMAKE_INSTALL_PREFIX=~/install \
 $ make
 $ make install
 ```
 
 ## Build the application
-The last step is to build the Lambda function in `main.cpp` and run the packaging command as follows:
+The last step is to build the Lambda function in `main.cpp` and run the packaging script as follows:
 
 ```bash
 $ cmake .. -DCMAKE_BUILD_TYPE=Release -DCMAKE_PREFIX_PATH=~/install