docs(*): Document how to build with an example Dockerfile (#25)

Provide a Dockerfile which can build a lambda for Amazon Linux. Add example for
testing provided Dockerfile. Update README to describe how to build and how to
setup the lambda.

.dockerignore

@@ -0,0 +1,4 @@
+target
+LICENSE
+README.md
+.travis.yml

.gitignore

@@ -14,3 +14,6 @@ Cargo.lock
 
 # Test artifacts
 *.rmeta
+
+.idea
+*.iml

README.md

@@ -132,8 +132,30 @@ fn main() {
 ```
 
 ### Deploy
+Note: These instructions will produce a MUSL binary of your rust code. If you are looking for non-MUSL binaries, you might try [docker-lambda](https://github.com/lambci/docker-lambda).
+
+To deploy on AWS lambda, you will need a zip file of your binary, built against amazonlinux with MUSL. A docker file is provided as an example, which will work for single project binaries that need OpenSSL. It is based off of [rust-musl-builder](https://github.com/emk/rust-musl-builder).
+
+    docker pull amazonlinux
+    docker build --force-rm -t aws-lambda:latest --build-arg SRC=example -f docker/dockerfile .
+    docker run -v /tmp/artifacts:/export --rm aws-lambda:latest
+
+Create your lambda function, uploading your zip file. Change your runtime to `go 1.x` and set your handler function to the name of your application as defined in your Cargo.toml.
+
+If using SSL functionality (e.g. rusoto), add the following environment variables
+
+    SSL_CERT_DIR=/etc/ssl/certs
+    SSL_CERT_FILE=/etc/ssl/certs/ca-bundle.crt
+
+If you are still running into SSL issues, you may need to modify your application per https://github.com/emk/rust-musl-builder#making-openssl-work.
+
+If you are using `error_chain` in your rust code, you will also have to disable default features for a musl build. Add the following to your Cargo.toml
+
+    #Error chain users will have to disable default-features for musl
+    [dependencies.error-chain]
+    version = "~0.12"
+    default-features = false
 
-TBD
 
 ### Troubleshooting
 

docker/cargo_config

@@ -0,0 +1,3 @@
+[build]
+# Target musl-libc by default when running Cargo.
+target = "x86_64-unknown-linux-musl"

docker/dockerfile

@@ -0,0 +1,98 @@
+FROM amazonlinux:latest AS builder
+
+ARG SRC
+
+ENV BUILD_DIR=/build \
+    OUTPUT_DIR=/output \
+    RUST_BACKTRACE=1 \
+    RUSTUP_HOME=/usr/local/rustup \
+    CARGO_HOME=/usr/local/cargo \
+    PATH=/usr/local/cargo/bin:$PATH \
+    PREFIX=/musl \
+    MUSL_VERSION=1.1.19 \
+    OPENSSL_VERSION=1.1.0i
+
+RUN mkdir -p /usr/local/cargo/bin \
+  && mkdir -p $BUILD_DIR \
+  && mkdir -p $OUTPUT_DIR \
+  && mkdir -p $PREFIX
+
+RUN curl https://sh.rustup.rs -sSf | sh -s -- --default-toolchain stable -y
+
+ENV BUILD_TARGET=x86_64-unknown-linux-musl
+
+RUN rustup target add $BUILD_TARGET
+
+RUN yum -y groupinstall "Development Tools"
+
+WORKDIR $PREFIX
+
+# Build any dependencies that aren't part of your build, e.g. thrift compiler
+
+# Build Musl
+ADD http://www.musl-libc.org/releases/musl-$MUSL_VERSION.tar.gz .
+RUN tar -xvzf musl-$MUSL_VERSION.tar.gz \
+    && cd musl-$MUSL_VERSION \
+    && ./configure --prefix=$PREFIX \
+    && make install \
+    && cd ..
+
+# Set environment for musl
+ENV CC=$PREFIX/bin/musl-gcc \
+    C_INCLUDE_PATH=$PREFIX/include/ \
+    CPPFLAGS=-I$PREFIX/include \
+    LDFLAGS=-L$PREFIX/lib
+
+# Build OpenSSL
+ADD https://www.openssl.org/source/openssl-$OPENSSL_VERSION.tar.gz .
+
+RUN echo "Building OpenSSL" \
+    && tar -xzf "openssl-$OPENSSL_VERSION.tar.gz" \
+    && cd openssl-$OPENSSL_VERSION \
+    && ./Configure no-async no-afalgeng no-shared no-zlib -fPIC --prefix=$PREFIX --openssldir=$PREFIX/ssl linux-x86_64 \
+    && make depend \
+    && make install
+
+WORKDIR $BUILD_DIR
+
+RUN mkdir .cargo
+ADD docker/cargo_config .cargo/config
+
+ENV OPENSSL_DIR=$PREFIX \
+    OPENSSL_STATIC=true
+
+ADD $SRC/src src
+ADD $SRC/Cargo.toml .
+
+RUN cargo build --target $BUILD_TARGET --release
+
+RUN find target/$BUILD_TARGET/release -maxdepth 1 -type f -executable -exec cp '{}' $OUTPUT_DIR \;
+
+FROM amazonlinux:latest AS package
+
+ENV OUTPUT_DIR=/output \
+    ARTIFACTS_DIR=/artifacts
+
+RUN mkdir -p $ARTIFACTS_DIR
+
+COPY --from=builder $OUTPUT_DIR $ARTIFACTS_DIR
+
+WORKDIR $ARTIFACTS_DIR
+
+RUN yum -y install zip
+
+RUN find . -maxdepth 1 -type f -executable -exec zip aws_lambda.zip '{}' \;
+
+RUN ls -a $ARTIFACTS_DIR
+
+FROM package
+
+ENV ARTIFACTS_DIR=/artifacts \
+    EXPORT_DIR=/export
+
+RUN mkdir -p $EXPORT_DIR
+
+#Snapshot the directory
+VOLUME $EXPORT_DIR
+
+CMD find $ARTIFACTS_DIR -type f -name "aws_lambda.zip" -exec cp '{}' $EXPORT_DIR \;

example/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "aws-lambda-example"
+version = "0.1.0"
+authors = ["Danny Browning <danny.browning@protectwise.com>"]
+
+[dependencies]
+aws_lambda = { git = "https://github.com/srijs/rust-aws-lambda" }
+log = "~0.4"

example/src/main.rs

@@ -0,0 +1,15 @@
+extern crate aws_lambda;
+#[macro_use] extern crate log;
+
+use aws_lambda::event::s3::S3Event;
+
+fn main() {
+    aws_lambda::logger::init();
+
+    // start the runtime, and do
+    aws_lambda::start(|input: S3Event| {
+        info!("Event received {:?}", input);
+
+        Ok(())
+    })
+}