Playing around with making API calls to Amazon S3 from Clojure CLR using the AwsSignatureVersion4 library from Nuget

get_from_s3.cljr

;; <PackageReference Include="AwsSignatureVersion4" Version="4.0.1" />
(ns get_from_s3
  (:import [Amazon.Runtime EnvironmentVariablesAWSCredentials SessionAWSCredentials]
           [System.Net.Http HttpClient GetAsyncExtensions HttpCompletionOption]
           [System Uri])
  ;(:use clojure.pprint clojure.repl clojure.reflect)
  (:require [clojure.clr.io :as io]))

;(assembly-load "AWSSDK.Core")
;(assembly-load "AwsSignatureVersion4")

(def client (new HttpClient))
(def creds (new EnvironmentVariablesAWSCredentials)) ; or new SessionAWSCredentials(key,secret,token)
(def obj-uri (new Uri "https://batch-jobs-dev.s3.ap-southeast-1.amazonaws.com/manifests/manifest-1234.csv.gz"))

(with-open [os (io/output-stream "output.csv.gz")]
  (let [res (.Result (GetAsyncExtensions/GetAsync client obj-uri HttpCompletionOption/ResponseHeadersRead "ap-southeast-1" "s3" creds))]
    (-> res .Content (.CopyToAsync os) .Result)))