awscurl

awscurl is a CLI tool allowing to send HTTP requests to AWS API. It automatically signs your requests with AWS Signature Version 4, so AWS can identify and authorize your request.

This implementation of awscurl tool is written in Go. It supports all AWS authentication methods available in AWS SDK for Go v2, including:

• AssumeRole profiles
• IAM roles for Amazon EC2 Instances or ECS Tasks

Installation

Cross-platform Binary (Recommended)

Download appropriate version for your platform from awscurl Releases. Once downloaded and unpacked, the binary can be run from anywhere. For convinience, you can place the binary to /usr/local/bin/

Docker

awscurl container images are also released on DockerHub as legal90/awscurl

$ docker run --rm \
    --env AWS_ACCESS_KEY_ID \
    --env AWS_SECRET_ACCESS_KEY \
    legal90/awscurl --help   # see Usage section for other available arguments

Note: This command assumes that you have AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY exported in your environment. You can find more details about AWS authentication in the Usage section below.

Build from Source

Prerequisites

• Git
• Go (at least Go v1.13)

Fetch from GitHub

awscurl uses the Go Modules support built into Go 1.11. The easiest way to get started is to clone awscurl in a directory outside of the $GOPATH, as in the following example:

mkdir $HOME/src
cd $HOME/src
git clone https://github.com/legal90/awscurl.git
cd awscurl
go build   # or `go install` to install it to your $GOPATH/bin

Usage

$ awscurl --help

A simple CLI utility with cURL-like syntax allowing to send HTTP requests to AWS resources.
It automatically adds Siganture Version 4 to the request. More details:
https://docs.aws.amazon.com/general/latest/gr/signature-version-4.html

Usage:
  awscurl [URL] [flags]

Flags:
      --access-key string      AWS Access Key ID to use for authentication
  -d, --data string            Data payload to send within a POST request
  -H, --header stringArray     Extra HTTP header to include in the request. Example: "Content-Type: application/json". Could be used multiple times
      --profile string         AWS awsProfile to use for authentication
      --region string          AWS region to use for the request
  -X, --request string         Custom request method to use (default "GET")
      --secret-key string      AWS Secret Access Key to use for authentication
      --service string         The name of AWS Service, used for signing the request (default "execute-api")
      --session-token string   AWS Session Key to use for authentication
  -h, --help                   help for awscurl
  -v, --version                version for awscurl

AWS Authentication

As you can see above, awscurl supports several argument, allowing you to choose the desired way to authenticate on AWS. You can also use common environmental variables instead:

CLI option	Environment variable
--access-key	AWS_ACCESS_KEY_ID
--secret-key	AWS_SECRET_ACCESS_KEY
--session-token	AWS_SESSION_TOKEN
--profile	AWS_PROFILE
--region	AWS_REGION

By default, none of these variables are defined and AWS SDK for Go (used in awscurl) will follow "the default provider chain". It looks for credentials in this order:

1. Environment variables (see table above).
2. Shared config and credentials file (~/.aws/config, ~/.aws/credentials)
3. IAM role for Amazon EC2 or Tasks (if you run awscurl on EC2 Instance or ECS task)

Examples

Call S3: List bucket content

This example also shows how to use a custom AWS profile "test". Please note that it has to be configured in your ~/.aws/config or ~/.aws/credentials.

$ awscurl --service s3 \
    --profile "test" \
    "https://awscurl-sample-bucket.s3.amazonaws.com"

Call EC2:

In this example we also pass static AWS credentials using CLI arguments:

$ awscurl --service ec2 \
    --access-key <your-aws-access-key-id> \
    --secret-key <your-aws-secret-access-key> \
    "https://ec2.amazonaws.com?Action=DescribeRegions&Version=2013-10-15"

Call API Gateway:

$ awscurl --service execute-api \
    -X POST \
    -d '{"key": "value"}' \
    -H "Content-Type: application/json" \
    "https://<prefix>.execute-api.us-east-1.amazonaws.com/<resource>"

or reading data from the file:

$ awscurl --service execute-api \
    -X POST \
    -d @./path/to/file.json \
    -H "Content-Type: application/json" \
    "https://<prefix>.execute-api.us-east-1.amazonaws.com/<resource>"

Related projects

• awscurl in Python: https://github.com/okigan/awscurl
• awscurl in Lisp: https://github.com/aw/picolisp-awscurl
• awscurl in Go (older implementation): https://github.com/allthings/awscurl

License

The MIT License

Copyright © 2020 Mikhail Zholobov legal90@gmail.com