Add tuftool dockerfile

CONTRIBUTING.md

@@ -6,7 +6,6 @@ documentation, we greatly value feedback and contributions from our community.
 Please read through this document before submitting any issues or pull requests to ensure we have all the necessary
 information to effectively respond to your bug report or contribution.
 
-
 ## Security issue notifications
 If you discover a potential security issue in this project we ask that you notify AWS/Amazon Security via our [vulnerability reporting page](http://aws.amazon.com/security/vulnerability-reporting/). Please do **not** create a public github issue.
 

tuftool/Dockerfile

@@ -0,0 +1,7 @@
+# syntax=docker/dockerfile:1
+
+FROM rust:slim
+RUN apt update && apt install -y openssl
+RUN cargo install --force --locked tuftool
+RUN mkdir /share
+ENTRYPOINT ["tuftool"]

tuftool/README.md

@@ -135,6 +135,25 @@ tuftool download \
 
 `tuftool` respects the `HTTPS_PROXY` and `NO_PROXY` environment variables.
 
+## Container
+
+You can build a simple container image to avoid needing to install the Rust toolchain and dependencies or your local machine.
+
+To build the image use Docker or Finch (same argument syntax, just replace 
+`docker` for `finch`):
+
+```shell
+docker build -t tuftool .
+```
+
+To use tuftool, mount the host working directory to `/share`.
+
+For example, to mount the current directory for `download` you would do something like:
+
+```shell
+docker run -it -v $(pwd):/share tuftool download "/share/some_directory" ...
+```
+
 ## Testing
 
 Unit tests are run in the usual manner: `cargo test`.