Add copyright attributions

Adds an initial ATTRIBUTIONS.md file containing the open source
components that source-controller depends on, and their copyright
information.

Signed-off-by: Paulo Gomes <paulo.gomes@weave.works>

Dockerfile

@@ -93,5 +93,7 @@ COPY --from=build /etc/passwd /etc/passwd
 # Copy over binary from build
 COPY --from=build /workspace/source-controller /usr/local/bin/
 
+COPY ATTRIBUTIONS.md /
+
 USER controller
 ENTRYPOINT [ "source-controller" ]

Makefile

@@ -222,3 +222,6 @@ endif
 .PHONY: help
 help:  ## Display this help menu
 	@awk 'BEGIN {FS = ":.*##"; printf "\nUsage:\n  make \033[36m<target>\033[0m\n"} /^[a-zA-Z_0-9-]+:.*?##/ { printf "  \033[36m%-20s\033[0m %s\n", $$1, $$2 } /^##@/ { printf "\n\033[1m%s\033[0m\n", substr($$0, 5) } ' $(MAKEFILE_LIST)
+
+update-attributions:
+	./hack/update-attributions.sh

hack/update-attributions.sh

@@ -0,0 +1,73 @@
+#!/usr/bin/env bash
+
+set -eoux pipefail
+
+SPLIT="----------------------------------------------------------------------"
+
+cat <<EOF > ATTRIBUTIONS.md
+ATTRIBUTIONS
+
+This application uses Open Source components. You can find the source
+code of their open source projects along with license information below.
+We acknowledge and are grateful to these developers for their contributions
+to open source.
+
+libssh2:
+
+Libssh2 was obtained in source-code form from its github repository: 
+https://github.com/libssh2/libssh2/
+
+No changes were made to its original source code. 
+
+Copyright notice (https://raw.githubusercontent.com/libssh2/libssh2/main/COPYING):
+
+$(curl -L https://raw.githubusercontent.com/libssh2/libssh2/master/COPYING)
+
+${SPLIT}
+
+libgit2:
+
+Libgit2 was obtained in source-code form from its github repository: 
+https://github.com/libgit2/libgit2/
+
+No changes were made to its original source code. 
+
+Copyright notice (https://raw.githubusercontent.com/libgit2/libgit2/main/COPYING):
+
+$(curl -L https://raw.githubusercontent.com/libgit2/libgit2/main/COPYING)
+
+${SPLIT}
+
+zlib:
+
+Zlib was obtained in binary form via official distribution channels.
+No changes were made to its original source code. 
+
+Copyright notice (https://zlib.net/zlib_license.html):
+
+ /* zlib.h -- interface of the 'zlib' general purpose compression library
+  version 1.2.11, January 15th, 2017
+
+  Copyright (C) 1995-2017 Jean-loup Gailly and Mark Adler
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+
+  Jean-loup Gailly        Mark Adler
+  jloup@gzip.org          madler@alumni.caltech.edu
+
+*/
+EOF