Adding PGP signing to the release process

Signed-off-by: Matt Farina <matt@mattfarina.com>

docs/release_checklist.md

@@ -250,7 +250,21 @@ git tag --sign --annotate "${RELEASE_NAME}" --message "Helm release ${RELEASE_NA
 git push upstream $RELEASE_NAME
 ```
 
-## 7. Write the Release Notes
+## 7. PGP Sign the downloads
+
+While hashes provide a signature that the content of the downloads is what it
+was generated, signed packages provide traceability of where the package came
+from.
+
+To do this follow the following steps:
+
+1. Download each of the release bundles generated by the CI system
+2. Sign each of them using GnuPG using the command `gpg --armor --detach-sign [FILE NAME]`.
+   This will generate a file name `[FILE NAME].asc` with an ascii armored signature.
+
+Each of the signature files needs to be uploaded to the release on GitHub.
+
+## 8. Write the Release Notes
 
 We will auto-generate a changelog based on the commits that occurred during a
 release cycle, but it is usually more beneficial to the end-user if the release
@@ -286,14 +300,14 @@ The community keeps growing, and we'd love to see you there!
 
 Download Helm X.Y. The common platform binaries are here:
 
-- [MacOS amd64](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-darwin-amd64.tar.gz) ([checksum](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-darwin-amd64.tar.gz.sha256))
+- [MacOS amd64](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-darwin-amd64.tar.gz) ([checksum](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-darwin-amd64.tar.gz.sha256) / CHECKSUM_VAL)
-- [Linux amd64](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-linux-amd64.tar.gz) ([checksum](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-linux-amd64.tar.gz.sha256))
+- [Linux amd64](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-linux-amd64.tar.gz) ([checksum](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-linux-amd64.tar.gz.sha256) / CHECKSUM_VAL)
-- [Linux arm](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-linux-arm.tar.gz) ([checksum](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-linux-arm.tar.gz.sha256))
+- [Linux arm](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-linux-arm.tar.gz) ([checksum](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-linux-arm.tar.gz.sha256) / CHECKSUM_VAL)
-- [Linux arm64](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-linux-arm64.tar.gz) ([checksum](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-linux-arm64.tar.gz.sha256))
+- [Linux arm64](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-linux-arm64.tar.gz) ([checksum](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-linux-arm64.tar.gz.sha256) / CHECKSUM_VAL)
-- [Linux i386](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-linux-386.tar.gz) ([checksum](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-linux-386.tar.gz.sha256))
+- [Linux i386](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-linux-386.tar.gz) ([checksum](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-linux-386.tar.gz.sha256) / CHECKSUM_VAL)
-- [Linux ppc64le](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-linux-ppc64le.tar.gz) ([checksum](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-linux-ppc64le.tar.gz.sha256))
+- [Linux ppc64le](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-linux-ppc64le.tar.gz) ([checksum](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-linux-ppc64le.tar.gz.sha256) / CHECKSUM_VAL)
-- [Linux s390x](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-linux-s390x.tar.gz) ([checksum](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-linux-s390x.tar.gz.sha256))
+- [Linux s390x](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-linux-s390x.tar.gz) ([checksum](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-linux-s390x.tar.gz.sha256) / CHECKSUM_VAL)
-- [Windows amd64](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-windows-amd64.zip) ([checksum](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-windows-amd64.zip.sha256))
+- [Windows amd64](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-windows-amd64.zip) ([checksum](https://storage.googleapis.com/kubernetes-helm/helm-vX.Y.Z-windows-amd64.zip.sha256) / CHECKSUM_VAL)
 
 Once you have the client installed, upgrade Tiller with `helm init --upgrade`.
 
@@ -335,7 +349,7 @@ in the example above.
 Once finished, go into GitHub and edit the release notes for the tagged release
 with the notes written here.
 
-## 8. Evangelize
+## 9. Evangelize
 
 Congratulations! You're done. Go grab yourself a $DRINK_OF_CHOICE. You've earned
 it.