Merge branch '16312-s3-signature-v4'

closes #16312

Arvados-DCO-1.1-Signed-off-by: Tom Clegg <tom@tomclegg.ca>

diff --cc doc/admin/upgrading.html.textile.liquid
index 070e58983a50fc01c8943d6d29aa46b3d0453361,dff4fc7e34c7c7c51055db42dc98dbced6ee62df..edd92fa0ea1a117a91d60f3453dc6c3bd146ca3d
--- 1/doc/admin/upgrading.html.textile.liquid
--- 2/doc/admin/upgrading.html.textile.liquid
+++ b/doc/admin/upgrading.html.textile.liquid
@@@ -38,12 -38,12 +38,16 @@@ h2(#master). development master (as of 
  
  "Upgrading from 2.0.0":#v2_0_0
  
 -None in current development master.
 +h3. Removing sso-provider
 +
 +The SSO (single sign-on) component is deprecated and will not be supported in future releases. Existing configurations will continue to work in this release, but you should switch to one of the built-in authentication mechanisms as soon as possible. See "setting up web based login":{{site.baseurl}}/install/setup-login.html for details.
 +
 +After migrating your configuration, uninstall the @arvados-sso-provider@ package.
  
+ h3. S3 signatures
+ 
+ Keepstore now uses "V4 signatures":https://docs.aws.amazon.com/AmazonS3/latest/API/sig-v4-authenticating-requests.html by default for S3 requests. If you are using Amazon S3, no action is needed; all regions support V4 signatures. If you are using a different S3-compatible service that does not support V4 signatures, add @V2Signature: true@ to your volume driver parameters to preserve the old behavior. See "configuring S3 object storage":{{site.baseurl}}/install/configure-s3-object-storage.html.
+ 
  h2(#v2_0_0). v2.0.0 (2020-02-07)
  
  "Upgrading from 1.4":#v1_4_1

diff --cc lib/config/config.default.yml
Simple merge

diff --cc lib/config/generated_config.go
Simple merge

diff --cc sdk/go/arvados/config.go
Simple merge