Sign off commit history

sign.sh

#!/bin/bash

# Add missing DCOs for current branch (starting from merge base to master)
# Following commit history as an example, this script will affect commits E,F,G.
#
#                     v master
# A - B - C - D - H - I
#          \
#           E - F - G
#                   ^ feature (HEAD)
#
# Please make sure the commits were submitted originated from you, or you have
# permission to submit the code. 

git filter-branch -f --msg-filter \
  'git interpret-trailers --if-missing add \
    --trailer "Signed-off-by: $(git config user.name) <$(git config user.email)>"' \
  master..HEAD