Correctly detect GPG key ID for go script

Check the key directly from Release.gpg instead of trying to introspect the
GPG keyring, which sometimes doesn't work if there is more than one key.

Author: Rohan Singh

debify.sh

@@ -48,7 +48,8 @@ mv ~/.aptly/public /repo
 
 if [ ! -z "$KEYSERVER" ] && [ ! -z "$URI" ]
 then
-    GPG_KEY_ID=$(gpg -K --with-colons | head -1 | cut -d: -f5)
+    release_sig_path=$(find /repo/dists -name Release.gpg | head -1) 
+    gpg_key_id=$(gpg --list-packets $release_sig_path | grep -oP "(?<=keyid ).+")
 
     echo "# setup script for $URI" > /repo/go
 
@@ -64,7 +65,7 @@ END
     esac
 
     cat >> /repo/go <<-END
-apt-key adv --keyserver $KEYSERVER --recv-keys $GPG_KEY_ID
+apt-key adv --keyserver $KEYSERVER --recv-keys $gpg_key_id
 echo "deb $URI $APTLY_DISTRIBUTION $APTLY_COMPONENT" >> /etc/apt/sources.list
 
 apt-get update