I was able to visit my one and only Bundesliga game for the closed 2016/2017 season.
Obviously, I brought my camera and took some footage of the goalkeeper warm-up of both teams.
Unfortunately it is not the entire warm-up as I focused on the teams later on. However, please enjoy the two videos below, the first one shows the FC Schalke and the second one the Eintracht Frankfurt goalkeeper warm-up.
Unfortunately, there will be a short part of the team warm-up inside the following video of the Eintracht Frankfurt goalkeeper. During these seconds, the goalkeepers are visible in the upper(-right) part of the screen. I apologize for inconvenience.