To get the logs of all the pods inside a project, one could use a bash script:

#!/usr/bin/env bash
for p in $(oc get pods -n $1 | cut -f 1 -d ' ' | tail -n +2); do
    oc logs $p
done

1. Save the code as pods-all-ns.sh
2. Run the bash script using the command line providing the project name ./pods-all-ns.sh default

To get all the logs of all the pods of a deployment, one could a label selector oc logs -l service=logevents