Tucu, after MR-3443, proxy users should work - at least the doAs part.
There's several issues after that
1. MiniMRYarnCluster - set the default app staging dir to the test Working dir. Ran into
testValidProxyUser(org.apache.hadoop.mapreduce.v2.TestMiniMRProxyUser): Permission denied: user=u1, access=EXECUTE, inode="/home":<REPLACED_USER>:supergroup:drwxr-x---
getJobConf needs -> conf.set(MRJobConfig.MR_AM_STAGING_DIR, "/tmp");
2. The host list for the proxy user - needs to include the host IP, instead of just "localhost"
3. After this, the proxy user cannot read the AppJar - since it was written out by the original user when creating the cluster (MiniMRClientClusterFactory).
4. Another possible issue after this, would be creation of additional dirs for job history on hdfs.