How do I configure the db2inst1 user to use Kaniko when building a db2 ibmcom/db2:11.5 image?

Question

I want to build a db2 image (v 11.5.8.0) with kaniko (latest v).

To do this I have a Dockerfile that initializes my db2 image, but when I build I don't have the user db2inst1 which is created by default nor the cli db2 (sqllib).

• Here's my dockerfile :

   FROM ibmcom/db2:11.5.8.0
    USER db2inst1
    COPY initDatabse.sh initDatabase.sh
    RUN source ~/.bashrc && initDatabase.sh
  

• Here's my init :

  #!/bin/bash -x
  
    set -euf -o pipefail
    db2start
    db2 CONNECT TO DB
    db2 DISCONNECT DB
    db2stop force
  

• here's the error :

error building image: error building stage: failed to execute command: credentials: get uid/gid: user db2inst1 is not a uid and does not exist on the system

• here's the command played :

   docker run -v /myFolder:/workspace \
        -v ~/.docker/config.json:/kaniko/.docker/config.json \
        gcr.io/kaniko-project/executor:debug \
        --context dir:///workspace/ \
        --dockerfile /workspace/Containerfile \
        --no-push