Gitlab Runner error exec: "sh": executable file not found in $PATH

I have this error when running a container on Gitlab CI

ERROR: Job failed (system failure): Error response from daemon: OCI runtime create failed: container_linux.go:380: starting container process caused: exec: "sh": executable file not found in $PATH: unknown (exec.go:57:0s)

My .Dockerfile

FROM golang:1.16-alpine AS builder
ENV \
	OUTDIR='/out' \
	GO111MODULE='on'    

WORKDIR /app
COPY go.mod /app/
COPY go.sum /app/
RUN go mod download
COPY . /app/
RUN CGO_ENABLED=0 GOBIN=${OUTDIR}/usr/bin/ go install .

FROM scratch
COPY --from=builder /out/ /
ENTRYPOINT ["/usr/bin/app-cli"]

My .gitlab-ci.yml

stages:
  - validation

validation:
  image:
    name: gitlab.mycompany.net:4567/myteam/app-cli:latest
    entrypoint: [""]
  stage: validation
  rules:
    - if: '$CI_MERGE_REQUEST_IID'
  script:
    - ls

Is this error related to my dockerfile or the gitlab ci ?

I can run this locally by
docker run --rm -ti gitlab.mycompany.net:4567/myteam/app-cli:latest
but not at gitlab runner

Giving an empty entrypoint and not giving the entrypoint at all are not the same thing.

In the docker run command, you are not giving any entrypoint. Hence, the docker image runs with the default entrypoint ENTRYPOINT ["/usr/bin/app-cli"].

In the gitlab-ci, you are overwriting the default entrypoint with an empty one entrypoint: [""] where executable file not found.

Try this:

validation:
  image:
    name: gitlab.mycompany.net:4567/myteam/app-cli:latest
    entrypoint: ["/usr/bin/app-cli"]

Besides overwriting the entrypoint as already pointed out, the issue is that you are calling ls as the script which requires a shell.
Try just calling your application in the script part /usr/bin/app-cli.

found the answer

I just need to change the
FROM scratch to
FROM alpine:latest
so now I can use the sh