K6 using docker in azure pipeline

MVB · October 7, 2021, 7:36am

I am trying to run K6 tests in azure pipeline using docker commands. K6 tests runs fine without --out option:
$ docker run -it --rm
-v :/scripts
-v :/jsonoutput
loadimpact/k6 run --out json=/jsonoutput/my_test_result.json /scripts/script.js

When I give --out option to generate output json file it gives me error as “permission denied”. All directories paths are valid.
Please guide if we need any specific permission while creating output file while running through pipeline.

olhayevtushenko · October 13, 2021, 11:05am

Hi @MVB,
It looks like an issue with the volume mount and/or mismatch of user rather than k6 itself. Please note how k6 image is run:

github.com

grafana/k6/blob/master/Dockerfile

FROM golang:1.20-alpine3.17 as builder
WORKDIR $GOPATH/src/go.k6.io/k6
COPY . .
RUN apk --no-cache add git=~2
RUN CGO_ENABLED=0 go install -a -trimpath -ldflags "-s -w -X go.k6.io/k6/lib/consts.VersionDetails=$(date -u +"%FT%T%z")/$(git describe --tags --always --long --dirty)"

# Runtime stage
FROM alpine:3.17 as release

# hadolint ignore=DL3018
RUN apk add --no-cache ca-certificates && \
    adduser -D -u 12345 -g 12345 k6
COPY --from=builder /go/bin/k6 /usr/bin/k6

USER k6
WORKDIR /home/k6

ENTRYPOINT ["k6"]

# Legacy loadimpact/k6 image

This file has been truncated. show original

I think it makes sense to check permissions set on /jsonoutput/ folder with this in mind.

MVB · October 14, 2021, 9:03am

Thanks for the response.
This problem has been solved by granting chmod 777 to the report file. Now it is generating report. But the generated json file is not valid. It is giving error as Data at root level is invalid. Any help on this one?

olhayevtushenko · October 15, 2021, 8:14am

Hm, k6 output works without such error with local Docker setup for me and looking here, it sounds as an exception generated by Azure VM? Can you see a full stack for this exception in logs / console / etc? That should help to diagnose what exactly causes it.