docker - Dockerize app cannot connect to Faktory worker

Question

I am trying to wrap my golang worker app into docker image. I have successfully build image. But when I run, it turns out that my docker container cannot connect to my faktory. Here is my docker file:

# builder image
FROM golang:1.14.11-alpine AS builder

# specific directory for build process
WORKDIR /usr/src/build

# copying the source code 
# to the current working directory
COPY . .
RUN apk add --no-cache git

ENV GOPRIVATE=gitlab.com/pinvest/backends/backend-structs
# RUN echo "machine gitlab.com login jais_pinhome password pinhome123" > ~/.netrc
COPY .netrc /root/.netrc

# executing build process
RUN GOOS=linux go build -ldflags="-s -w" -o app

# runtime image
FROM golang:1.14.11-alpine AS runtime

# create and use non-root user
# to increase container security 
# ref https://pythonspeed.com/articles/root-capabilities-docker-security/
RUN adduser myuser --disabled-password

USER myuser

WORKDIR /home/myuser

# copy the executable binary file from builder directory
# to the current working directory
COPY --from=builder /usr/src/build/app .

# exposing port
EXPOSE 8080

# run the application
CMD ["./app"]

and here is the log my faktory:

jaisanas@DESKTOP-H2GJLP8:~/work/worker$ faktory
Faktory 1.4.0
Copyright ? 2021 Contributed Systems LLC
Licensed under the GNU Public License 3.0
I 2021-01-23T01:52:15.239Z Initializing redis storage at /home/jaisanas/.faktory/db, socket /home/jaisanas/.faktory/db/redis.sock
I 2021-01-23T01:52:15.251Z Web server now listening at localhost:7420
I 2021-01-23T01:52:15.251Z PID 6897 listening at localhost:7419, press Ctrl-C to stop

If I run the worker container returns error like below:

jaisanas@DESKTOP-H2GJLP8:~/work/worker$ docker run --env-file docker_env.sh -p 8080:27017 --name woker worker
2021/01/23 01:48:40.502243 [0 <nil>] unsupported protocol scheme ""
2021/01/23 01:48:40.502380 faktory_worker_go PID 1 now ready to process jobs
2021/01/23 01:48:40.681601 dial tcp 127.0.0.1:7419: connect: connection refused
2021/01/23 01:48:40.704490 dial tcp 127.0.0.1:7419: connect: connection refused
2021/01/23 01:48:40.711848 dial tcp 127.0.0.1:7419: connect: connection refused
2021/01/23 01:48:40.845921 dial tcp 127.0.0.1:7419: connect: connection refused
2021/01/23 01:48:40.876556 dial tcp 127.0.0.1:7419: connect: connection refused

Is anyone here familiar with wrapping up golang faktory app into docker and facing the similar issue?

question from:https://stackoverflow.com/questions/65878947/dockerize-app-cannot-connect-to-faktory-worker

Answer 1

Inside your docker container, where the worker is running, localhost 127.0.0.1 refers to the container itself, not your host machine (where faktory is running). To access the host machine from inside the Docker container, you need to connect to the special address host.docker.internal.

In other words, you should set up your worker to connect to faktory at host.docker.internal:7419 instead of 127.0.0.1:7419

See the official Docker documentation for more details.