Cannot connect to Elasticsearch from Go server running in Docker [duplicate] - docker

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Connection refused on docker container
(7 answers)
Closed 3 years ago.
I have set up an environment today that runs a golang:1.13-alpine image, along with the latest images for Elasticsearch and Kibana.
Elasticsearch and Kibana are running fine when accessing from my local machine, but I cannot connect to Elasticsearch through the Go server. I have put this together from guides I have found and followed.
I am still a bit green using Docker. I have an idea that I am pointing at the wrong ip address in the container, but I am unsure how to fix it. Hope someone can guide me in the right direction.
docker-compose.yml:
version: "3.7"
services:
web:
image: go-docker-webserver
build: .
ports:
- "8080:8080"
elasticsearch:
image: docker.elastic.co/elasticsearch/elasticsearch:7.4.2
environment:
node.name: elasticsearch
cluster.initial_master_nodes: elasticsearch
cluster.name: docker-cluster
bootstrap.memory_lock: "true"
ES_JAVA_OPTS: -Xms256m -Xmx256m
ulimits:
memlock:
soft: -1
hard: -1
ports:
- "9200:9200"
kibana:
image: docker.elastic.co/kibana/kibana:7.4.2
ports:
- "5601:5601"
links:
- elasticsearch
Dockefile:
FROM golang:1.13-alpine as builder
RUN apk add --no-cache --virtual .build-deps \
bash \
gcc \
git \
musl-dev
RUN mkdir build
COPY . /build
WORKDIR /build
RUN go get
RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -ldflags '-extldflags "-static"' -o webserver .
RUN adduser -S -D -H -h /build webserver
USER webserver
FROM scratch
COPY --from=builder /build/webserver /app/
WORKDIR /app
EXPOSE 8080
EXPOSE 9200
CMD ["./webserver"]
main.go:
func webserver(logger *log.Logger) *http.Server {
router := http.NewServeMux()
router.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
es, err := elasticsearch.NewDefaultClient()
if err != nil {
log.Fatalf("Error creating the client: %s", err)
}
res, err := es.Info()
if err != nil {
log.Fatalf("Error getting response: %s", err)
}
log.Println(res)
})
return &http.Server{
Addr: listenAddr,
Handler: router,
ErrorLog: logger,
ReadTimeout: 5 * time.Second,
WriteTimeout: 10 * time.Second,
IdleTimeout: 15 * time.Second,
}
}
When I boot the server, everything is running fine and I can access Kibana and query the data that I have indexed, but as soon as I hit localhost:8080 in Postman, the server dies and outputs:
web_1 | 2019/11/26 16:40:40 Error getting response: dial tcp 127.0.0.1:9200: connect: connection refused
go-api_web_1 exited with code 1

Answer 1

You can mention the network as bridge in the docker-compose file and verify once , How it works .
version: "3.7"
services:
web:
image: go-docker-webserver
build: .
ports:
- "8080:8080"
networks:
- elastic
elasticsearch:
image: docker.elastic.co/elasticsearch/elasticsearch:7.4.2
environment:
node.name: elasticsearch
cluster.initial_master_nodes: elasticsearch
cluster.name: docker-cluster
bootstrap.memory_lock: "true"
ES_JAVA_OPTS: -Xms256m -Xmx256m
ulimits:
memlock:
soft: -1
hard: -1
ports:
- "9200:9200"
networks:
- elastic
kibana:
image: docker.elastic.co/kibana/kibana:7.4.2
ports:
- "5601:5601"
links:
- elasticsearch
networks:
- elastic
networks:
elastic:
driver: bridge
set the kernal setting to 262144 :
sysctl -w vm.max_map_count=262144