I have been reading a lot of similar issues on different languages, none of them are Go.
I just created a Dockerfile with the instructions I followed on official Docker hub page:
FROM golang:1.17.3
WORKDIR /go/src/app
COPY . .
RUN go get -d -v ./...
RUN go install -v ./...
CMD ["app"]
This is my folder structure:
users-service
|-> .gitignore
|-> Dockerfile
|-> go.mod
|-> main.go
|-> README.md
If anyone needs to see some code, this is how my main.go looks like:
package main
import "fmt"
func main() {
fmt.Println("Hello, World!")
}
- I ran
docker build -t users-service .:
$ docker build -t users-service .
[ ] Building 5.5s (11/11) FINISHED
=> [internal] load build definition from Dockerfile 0.1s
=> => transferring dockerfile: 154B 0.1s
=> [internal] load .dockerignore 0.0s
=> => transferring context: 2B 0.0s
=> [internal] load metadata for docker.io/library/golang:1.17.3 3.3s
=> [auth] library/golang:pull token for registry-1.docker.io 0.0s
=> [1/5] FROM docker.io/library/golang:1.17.3@sha256:6556ce40115451e40d6afbc12658567906c9250b0fda250302dffbee9d529987 0.3s
=> [internal] load build context 0.1s
=> => transferring context: 2.05kB 0.0s
=> [2/5] WORKDIR /go/src/app 0.1s
=> [3/5] COPY . . 0.1s
=> [4/5] RUN go get -d -v ./... 0.6s
=> [5/5] RUN go install -v ./... 0.7s
=> exporting to image 0.2s
=> => exporting layers 0.1s
=> => writing image sha256:1f0e97ed123b079f80eb259dh3e34c90a48bf93e8f55629d05044fec8bfcaca6 0.0s
=> => naming to docker.io/library/users-service 0.0s
Use 'docker scan' to run Snyk tests against images to find vulnerabilities and learn how to fix them
- Then I ran
docker run users-servicebut I get that error:
$ docker run users-service
docker: Error response from daemon: OCI runtime create failed: container_linux.go:380: starting container process caused: exec: "app": executable file not found in $PATH: unknown.
I remember I had some troubles with GOPATH environment variable in Visual Studio Code on Windows, maybe it's related... Any sugguestions?
CodePudding user response：
The official Docker documentation has useful instructions for building a Go image: https://docs.docker.com/language/golang/build-images/
In summary, you need to build your Go binary and you need to configure the CMD appropriately, e.g.:
FROM golang:1.17.3
WORKDIR /app
COPY main.go .
COPY go.mod ./
RUN go build -o /my-go-app
CMD ["/my-go-app"]
Build the container:
$ docker build -t users-service .
Run the docker container:
$ docker run --rm -it users-service
Hello, World!
CodePudding user response：
Your "app" executable binary should be available in your $PATH to call globally without any path prefix. Otherwise, you have to supply your full path to your executable like CMD ["/my/app"]
Also, I recommend using an ENTRYPOINT instruction. ENTRYPOINT indicates the direct path to the executable, while CMD indicates arguments supplied to the ENTRYPOINT.
Using combined RUN instructions make your image layers minimal, your overall image size becomes little bit smaller compared to using multiple RUNs.