olliefr / docker-gs-ping

[ARCHIVED] A simple Go server example for Docker's "Getting Started with Docker and Go".

Caution

This repo is out-of-date and archived. The development continues at docker/docker-gs-ping.

docker-gs-ping

A simple Go server/microservice example for Docker's Go Language Guide.

Notable features:

• Includes a multi-stage Dockerfile.
• Has a CI pipeline using GitHub Actions to run tests.
• Has a CD pipeline using GitHub Actions to publish to Docker Hub.

Want moar?!

There is a more advanced example in olliefr/docker-gs-ping-roach using CockroachDB.

Contributing

This was written for an introduction section of the Docker tutorial and as such it favours brevity and pedagogical clarity over robustness.

Thus, feedback is welcome, but please no nits or pedantry. Ain't nobody got time for that 🙃

License

Apache-2.0 License

docker-gs-ping's Issues

Adding Testconstainers for Go

Hi 👋 from Testcontainers for Go community!

We'd like to contribute a PR including copies of the existing tests, using Testcontainers for Go.

Do you think it could be something to discuss? Thanks in advance!

CI/CD Tutorial: Push to Docker fails if GitHub and Docker usernames are different

docker-gs-ping/.github/workflows/release.yml

Line 37 in 003af37

tags: ${{ github.repository }}:latest

I think the above line requires modification if the user's GitHub and Docker Hub usernames don't match. It might be worth noting in the CI/CD portion of the tutorial.

I'd be happy to submit a PR, but I think my own solution is a bit of a hack and probably not what you want either here or in the tutorial. I'm sure there's a smarter way to use secrets.DOCKER_HUB_USERNAME, but I can't figure it out.

I'm also not sure whether the PR should start with the code repo or the tutorial repo, so I figured I'd start with a discussion here first.

More details below.

---

First, this is such a useful tutorial. The CI/CD portion particularly has been tremendously helpful. I'm new to Docker (hence going through tutorials) and had no real intuition for how people were using it for CD in particular. The tutorial's style and simple examples have brought me a long way. Thank you.

Now to the issue:

The release workflow was failing during the Build and push Docker image step with the following:

#12 pushing dodsonmg/docker-gs-ping:latest with docker
#12 pushing layer bb0e01146d01
...
#12 pushing layer 72e830a4dff5 0.3s done
#12 ERROR: denied: requested access to the resource is denied
------
 > pushing dodsonmg/docker-gs-ping:latest with docker:
------
error: denied: requested access to the resource is denied
Error: buildx failed with: error: denied: requested access to the resource is denied

For no useful reason, I had different usernames for GitHub and Docker Hub. ${{ github.repository }} resolves to dodsonmg/docker-gs-ping (as you can see above...); however, since dodsonmg wasn't my Docker Hub username, the push was failing, despite the fact that the Login to Docker Hub step was passing.

I modified the line to:
tags: md403/docker-gs-ping:latest (md403 being my Docker Hub username) and it worked fine.

Thankfully, my GitHub username is also available on Docker Hub, so I changed it and the repo code works as expected without modifications.

Encountered Docker Error: "When using COPY with more than one source file, the destination must be a directory and end with a /""

OS & Docker version
My docker version: 20.10.7, build f0df35096d
OS: arch-linux

Reproducing the Error:
Good day olliefr, I encountered an error when going through the golang docker tutorial.

The following commands were run:
git clone https://github.com/olliefr/docker-gs-ping
cd docker-gs-ping
docker build --tag docker-gs-ping .

The Error
When using COPY with more than one source file, the destination must be a directory and end with a /

The Solution
By changing line 12 in the Dockerfile from:
COPY *.go .
to
COPY *.go ./

I am not sure if this solution will cause other issues. I doubt it but I can investigate and make a pull request if this error is significant enough.

I am also curious if other people encountered this error or if it is only on my machine.

Go version no longer officially supported

Hi @olliefr,

Since Go 1.16 is no longer officially supported, can this sample be updated to a newer version?
If necessary, I can help create a PR here and in the Docker Docs if no concerns.