Troubleshooting

Development

Restart buildkit

Often times when coming back to a docker build, the buildkit container needs to be restarted for some reason.

------                                                                                                                                                                                                             
 > [base 4/4] RUN   echo "**** install packages ****" &&   apk add --no-cache     wget=1.21.1-r1     gzip=1.10-r1:
#9 0.139 container_linux.go:367: starting container process caused: process_linux.go:340: applying cgroup configuration for process caused: mkdir /sys/fs/cgroup/blkio/buildkit: no such file or directory
------

To fix this, run the following command to get the container name and then manually restart the container.

$ docker ps
CONTAINER ID        IMAGE                           ...  NAMES
75316abfd2e3        moby/buildkit:buildx-stable-1   ...  buildx_buildkit_mybuilder0
$ docker restart buildx_buildkit_mybuilder0

Alpine Packages

Hadolint recommends that the package version be pinned (DL3018). However, Alpine repositories don't keep older version of packages and so building older versions of Docker images may give errors. To solve these errors, the package versions need to be updated.

There are multiple ways to get the package version.

1. Use the online database to lookup the package version.
2. Use the error output to get the latest version of the package.

#42 0.206 **** install packages ****
#42 0.210 fetch http://dl-cdn.alpinelinux.org/alpine/v3.12/main/x86_64/APKINDEX.tar.gz
#42 0.332 fetch http://dl-cdn.alpinelinux.org/alpine/v3.12/community/x86_64/APKINDEX.tar.gz
#42 0.442 ERROR: unsatisfiable constraints:
#42 0.458   mysql-client-10.4.17-r1:
#42 0.458     breaks: world[mysql-client=10.4.15-r0]

In the above example, the mysql-client package version needs to be set to 10.4.17-r1.

3. Launch a shell of the Alpine base image and get the policy of the package you're trying to install.

$ docker run --rm -it alpine:3.13.1 /bin/ash
$ apk policy <package name>

4. Alternatively, you can get the package version directly.

$ docker run --rm -it alpine:3.13.1 /bin/ash -c "apk update && apk policy <package name>"
...
<package name> policy:
  1.21.1-r1:
...

Make sure alpine:3.13.1 is replaced with the base image version that you're using and that <package name> is replaced with the name of the package you're trying to install.

Makefile

Most issues with the Makefile are because the command lines underneath the target are not prefixed with Tab. See reference.

Publishing

If you receive an unauthorized error when trying to publish the image using the ci github action, it's most likely because you either have invalid credentials, or with respect to quay.io, the repository hasn't been created or the robot account hasn't been given write access. See Publishing#Quay.io

Unauthorized 401