FileNotFoundError when attempting to generate code for Gateway API CRDs #4512
Description
I am attempting to generate the code for multiple new CRDs, my goal is to use the client to dynamically generate resources for Gateway API and kgateway.
Describe the bug
I initially followed this tutorial.
First issue I had was that the ghcr.io/kubernetes-client/java/crd-model-gen:v1.0.6 suggested image relied on an outdated docker version:
Error response from daemon: client version 1.40 is too old. Minimum supported API version is 1.44, please upgrade your client to a newer version
I am on Linux Mint with docker 29.1.4 which uses the 1.52 API version which require 1.44 as showed in docker version output.
I fixed this issue by cloning the project, editing client-java-contrib/Dockerfile from docker:stable to docker:latest and rebuilding the image with docker build --tag local-crd-model-gen ..
So the commands I am running are now:
mkdir -p /tmp/java && cd /tmp/java
docker run --rm \
-v /var/run/docker.sock:/var/run/docker.sock \
-v "$(pwd)":"$(pwd)" \
-it \
--network host \
local-crd-model-gen \
/generate.sh \
https://github.com/kubernetes-sigs/gateway-api/releases/download/v1.4.1/experimental-install.yaml \
-n io.k8s.networking.gateway \
-p io.k8s.networking.gateway \
-o "$(pwd)"Given output is:
Creating cluster "crd-model-gen" ...
✓ Ensuring node image (kindest/node:v1.25.3) 🖼
✓ Preparing nodes 📦
✓ Writing configuration 📜
✓ Starting control-plane 🕹️
✓ Installing CNI 🔌
✓ Installing StorageClass 💾
Set kubectl context to "kind-crd-model-gen"
You can now use your cluster with:
kubectl cluster-info --context kind-crd-model-gen
Have a nice day! 👋
Verifying CRD installation..
Deleting cluster "crd-model-gen" ...
KUBERNETES_CRD_GROUP_PREFIX:
OPENAPI_MODEL_LENGTH: 2
PACKAGE_NAME:
GENERATE_APIS: false
CLIENT_VERSION: 5.0-SNAPSHOT
OUTPUT_DIR: /gen
HIDE_GENERATION_TIMESTAMP: false
LIBRARY: okhttp-gson
rendering settings file to /tmp/settings
reading input openapi specs
--- Building docker image kubernetes-java-client-gen-with-openapi-generator:v1...
[+] Building 0.4s (13/13) FINISHED docker:default
=> [internal] load build definition from Dockerfile 0.0s
=> => transferring dockerfile: 1.88kB 0.0s
=> [internal] load metadata for docker.io/library/maven:3.9.6-eclipse-temurin-11 0.3s
=> [internal] load .dockerignore 0.0s
=> => transferring context: 2B 0.0s
=> [1/8] FROM docker.io/library/maven:3.9.6-eclipse-temurin-11@sha256:b3573fcc754a04d96c00a4bb932a5c723493ebbb3d5676e0adaa59d386a5448c 0.0s
=> [internal] load build context 0.0s
=> => transferring context: 112.11kB 0.0s
=> CACHED [2/8] RUN apt-get update && apt-get -y install git python3-pip && pip install urllib3==1.24.2 0.0s
=> CACHED [3/8] RUN mkdir /source && cd /source && mkdir openapi-generator && cd openapi-generator && git init && git remote add origin https://g 0.0s
=> CACHED [4/8] RUN chmod -R go+rwx /root && umask 0 && cd /source/openapi-generator && mvn install -DskipTests -Dmaven.test.skip=true -pl modules/openapi-genera 0.0s
=> CACHED [5/8] COPY openapi-generator/generate_client_in_container.sh /generate_client.sh 0.0s
=> CACHED [6/8] COPY preprocess_spec.py / 0.0s
=> CACHED [7/8] COPY custom_objects_spec.json / 0.0s
=> CACHED [8/8] COPY java.xml /generation_params.xml 0.0s
=> exporting to image 0.0s
=> => exporting layers 0.0s
=> => writing image sha256:d63b354f39443c75b7984c85e8cca75eb1311ffcded55ef7292bb2c168db43ca 0.0s
=> => naming to docker.io/library/kubernetes-java-client-gen-with-openapi-generator:v1 0.0s
--- Running generator inside container...
/source/openapi-generator /
/
--- Downloading and pre-processing OpenAPI spec
Traceback (most recent call last):
File "//preprocess_spec.py", line 592, in <module>
sys.exit(main())
File "//preprocess_spec.py", line 568, in main
with open(unprocessed_spec, 'r') as content:
FileNotFoundError: [Errno 2] No such file or directory: '/output_dir/swagger.json.unprocessed'
This error is similar to Issue 1497, except I am on an up to date Linux Mint 22 with no specific configuration that I am aware of.
Details of used versions
Client Version
NA, this is about the CRD code generation, I built the docker image from the latest master commit (5a74f7b)
Kubernetes Version
kubectl version output on the container:
Client Version: v1.28.2
Kustomize Version: v5.0.4-0.20230601165947-6ce0bf390ce3
Error from server (NotFound): the server could not find the requested resource
Java Version
NA
To Reproduce
Specified in the bug description
Expected behavior
No error
KubeConfig
NA
Server (please complete the following information):
- OS: Linux Mint 22
- Environment docker:latest container
- Cloud NA (CRD generation)
Additional context
docker version output on the container built from the ghcr.io/kubernetes-client/java/crd-model-gen:v1.0.6 image:
Client: Docker Engine - Community
Version: 19.03.14
API version: 1.40
Go version: go1.13.15
Git commit: 5eb3275
Built: Tue Dec 1 19:14:24 2020
OS/Arch: linux/amd64
Experimental: false
Error response from daemon: client version 1.40 is too old. Minimum supported API version is 1.44, please upgrade your client to a newer version
docker version output on the container built from the Dockerfile:
Client:
Version: 29.1.4
API version: 1.52
Go version: go1.25.5
Git commit: 0e6fee6
Built: Thu Jan 8 19:55:48 2026
OS/Arch: linux/amd64
Context: default
Server: Docker Engine - Community
Engine:
Version: 29.1.4
API version: 1.52 (minimum version 1.44)
Go version: go1.25.5
Git commit: 08440b6
Built: Thu Jan 8 19:57:04 2026
OS/Arch: linux/amd64
Experimental: false
containerd:
Version: v2.2.1
GitCommit: dea7da592f5d1d2b7755e3a161be07f43fad8f75
runc:
Version: 1.3.4
GitCommit: v1.3.4-0-gd6d73eb8
docker-init:
Version: 0.19.0
GitCommit: de40ad0
docker version output on the host machine:
Client: Docker Engine - Community
Version: 29.1.4
API version: 1.52
Go version: go1.25.5
Git commit: 0e6fee6
Built: Thu Jan 8 19:57:04 2026
OS/Arch: linux/amd64
Context: default
Server: Docker Engine - Community
Engine:
Version: 29.1.4
API version: 1.52 (minimum version 1.44)
Go version: go1.25.5
Git commit: 08440b6
Built: Thu Jan 8 19:57:04 2026
OS/Arch: linux/amd64
Experimental: false
containerd:
Version: v2.2.1
GitCommit: dea7da592f5d1d2b7755e3a161be07f43fad8f75
runc:
Version: 1.3.4
GitCommit: v1.3.4-0-gd6d73eb8
docker-init:
Version: 0.19.0
GitCommit: de40ad0