Retrieve the latest kindest/node image for tests by joaopapereira · Pull Request #1120 · carvel-dev/kapp

joaopapereira · 2026-03-27T21:00:57Z

What this PR does / why we need it:

After talking with Release team of K8s they told me that they do not always create images for every version of k8s. In this PR we are changing our logic to retrieve the latest publish image of kindest/node from docker hub itself.

As part of the change we are also adding a warning, because now these 2 versions are decoupled, whenever a new minor of k8s is released and they do not publish a new kindest/node image, we write a warning in the output.

Does this PR introduce a user-facing change?

None

Additional Notes for your reviewer:

Review Checklist:

Follows the developer guidelines
Relevant tests are added or updated
Relevant docs in this repo added or updated
Relevant carvel.dev docs added or updated in a separate PR and there's
a link to that PR
Code is at least as readable and maintainable as it was before this
change

Copilot

Pull request overview

Updates the CI workflow to determine the latest Kubernetes version used for tests by querying Docker Hub for the newest kindest/node image tag, and emits a warning when kind images lag behind upstream Kubernetes releases.

Changes:

Resolve latest test version from Docker Hub kindest/node tags rather than GitHub Kubernetes releases.
Add a warning when the latest kind image minor version is behind the upstream Kubernetes latest minor.
Simplify kind cluster creation to always use kindest/node:${k8s_version}.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

Copilot · 2026-03-27T21:04:04Z

+          k8s_version=$(curl -s "https://hub.docker.com/v2/repositories/kindest/node/tags?page_size=100&ordering=last_updated" \
+            | grep -oE '"name":"v[0-9]+\.[0-9]+\.[0-9]+"' \
+            | grep -oE 'v[0-9]+\.[0-9]+\.[0-9]+' \
+            | sort -V | tail -1)


The Docker Hub request only fetches the first page (page_size=100) ordered by last_updated, then picks the highest semver from that subset. If the highest kindest/node tag isn’t in the most-recently-updated 100 tags, this can resolve to an older Kubernetes version. Consider paginating until exhaustion (following the next link) or using an API query that guarantees you’re considering all version tags (e.g., ordering by name and iterating pages) before selecting the max.

Suggested change

k8s_version=$(curl -s "https://hub.docker.com/v2/repositories/kindest/node/tags?page_size=100&ordering=last_updated" \

| grep -oE '"name":"v[0-9]+\.[0-9]+\.[0-9]+"' \

| grep -oE 'v[0-9]+\.[0-9]+\.[0-9]+' \

| sort -V | tail -1)

url="https://hub.docker.com/v2/repositories/kindest/node/tags?page_size=100&ordering=last_updated"

all_tags=""

while [ -n "$url" ]; do

response=$(curl -s "$url")

# Collect all semver tags from this page

page_tags=$(printf '%s\n' "$response" \

| grep -oE '"name":"v[0-9]+\.[0-9]+\.[0-9]+"' \

| grep -oE 'v[0-9]+\.[0-9]+\.[0-9]+')

if [ -n "$page_tags" ]; then

all_tags="${all_tags}"$'\n'"${page_tags}"

fi

# Follow pagination via the "next" field; it is either a URL or null

next_url=$(printf '%s\n' "$response" | grep -oE '"next":[^,]*' | sed -E 's/"next":(null|"([^"]*)")/\2/')

if [ -z "$next_url" ]; then

url=""

else

url="$next_url"

fi

done

k8s_version=$(printf '%s\n' "$all_tags" | grep -E '^v[0-9]+\.[0-9]+\.[0-9]+' | sort -V | tail -1)

Copilot · 2026-03-27T21:04:05Z

+          k8s_version=$(curl -s "https://hub.docker.com/v2/repositories/kindest/node/tags?page_size=100&ordering=last_updated" \
+            | grep -oE '"name":"v[0-9]+\.[0-9]+\.[0-9]+"' \
+            | grep -oE 'v[0-9]+\.[0-9]+\.[0-9]+' \
+            | sort -V | tail -1)
+          echo "Resolved latest kindest/node version to: $k8s_version"
+
+          # Warn if kind's latest minor version lags behind the latest upstream Kubernetes minor version
+          k8s_latest=$(curl -Ls -o /dev/null -w %{url_effective} https://github.com/kubernetes/kubernetes/releases/latest \
+            | grep -oE 'v[0-9]+\.[0-9]+\.[0-9]+')


curl -s will succeed even on HTTP errors, and if the grep/sort pipeline finds no matching tags, k8s_version becomes empty. That will later cause kind create cluster --image kindest/node: to fail with a confusing error (and the minor-version comparison may emit “integer expression expected”). Consider using curl -fsSL (and/or retries) and explicitly validating that k8s_version and k8s_latest are non-empty before continuing; otherwise exit 1 with a clear message.

Suggested change

k8s_version=$(curl -s "https://hub.docker.com/v2/repositories/kindest/node/tags?page_size=100&ordering=last_updated" \

| grep -oE '"name":"v[0-9]+\.[0-9]+\.[0-9]+"' \

| grep -oE 'v[0-9]+\.[0-9]+\.[0-9]+' \

| sort -V | tail -1)

echo "Resolved latest kindest/node version to: $k8s_version"

# Warn if kind's latest minor version lags behind the latest upstream Kubernetes minor version

k8s_latest=$(curl -Ls -o /dev/null -w %{url_effective} https://github.com/kubernetes/kubernetes/releases/latest \

| grep -oE 'v[0-9]+\.[0-9]+\.[0-9]+')

k8s_version=$(curl -fsSL "https://hub.docker.com/v2/repositories/kindest/node/tags?page_size=100&ordering=last_updated" \

| grep -oE '"name":"v[0-9]+\.[0-9]+\.[0-9]+"' \

| grep -oE 'v[0-9]+\.[0-9]+\.[0-9]+' \

| sort -V | tail -1)

if [ -z "$k8s_version" ]; then

echo "::error::Failed to resolve latest kindest/node version from Docker Hub."

exit 1

fi

echo "Resolved latest kindest/node version to: $k8s_version"

# Warn if kind's latest minor version lags behind the latest upstream Kubernetes minor version

k8s_latest=$(curl -fsSL -o /dev/null -w '%{url_effective}' https://github.com/kubernetes/kubernetes/releases/latest \

| grep -oE 'v[0-9]+\.[0-9]+\.[0-9]+')

if [ -z "$k8s_latest" ]; then

echo "::error::Failed to resolve latest upstream Kubernetes version from GitHub releases."

exit 1

fi

Copilot · 2026-03-27T21:04:05Z

+            | grep -oE '"name":"v[0-9]+\.[0-9]+\.[0-9]+"' \
+            | grep -oE 'v[0-9]+\.[0-9]+\.[0-9]+' \


The Docker Hub response is JSON, but it’s being parsed with grep. This is brittle (formatting/escaping changes can break it) and can accidentally match unrelated "name" fields. Prefer parsing the JSON with a proper tool available on GitHub-hosted runners (e.g., jq -r '.results[].name' or a small python -c JSON parser) and then apply the semver selection on those values.

Suggested change

| grep -oE '"name":"v[0-9]+\.[0-9]+\.[0-9]+"' \

| grep -oE 'v[0-9]+\.[0-9]+\.[0-9]+' \

| jq -r '.results[].name' \

| grep -E '^v[0-9]+\.[0-9]+\.[0-9]+$' \

Copilot · 2026-03-27T21:04:05Z

-        echo "k8s_version=$k8s_version" >> $GITHUB_ENV
-    - name: Create Kind Cluster(k8s version ${{ env.k8s_version }})
+        echo "k8s_version=${k8s_version}" >> $GITHUB_ENV
+    - name: Create Kind Cluster (k8s version ${{ env.k8s_version }})


${{ env.k8s_version }} in the step name won’t be populated by values written to $GITHUB_ENV at runtime (those affect the shell environment, not the expression env context). If you want the resolved version in the step name, emit it as a step output and reference steps.resolve-k8s-version.outputs..., or keep the name static and just echo the chosen version in the step logs.

Suggested change

- name: Create Kind Cluster (k8s version ${{ env.k8s_version }})

echo "k8s_version=${k8s_version}" >> "$GITHUB_OUTPUT"

- name: Create Kind Cluster (k8s version ${{ steps.resolve-k8s-version.outputs.k8s_version }})

After talking with Release team of K8s they told me that they do not always create images for every version of k8s. In this PR we are changing our logic to retrieve the latest publish image of kindest/node from docker hub itself. As part of the change we are also adding a warning, because now these 2 versions are decoupled, whenever a new minor of k8s is released and they do not publish a new kindest/node image, we write a warning in the output. Signed-off-by: Joao Pereira <joaopapereira@gmail.com>

Copilot

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

joaopapereira requested a review from Copilot March 27, 2026 21:01

carvel-bot added this to Carvel Mar 27, 2026

Copilot started reviewing on behalf of joaopapereira March 27, 2026 21:01 View session

Copilot AI reviewed Mar 27, 2026

View reviewed changes

joaopapereira force-pushed the change-tests branch from d34f98b to e8f7b71 Compare March 27, 2026 21:43

joaopapereira requested a review from Copilot April 8, 2026 14:26

Copilot started reviewing on behalf of joaopapereira April 8, 2026 14:27 View session

Copilot AI reviewed Apr 8, 2026

View reviewed changes

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Retrieve the latest kindest/node image for tests#1120

Retrieve the latest kindest/node image for tests#1120
joaopapereira wants to merge 1 commit into
carvel-dev:developfrom
joaopapereira:change-tests

joaopapereira commented Mar 27, 2026

Uh oh!

Copilot AI left a comment

Uh oh!

Copilot AI Mar 27, 2026

Uh oh!

Copilot AI Mar 27, 2026

Uh oh!

Copilot AI Mar 27, 2026

Uh oh!

Copilot AI Mar 27, 2026

Uh oh!

Copilot AI left a comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

-          k8s_version=$(curl -s "https://hub.docker.com/v2/repositories/kindest/node/tags?page_size=100&ordering=last_updated" \
-            | grep -oE '"name":"v[0-9]+\.[0-9]+\.[0-9]+"' \
-            | grep -oE 'v[0-9]+\.[0-9]+\.[0-9]+' \
-            | sort -V | tail -1)
+          url="https://hub.docker.com/v2/repositories/kindest/node/tags?page_size=100&ordering=last_updated"
+          all_tags=""
+          while [ -n "$url" ]; do
+            response=$(curl -s "$url")
+            # Collect all semver tags from this page
+            page_tags=$(printf '%s\n' "$response" \
+              | grep -oE '"name":"v[0-9]+\.[0-9]+\.[0-9]+"' \
+              | grep -oE 'v[0-9]+\.[0-9]+\.[0-9]+')
+            if [ -n "$page_tags" ]; then
+              all_tags="${all_tags}"$'\n'"${page_tags}"
+            fi
+            # Follow pagination via the "next" field; it is either a URL or null
+            next_url=$(printf '%s\n' "$response" | grep -oE '"next":[^,]*' | sed -E 's/"next":(null|"([^"]*)")/\2/')
+            if [ -z "$next_url" ]; then
+              url=""
+            else
+              url="$next_url"
+            fi
+          done
+          k8s_version=$(printf '%s\n' "$all_tags" | grep -E '^v[0-9]+\.[0-9]+\.[0-9]+' | sort -V | tail -1)

		\| grep -oE '"name":"v[0-9]+\.[0-9]+\.[0-9]+"' \
		\| grep -oE 'v[0-9]+\.[0-9]+\.[0-9]+' \

	- name: Create Kind Cluster (k8s version ${{ env.k8s_version }})
	echo "k8s_version=${k8s_version}" >> "$GITHUB_OUTPUT"
	- name: Create Kind Cluster (k8s version ${{ steps.resolve-k8s-version.outputs.k8s_version }})

Conversation

joaopapereira commented Mar 27, 2026

What this PR does / why we need it:

Does this PR introduce a user-facing change?

Additional Notes for your reviewer:

Review Checklist:

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

Copilot AI Mar 27, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 27, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 27, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 27, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants