Add article: Flux-aio, Kubernetes mTLS and the Chicken and Egg Problem #381
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Note Other AI code review bot(s) detectedCodeRabbit has detected other AI code review bot(s) in this pull request and will avoid duplicating their findings in the review comments. This may lead to a less comprehensive review. WalkthroughA new blog post was added documenting how to deploy CNI and kube-proxy through Flux using Flux-aio while Flux itself operates without CNI/kube-proxy by routing traffic through the Kubernetes API and using mTLS client certificates for authentication. Changes
Estimated code review effort🎯 1 (Trivial) | ⏱️ ~3 minutes This is a straightforward content addition with no code changes or functional impact—primarily a documentation file review for accuracy, clarity, and consistency with existing blog standards. Poem
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Summary of ChangesHello @kvaps, I'm Gemini Code Assist1! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed! This pull request adds a comprehensive blog post that addresses a significant challenge in Kubernetes deployments: enabling Flux to manage CNI and kube-proxy while Flux itself is bootstrapping without these critical networking components. The article presents an innovative workaround involving Kubernetes API routing and mTLS authentication using dynamically generated client certificates, providing a detailed explanation of the implementation steps and the rationale behind them. It offers valuable insights into advanced Kubernetes API usage for bootstrapping and internal communication. Highlights
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Signed-off-by: Andrei Kvapil <kvapss@gmail.com>
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Code Review
This is a well-written and interesting article explaining a clever solution to a classic chicken-and-egg problem in Kubernetes bootstrapping with Flux. The explanation is clear and the code snippets are very helpful. I've found a couple of technical inaccuracies in the Kubernetes and Flux resource definitions which could confuse readers or cause errors if copied directly. My suggestions aim to correct these to ensure the examples are accurate and functional. Overall, great work on documenting this complex scenario!
| kubectl create secret generic "cozystack-assets-tls" \ | ||
| --namespace='cozy-system' \ | ||
| --type='kubernetes.io/tls' \ | ||
| --from-file=tls.crt \ | ||
| --from-file=tls.key \ | ||
| --from-file=ca.crt |
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The kubectl create secret generic command shown here is incorrect because the generic subcommand does not have a --type flag. This command will fail when executed.
Furthermore, Flux's certSecretRef requires a secret of type kubernetes.io/tls. The kubectl create secret tls command is the correct one for this type, but it doesn't support adding an arbitrary file like ca.crt directly.
A more robust and declarative way to create this secret is by defining it in YAML and applying it with kubectl apply. This ensures the correct type and allows including the ca.crt data.
Here is a corrected snippet that you could use in the article:
# Create a secret for Flux
kubectl apply -f - <<EOF
apiVersion: v1
kind: Secret
metadata:
name: cozystack-assets-tls
namespace: cozy-system
type: kubernetes.io/tls
data:
tls.crt: $(base64 < tls.crt | tr -d '\n')
tls.key: $(base64 < tls.key | tr -d '\n')
ca.crt: $(base64 < ca.crt | tr -d '\n')
EOF| Now this secret can be used to access our server directly through the Kubernetes API. In the `HelmRepository` spec, we specify: | ||
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| ```yaml | ||
| apiVersion: source.toolkit.fluxcd.io/v1 |
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The apiVersion for a Flux HelmRepository resource is incorrect. It should be source.toolkit.fluxcd.io/v1beta2, not source.toolkit.fluxcd.io/v1. Using v1 will result in a failure to apply this manifest to a cluster with Flux installed.
| apiVersion: source.toolkit.fluxcd.io/v1 | |
| apiVersion: source.toolkit.fluxcd.io/v1beta2 |
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Actionable comments posted: 3
♻️ Duplicate comments (2)
content/en/blog/2025-12-12-flux-aio-kubernetes-mtls-and-the-chicken-and-egg-problem/index.md (2)
39-75: Fix the TLS secret creation command (it currently won’t work as written).Lines 69-74:
kubectl create secret genericdoesn’t support--type, and Flux’scertSecretRefexpects a TLS-formatted secret (commonlykubernetes.io/tls) but you also want to includeca.crt. Prefer a small YAML-applied secret (as suggested in the prior review comment) to ensure type + keys are correct.
112-121: FluxHelmRepositoryapiVersion looks wrong (will fail to apply on many clusters).Line 113 uses
source.toolkit.fluxcd.io/v1; prior review notedv1beta2. Please verify the correct apiVersion for the Flux version Cozystack targets and update the snippet accordingly.FluxCD HelmRepository apiVersion: for Flux v2.x, what is the correct apiVersion for kind HelmRepository (source.toolkit.fluxcd.io)? Is it v1beta2 or v1, and since which version?
🧹 Nitpick comments (1)
content/en/blog/2025-12-12-flux-aio-kubernetes-mtls-and-the-chicken-and-egg-problem/index.md (1)
79-108: RBAC: consider calling out required privileges + rotation for the client cert.The Role/RoleBinding is fine, but the doc would be stronger if it mentioned:
- CSR approval typically requires elevated privileges (cluster-admin or delegated signer approval).
- cert lifetime/rotation (CSRs expire; you may want an automation note).
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🧰 Additional context used
🪛 markdownlint-cli2 (0.18.1)
content/en/blog/2025-12-12-flux-aio-kubernetes-mtls-and-the-chicken-and-egg-problem/index.md
9-9: Images should have alternate text (alt text)
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27-27: Fenced code blocks should have a language specified
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131-131: Bare URL used
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| description: "How we solved the chicken-and-egg problem of deploying CNI and kube-proxy through Flux while ensuring Flux itself works without CNI and kube-proxy, using Kubernetes API routing and mTLS certificates." | ||
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Add alt text for the image (markdownlint MD045).
Line 9 should include descriptive alt text for accessibility.
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+📝 Committable suggestion
‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.
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🪛 markdownlint-cli2 (0.18.1)
9-9: Images should have alternate text (alt text)
(MD045, no-alt-text)
🤖 Prompt for AI Agents
content/en/blog/2025-12-12-flux-aio-kubernetes-mtls-and-the-chicken-and-egg-problem/index.md
around line 9: the Markdown image lacks alt text which violates accessibility
rule MD045; update the image tag to include a concise, descriptive alt text that
summarizes the image (e.g., "Diagram illustrating the chicken-and-egg problem in
Kubernetes mTLS setup") so screen readers and markdownlint can detect meaningful
alt text.
| ``` | ||
| https://example.org:6443/api/v1/namespaces/cozy-system/pods/cozystack-assets-0/proxy | ||
| ``` | ||
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Specify a language for the fenced code block (markdownlint MD040).
Line 27 should be something like text (or url) to satisfy linters.
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https://example.org:6443/api/v1/namespaces/cozy-system/pods/cozystack-assets-0/proxy
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<summary>🧰 Tools</summary>
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<summary>🪛 markdownlint-cli2 (0.18.1)</summary>
27-27: Fenced code blocks should have a language specified
(MD040, fenced-code-language)
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<summary>🤖 Prompt for AI Agents</summary>
content/en/blog/2025-12-12-flux-aio-kubernetes-mtls-and-the-chicken-and-egg-problem/index.md
lines 27-30: the fenced code block lacks a language tag which trips markdownlint
MD040; add an appropriate info string such as "text" or "url" after the opening
backticks (e.g., ```text) so the block becomes fenced with a language and
linting passes.
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| You can view (and review) the full code of the PR here: | ||
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| - https://github.com/cozystack/cozystack/pull/1698 | ||
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Avoid bare URLs (markdownlint MD034).
Convert to a proper Markdown link:
-- https://github.com/cozystack/cozystack/pull/1698
+- [cozystack/cozystack#1698](https://github.com/cozystack/cozystack/pull/1698)📝 Committable suggestion
‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.
| You can view (and review) the full code of the PR here: | |
| - https://github.com/cozystack/cozystack/pull/1698 | |
| You can view (and review) the full code of the PR here: | |
| - [cozystack/cozystack#1698](https://github.com/cozystack/cozystack/pull/1698) |
🧰 Tools
🪛 markdownlint-cli2 (0.18.1)
131-131: Bare URL used
(MD034, no-bare-urls)
🤖 Prompt for AI Agents
In
content/en/blog/2025-12-12-flux-aio-kubernetes-mtls-and-the-chicken-and-egg-problem/index.md
around lines 129 to 132, there is a bare URL which violates markdownlint MD034;
replace the plain URL with a proper Markdown link by wrapping the URL in
brackets with descriptive link text (e.g., "PR #1698 on GitHub" or "cozystack PR
#1698") followed by the URL in parentheses so the link reads like [PR #1698 on
GitHub](https://github.com/cozystack/cozystack/pull/1698).
This PR adds a new blog article about solving the chicken-and-egg problem of deploying CNI and kube-proxy through Flux while ensuring Flux itself works without CNI and kube-proxy, using Kubernetes API routing and mTLS certificates.
The article explains how we:
Related PR: cozystack/cozystack#1698
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