Do you still need a GitOps book when the Argo CD and Flux docs are this good? Usually yes, but only one of two kinds: a book that went to print after Argo CD 3.0 changed its defaults, or an older one you read for the operating ideas while the docs supply the current syntax. In our replay, examples from Argo CD: Up and Running, Argo CD in Practice and Implementing GitOps with Kubernetes broke on images and repositories that no longer exist.
We ranked eight GitOps and Argo CD books for 2026, then ran companion code from four of them on a single-node cluster and checked a fifth book’s RBAC policy offline, to see which examples still work today. You get the picks, a reading path for Argo CD and Flux shops, and the exact errors with a fix for each. I ran the replay on a K3s box in my homelab in October 2026 with Argo CD 3.5 and Flux 2.9, and every Synced, Healthy and error result in the replay table comes from that run.
Which GitOps book to buy first
Start with Argo CD: Up and Running unless you already know you run Flux, because it is a 2025 O’Reilly title and its chapter 5 example synced on Argo CD 3.5 with no edits. The other picks each win a narrower job:
- Best overall: Argo CD: Up and Running (O’Reilly, 2025)
- Best lab-first build: GitOps the Hard Way, with Argo CD (FAUN.dev, 2026)
- Best for Flux, or both tools: Implementing GitOps with Kubernetes (Packt, 2024)
- Best for running Argo CD in production: Argo CD in Practice (Packt, 2022)
- Best for the whole Argo suite: Argo CD and Argo Workflows on Kubernetes (BPB, 2025)
- Best for the delivery thinking underneath: Grokking Continuous Delivery (Manning, 2022)
GitOps Cookbook and GitOps and Kubernetes stay on the list as second reads. Both are good books, but their tool chapters were written for Argo CD 2.x and Flux v1, so you buy them for the patterns and the reasoning, not to copy commands.
How we tested the book code on Argo CD 3.5 and Flux 2.9
A review of a GitOps book that never touches a cluster only tells you what the table of contents says. So we cloned four of the public companion repositories, applied their manifests to a fresh cluster and watched what Argo CD and the kubelet did with them. The lab was one Proxmox VM in my homelab:
- Ubuntu 26.04.1 LTS, 4 vCPU, 8 GB RAM
- K3s v1.36.5+k3s1 as the cluster
- Argo CD v3.5.6 from the upstream install manifest
- Flux v2.9.6 installed with
flux install - kubectl with its bundled Kustomize v5.8.1
All seven tool books publish code on GitHub. We ran code from four of them on the cluster: Up and Running, Argo CD in Practice, Implementing GitOps with Kubernetes and GitOps Cookbook. GitOps and Kubernetes got an offline check of its chapter 9 RBAC policy only, since its Flux chapter targets the archived Flux v1. GitOps Cookbook spreads its code across several repositories in the gitops-cookbook GitHub organization (chapter sources, the pacman-kikd-manifests app, Helm charts), so we deployed only its pacman manifests with an Application we wrote. The FAUN and BPB books also have public code repositories, the GitOps the Hard Way companion toolkit and the code for the BPB book, but we did not replay either, so those two were judged on their contents and publisher pages. Grokking Continuous Delivery is tool-agnostic and has nothing to deploy. This is what the replay showed:
| Book (repo last commit) | What we applied | Result on Argo CD 3.5.6 / Flux 2.9.6 |
|---|---|---|
| Argo CD: Up and Running (Nov 2025) | Ch 5 pricelist app (Kustomize, sync waves, PostSync job) | Synced and Healthy, no edits. Resources tracked by annotation |
| Argo CD: Up and Running (Nov 2025) | Ch 8 golist-db (Bitnami MariaDB chart 11.1.0) | Synced, then ImagePullBackOff: image gone from docker.io/bitnami |
| Argo CD in Practice (Apr 2024) | Ch 2 nginx app (Bitnami nginx chart 13.2.10) | Synced, then ImagePullBackOff: same Bitnami cause |
| Argo CD in Practice (Apr 2024) | Ch 4 Kustomize install | Builds, with three deprecation warnings; pins Argo CD v2.1.1 |
| Implementing GitOps with Kubernetes (Sep 2025) | Ch 4 weather app | Source repo returns 404; app image not on Docker Hub |
| GitOps Cookbook (pacman-kikd-manifests, Dec 2022) | pacman app from k8s/, our own Application | Synced and Healthy; image on quay.io still pulls |
| GitOps and Kubernetes (Aug 2022) | Ch 9 RBAC policy | Policy check: still grants pod logs, but only through role:readonly |
| GitOps and Kubernetes (Aug 2022) | Ch 11 Flux setup | Not run: written for Flux v1, archived in Nov 2022 |
Line the rows up and you see the pattern. Argo CD itself accepted every Application we applied, including ones written against v2.1, and synced every one whose source repository still exists. What broke sat around Argo CD: container images that were deleted upstream, a personal repo that is gone (404), and deprecated Kustomize fields. That is the real cost of an older GitOps book, and it is why the publish year matters more here than in most book categories.
GitOps books compared
Page counts come from the Amazon print listings, except Grokking Continuous Delivery, where the Manning page gives 424 against 300 on Amazon. The “written for” column is the tool generation the examples assume, which is the first thing to check against your own cluster:
| Book | Publisher, year | Pages | Tools covered | Written for |
|---|---|---|---|---|
| Argo CD: Up and Running | O’Reilly, Jul 2025 | 308 | Argo CD | Published Jul 2025; ch 5 still syncs on 3.5 |
| GitOps the Hard Way, with Argo CD | FAUN.dev, May 2026 | 236 | Argo CD, K3s, Helm | Pinned versions, not named on the listing |
| Implementing GitOps with Kubernetes | Packt, Aug 2024 | 444 | Flux, Argo CD, AWS, Azure | Argo CD 2.x, Flux v2 GA APIs |
| Argo CD in Practice | Packt, Nov 2022 | 236 | Argo CD | Argo CD 2.1 to 2.6 |
| Argo CD and Argo Workflows on Kubernetes | BPB, Jan 2025 | 290 | Argo CD, Workflows, Events, Rollouts | Argo CD 2.x |
| GitOps Cookbook | O’Reilly, Feb 2023 | 242 | Argo CD, Tekton, Kustomize, Helm | Argo CD 2.x |
| GitOps and Kubernetes | Manning, Mar 2021 | 344 | Argo CD, Flux v1, Jenkins X | Argo CD 1.x, Flux v1 |
| Grokking Continuous Delivery | Manning, 2022 | 424 | Tool-agnostic CD | Any pipeline |
1. Argo CD: Up and Running
Buy this one first. It came out from O’Reilly in July 2025, and the author pairing is about as credible as Argo CD coverage gets: Andrew Block is a distinguished architect at Red Hat and Christian Hernandez works at Akuity, the company founded by the creators of Argo.
It walks the whole arc: installing Argo CD, structuring repositories, Application and ApplicationSet patterns, sync waves, security and RBAC, then wiring it into a real delivery workflow. It went to print in July 2025, about eleven weeks after Argo CD 3.0 shipped, and its companion repository was still getting fixes in November 2025. In our replay the chapter 5 pricelist app synced and went Healthy on Argo CD 3.5.6 without a single edit, with its MySQL database, its sync waves and its PostSync job all completing in order.
One chapter did trip. The chapter 8 golist database pulls a Bitnami MariaDB chart whose image tag is no longer in docker.io/bitnami (it lives on only under bitnamilegacy), so you will need the one-line fix from the troubleshooting section at the end. That is a Bitnami change, not a mistake in the book, but it is the first wall a 2026 reader hits. Apply the chapter 8 project file with -n argocd as well, because ch08/argocd/projects/golist.yaml sets no namespace. We first applied it without the flag, the AppProject landed in default, and golist-db sat at Unknown with “Application referencing project golist which does not exist”.
Buy it if you are adopting Argo CD in 2026, or your older Argo book no longer matches the UI you see. Pass on it if your shop runs Flux and nothing else, since Argo CD is the entire book. It typically sits in the $45 to $66 band new. Check the current price on Amazon.
2. GitOps the Hard Way, with Argo CD
GitOps the Hard Way is the new entry for 2026, and the one closest to how we learn things in a homelab. Aymen El Amri, who founded the FAUN.dev developer community, has you build the environment yourself instead of handing you a demo cluster: two servers, K3s, then Argo CD from kubectl apply to argocd login.
The chapter list reads like a lab plan, which is why we rate it above the older Packt titles for a first hands-on read. It moves from the reconciliation loop and the components of Argo CD into sync policy (every field and sync option), sync phases and hooks, local users and RBAC for a single teammate, Helm, ApplicationSets and finally one Argo CD Application per Git branch. The Leanpub edition was last updated in June 2026 and states that tool versions are pinned and called out in the text. Leanpub also describes a companion kit that holds every code listing, diagram and screenshot.
We did not replay this one. Its companion toolkit is public on GitHub, one markdown file per chapter, so you can read the commands before you buy. It comes from a single author through his own FAUN.dev imprint, and multi-cluster gets one section of the install chapter (adding more clusters), so it is thinner on production operations than Argo CD in Practice. It fits you if you learn by building the cluster from nothing and want a K3s path that matches a homelab. Not the right buy if you need Flux or multi-cluster operations. It usually runs $30 to $35. Check the current price on Amazon.
3. Implementing GitOps with Kubernetes
For Flux users, the Packt title from Pietro Libro and Artem Lajko is still the closest thing to a Flux book from a major publisher. The authors treat Flux and Argo CD as equals across 444 pages, then push into the part most books skip: running GitOps against managed clusters on AWS and Azure, with security, multi-tenancy and scaling treated as first-class topics.
The Flux manifests in its repository use the GA source.toolkit.fluxcd.io/v1 API, which matters more than it sounds, because Flux 2.8 and 2.9 deleted the older beta APIs that many 2023 tutorials still print. The Argo CD side aged less well. The chapter 4 Application points at a personal weather-app repository owned by one of the authors, which now returns 404, and the pietrolibro/zurich-weather-app:1.0 image it deploys is not on Docker Hub. Repointing the Application at the same manifests inside the Packt repository got it to Synced, but you still have to build the image from the Dockerfile in that chapter before the pod starts.
Get it if you run Flux, or you have to pick between Flux and Argo CD and want both explained by the same authors. Leave it on the shelf if you want copy-and-run labs, because you will be rebuilding images and fixing repo URLs. The paperback is usually $40 to $50. Check the current price on Amazon.
4. Argo CD in Practice
Where Up and Running gets you productive, Argo CD in Practice is about keeping Argo CD alive once real teams depend on it. Liviu Costea and Spiros Economakis cover declarative configuration of Argo CD itself, SSO and RBAC, observability, disaster recovery and the performance tuning that starts to matter when the application count climbs.
Expect 2.x syntax throughout, because you are reading a 2022 book. The chapter 4 Kustomize install pins Argo CD v2.1.1, and the Kustomize v5.8.1 bundled with kubectl warns about every deprecated field in it. The chapter 2 sample app deploys the Bitnami nginx chart 13.2.10, whose docker.io/bitnami/nginx:1.23.1-debian-11-r32 image is gone, so Argo CD reported it Synced while the pod sat in ImagePullBackOff. The operating advice holds up better than the YAML: backup and restore, RBAC design and controller sharding read the same on 3.5 as they did on 2.x.
Reach for it when you carry the pager for Argo CD, or your team is already past its first install. Pass on it as a first book, because you will spend the early chapters translating 2.x syntax. It usually sells in the $45 to $55 band. Check the current price on Amazon.
5. Argo CD and Argo Workflows on Kubernetes
Of the eight, only this book covers the whole Argo project rather than Argo CD alone. Md Nahidul Kibria, a platform engineer at HelloFresh, gives Argo CD three chapters (concepts, production setup and security), then moves through Argo Workflows, Argo Events and Argo Rollouts, and finishes by wiring all four together into one delivery pipeline.
Because Argo CD gets three of its eleven chapters, it goes less deep on Argo CD than the two books above it. Its value is in the joins: event-driven Workflows that hand off to Argo CD, then Rollouts doing the canary. If that is the shape you are building, pair it with our Argo Rollouts canary walkthrough for a run you can verify yourself. The book uses minikube for its labs and went to print in January 2025, before Argo CD 3.0, so expect the label-tracking and RBAC defaults described in the next section.
It earns its place when your platform already runs, or plans to run, Workflows or Rollouts next to Argo CD. Skip this pick if you only need GitOps delivery. It sits in the $30 to $40 band. Check the current price on Amazon.
6. GitOps Cookbook
Natale Vinto and Alex Soto Bueno, both at Red Hat, wrote this as problem and solution recipes rather than a cover-to-cover read. It runs from container builds (Buildah, Buildpacks, Shipwright) through Kustomize, Helm and Tekton pipelines to Argo CD and progressive delivery, so it covers the build half of the loop that pure Argo CD books leave out.
It has no Flux chapter, which surprises people given the title. Its code is spread across several repositories in the gitops-cookbook GitHub organization. We pointed an Argo CD Application of our own at the k8s/ directory of its pacman-kikd-manifests repository, and the pacman app synced and went Healthy on Argo CD 3.5.6 with its quay.io/gitops-cookbook/pacman-kikd:1.0.0 image still pulling. That covers one app, not the recipes. The recipes are still the quickest way to answer “how do I do X with Kustomize and Argo CD”, but treat every Argo CD recipe as 2.x-era and check it against the upgrade notes before you trust it.
Pick it up if you want a reference to dip into, or your team builds images on Tekton. Not the right buy if you want one continuous narrative. On Amazon it usually lands in the $40 to $50 band. Check the current price on Amazon.
7. GitOps and Kubernetes
Four Intuit engineers wrote this, and two of them, Alexander Matyushentsev and Jesse Suen, co-created Argo CD. It is the GitOps theory book from the people who built the tool, which is why it stays on the list in 2026 even though it is the oldest pick.
Its tool chapters have aged badly. The Flux chapter configures Flux v1 (fluxd flags such as --git-label), whose repository was archived in November 2022. The chapter 9 RBAC policy still grants pod logs when we checked it against Argo CD 3.5.6, but only because its developer role inherits role:readonly. The built-in readonly role is what holds the logs grant now that Argo CD 3.0 enforces logs RBAC, so a copy of the policy without that inheritance line loses the logs tab.
Get it for the why from the source: environment management, secrets and pipelines treated as GitOps problems. Pass on it if you need current walkthroughs. It is usually $40 to $50. Check the current price on Amazon.
8. Grokking Continuous Delivery
The wildcard pick, and the one we recommend more often than people expect. GitOps is continuous delivery with Git as the control plane, and teams that struggle with GitOps are usually struggling with CD itself: flaky tests, an unreleasable main branch, deployments nobody trusts. Christie Wilson, who co-created the Tekton pipeline framework at Google, fixes the thinking underneath.
You will not find a single Argo CD command in it. The book is tool-agnostic and heavily illustrated in the Grokking style Manning uses, which makes it the easiest read here and the one that ages the slowest. Version control as the source of truth, pipelines that give a trustworthy signal and safe automated rollouts are each a GitOps prerequisite under a different name, and none of them depends on an Argo CD default.
Hand it to anyone whose delivery pipeline is the real bottleneck, and for juniors who would bounce off a tool manual. Leave it out if your CD practice is already solid and you only need Argo CD specifics. It usually sits between $45 and $60. Check the current price on Amazon.
What changed in Argo CD 3.x that older books miss
Five of the eight books were written for Argo CD 2.x or earlier. Argo CD 3.0 (May 2025) was billed as a low-risk upgrade, but it changed several defaults that a pre-3.0 book will describe the old way. These are the ones that matter when you read along, taken from the official 2.14 to 3.0 upgrade notes. We saw the first two directly in the lab. The third lives in the API server, as the RBAC checks below explain:
- Resources tracked by annotation, not the
app.kubernetes.io/instancelabel - Pod logs gated by an explicit
logs, getgrant updateanddeletegrants no longer reaching the resources inside an Application- Repository config in argocd-cm removed in favour of Secrets
- Helm 3.17, where a null in values.yaml now overrides the chart default
You can see the tracking change directly on any synced resource. The pricelist Deployment from Up and Running carried an argocd.argoproj.io/tracking-id annotation and only its own app and tier labels, so a pre-3.0 book that tells you to find Argo-managed resources by label will come back empty on a new install.
You can test the logs change with argocd admin settings rbac can, which evaluates a policy file against the built-in roles without a running app. It still builds a Kubernetes client, though, so it needs a kubeconfig your user can read. On a default K3s install /etc/rancher/k3s/k3s.yaml is root-only, and the check died with could not create k8s client until we copied it to ~/.kube/config. Then save the developer policy from GitOps and Kubernetes chapter 9, with alice in place of its <username> placeholder:
vim gk-policy.csvThe file holds the three policy lines from the book:
p, role:developer, applications, *, */*, allow
g, role:developer, role:readonly
g, alice, role:developerAsk whether alice can read pod logs:
argocd admin settings rbac can alice get logs default/guestbook --policy-file gk-policy.csvThe answer is Yes. The warning is expected, because role:readonly is a built-in role rather than one the file defines, and it is that built-in role which carries the logs, get grant:
{"level":"warning","msg":"user defined roles not found in policies: role:readonly","time":"2026-10-21T13:13:21Z"}
YesDelete the g, role:developer, role:readonly line and the same check prints No, even though the role still holds applications, *. On Argo CD 3.0 and later, logs need their own grant or a role that already has one.
The update change is different, and this offline check cannot show it. The rbac can command is a plain policy match, and the matcher is the same in 2.14 and 3.5, so both versions answer No when a role that only holds update asks about a Deployment inside the Application. We bound bob to that kind of role in fg.csv:
p, role:deployer, applications, update, default/*, allow
g, bob, role:deployerBob gets Yes for the Application itself, and this for the Deployment inside it:
argocd admin settings rbac can bob update/apps/Deployment/default/web applications default/guestbook --policy-file fg.csvThe check prints a single word:
NoWhat changed in 3.0 lives in the API server. Argo CD 2.x checked the plain application update grant first and only fell back to the fine-grained resource action when that was denied, so bob could still edit that Deployment through the UI or API. Argo CD 3.0 dropped that fallback by defaulting server.rbac.disableApplicationFineGrainedRBACInheritance to true. Grant update/* to a role that really needs to edit the resources inside an Application, or set that key to false in argocd-cm to keep the 2.x behavior.
Flux readers have a parallel problem. Flux 2.7 removed the v1beta1 and v2beta1 APIs, Flux 2.8 removed v1beta2 and v2beta2, and Flux 2.9 removed the image and notification v1beta2 APIs, per the Flux release notes. Any book or tutorial printed with v1beta2 sources now fails at apply time, as the next section shows.
Argo CD or Flux: a reading path for each
No major publisher has a dedicated Flux book yet. We searched the Amazon catalog by publisher (O’Reilly, Manning and Packt) again in October 2026, and the Flux-only titles on Amazon are recent self-published books we could not verify. The official Flux documentation is good enough that the gap hurts less than it sounds. Pick the path that matches the controller you run:
- Argo CD shop: Up and Running, then Argo CD in Practice once you own the install, then Grokking Continuous Delivery when the pipeline is what hurts
- Homelab, learning from zero: GitOps the Hard Way on a K3s box, then Up and Running for the patterns it skips
- Flux shop: Implementing GitOps with Kubernetes plus the Flux docs, then GitOps and Kubernetes for the theory
- Platform team on the full Argo suite: Up and Running, then Argo CD and Argo Workflows on Kubernetes
Whichever path you take, read with a cluster open. In my homelab the loop that worked was reading a chapter, then rebuilding the same thing on a scratch cluster: stand up K3s, install Argo CD and drive it from the argocd CLI. Flux readers can follow our Flux bootstrap with GitHub and the Flux Kustomization tutorial, and if you are still choosing a controller, the Flux vs Argo CD comparison covers the multi-cluster differences the books only touch on. For the wider shelf, the Kubernetes book roundup and the platform engineering books pick up where these stop.
What broke when we replayed the book code
Book code failed in three ways during the replay, all of them in Argo CD: Up and Running, Argo CD in Practice and Implementing GitOps with Kubernetes. The GitOps Cookbook pacman app ran clean, and the GitOps and Kubernetes policy check hit none of them:
- Bitnami image tags no longer in docker.io/bitnami (two books)
- A source repository that returns 404 (Implementing GitOps)
- An app image that is not on Docker Hub (the same chapter)
The missing repository and image are covered under pick 3, because the only fix is to build the image yourself. Below are the errors you can fix in place, verbatim, plus one Kustomize warning and one Flux API check we ran with our own manifest, since a Flux book from 2023 would fail the same way.
Error: “docker.io/bitnami/nginx:1.23.1-debian-11-r32: not found”
Both the Up and Running chapter 8 database and the Argo CD in Practice chapter 2 nginx app use pinned Bitnami charts. Argo CD synced both fine, then the kubelet failed the pull. This is the event on the nginx pod:
Failed to pull image "docker.io/bitnami/nginx:1.23.1-debian-11-r32": rpc error: code = NotFound desc = failed to pull and unpack image "docker.io/bitnami/nginx:1.23.1-debian-11-r32": failed to resolve reference "docker.io/bitnami/nginx:1.23.1-debian-11-r32": docker.io/bitnami/nginx:1.23.1-debian-11-r32: not foundBitnami moved its versioned tags out of docker.io/bitnami into docker.io/bitnamilegacy in September 2025, as its catalog change notice explains, and the legacy repository gets no updates. For a book exercise, point the chart at the legacy repository with a Helm parameter. The chapter 2 nginx Application has no helm block at all, so a JSON patch that appends to helm/parameters fails there. A merge patch creates the block instead:
kubectl -n argocd patch application nginx --type merge -p '{"spec":{"source":{"helm":{"parameters":[{"name":"image.repository","value":"bitnamilegacy/nginx"}]}}}}'nginx is a Deployment, so the rollout replaced the failing pod by itself, with no manual delete. The new pod came up Running on the legacy image:
NAME READY STATUS RESTARTS AGE
nginx-7b6f948694-krn69 1/1 Running 0 46sArgo CD still showed the app as Progressing afterwards, and that part comes from the lab cluster, not the book. The chart creates a LoadBalancer Service on port 80, and the K3s ServiceLB pod for it stayed Pending because the scheduler reported the single node didn't have free ports for the requested pod ports, so the Service never got an external IP. On a cluster with a free port 80 or a real load balancer that wait goes away; the image fix is the part the chapter needs.
The Up and Running chapter 8 database failed the same way on bitnami/mariadb:10.6.8-debian-11-r9. That Application already has a helm.parameters list, so appending one more entry works:
kubectl -n argocd patch application golist-db --type json -p '[{"op":"add","path":"/spec/source/helm/parameters/-","value":{"name":"image.repository","value":"bitnamilegacy/mariadb"}}]'Argo CD updated the StatefulSet template, but the pod stayed in ImagePullBackOff, because a StatefulSet will not replace a pod that never became ready. Deleting the stuck pod let the controller recreate it from the new template, and the Application went Synced and Healthy:
kubectl -n golist delete pod golist-db-mariadb-0Use this only to finish the chapter. For anything you keep running, swap the Bitnami chart for one whose images are still maintained.
Error: no matches for kind “GitRepository” in version “source.toolkit.fluxcd.io/v1beta2”
This one is our own test manifest, not code from one of the books: a GitRepository for podinfo written with the v1beta2 API that 2023-era Flux tutorials printed. Flux 2.9.6 rejected it outright:
error: resource mapping not found for name: "podinfo" namespace: "flux-system" from "gr-v1beta2.yaml": no matches for kind "GitRepository" in version "source.toolkit.fluxcd.io/v1beta2"
ensure CRDs are installed firstThe CRDs are installed. flux check passed on the same cluster and listed gitrepositories.source.toolkit.fluxcd.io/v1, so the CRD simply no longer serves the beta version. Changing the apiVersion line to source.toolkit.fluxcd.io/v1 was the only edit needed: the next apply printed gitrepository.source.toolkit.fluxcd.io/podinfo created and the source went Ready with the podinfo artifact stored.
Warning: ‘bases’ is deprecated. Please use ‘resources’ instead
The Argo CD in Practice Kustomize installs still build, but kubectl prints three deprecation warnings for bases, patchesStrategicMerge and vars. Run kustomize edit fix (the standalone kustomize binary, because the Kustomize built into kubectl has no edit fix subcommand) in the chapter directory to rewrite the first two into resources and patches:
kustomize edit fixOne warning, for vars, stayed after the fix because it comes from the Argo CD v2.1.1 manifests the chapter pins, not from the Kustomization file in the book. Bump the ?ref= to a current release, which you want anyway, because a v2.1.1 install from 2021 runs without five years of security fixes.
