kandev/docs/k8s.md

Kubernetes Deployment Guide

This guide covers building the Kandev Docker image and deploying it to a Kubernetes cluster.

Prerequisites

• Docker (for building the image)
• A container registry (Docker Hub, GHCR, ECR, etc.)
• A Kubernetes cluster with kubectl configured
• A StorageClass that supports ReadWriteOnce PVCs (for SQLite persistence)

Building the Image

From the repository root:

# Build for your current architecture
docker build -t kandev:latest .

# Build for a specific architecture (e.g., for amd64 clusters)
docker build --platform linux/amd64 -t kandev:latest .

# Multi-arch build (requires buildx)
docker buildx build --platform linux/amd64,linux/arm64 -t kandev:latest .

Using the Pre-built Image

Kandev publishes images to GitHub Container Registry. Pull directly:

docker pull ghcr.io/kdlbs/kandev:latest

Or reference it in your K8s deployment:

image: ghcr.io/kdlbs/kandev:latest

Choosing your image: vanilla vs. universal

Kandev publishes two flavors: the default vanilla image (smallest, npm-installable agent CLIs only) and a :universal image (~1.4 GB) that adds language toolchains (Go, Rust, build-essential), linters, and Playwright Chromium system libs - useful when your agents work on Go/Rust/Python projects or drive headless browsers.

image: ghcr.io/kdlbs/kandev:universal

See images.md for the full comparison, inclusion policy, and recipes for deriving your own image when you need something neither flavor includes.

Deploying to Kubernetes

Quick Start

# Apply all manifests
kubectl apply -f k8s/

# Check status
kubectl get pods -l app=kandev
kubectl logs -l app=kandev -f

What Gets Created

Resource	File	Purpose
Deployment	deployment.yaml	Single-replica pod running backend + web
Service	service.yaml	ClusterIP exposing port 38429
ConfigMap	configmap.yaml	Non-sensitive environment configuration
PVC	pvc.yaml	10Gi persistent volume for SQLite + worktrees
Ingress	ingress.yaml	Example ingress with WebSocket support

Accessing the UI

Port-forward (quickest for testing):

kubectl port-forward svc/kandev 38429:38429
# Open http://localhost:38429

Ingress: Edit k8s/ingress.yaml to set your domain, then apply. The ingress routes all traffic to the backend on port 38429 (the Go backend reverse-proxies the Next.js frontend internally).

Custom Domain / Reverse Proxy

No extra configuration is needed. The frontend automatically uses window.location.origin to reach the API, which works with any domain, reverse proxy, or ingress setup.

Installing Agent CLIs

The kandev image ships with git, gh (GitHub CLI), node, and npm, but does not bundle the coding-agent CLIs (claude-code, codex, auggie, etc.) — agent choice is per-user, and bundling all of them would bloat the image significantly.

Looking to add tools beyond agent CLIs - language toolchains, build tools, internal CLIs? See images.md for the universal-image option and recipes for deriving your own image.

To install an agent inside the running pod, open Settings → Agents in the UI and click Install on the agent card under "Available to Install". The backend runs the agent's hard-coded install script (npm install -g <pkg>) and rescans on success.

The image sets NPM_CONFIG_PREFIX=/data/.npm-global so user-installed npm globals land on the PV and survive pod restarts and image upgrades. The same persistence applies if you kubectl exec and install manually:

kubectl exec -it deployment/kandev -- npm install -g @anthropic-ai/claude-code

After installing, log in with the agent's own auth (e.g. claude login), then click Rescan on the agents page.

Persistent agent and gh CLI auth

The image sets HOME=/data/home for the kandev user, so every CLI that writes its auth state under $HOME lands on the PV and survives pod restarts and image upgrades. This includes:

• gh CLI — ~/.config/gh/hosts.yml
• Claude Code — ~/.claude/.credentials.json, ~/.claude.json
• Codex — ~/.codex/auth.json, ~/.codex/config.toml
• Auggie — ~/.augment/session.json
• GitHub Copilot — ~/.copilot/...
• OpenCode, Amp — ~/.config/<tool>/...

So a one-time kubectl exec -it deployment/kandev -- gh auth login (or claude login, codex login, etc.) is enough; you do not need to redo it after kubectl set image or a helm upgrade.

The GitHub PAT configured in Settings → Integrations → GitHub is stored as a secret in the SQLite DB (or your external Postgres) and has always persisted. The HOME=/data/home setup covers the separate gh auth login flow that the backend falls back to when no GITHUB_TOKEN secret is set.

Configuration

Kandev reads configuration via KANDEV_-prefixed environment variables (Viper). Set these in k8s/configmap.yaml or as environment variables in the deployment.

Core Settings

See configuration.md for the full reference (every backend knob and its YAML form). The tables below cover what's most commonly set in K8s manifests.

Env Var	Required	Default	Description
KANDEV_SERVER_PORT	No	38429	Server port (API + WebSocket + Web UI)
KANDEV_HOME_DIR	No	/data	Kandev home directory - contains data/ (DB), tasks/, worktrees/, repos/, sessions/, and lsp-servers/
KANDEV_DATABASE_DRIVER	No	sqlite	Database driver (sqlite or postgres)
KANDEV_DATABASE_PATH	No	$KANDEV_HOME_DIR/data/kandev.db	SQLite database file path (override)
KANDEV_DOCKER_ENABLED	No	false	Enable Docker runtime for agents (requires DinD)
KANDEV_LOG_LEVEL	No	info	Log level: debug, info, warn, error
KANDEV_LOGGING_FORMAT	No	auto	Log format: json (auto-detected in K8s) or text
KANDEV_LOGGING_OUTPUTPATH	No	stdout	Log destination: stdout, stderr, or a file path (rotated when a file)
KANDEV_LOGGING_MAXSIZEMB	No	100	Rotate the log file when it exceeds this size (MB). File output only.
KANDEV_LOGGING_MAXBACKUPS	No	5	Max rotated files to retain (0 = unlimited). File output only.
KANDEV_LOGGING_MAXAGEDAYS	No	30	Max age of rotated files in days (0 = unlimited). File output only.
KANDEV_LOGGING_COMPRESS	No	true	Gzip rotated files. File output only.

Logging in K8s: prefer the default stdout so kubelet collects logs. If you set KANDEV_LOGGING_OUTPUTPATH to a file, the active log is created with mode 0600 (owner read/write only); any sidecar reading it must run as the same user.

Upgrading from a pre-KANDEV_HOME_DIR deployment? The SQLite DB path moved from /data/kandev.db to /data/data/kandev.db, and KANDEV_DATA_DIR is gone — point KANDEV_HOME_DIR at the same volume mount (/data) instead. (KANDEV_WORKTREE_BASEPATH still works as an explicit override if you want to keep worktrees outside the home dir.) The backend auto-migrates the legacy kandev.db (plus any -wal/-shm files) on first boot — look for Migrated SQLite database from pre-KANDEV_HOME_DIR location in the pod logs. If you'd rather pin the old path, set KANDEV_DATABASE_PATH=/data/kandev.db in the ConfigMap.

PostgreSQL Settings (when KANDEV_DATABASE_DRIVER=postgres)

Env Var	Required	Default	Description
KANDEV_DATABASE_HOST	No	localhost	PostgreSQL host
KANDEV_DATABASE_PORT	No	5432	PostgreSQL port
KANDEV_DATABASE_USER	Yes	kandev	Database user
KANDEV_DATABASE_PASSWORD	Usually	(empty)	Database password - required unless your Postgres allows passwordless auth
KANDEV_DATABASE_DBNAME	Yes	kandev	Database name
KANDEV_DATABASE_SSLMODE	No	disable	SSL mode (disable, require, verify-ca, verify-full)

Database: SQLite vs PostgreSQL

SQLite (default)

• Zero-config, works out of the box
• Database stored at /data/data/kandev.db on the PV (derived from KANDEV_HOME_DIR=/data)
• Single replica only (SQLite is single-writer)
• Deployment strategy is Recreate to prevent concurrent writes
• Good for small teams / personal use

PostgreSQL (recommended for production)

• Supports multiple replicas for horizontal scaling
• Change deployment strategy to RollingUpdate
• Set via environment variables:

# In configmap.yaml or a Secret
KANDEV_DATABASE_DRIVER: postgres
KANDEV_DATABASE_HOST: postgres.default.svc.cluster.local
KANDEV_DATABASE_PORT: "5432"
KANDEV_DATABASE_USER: kandev
KANDEV_DATABASE_PASSWORD: <from-secret>
KANDEV_DATABASE_DBNAME: kandev

When using Postgres, the PVC is still needed for worktree storage but the database itself is external.

Persistent Storage

The PVC at /data stores:

• SQLite database (/data/data/kandev.db, /data/data/kandev.db-wal, /data/data/kandev.db-shm)
• Git worktrees (/data/worktrees/), tasks (/data/tasks/), repos (/data/repos/), sessions (/data/sessions/), and LSP servers (/data/lsp-servers/)
• User home (/data/home/) — $HOME for the in-pod kandev user; holds gh CLI auth and agent CLI auth state (see Persistent agent and gh CLI auth above)
• npm globals (/data/.npm-global/) — agent CLIs installed via npm install -g

The PVC uses ReadWriteOnce access mode. If your cluster requires a specific StorageClass, add it to k8s/pvc.yaml:

spec:
  storageClassName: your-storage-class

Health Checks

The deployment includes both probes on the /health endpoint:

• Liveness probe: Restarts the pod if the backend becomes unresponsive (30s interval, 3 failures)
• Readiness probe: Removes the pod from service during startup or issues (10s interval, 3 failures)

The CLI launcher also performs an internal health check — it waits for the backend to be healthy before starting the web server.

Scaling

Single replica (SQLite): The default configuration uses replicas: 1 with Recreate strategy. This ensures only one instance writes to SQLite at a time.

Multiple replicas (PostgreSQL): Switch to Postgres, change the deployment strategy to RollingUpdate, and increase replicas:

spec:
  replicas: 3
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 0

Upgrading

# Build and push new image
docker build -t your-registry.com/kandev:v1.1.0 .
docker push your-registry.com/kandev:v1.1.0

# Update deployment
kubectl set image deployment/kandev kandev=your-registry.com/kandev:v1.1.0

# Or edit the deployment directly
kubectl edit deployment kandev

SQLite migrations run automatically on startup — no manual migration step needed.

Upgrading across the HOME=/data/home change: if you used kubectl exec to gh auth login or log in to agent CLIs on a pre-HOME=/data/home image, that state lived in the ephemeral /home/kandev and is not carried over. Log in once on the new pod and it will persist for all subsequent upgrades. If you want to keep the old state, copy it onto the PV before upgrading:

kubectl exec deployment/kandev -- sh -c 'cp -a /home/kandev/. /data/home/ 2>/dev/null || true'

Troubleshooting

# Check pod status
kubectl get pods -l app=kandev

# View logs
kubectl logs -l app=kandev -f

# Shell into the pod (if needed)
kubectl exec -it deployment/kandev -- /bin/bash

# Check PVC status
kubectl get pvc kandev-data

# Describe pod for events
kubectl describe pod -l app=kandev