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Initial implementation: NATS->S3 archiver + search/retrieve CLI
logarchiver replaces the plain Vector archiver leg of the centralized
logging stack (argocd-apps #296) with a Go service that archives raw logs
from NATS JetStream to S3 as zstd-compressed, OpenPGP-encrypted, indexed
objects, plus an operator CLI to search the index and retrieve/decrypt
archived logs. It adds the things that outgrew Vector: zstd compression,
encryption keyed from Ben's Vault GPG secrets engine, a searchable
ClickHouse index, and sink-conditional acks (a batch is acknowledged to
JetStream only after the object is durably in S3 AND indexed).

Service (`logarchiver run`):
- Durable JetStream pull consumer (stream LOGS, durable archiver, subject
  filter default logs.k8s.vault.>), explicit acks, independent offsets.
- Batch per subject by size/count/time -> NDJSON -> zstd -> encrypt -> S3
  PUT -> ClickHouse index row -> ack. On any failure the batch is Nak'd and
  redelivered, so nothing is lost on a sink outage.
- Encryption is a wrapped-DEK envelope (container LARC1): the bulk is
  AES-256-GCM framed under a random data key, and only that 32-byte key is
  OpenPGP-encrypted to the engine's public key. This is because the Vault
  GPG engine does whole-payload decrypt only; retrieval round-trips just the
  tiny wrapped key regardless of object size. Public key fetched from the
  engine or a mounted file (configurable); key fingerprint recorded per
  object; periodic pubkey refresh for rotation.
- Prometheus metrics, structured slog, graceful drain on shutdown.

CLI:
- `search` queries the index (subject/host/time) and lists matching objects.
- `fetch` downloads, decrypts via the Vault GPG engine, unzstds and emits
  NDJSON (optionally re-filtered by host/time).
- `init-schema` creates/prints the ClickHouse archive_index DDL.
- cobra `completion` subcommands.

Config via file+env (k8s-friendly, secrets from env), boundaries (NATS/S3/
ClickHouse/Vault) behind interfaces with unit tests (config, batching,
host/subject extraction, crypto roundtrip with a test key, ack-after-persist
with fakes, search query building). go build/vet/test -race clean;
golangci-lint v2 clean. Woodpecker CI: build/test/pre-commit on PR; on v*
tag a container image plus a Gitea binary release + rpm-internal RPM. Docs
per subcommand + architecture + retrieval runbook + deployment drop-in.

Claude-Session: https://claude.ai/code/session_015ur3i7D2azsMAWTSVABApv
2026-07-27 23:22:40 +10:00

3.8 KiB

logarchiver

Archive raw logs from the centralized logging NATS JetStream stream to S3 as zstd-compressed, OpenPGP-encrypted, indexed objects — and a CLI to search the index and retrieve/decrypt archived logs.

logarchiver replaces the plain Vector archiver leg of the logging stack (argocd-apps #296). Where Vector wrote gzipped NDJSON to Ceph RGW with no index and no encryption, logarchiver adds:

  • zstd compression (github.com/klauspost/compress/zstd);
  • OpenPGP encryption with a key held in Ben's Vault GPG secrets engine (vault-plugin-secrets-gpg) — the private key never leaves Vault;
  • a searchable ClickHouse index so you can answer "vault logs from host X between dates Y and Z" without scanning S3;
  • sink-conditional acks: a batch's JetStream messages are acknowledged only after the object is durably in S3 and indexed — something a stock Vector NATS consumer cannot do.

It is a single Go binary that is both the service (logarchiver run) and the operator CLI (search / fetch / init-schema).

Quick start

# Service (in-cluster): drains the JetStream 'archiver' consumer to S3 + index.
logarchiver run                       # defaults suit the logging stack; env supplies secrets

# Operator CLI (laptop, with VAULT_TOKEN / ~/.vault-token and S3/ClickHouse creds):
logarchiver search --subject 'logs.k8s.vault.>' --host node-1 --from -24h
logarchiver fetch  --subject 'logs.vm.*' --host db-1 --from -24h -o ./out
logarchiver fetch  archive/logs.k8s.vault._/2026/07/27/…​.ndjson.zst.larc -o -

# Schema (local/dev; in-cluster the argocd bootstrap Job owns this):
logarchiver init-schema            # or: init-schema --print  to emit the DDL

How it works (short version)

JetStream LOGS / durable "archiver"  ──▶  batch by subject (size/count/time)
   │                                            │
   │                                       NDJSON ─▶ zstd ─▶ AES-256-GCM frames
   │                                            │        (random per-object data key)
   │                                       data key ─▶ OpenPGP-encrypt to Vault pubkey
   │                                            ▼
   └── ack ONLY after ─────────────────  S3 PUT (LARC1 object)  +  ClickHouse index row

Retrieval sends only the tiny wrapped data key to the Vault GPG engine (which does whole-payload decrypt only), recovers it, and streams the bulk locally. See docs/architecture.md and the retrieval runbook for the full design and the honest account of what the GPG engine supports.

Documentation

Build / test / lint

make build            # -> dist/logarchiver
make test             # go test -race ./...
make lint             # golangci-lint run ./...
make rpm              # build + package the CLI RPM (nfpm)
make patch|minor|major# tag + push a release (triggers the Woodpecker pipeline)

Releases (on a v* tag): a container image git.unkin.net/unkin/logarchiver for the service, and a Gitea binary release + rpm-internal RPM for the CLI.