the-other-dude/.planning/phases/02-poller-config-collection/02-01-PLAN.md

---
phase: 02-poller-config-collection
plan: 01
type: execute
wave: 1
depends_on: []
files_modified:
  - poller/internal/device/ssh_executor.go
  - poller/internal/device/ssh_executor_test.go
  - poller/internal/device/normalize.go
  - poller/internal/device/normalize_test.go
  - poller/internal/config/config.go
  - poller/internal/bus/publisher.go
  - poller/internal/observability/metrics.go
  - poller/internal/store/devices.go
  - backend/alembic/versions/028_device_ssh_host_key.py
autonomous: true
requirements: [COLL-01, COLL-02, COLL-06]

must_haves:
  truths:
    - "SSH executor can run a command on a RouterOS device and return stdout, stderr, exit code, duration, and typed errors"
    - "Config output is normalized deterministically (timestamp stripped, whitespace trimmed, line endings unified, blank lines collapsed)"
    - "SHA256 hash is computed on normalized output"
    - "Config backup interval and concurrency are configurable via environment variables"
    - "Host key fingerprint is stored on device record for TOFU verification"
  artifacts:
    - path: "poller/internal/device/ssh_executor.go"
      provides: "RunCommand SSH executor with TOFU host key verification and typed errors"
      exports: ["RunCommand", "CommandResult", "SSHError", "SSHErrorKind"]
    - path: "poller/internal/device/normalize.go"
      provides: "NormalizeConfig function and SHA256 hashing"
      exports: ["NormalizeConfig", "HashConfig"]
    - path: "poller/internal/device/ssh_executor_test.go"
      provides: "Unit tests for SSH executor error classification"
    - path: "poller/internal/device/normalize_test.go"
      provides: "Unit tests for config normalization with edge cases"
    - path: "poller/internal/config/config.go"
      provides: "CONFIG_BACKUP_INTERVAL, CONFIG_BACKUP_MAX_CONCURRENT, CONFIG_BACKUP_COMMAND_TIMEOUT env vars"
    - path: "poller/internal/bus/publisher.go"
      provides: "ConfigSnapshotEvent type and PublishConfigSnapshot method, config.snapshot.create subject in stream"
    - path: "poller/internal/store/devices.go"
      provides: "SSHPort and SSHHostKeyFingerprint fields on Device struct, UpdateSSHHostKey method"
    - path: "backend/alembic/versions/028_device_ssh_host_key.py"
      provides: "Migration adding ssh_port, ssh_host_key_fingerprint columns to devices table"
  key_links:
    - from: "poller/internal/device/ssh_executor.go"
      to: "poller/internal/store/devices.go"
      via: "Uses Device.SSHPort and Device.SSHHostKeyFingerprint for connection"
      pattern: "dev\\.SSHPort|dev\\.SSHHostKeyFingerprint"
    - from: "poller/internal/device/normalize.go"
      to: "poller/internal/bus/publisher.go"
      via: "Normalized config text and SHA256 hash populate ConfigSnapshotEvent fields"
      pattern: "NormalizeConfig|HashConfig"
---

<objective>
Build the reusable primitives for config backup collection: SSH command executor with TOFU host key verification, config output normalizer with SHA256 hashing, environment variable configuration, NATS event type, and device model extensions.

Purpose: These are the building blocks that the backup scheduler (Plan 02) wires together. Each is independently testable and follows existing codebase patterns.
Output: SSH executor module, normalization module, extended config/store/bus/metrics, Alembic migration for device SSH columns.
</objective>

<execution_context>
@/Users/jasonstaack/.claude/get-shit-done/workflows/execute-plan.md
@/Users/jasonstaack/.claude/get-shit-done/templates/summary.md
</execution_context>

<context>
@.planning/PROJECT.md
@.planning/ROADMAP.md
@.planning/STATE.md
@.planning/phases/02-poller-config-collection/02-CONTEXT.md
@.planning/phases/01-database-schema/01-01-SUMMARY.md

@poller/internal/device/sftp.go
@poller/internal/bus/publisher.go
@poller/internal/config/config.go
@poller/internal/store/devices.go
@poller/internal/observability/metrics.go
@poller/internal/poller/scheduler.go
@poller/go.mod

<interfaces>
<!-- Existing patterns the executor must follow -->

From poller/internal/device/sftp.go:
```go
func NewSSHClient(ip string, port int, username, password string, timeout time.Duration) (*ssh.Client, error)
// Uses ssh.InsecureIgnoreHostKey() — executor replaces this with TOFU callback
```

From poller/internal/store/devices.go:
```go
type Device struct {
    ID                          string
    TenantID                    string
    IPAddress                   string
    APIPort                     int
    APISSLPort                  int
    EncryptedCredentials        []byte
    EncryptedCredentialsTransit *string
    RouterOSVersion             *string
    MajorVersion                *int
    TLSMode                     string
    CACertPEM                   *string
}
// SSHPort and SSHHostKeyFingerprint need to be added
```

From poller/internal/bus/publisher.go:
```go
type Publisher struct { nc *nats.Conn; js jetstream.JetStream }
func (p *Publisher) PublishStatus(ctx context.Context, event DeviceStatusEvent) error
// Follow this pattern for PublishConfigSnapshot
// Stream subjects list needs "config.snapshot.>" added
```

From poller/internal/config/config.go:
```go
func Load() (*Config, error)
// Uses getEnv(key, default) and getEnvInt(key, default) helpers
```
</interfaces>
</context>

<tasks>

<task type="auto" tdd="true">
  <name>Task 1: SSH executor, normalizer, and their tests</name>
  <files>
    poller/internal/device/ssh_executor.go,
    poller/internal/device/ssh_executor_test.go,
    poller/internal/device/normalize.go,
    poller/internal/device/normalize_test.go
  </files>
  <behavior>
    SSH Executor (ssh_executor_test.go):
    - Test SSHErrorKind classification: given various ssh/net error types, classifySSHError returns correct kind (AuthFailed, HostKeyMismatch, Timeout, ConnectionRefused, Unknown)
    - Test TOFU host key callback: when fingerprint is empty (first connect), callback accepts and returns fingerprint; when fingerprint matches, callback accepts; when fingerprint mismatches, callback rejects with HostKeyMismatch error
    - Test CommandResult: verify struct fields (Stdout, Stderr, ExitCode, Duration, Error)

    Normalizer (normalize_test.go):
    - Test timestamp stripping: input with "# 2024/01/15 10:30:00 by RouterOS 7.x\n# software id = XXXX\n" strips only the timestamp line and following blank line, preserves software id comment
    - Test line ending normalization: "\r\n" becomes "\n"
    - Test trailing whitespace trimming: "  /ip address  \n" becomes "/ip address\n"
    - Test blank line collapsing: three consecutive blank lines become one
    - Test trailing newline: output always ends with exactly one "\n"
    - Test comment preservation: lines starting with "# " that are NOT the timestamp header are preserved
    - Test full normalization pipeline: realistic RouterOS export with all issues produces clean output
    - Test HashConfig: returns lowercase hex SHA256 of the normalized string (64 chars)
    - Test idempotency: NormalizeConfig(NormalizeConfig(input)) == NormalizeConfig(input)
  </behavior>
  <action>
    Create `poller/internal/device/ssh_executor.go`:

    1. Define types:
       - `SSHErrorKind` string enum: `ErrAuthFailed`, `ErrHostKeyMismatch`, `ErrTimeout`, `ErrTruncatedOutput`, `ErrConnectionRefused`, `ErrUnknown`
       - `SSHError` struct implementing `error`: `Kind SSHErrorKind`, `Err error`, `Message string`
       - `CommandResult` struct: `Stdout string`, `Stderr string`, `ExitCode int`, `Duration time.Duration`

    2. `RunCommand(ctx context.Context, ip string, port int, username, password string, timeout time.Duration, knownFingerprint string, command string) (*CommandResult, string, error)`:
       - Returns (result, observedFingerprint, error)
       - Build ssh.ClientConfig with password auth and custom HostKeyCallback for TOFU:
         - If knownFingerprint == "": accept any key, compute and return SHA256 fingerprint
         - If knownFingerprint matches: accept
         - If knownFingerprint mismatches: reject with SSHError{Kind: ErrHostKeyMismatch}
       - Fingerprint format: `SHA256:base64(sha256(publicKeyBytes))` (same as ssh-keygen)
       - Dial with context-aware timeout
       - Create session, run command via session.Run()
       - Capture stdout/stderr via session.StdoutPipe/StderrPipe or CombinedOutput pattern
       - Classify errors using `classifySSHError(err)` helper that inspects error strings and types
       - Detect truncated output: if command times out mid-stream, return SSHError{Kind: ErrTruncatedOutput}

    3. `classifySSHError(err error) SSHErrorKind`: inspect error for "unable to authenticate", "host key", "i/o timeout", "connection refused" patterns

    Create `poller/internal/device/normalize.go`:

    1. `NormalizeConfig(raw string) string`:
       - Use regexp to strip timestamp header line matching `^# \d{4}/\d{2}/\d{2} \d{2}:\d{2}:\d{2} by RouterOS.*\n` and the blank line immediately following it
       - Replace \r\n with \n (before other processing)
       - Split into lines, trim trailing whitespace from each line
       - Collapse consecutive blank lines (2+ empty lines become 1)
       - Ensure single trailing newline
       - Return normalized string

    2. `HashConfig(normalized string) string`:
       - Compute SHA256 of the normalized string bytes
       - Return lowercase hex string (64 chars)

    3. `const NormalizationVersion = 1` — for future tracking in NATS payload

    Write tests FIRST (RED), then implement (GREEN). Tests for normalizer use table-driven test style matching Go conventions. SSH executor tests use mock/classification tests (no real SSH connection needed for unit tests).
  </action>
  <verify>
    <automated>cd /Volumes/ssd01/v9/the-other-dude/poller && go test ./internal/device/ -run "TestNormalize|TestHash|TestSSH|TestClassify|TestTOFU" -v -count=1</automated>
  </verify>
  <done>
    - RunCommand function compiles with correct signature returning (CommandResult, fingerprint, error)
    - SSHError type with Kind field covers all 6 error classifications
    - TOFU host key callback accepts on first connect, validates on subsequent, rejects on mismatch
    - NormalizeConfig strips timestamp, normalizes line endings, trims whitespace, collapses blanks, ensures trailing newline
    - HashConfig returns 64-char lowercase hex SHA256
    - All unit tests pass
  </done>
</task>

<task type="auto">
  <name>Task 2: Config env vars, NATS event type, device model extensions, Alembic migration, metrics</name>
  <files>
    poller/internal/config/config.go,
    poller/internal/bus/publisher.go,
    poller/internal/store/devices.go,
    poller/internal/observability/metrics.go,
    backend/alembic/versions/028_device_ssh_host_key.py
  </files>
  <action>
    **1. Config env vars** (`config.go`):
    Add three fields to the Config struct and load them in Load():
    - `ConfigBackupIntervalSeconds int` — `getEnvInt("CONFIG_BACKUP_INTERVAL", 21600)` (6h = 21600s)
    - `ConfigBackupMaxConcurrent int` — `getEnvInt("CONFIG_BACKUP_MAX_CONCURRENT", 10)`
    - `ConfigBackupCommandTimeoutSeconds int` — `getEnvInt("CONFIG_BACKUP_COMMAND_TIMEOUT", 60)`

    **2. NATS event type and publisher** (`publisher.go`):
    - Add `ConfigSnapshotEvent` struct:
      ```go
      type ConfigSnapshotEvent struct {
          DeviceID             string `json:"device_id"`
          TenantID             string `json:"tenant_id"`
          RouterOSVersion      string `json:"routeros_version,omitempty"`
          CollectedAt          string `json:"collected_at"`          // RFC3339
          SHA256Hash           string `json:"sha256_hash"`
          ConfigText           string `json:"config_text"`
          NormalizationVersion int    `json:"normalization_version"`
      }
      ```
    - Add `PublishConfigSnapshot(ctx, event) error` method on Publisher following the exact pattern of PublishStatus/PublishMetrics
    - Subject: `fmt.Sprintf("config.snapshot.create.%s", event.DeviceID)`
    - Add `"config.snapshot.>"` to the DEVICE_EVENTS stream subjects list in `NewPublisher`

    **3. Device model extensions** (`devices.go`):
    - Add fields to Device struct: `SSHPort int`, `SSHHostKeyFingerprint *string`
    - Update FetchDevices query to SELECT `COALESCE(d.ssh_port, 22)` and `d.ssh_host_key_fingerprint`
    - Update GetDevice query similarly
    - Update both Scan calls to include the new fields
    - Add `UpdateSSHHostKey(ctx context.Context, deviceID string, fingerprint string) error` method on DeviceStore:
      ```go
      const query = `UPDATE devices SET ssh_host_key_fingerprint = $1 WHERE id = $2`
      ```
      (This requires poller_user to have UPDATE on devices(ssh_host_key_fingerprint) — handled in migration)

    **4. Alembic migration** (`028_device_ssh_host_key.py`):
    Follow the raw SQL pattern from migration 027. Create migration that:
    - `ALTER TABLE devices ADD COLUMN ssh_port INTEGER DEFAULT 22`
    - `ALTER TABLE devices ADD COLUMN ssh_host_key_fingerprint TEXT`
    - `ALTER TABLE devices ADD COLUMN ssh_host_key_first_seen TIMESTAMPTZ`
    - `ALTER TABLE devices ADD COLUMN ssh_host_key_last_verified TIMESTAMPTZ`
    - `GRANT UPDATE (ssh_host_key_fingerprint, ssh_host_key_first_seen, ssh_host_key_last_verified) ON devices TO poller_user`
    - Downgrade: `ALTER TABLE devices DROP COLUMN ssh_port, DROP COLUMN ssh_host_key_fingerprint, DROP COLUMN ssh_host_key_first_seen, DROP COLUMN ssh_host_key_last_verified`
    - `REVOKE UPDATE (ssh_host_key_fingerprint, ssh_host_key_first_seen, ssh_host_key_last_verified) ON devices FROM poller_user`

    **5. Prometheus metrics** (`metrics.go`):
    Add config backup specific metrics:
    - `ConfigBackupTotal` CounterVec with labels ["status"] — status: "success", "error", "skipped_offline", "skipped_auth_blocked", "skipped_hostkey_blocked"
    - `ConfigBackupDuration` Histogram — buckets: [1, 5, 10, 30, 60, 120, 300]
    - `ConfigBackupActive` Gauge — number of concurrent backup jobs running
  </action>
  <verify>
    <automated>cd /Volumes/ssd01/v9/the-other-dude/poller && go build ./... && go vet ./... && go test ./internal/config/ -v -count=1</automated>
  </verify>
  <done>
    - Config struct has 3 new backup config fields loading from env vars with correct defaults
    - ConfigSnapshotEvent type exists with all required JSON fields
    - PublishConfigSnapshot method exists following existing publisher pattern
    - config.snapshot.> added to DEVICE_EVENTS stream subjects
    - Device struct has SSHPort and SSHHostKeyFingerprint fields
    - FetchDevices and GetDevice queries select and scan the new columns
    - UpdateSSHHostKey method exists for TOFU fingerprint storage
    - Alembic migration 028 adds ssh_port, ssh_host_key_fingerprint, timestamp columns with correct grants
    - Three new Prometheus metrics registered for config backup observability
    - All existing tests still pass, project compiles clean
  </done>
</task>

</tasks>

<verification>
1. `cd poller && go build ./...` — entire project compiles
2. `cd poller && go vet ./...` — no static analysis issues
3. `cd poller && go test ./internal/device/ -v -count=1` — SSH executor and normalizer tests pass
4. `cd poller && go test ./internal/config/ -v -count=1` — config tests pass
5. Migration file exists at `backend/alembic/versions/028_device_ssh_host_key.py`
</verification>

<success_criteria>
- SSH executor RunCommand function exists with TOFU host key verification and typed error classification
- Config normalizer strips timestamps, normalizes whitespace, and computes SHA256 hashes deterministically
- All config backup environment variables load with correct defaults (6h interval, 10 concurrent, 60s timeout)
- ConfigSnapshotEvent and PublishConfigSnapshot are ready for the scheduler to use
- Device model includes SSH port and host key fingerprint fields
- Database migration ready to add SSH columns to devices table
- Prometheus metrics registered for backup collection observability
- All tests pass, project compiles clean
</success_criteria>

<output>
After completion, create `.planning/phases/02-poller-config-collection/02-01-SUMMARY.md`
</output>