Forwarding Audit Logs to Graylog

Graylog accepts RFC 5424 syslog via its Syslog TCP or Syslog UDP inputs. This page covers the TLS-encrypted TCP path; UDP and plaintext-TCP setups are simpler and follow the same pattern.

Graylog-side setup

Create a Syslog TCP input

In Graylog's web UI:

1. System → Inputs
2. Select Syslog TCP from the dropdown and click Launch new input
3. Configure:
   • Title: Stratora Audit
   • Bind address: 0.0.0.0
   • Port: 6514
   • Allow throttling this input: unchecked
   • TLS cert file: /etc/graylog/server/certs/graylog.pem
   • TLS key file: /etc/graylog/server/certs/graylog.key
   • TLS client authentication: disabled (Stratora does not present a client cert in v2.2.0)
   • TLS Enable: ON
   • Allow overriding date? OFF (use Stratora's wire timestamp)
   • Store full message: ON (preserves the full RFC 5424 wire for forensics)
4. Click Save

The input starts immediately. Confirm it shows "running" with no errors in the Graylog UI.

Firewall configuration

If your Graylog runs on a RHEL-family Linux distribution (RHEL, Rocky Linux, AlmaLinux, CentOS Stream), the default firewalld policy blocks incoming syslog ports. Allow the port with:

sudo firewall-cmd --add-port=6514/tcp --permanent
sudo firewall-cmd --reload

Debian and Ubuntu deployments don't have this gate by default.

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Certificate setup

Graylog's TLS input requires the cert + key paths in the input config. Generate a cert with SAN entries matching the destination Host you configure in Stratora:

openssl req -x509 -newkey rsa:2048 -keyout graylog.key -out graylog.pem \
  -days 365 -nodes \
  -subj "/CN=graylog-01.example.com" \
  -addext "subjectAltName=DNS:graylog-01.example.com,DNS:graylog-01"

sudo chown graylog:graylog graylog.pem graylog.key
sudo chmod 640 graylog.key
sudo chmod 644 graylog.pem
sudo mv graylog.pem graylog.key /etc/graylog/server/certs/

For internal CAs, paste the CA PEM into Stratora's Custom CA Certificate field at wizard Step 3.

Restart Graylog after the cert is in place:

sudo systemctl restart graylog-server

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Stratora-side configuration

Navigate to Settings → Syslog Destinations → Add Destination and walk through the wizard:

Step	Field	Value
1 — Details	Name	Graylog Production (or your own naming convention)
2 — Connection	Host	The Graylog hostname matching the cert SAN
2 — Connection	Port	6514
2 — Connection	Protocol	TCP + TLS (recommended)
3 — Format	RFC Format	RFC 5424 (modern)
3 — Format	Facility	local0
3 — Format	Verify server certificate	ON
3 — Format	Custom CA Certificate	Paste your CA cert PEM here if self-signed or internal CA
4 — Review	Enabled	ON
4 — Review	—	Click Test Connection; expect "Test event sent successfully"
4 — Review	—	Click Create

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Verifying ingest in Graylog

In Graylog's web UI, Search → use a query like:

source:stratora-host AND application_name:stratora

Graylog's structured-data extraction populates fields directly from RFC 5424 wire bytes:

Graylog field	Stratora wire field
application_name	APP-NAME (stratora)
process_id	PROCID (backend PID)
level	computed from PRI (notice=5)
facility	computed from PRI (local0=16)
source	HOSTNAME
message	MSG body (user=admin resource=… ip=…)

Extracting key=value pairs from MSG

Graylog's Key=Value Pairs Extractor can split the MSG body into individual fields. Configure on the input:

1. Input → Manage extractors
2. Add extractor → Key=Value Pairs
3. Source field: message
4. Save

After the extractor is in place, audit metadata appears as top-level Graylog fields: user, resource, ip, resource_id, etc.

Streams and alerts

Route Stratora audit events into a dedicated stream with rule application_name = stratora. From there, build alert rules on specific actions — e.g., audit_action = user_disable AND resource = admin to flag admin-level user disables.

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Operational notes

• Graylog journal: if Elasticsearch is slow or down, Graylog's journal buffers incoming syslog to disk; events resume processing when Elasticsearch recovers.
• Throttling: the Stratora destination's per-queue cap (1,000 events) means extreme bursts may drop events before they reach Graylog. Monitor events_dropped_total on the destination during heavy use.
• Test isolation: Test Connection events are tagged as syslog_destination_test and bypass Stratora's audit_logs table — they appear at Graylog but are not part of Stratora's persistent audit history.