logwisp/doc/sources.md

Input Sources

Sources produce core.LogEntry values for a pipeline. Every source is declared as a [[pipelines.plugin_sources]] entry with an id, a type, and a type-specific config table.

[[pipelines.plugin_sources]]
id   = "app_logs"
type = "file"
[pipelines.plugin_sources.config]
directory = "/var/log/myapp"

Registered types: file, console, random, null, tcp_chain, http_chain.

Publication from any source is non-blocking. When a subscriber channel is full the entry is dropped and counted in dropped_entries.

---

file

Tails every file in a directory whose name matches a glob.

[[pipelines.plugin_sources]]
id   = "app_logs"
type = "file"
[pipelines.plugin_sources.config]
directory         = "/var/log/myapp"
pattern           = "*.log"
check_interval_ms = 100

Option	Type	Default	Description
directory	string	required	Directory to scan; not recursive
pattern	string	*	Glob over filenames; * and ? only
check_interval_ms	int	100	Directory rescan interval; minimum 10

Behaviour

• check_interval_ms governs how often the directory is rescanned for new or removed files. Tailing an already-open file polls on a fixed 100 ms interval that this option does not change.
• Each matched file gets its own watcher. Watchers for files that disappear are stopped and removed on the next scan.
• A new watcher seeks to end-of-file. Positions live in memory only, so a restart resumes from the current end of each file and content written while LogWisp was down is not read.
• Rotation is detected from size decrease, modification-time reset, a position beyond end-of-file, or an inode change. An inode change where the new file is already larger than the recorded position is treated as an atomic save, not a rotation, and the position is preserved.
• Lines are parsed as JSON when they contain time, level, msg, and fields keys; time is read as RFC3339Nano. Anything else is kept as plain text with the level inferred from common markers ([ERROR], WARN:, and so on).
• Source is set to the file's base name.

Statistics: per-watcher size, position, entries read, rotation count, and last read time, plus active_watchers.

---

console

Reads newline-delimited entries from standard input.

[[pipelines.plugin_sources]]
id   = "stdin"
type = "console"
[pipelines.plugin_sources.config]
buffer_size = 1000

Option	Type	Default	Description
buffer_size	int	1000	Subscriber channel depth

At most one instance per pipeline: the type is registered with MaxInstances: 1, and a second instance is rejected at pipeline construction. The level is inferred from the line text, and Source is set to console.

---

random

Synthetic entry generator for development, smoke tests, and sanitizer testing.

[[pipelines.plugin_sources]]
id   = "generator"
type = "random"
[pipelines.plugin_sources.config]
interval_ms = 500
jitter_ms   = 0
format      = "txt"
length      = 20
special     = false

Option	Type	Default	Description
interval_ms	int	500	Emission period
jitter_ms	int	0	Symmetric jitter; clamped to interval_ms, must be non-negative
format	string	txt	raw (message only), txt (bracketed line), json (JSON object as the message)
length	int	20	Message length in characters
special	bool	false	Inject control and non-ASCII characters

special = true is the intended way to exercise sanitizer policies: it inserts control bytes and multi-byte Unicode into otherwise ordinary messages. Levels are chosen at random from DEBUG, INFO, WARN, ERROR.

---

null

Produces nothing. Useful as a placeholder so a sink-only pipeline satisfies the "at least one source" requirement.

[[pipelines.plugin_sources]]
id   = "void"
type = "null"

No options.

---

tcp_chain

Listens for persistent NDJSON streams from upstream LogWisp tcp_chain sinks. See Chaining for the protocol.

[[pipelines.plugin_sources]]
id   = "ingest_tcp"
type = "tcp_chain"
[pipelines.plugin_sources.config]
host             = "0.0.0.0"
port             = 15801
buffer_size      = 1000
max_connections  = 0
read_timeout_ms  = 0
hello_timeout_ms = 10000
trust_node       = true

[pipelines.plugin_sources.config.tls]
enabled        = true
cert_file      = "/etc/logwisp/tls/server.crt"
key_file       = "/etc/logwisp/tls/server.key"
client_auth    = true
client_ca_file = "/etc/logwisp/tls/client-ca.crt"
min_version    = "1.3"

Option	Type	Default	Description
host	string	0.0.0.0	Bind address; IPv4 only
port	int	required	Listen port, 1–65535
buffer_size	int	1000	Subscriber channel depth
max_connections	int	0	Concurrent connection cap; 0 = unlimited
read_timeout_ms	int	0	Per-connection idle read deadline; 0 = none
hello_timeout_ms	int	10000	Deadline for the hello preamble
trust_node	bool	true	false overrides the sender's node label with its remote address
tls	table	—	Listener TLS; see Security

Behaviour

• TLS handshakes run explicitly with a 10 s bound before the preamble is read, after the max_connections admission check.
• A connection is rejected if the first line is not a valid hello with a matching protocol version.
• Each accepted connection gets a session recording the remote address, node label, and — under TLS — tls and tls_peer_cn.
• A malformed entry line increments parse_errors and is skipped; the connection survives. A line over 1 MiB is a protocol violation and terminates the connection.

Statistics: active_connections, rejected_conns, parse_errors, tls_handshake_errors, trust_node.

---

http_chain

Accepts NDJSON batches POSTed by upstream LogWisp http_chain sinks.

[[pipelines.plugin_sources]]
id   = "ingest_http"
type = "http_chain"
[pipelines.plugin_sources.config]
host            = "0.0.0.0"
port            = 15802
ingest_path     = "/ingest"
buffer_size     = 1000
max_body_bytes  = 8388608
read_timeout_ms = 30000
trust_node      = true

[pipelines.plugin_sources.config.tls]
enabled        = true
cert_file      = "/etc/logwisp/tls/server.crt"
key_file       = "/etc/logwisp/tls/server.key"
client_auth    = true
client_ca_file = "/etc/logwisp/tls/client-ca.crt"

Option	Type	Default	Description
host	string	0.0.0.0	Bind address; IPv4 only
port	int	required	Listen port
ingest_path	string	/ingest	Endpoint path; must start with /
buffer_size	int	1000	Subscriber channel depth
max_body_bytes	int	8388608	Per-request body cap (8 MiB)
read_timeout_ms	int	30000	Full request read deadline
trust_node	bool	true	false overrides the sender's node label with its remote address
tls	table	—	Listener TLS

Behaviour

• Only POST to ingest_path is routed; other methods get 405 with an Allow header, and other paths get 404.
• A missing or mismatched X-Logwisp-Protocol header is rejected with 400.
• Batch acceptance is atomic: entries are published only after the body reads cleanly end to end. A transfer error rejects the whole batch (400, or 413 when the body cap is hit) so the sender retries it. A malformed line inside an otherwise clean transfer is skipped and counted in parse_errors.
• Success is 204 No Content with X-Logwisp-Accepted set to the number of entries ingested.
• Sessions are cached per remote host + declared node and recreated after idle expiry.

Statistics: total_requests, rejected_requests, parse_errors, cached_sessions, trust_node.

---

Source Statistics

Every source reports: id, type, total_entries, dropped_entries, start_time, last_entry_time, and a type-specific details map. These appear in the status reporter output and in the http sink's status endpoint.