Adding upstream version 1.34.4.

Signed-off-by: Daniel Baumann <daniel@debian.org>

plugins/inputs/wireguard/README.md

@@ -0,0 +1,85 @@
+# Wireguard Input Plugin
+
+The Wireguard input plugin collects statistics on the local Wireguard server
+using the [`wgctrl`](https://github.com/WireGuard/wgctrl-go) library. It
+reports gauge metrics for Wireguard interface device(s) and its peers.
+
+## Global configuration options <!-- @/docs/includes/plugin_config.md -->
+
+In addition to the plugin-specific configuration settings, plugins support
+additional global and plugin configuration settings. These settings are used to
+modify metrics, tags, and field or create aliases and configure ordering, etc.
+See the [CONFIGURATION.md][CONFIGURATION.md] for more details.
+
+[CONFIGURATION.md]: ../../../docs/CONFIGURATION.md#plugins
+
+## Configuration
+
+```toml @sample.conf
+# Collect Wireguard server interface and peer statistics
+[[inputs.wireguard]]
+  ## Optional list of Wireguard device/interface names to query.
+  ## If omitted, all Wireguard interfaces are queried.
+  # devices = ["wg0"]
+```
+
+## Metrics
+
+- `wireguard_device`
+  - tags:
+    - `name` (interface device name, e.g. `wg0`)
+    - `type` (Wireguard tunnel type, e.g. `linux_kernel` or `userspace`)
+  - fields:
+    - `listen_port` (int, UDP port on which the interface is listening)
+    - `firewall_mark` (int, device's current firewall mark)
+    - `peers` (int, number of peers associated with the device)
+
+- `wireguard_peer`
+  - tags:
+    - `device` (associated interface device name, e.g. `wg0`)
+    - `public_key` (peer public key, e.g. `NZTRIrv/ClTcQoNAnChEot+WL7OH7uEGQmx8oAN9rWE=`)
+  - fields:
+    - `persistent_keepalive_interval_ns` (int, keepalive interval in
+    nanoseconds; 0 if unset)
+    - `protocol_version` (int, Wireguard protocol version number)
+    - `allowed_ips` (int, number of allowed IPs for this peer)
+    - `last_handshake_time_ns` (int, Unix timestamp of the last handshake for
+       this peer in nanoseconds)
+    - `rx_bytes` (int, number of bytes received from this peer)
+    - `tx_bytes` (int, number of bytes transmitted to this peer)
+    - `allowed_peer_cidr` (string, comma separated list of allowed peer CIDRs)
+
+## Troubleshooting
+
+### Error: `operation not permitted`
+
+When the kernelspace implementation of Wireguard is in use (as opposed to its
+userspace implementations), Telegraf communicates with the module over netlink.
+This requires Telegraf to either run as root, or for the Telegraf binary to
+have the `CAP_NET_ADMIN` capability.
+
+To add this capability to the Telegraf binary (to allow this communication under
+the default user `telegraf`):
+
+```bash
+sudo setcap CAP_NET_ADMIN+epi $(which telegraf)
+```
+
+N.B.: This capability is a filesystem attribute on the binary itself. The
+attribute needs to be re-applied if the Telegraf binary is rotated (e.g.
+on installation of new a Telegraf version from the system package manager).
+
+### Error: `error enumerating Wireguard devices`
+
+This usually happens when the device names specified in config are invalid.
+Ensure that `sudo wg show` succeeds, and that the device names in config match
+those printed by this command.
+
+## Example Output
+
+```text
+wireguard_device,host=WGVPN,name=wg0,type=linux_kernel firewall_mark=51820i,listen_port=58216i 1582513589000000000
+wireguard_device,host=WGVPN,name=wg0,type=linux_kernel peers=1i 1582513589000000000
+wireguard_peer,device=wg0,host=WGVPN,public_key=NZTRIrv/ClTcQoNAnChEot+WL7OH7uEGQmx8oAN9rWE= allowed_ips=2i,persistent_keepalive_interval_ns=60000000000i,protocol_version=1i,allowed_peer_cidr=192.168.1.0/24,10.0.0.0/8 1582513589000000000
+wireguard_peer,device=wg0,host=WGVPN,public_key=NZTRIrv/ClTcQoNAnChEot+WL7OH7uEGQmx8oAN9rWE= last_handshake_time_ns=1582513584530013376i,rx_bytes=6484i,tx_bytes=13540i 1582513589000000000
+```