feat: journald collector doc (#569)

Co-authored-by: Paige Calvert <[email protected]>
Co-authored-by: ada mancini <[email protected]>

docs/gatsby-config.js

@@ -134,6 +134,7 @@ module.exports = {
             "host-collect-analyze/http",
             "host-collect-analyze/httpLoadBalancer",
             "host-collect-analyze/ipv4Interfaces",
+            "host-collect-analyze/journald",
             "host-collect-analyze/kernelConfigs",
             "host-collect-analyze/memory",
             "host-collect-analyze/regex",

docs/source/host-collect-analyze/all.md

@@ -42,3 +42,4 @@ description: A list of all available host collectors and analyzers.
 - [systemPackages](./systemPackages) Collects and analyzes information about the host system packages for the specified operating system.
 - [time](./time): Collects and analyzes information about the system clock.
 - [kernelConfigs](./kernelConfigs): Collects and analyzes information about available Kernel Configs on the machine.
+- [journald](./journald): Collects journal entries from journald service.

docs/source/host-collect-analyze/journald.md

@@ -0,0 +1,94 @@
+---
+title: Journald
+description: Collect logs from journald
+---
+
+## Journald Collector
+
+To collect log entries from the journald service, you can use the `journald` collector.
+
+### Parameters
+
+In addition to the [shared collector properties](/collect/collectors/#shared-properties), the `journald` collector accepts the following parameters to filter journal records:
+
+#### `system` (Optional)
+
+Show messages from system services and the kernel. Default to `false`
+
+#### `dmesg` (Optional)
+
+Include messages from the kernel ring buffer. Default to `false`
+
+#### `units` (Optional)
+
+A list of systemd units to include messages from. If empty, messages from all units will be included.
+
+#### `since` (Optional)
+
+Specify a starting point for the journal entries. This can be a timestamp or a relative time (for example, `"1 day ago"` for the previous day).
+
+#### `until` (Optional)
+
+Specify an endpoint for the journal entries. This can be a timestamp or a relative time.
+
+#### `output` (Optional)
+
+Specify the format for the collected logs. Default is `"short"`.
+
+#### `lines` (Optional)
+
+Limit the number of lines to fetch from the journal. If set to `0`, all lines will be fetched. Default is `0`.
+
+#### `reverse` (Optional)
+
+Show the newest entries first. Default to `false`.
+
+#### `utc` (Optional)
+
+Show timestamps in UTC. Default to `false`.
+
+#### `timeout` (Optional)
+
+Specify a timeout for collecting the logs. Default to `"30s"`.
+
+### Example Collector Definition
+
+```yaml
+apiVersion: troubleshoot.sh/v1beta2
+kind: SupportBundle
+metadata:
+  name: logs
+spec:
+  hostCollectors:
+    - journald:
+        collectorName: "k0s"
+        system: false
+        dmesg: false
+        units:
+          - k0scontroller
+          - containerd
+        since: "1 day ago"
+        output: "json"
+        lines: 1000
+        reverse: true
+        utc: true
+        timeout: "30s"
+```
+
+### Included Resources
+
+The results of the `journald` collector are stored in the `host-collectors/journald` directory of the bundle. Two files per collector execution will be stored in this directory.
+
+- `[collector-name].txt` - output of the logs from `journalctl`
+- `[collector-name]-info.json` - the command that was executed, its exit code and any output read from `stderr`. See the example below:
+
+```json
+{
+  "command": "/usr/bin/journalctl -u k0scontroller -n 100 --reverse --utc --no-pager",
+  "exitCode": "0",
+  "error": "",
+  "outputDir": "",
+  "input": "",
+  "env": null
+}
+```