[receiver/journald]: add support for all configuration (#30971)

**Description:** 
This commit adds support for `all` to journald
receiver, which allows full output, including
unprintable characters and lines that are too long.

**Link to tracking Issue:** #30920 

**Testing:** unit test and manual test.

**Documentation:** receiver/journaldreceiver/README.md and
pkg/stanza/docs/operators/journald_input.md

.chloggen/add-all-to-journald-receiver.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: receiver/journald
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: add a new config option "all" that turns on full output from journalctl, including lines that are too long.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [30920]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user]

pkg/stanza/docs/operators/journald_input.md

@@ -21,6 +21,7 @@ The `journald_input` operator will use the `__REALTIME_TIMESTAMP` field of the j
 | `start_at`        | `end`            | At startup, where to start reading logs from the file. Options are `beginning` or `end`. |
 | `attributes`      | {}               | A map of `key: value` pairs to add to the entry's attributes. |
 | `resource`        | {}               | A map of `key: value` pairs to add to the entry's resource. |
+| `all`             | 'false'          | If `true`, very long logs and logs with unprintable characters will also be included. |
 
 ### Example Configurations
 

pkg/stanza/operator/input/journald/config.go

@@ -36,6 +36,7 @@ type Config struct {
 	Identifiers []string      `mapstructure:"identifiers,omitempty"`
 	Grep        string        `mapstructure:"grep,omitempty"`
 	Dmesg       bool          `mapstructure:"dmesg,omitempty"`
+	All         bool          `mapstructure:"all,omitempty"`
 }
 
 type MatchConfig map[string]string

pkg/stanza/operator/input/journald/journald.go

@@ -113,6 +113,10 @@ func (c Config) buildArgs() ([]string, error) {
 		args = append(args, matches...)
 	}
 
+	if c.All {
+		args = append(args, "--all")
+	}
+
 	return args, nil
 }
 

pkg/stanza/operator/input/journald/journald_test.go

@@ -203,6 +203,13 @@ func TestBuildConfig(t *testing.T) {
 			},
 			Expected: []string{"--utc", "--output=json", "--follow", "--priority", "info", "--dmesg"},
 		},
+		{
+			Name: "all",
+			Config: func(cfg *Config) {
+				cfg.All = true
+			},
+			Expected: []string{"--utc", "--output=json", "--follow", "--priority", "info", "--all"},
+		},
 	}
 
 	for _, tt := range testCases {

receiver/journaldreceiver/README.md

@@ -35,6 +35,7 @@ Journald receiver requires that:
 | `grep`                              |                                      | Filter output to entries where the MESSAGE= field matches the specified regular expression. See [Multiple filtering options](#multiple-filtering-options) examples.                                                                      |
 | `dmesg`                             | 'false'                              | Show only kernel messages. This shows logs from current boot and adds the match `_TRANSPORT=kernel`. See [Multiple filtering options](#multiple-filtering-options) examples.                                                             |
 | `storage`                           | none                                 | The ID of a storage extension to be used to store cursors. Cursors allow the receiver to pick up where it left off in the case of a collector restart. If no storage extension is used, the receiver will manage cursors in memory only. |
+| `all`                               | 'false'                              | If `true`, very long logs and logs with unprintable characters will also be included.                                                                                                                                                    |
 | `retry_on_failure.enabled`          | `false`                              | If `true`, the receiver will pause reading a file and attempt to resend the current batch of logs if it encounters an error from downstream components.                                                                                  |
 | `retry_on_failure.initial_interval` | `1 second`                           | Time to wait after the first failure before retrying.                                                                                                                                                                                    |
 | `retry_on_failure.max_interval`     | `30 seconds`                         | Upper bound on retry backoff interval. Once this value is reached the delay between consecutive retries will remain constant at the specified value.                                                                                     |