iotedge check "container-engine-logrotate" should not require rotate options when driver is "local"

[damonbarry]

Expected Behavior

iotedge check should not warn me that the "Container engine is not configured to rotate module logs..." when I use Docker's local log driver. The container engine is configured to rotate module logs; the local driver provides default values for max-size and max-file if the user does not explicitly give them.

Current Behavior

IoT Edge docs recommend that I use Docker's local log driver. When I follow that recommendation by creating daemon.json like this:

{
  "log-driver": "local"
}

...then the iotedge tool's "container-engine-logrotate" check emits a warning because I didn't explicitly add a log-opts object with max-file and max-size values to daemon.json.

Runtime Versions

• aziot-edged [run iotedge version]: 1.4
• Edge Agent [image tag (e.g. 1.0.0)]: 1.4
• Edge Hub [image tag (e.g. 1.0.0)]: 1.4
• Docker/Moby [run docker version]: any version that supports the local log driver

Additional Information

@drwill-ms originally filed this as doc issue MicrosoftDocs/azure-docs#100762. I'm filing this issue because I believe the fix should be made in iotedge check instead.

[damonbarry]

I think we just need to add a match arm for "local" that behaves like the journald arm, here:

iotedge/edgelet/iotedge/src/check/checks/container_engine_logrotate.rs

Lines 58 to 62 in d796a36

	match daemon_config.log_driver.as_deref() {
	Some("journald") => return Ok(CheckResult::Ok),
	None => return Ok(CheckResult::Warning(anyhow!(MESSAGE))),
	_ => (),
	}

[mtrensch]

I've sent the PR for the journald part, but when looking deeper into it, it seems like all logging drivers, but the default json-file logger, do rotate logs automatically.

So maybe the following would be better instead of a separate match of "local" driver:

        match daemon_config.log_driver.as_deref() {
            None | Some("json-file") => {
                if let Some(log_opts) = &daemon_config.log_opts {
                    if log_opts.max_file.is_none() {
                        return Ok(CheckResult::Warning(anyhow!(MESSAGE)));
                    }

                    if log_opts.max_size.is_none() {
                        return Ok(CheckResult::Warning(anyhow!(MESSAGE)));
                    }
                } else {
                    return Ok(CheckResult::Warning(anyhow!(MESSAGE)));
                }
            },
            _ => (),
        }
        Ok(CheckResult::Ok)

[github-actions]

This issue is being marked as stale because it has been open for 30 days with no activity.