Fix error logging for provider failures (#10217)

* Fix error logging for provider failures

* Add changelog fragment

* Omit nil error detail from logs

(cherry picked from commit 0a5c2a4)

Author: straistaru

changelog/fragments/1759334752-fix-error-logging-for-provider-failures.yaml

@@ -0,0 +1,45 @@
+# REQUIRED
+# Kind can be one of:
+# - breaking-change: a change to previously-documented behavior
+# - deprecation: functionality that is being removed in a later release
+# - bug-fix: fixes a problem in a previous version
+# - enhancement: extends functionality but does not break or fix existing behavior
+# - feature: new functionality
+# - known-issue: problems that we are aware of in a given version
+# - security: impacts on the security of a product or a user’s deployment.
+# - upgrade: important information for someone upgrading from a prior version
+# - other: does not fit into any of the other categories
+kind: bug-fix
+
+# REQUIRED for all kinds
+# Change summary; a 80ish characters long description of the change.
+summary: Fix an incorrectly formatted log message when a provider fails
+
+# REQUIRED for breaking-change, deprecation, known-issue
+# Long description; in case the summary is not enough to describe the change
+# this field accommodate a description without length limits.
+# description:
+
+# REQUIRED for breaking-change, deprecation, known-issue
+# impact:
+
+# REQUIRED for breaking-change, deprecation, known-issue
+# action:
+
+# REQUIRED for all kinds
+# Affected component; usually one of "elastic-agent", "fleet-server", "filebeat", "metricbeat", "auditbeat", "all", etc.
+component: elastic-agent
+
+# AUTOMATED
+# OPTIONAL to manually add other PR URLs
+# PR URL: A link the PR that added the changeset.
+# If not present is automatically filled by the tooling finding the PR where this changelog fragment has been added.
+# NOTE: the tooling supports backports, so it's able to fill the original PR number instead of the backport PR number.
+# Please provide it if you are adding a fragment for a different PR.
+# pr: https://github.com/owner/repo/1234
+
+# AUTOMATED
+# OPTIONAL to manually add other issue URLs
+# Issue URL; optional; the GitHub issue related to this changeset (either closes or is part of).
+# If not present is automatically filled by the tooling with the issue linked to the PR number.
+# issue: https://github.com/owner/repo/1234

internal/pkg/composable/controller.go

@@ -469,7 +469,11 @@ func (c *controller) startContextProvider(ctx context.Context, wg *sync.WaitGrou
 				return
 			}
 			// all other exits are bad, even a nil error
-			l.Errorf("provider %q failed to run (will retry in %s): %s", name, c.restartInterval.String(), err)
+			cause := ""
+			if err != nil {
+				cause = fmt.Sprintf(": %v", err)
+			}
+			l.Errorf("provider %q failed to run (will retry in %s)%s", name, c.restartInterval.String(), cause)
 			if fpok {
 				// turn off fetch provider
 				sendFetchProvider(ctx, fetchCh, name, nil)
@@ -527,7 +531,11 @@ func (c *controller) startDynamicProvider(ctx context.Context, wg *sync.WaitGrou
 				return
 			}
 			// all other exits are bad, even a nil error
-			l.Errorf("provider %q failed to run (will restart in %s): %s", name, c.restartInterval.String(), err)
+			cause := ""
+			if err != nil {
+				cause = fmt.Sprintf(": %v", err)
+			}
+			l.Errorf("provider %q failed to run (will restart in %s)%s", name, c.restartInterval.String(), cause)
 			select {
 			case <-ctx.Done():
 				return