Fix non-JSON log messages when using -log-format JSON

changelog/24252.txt

@@ -0,0 +1,3 @@
+```release-note:bug
+agent/logging: Agent should now honor correct -log-format setting in logs generated by the consul-template library.
+```

command/agent.go

@@ -20,7 +20,7 @@ import (
 
 	systemd "github.com/coreos/go-systemd/daemon"
 	ctconfig "github.com/hashicorp/consul-template/config"
-	log "github.com/hashicorp/go-hclog"
+	hclog "github.com/hashicorp/go-hclog"
 	"github.com/hashicorp/go-multierror"
 	"github.com/hashicorp/go-secure-stdlib/gatedwriter"
 	"github.com/hashicorp/go-secure-stdlib/parseutil"
@@ -78,7 +78,7 @@ type AgentCommand struct {
 
 	logWriter io.Writer
 	logGate   *gatedwriter.Writer
-	logger    log.Logger
+	logger    hclog.Logger
 
 	// Telemetry object
 	metricsHelper *metricsutil.MetricsHelper
@@ -210,7 +210,16 @@ func (c *AgentCommand) Run(args []string) int {
 		c.outputErrors(err)
 		return 1
 	}
+
+	// Update the logger and then base the log writer on that logger.
+	// Log writer is supplied to consul-template runners for templates and execs.
+	// We want to ensure that consul-template will honor the settings, for example
+	// if the -log-format is JSON we want JSON, not a mix of JSON and non-JSON messages.
 	c.logger = l
+	c.logWriter = l.StandardWriter(&hclog.StandardLoggerOptions{
+		InferLevels:              true,
+		InferLevelsWithTimestamp: true,
+	})
 
 	infoKeys := make([]string, 0, 10)
 	info := make(map[string]string)
@@ -1093,31 +1102,31 @@ func (c *AgentCommand) handleQuit(enabled bool) http.Handler {
 }
 
 // newLogger creates a logger based on parsed config field on the Agent Command struct.
-func (c *AgentCommand) newLogger() (log.InterceptLogger, error) {
+func (c *AgentCommand) newLogger() (hclog.InterceptLogger, error) {
 	if c.config == nil {
 		return nil, fmt.Errorf("cannot create logger, no config")
 	}
 
-	var errors error
+	var errs *multierror.Error
 
 	// Parse all the log related config
 	logLevel, err := logging.ParseLogLevel(c.config.LogLevel)
 	if err != nil {
-		errors = multierror.Append(errors, err)
+		errs = multierror.Append(errs, err)
 	}
 
 	logFormat, err := logging.ParseLogFormat(c.config.LogFormat)
 	if err != nil {
-		errors = multierror.Append(errors, err)
+		errs = multierror.Append(errs, err)
 	}
 
 	logRotateDuration, err := parseutil.ParseDurationSecond(c.config.LogRotateDuration)
 	if err != nil {
-		errors = multierror.Append(errors, err)
+		errs = multierror.Append(errs, err)
 	}
 
-	if errors != nil {
-		return nil, errors
+	if errs != nil {
+		return nil, errs
 	}
 
 	logCfg := &logging.LogConfig{
@@ -1140,20 +1149,20 @@ func (c *AgentCommand) newLogger() (log.InterceptLogger, error) {
 
 // loadConfig attempts to generate an Agent config from the file(s) specified.
 func (c *AgentCommand) loadConfig(paths []string) (*agentConfig.Config, error) {
-	var errors error
+	var errs *multierror.Error
 	cfg := agentConfig.NewConfig()
 
 	for _, configPath := range paths {
 		configFromPath, err := agentConfig.LoadConfig(configPath)
 		if err != nil {
-			errors = multierror.Append(errors, fmt.Errorf("error loading configuration from %s: %w", configPath, err))
+			errs = multierror.Append(errs, fmt.Errorf("error loading configuration from %s: %w", configPath, err))
 		} else {
 			cfg = cfg.Merge(configFromPath)
 		}
 	}
 
-	if errors != nil {
-		return nil, errors
+	if errs != nil {
+		return nil, errs
 	}
 
 	if err := cfg.ValidateConfig(); err != nil {

command/agent/internal/ctmanager/runner_config.go

@@ -11,7 +11,6 @@ import (
 	ctconfig "github.com/hashicorp/consul-template/config"
 	ctlogging "github.com/hashicorp/consul-template/logging"
 	"github.com/hashicorp/go-hclog"
-
 	"github.com/hashicorp/vault/command/agent/config"
 	"github.com/hashicorp/vault/sdk/helper/pointerutil"
 )