From b3b4d7b9a3a71d3e5db0026fb4eb975512104b7c Mon Sep 17 00:00:00 2001
From: Preetha Appan <preetha@hashicorp.com>
Date: Tue, 19 Feb 2019 17:53:14 -0600
Subject: [PATCH] cli Ui implementation that logs to a hclogger

This makes it so any messages output to the UI *after* the agent has started
will be logged in json format correctly
---
 command/agent/command.go  | 19 +++++++++++++------
 helper/logging/logging.go | 38 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 51 insertions(+), 6 deletions(-)
 create mode 100644 helper/logging/logging.go

diff --git a/command/agent/command.go b/command/agent/command.go
index 47da7e272..0f15d15c6 100644
--- a/command/agent/command.go
+++ b/command/agent/command.go
@@ -15,18 +15,19 @@ import (
 	"syscall"
 	"time"
 
-	metrics "github.com/armon/go-metrics"
+	"github.com/armon/go-metrics"
 	"github.com/armon/go-metrics/circonus"
 	"github.com/armon/go-metrics/datadog"
 	"github.com/armon/go-metrics/prometheus"
 	"github.com/hashicorp/consul/lib"
-	checkpoint "github.com/hashicorp/go-checkpoint"
-	discover "github.com/hashicorp/go-discover"
-	gsyslog "github.com/hashicorp/go-syslog"
+	"github.com/hashicorp/go-checkpoint"
+	"github.com/hashicorp/go-discover"
+	"github.com/hashicorp/go-syslog"
 	"github.com/hashicorp/logutils"
 	"github.com/hashicorp/nomad/helper"
-	flaghelper "github.com/hashicorp/nomad/helper/flag-helpers"
-	gatedwriter "github.com/hashicorp/nomad/helper/gated-writer"
+	"github.com/hashicorp/nomad/helper/flag-helpers"
+	"github.com/hashicorp/nomad/helper/gated-writer"
+	"github.com/hashicorp/nomad/helper/logging"
 	"github.com/hashicorp/nomad/nomad/structs/config"
 	"github.com/hashicorp/nomad/version"
 	"github.com/mitchellh/cli"
@@ -576,6 +577,12 @@ func (c *Command) Run(args []string) int {
 	}
 	defer c.agent.Shutdown()
 
+	// After the agent is created we have a logger, so swap out the implementation
+	// of the UI if json logging is enabled
+	if config.LogJson {
+		c.Ui = &logging.HcLogUI{Log: c.agent.logger}
+	}
+
 	// Shutdown the HTTP server at the end
 	defer func() {
 		if c.httpServer != nil {
diff --git a/helper/logging/logging.go b/helper/logging/logging.go
new file mode 100644
index 000000000..c85659ff0
--- /dev/null
+++ b/helper/logging/logging.go
@@ -0,0 +1,38 @@
+package logging
+
+import (
+	"fmt"
+
+	"github.com/hashicorp/go-hclog"
+)
+
+// HcLogUI is an implementation of Ui that takes a hclogger
+// and uses it to Log the output. It is intended for write only
+// use cases and the Ask/AskSecret methods are not implemented.
+type HcLogUI struct {
+	Log hclog.Logger
+}
+
+func (l *HcLogUI) Ask(query string) (string, error) {
+	return "", fmt.Errorf("Ask is not supported in this implementation")
+}
+
+func (l *HcLogUI) AskSecret(query string) (string, error) {
+	return "", fmt.Errorf("AskSecret is not supported in this implementation")
+}
+
+func (l *HcLogUI) Output(message string) {
+	l.Log.Info(message)
+}
+
+func (l *HcLogUI) Info(message string) {
+	l.Log.Info(message)
+}
+
+func (l *HcLogUI) Error(message string) {
+	l.Log.Error(message)
+}
+
+func (l *HcLogUI) Warn(message string) {
+	l.Log.Warn(message)
+}