Add CLI Upgrade command

CHANGELOG.md

@@ -3,6 +3,10 @@
 BREAKING CHANGES:
 * Update minimum go version for project to 1.17 [[GH-878](https://github.com/hashicorp/consul-k8s/pull/878)]
 
+FEATURES:
+* CLI
+   * Add `upgrade` command to modify Consul installation on Kubernetes. [[GH-898](https://github.com/hashicorp/consul-k8s/pull/898)]
+
 IMPROVEMENTS:
 * CLI
    * Pre-check in the `install` command to verify the correct license secret exists when using an enterprise Consul image. [[GH-875](https://github.com/hashicorp/consul-k8s/pull/875)]

cli/cmd/install/install.go

@@ -3,16 +3,18 @@ package install
 import (
 	"errors"
 	"fmt"
-	k8serrors "k8s.io/apimachinery/pkg/api/errors"
 	"os"
 	"strings"
 	"sync"
 	"time"
 
+	k8serrors "k8s.io/apimachinery/pkg/api/errors"
+
 	consulChart "github.com/hashicorp/consul-k8s/charts"
 	"github.com/hashicorp/consul-k8s/cli/cmd/common"
 	"github.com/hashicorp/consul-k8s/cli/cmd/common/flag"
 	"github.com/hashicorp/consul-k8s/cli/cmd/common/terminal"
+	"github.com/hashicorp/consul-k8s/cli/config"
 	"helm.sh/helm/v3/pkg/action"
 	"helm.sh/helm/v3/pkg/chart/loader"
 	helmCLI "helm.sh/helm/v3/pkg/cli"
@@ -81,7 +83,7 @@ type Command struct {
 func (c *Command) init() {
 	// Store all the possible preset values in 'presetList'. Printed in the help message.
 	var presetList []string
-	for name := range presets {
+	for name := range config.Presets {
 		presetList = append(presetList, name)
 	}
 
@@ -313,7 +315,7 @@ func (c *Command) Run(args []string) int {
 	// Without informing the user, default global.name to consul if it hasn't been set already. We don't allow setting
 	// the release name, and since that is hardcoded to "consul", setting global.name to "consul" makes it so resources
 	// aren't double prefixed with "consul-consul-...".
-	vals = mergeMaps(convert(globalNameConsul), vals)
+	vals = MergeMaps(config.Convert(config.GlobalNameConsul), vals)
 
 	// Dry Run should exit here, no need to actual locate/download the charts.
 	if c.flagDryRun {
@@ -454,15 +456,15 @@ func (c *Command) mergeValuesFlagsWithPrecedence(settings *helmCLI.EnvSettings)
 	}
 	if c.flagPreset != defaultPreset {
 		// Note the ordering of the function call, presets have lower precedence than set vals.
-		presetMap := presets[c.flagPreset].(map[string]interface{})
-		vals = mergeMaps(presetMap, vals)
+		presetMap := config.Presets[c.flagPreset].(map[string]interface{})
+		vals = MergeMaps(presetMap, vals)
 	}
 	return vals, err
 }
 
-// mergeMaps is a helper function used in Run. Merges two maps giving b precedent.
+// MergeMaps is a helper function used in Run. Merges two maps giving b precedent.
 // @source: https://github.com/helm/helm/blob/main/pkg/cli/values/options.go
-func mergeMaps(a, b map[string]interface{}) map[string]interface{} {
+func MergeMaps(a, b map[string]interface{}) map[string]interface{} {
 	out := make(map[string]interface{}, len(a))
 	for k, v := range a {
 		out[k] = v
@@ -471,7 +473,7 @@ func mergeMaps(a, b map[string]interface{}) map[string]interface{} {
 		if v, ok := v.(map[string]interface{}); ok {
 			if bv, ok := out[k]; ok {
 				if bv, ok := bv.(map[string]interface{}); ok {
-					out[k] = mergeMaps(bv, v)
+					out[k] = MergeMaps(bv, v)
 					continue
 				}
 			}
@@ -492,7 +494,7 @@ func (c *Command) validateFlags(args []string) error {
 	if len(c.flagValueFiles) != 0 && c.flagPreset != defaultPreset {
 		return fmt.Errorf("Cannot set both -%s and -%s", flagNameConfigFile, flagNamePreset)
 	}
-	if _, ok := presets[c.flagPreset]; c.flagPreset != defaultPreset && !ok {
+	if _, ok := config.Presets[c.flagPreset]; c.flagPreset != defaultPreset && !ok {
 		return fmt.Errorf("'%s' is not a valid preset", c.flagPreset)
 	}
 	if !validLabel(c.flagNamespace) {