Merge pull request #12037 from hmlanigan/juju-info-add-config

#12037

## Description of change

Allow channels to be displayed again, real vs canned data issue. Instead of latest, the tracks that are latest are an empty string, insert "latest" for display purposes.

Add the ability to display charm config options in the juju info output. Handy to know before deploying.

## QA steps

```console
$ export JUJU_DEV_FEATURE_FLAGS="charm-hub"
$ juju bootstrap localhost testme
$ juju add-model seven --config charm-hub-url="https://api.staging.snapcraft.io"
$ juju info apitest-ubuntu-qa --config
name: apitest-ubuntu-qa
charm-id: 4HVy9HLeoMQ0eUALfsvE6ifqtL6DqUPm
summary: |
 juju-qa version of the ubuntu charm.
publisher: Heather Lanigan
supports: focal, xenial, bionic
subordinate: false
store-url: https://api.staging.snapcraft.io/v2/charms/apitest-ubuntu-qa
description: |
 juju-qa version of the ubuntu charm.
channels: |
 latest/stable: 1 (1) 250kB
 latest/candidate: 1 (1) 250kB
 latest/beta: 1 (1) 250kB
 latest/edge: 2 (2) 250kB
settings:
 status:
 type: string
 description: temporary string for unit status
 default: hello
 thing:
 type: string
 description: A thing used by the charm.
 default: "\U0001F381"

```

apiserver/facades/client/charmhub/convert.go

@@ -103,6 +103,10 @@ func transformChannelMap(channelMap []transport.ChannelMap) ([]string, map[strin
 	channels := make(map[string]params.Channel, len(channelMap))
 	for _, cm := range channelMap {
 		ch := cm.Channel
+		// Per the charmhub/snap channel spec.
+		if ch.Track == "" {
+			ch.Track = "latest"
+		}
 		chName := ch.Track + "/" + ch.Risk
 		channels[chName] = params.Channel{
 			Revision:   cm.Revision.Revision,

cmd/juju/charmhub/info.go

@@ -43,7 +43,7 @@ type infoCommand struct {
 
 	api InfoCommandAPI
 
-	verbose       bool
+	config        bool
 	charmOrBundle string
 }
 
@@ -63,6 +63,7 @@ func (c *infoCommand) Info() *cmd.Info {
 // It implements part of the cmd.Command interface.
 func (c *infoCommand) SetFlags(f *gnuflag.FlagSet) {
 	c.ModelCommandBase.SetFlags(f)
+	f.BoolVar(&c.config, "config", false, "display config for this charm")
 	c.out.AddFlags(f, "tabular", map[string]cmd.Formatter{
 		"yaml":    cmd.FormatYaml,
 		"json":    cmd.FormatJson,
@@ -107,7 +108,6 @@ func (c *infoCommand) Run(ctx *cmd.Context) error {
 	if err != nil {
 		return errors.Trace(err)
 	}
-
 	return c.out.Write(ctx, &view)
 }
 
@@ -138,7 +138,7 @@ func (c *infoCommand) formatter(writer io.Writer, value interface{}) error {
 		return errors.Errorf("unexpected results")
 	}
 
-	if err := makeInfoWriter(writer, c.warningLog, results).Print(); err != nil {
+	if err := makeInfoWriter(writer, c.warningLog, c.config, results).Print(); err != nil {
 		return errors.Trace(err)
 	}
 

cmd/juju/charmhub/infowriter.go

@@ -23,11 +23,12 @@ import (
 // There are exceptions, slices of strings and tables.  These
 // are transformed into strings.
 
-func makeInfoWriter(w io.Writer, warningLog Log, in *InfoResponse) Printer {
+func makeInfoWriter(w io.Writer, warningLog Log, config bool, in *InfoResponse) Printer {
 	iw := infoWriter{
-		w:        w,
-		warningf: warningLog,
-		in:       in,
+		w:             w,
+		warningf:      warningLog,
+		in:            in,
+		displayConfig: config,
 	}
 	if iw.in.Type == "charm" {
 		return charmInfoWriter{infoWriter: iw}
@@ -36,9 +37,10 @@ func makeInfoWriter(w io.Writer, warningLog Log, in *InfoResponse) Printer {
 }
 
 type infoWriter struct {
-	warningf Log
-	w        io.Writer
-	in       *InfoResponse
+	warningf      Log
+	w             io.Writer
+	in            *InfoResponse
+	displayConfig bool
 }
 
 func (iw infoWriter) print(info interface{}) error {
@@ -136,18 +138,19 @@ func (b bundleInfoWriter) Print() error {
 }
 
 type charmInfoOutput struct {
-	Name        string         `yaml:"name,omitempty"`
-	ID          string         `yaml:"charm-id,omitempty"`
-	Summary     string         `yaml:"summary,omitempty"`
-	Publisher   string         `yaml:"publisher,omitempty"`
-	Supports    string         `yaml:"supports,omitempty"`
-	Tags        string         `yaml:"tags,omitempty"`
-	Subordinate bool           `yaml:"subordinate"`
-	StoreURL    string         `yaml:"store-url,omitempty"`
-	Description string         `yaml:"description,omitempty"`
-	Relations   relationOutput `yaml:"relations,omitempty"`
-	Channels    string         `yaml:"channels,omitempty"`
-	Installed   string         `yaml:"installed,omitempty"`
+	Name        string                 `yaml:"name,omitempty"`
+	ID          string                 `yaml:"charm-id,omitempty"`
+	Summary     string                 `yaml:"summary,omitempty"`
+	Publisher   string                 `yaml:"publisher,omitempty"`
+	Supports    string                 `yaml:"supports,omitempty"`
+	Tags        string                 `yaml:"tags,omitempty"`
+	Subordinate bool                   `yaml:"subordinate"`
+	StoreURL    string                 `yaml:"store-url,omitempty"`
+	Description string                 `yaml:"description,omitempty"`
+	Relations   relationOutput         `yaml:"relations,omitempty"`
+	Channels    string                 `yaml:"channels,omitempty"`
+	Installed   string                 `yaml:"installed,omitempty"`
+	Config      map[string]interface{} `yaml:"config,omitempty"`
 }
 
 type relationOutput struct {
@@ -166,12 +169,17 @@ func (c charmInfoWriter) Print() error {
 		Summary:     c.in.Summary,
 		Publisher:   c.in.Publisher,
 		Supports:    strings.Join(c.in.Series, ", "),
+		StoreURL:    c.in.StoreURL,
 		Description: c.in.Description,
 		Channels:    c.channels(),
 		Tags:        strings.Join(c.in.Tags, ", "),
 	}
 	if c.in.Charm != nil {
 		out.Subordinate = c.in.Charm.Subordinate
+		if c.displayConfig && c.in.Charm.Config != nil {
+			out.Config = make(map[string]interface{}, 1)
+			out.Config["settings"] = c.in.Charm.Config.Options
+		}
 	}
 	if rels, err := c.relations(); err == nil {
 		out.Relations = rels

cmd/juju/charmhub/infowriter_test.go

@@ -6,6 +6,7 @@ package charmhub
 import (
 	"bytes"
 
+	"github.com/juju/charm/v8"
 	jc "github.com/juju/testing/checkers"
 	gc "gopkg.in/check.v1"
 )
@@ -17,7 +18,7 @@ var _ = gc.Suite(&printInfoSuite{})
 func (s *printInfoSuite) TestCharmPrintInfo(c *gc.C) {
 	ir := getCharmInfoResponse()
 	ctx := commandContextForTest(c)
-	iw := makeInfoWriter(ctx.Stdout, ctx.Warningf, &ir)
+	iw := makeInfoWriter(ctx.Stdout, ctx.Warningf, false, &ir)
 	err := iw.Print()
 	c.Assert(err, jc.ErrorIsNil)
 
@@ -48,10 +49,54 @@ channels: |
 	c.Assert(obtained, gc.Equals, expected)
 }
 
+func (s *printInfoSuite) TestCharmPrintInfoWithConfig(c *gc.C) {
+	ir := getCharmInfoResponse()
+	ctx := commandContextForTest(c)
+	iw := makeInfoWriter(ctx.Stdout, ctx.Warningf, true, &ir)
+	err := iw.Print()
+	c.Assert(err, jc.ErrorIsNil)
+
+	obtained := ctx.Stdout.(*bytes.Buffer).String()
+	expected := `name: wordpress
+charm-id: charmCHARMcharmCHARMcharmCHARM01
+summary: WordPress is a full featured web blogging tool, this charm deploys it.
+publisher: Wordress Charmers
+supports: bionic, xenial
+tags: app, seven
+subordinate: true
+description: |-
+  This will install and setup WordPress optimized to run in the cloud.
+  By default it will place Ngnix and php-fpm configured to scale horizontally with
+  Nginx's reverse proxy.
+relations:
+  provides:
+    one: two
+    three: four
+  requires:
+    five: six
+channels: |
+  latest/stable:     1.0.3  2019-12-16  (16)  12MB
+  latest/candidate:  1.0.3  2019-12-16  (17)  12MB
+  latest/beta:       1.0.3  2019-12-16  (17)  12MB
+  latest/edge:       1.0.3  2019-12-16  (18)  12MB
+config:
+  settings:
+    status:
+      type: string
+      description: temporary string for unit status
+      default: hello
+    thing:
+      type: string
+      description: A thing used by the charm.
+      default: "\U0001F381"
+`
+	c.Assert(obtained, gc.Equals, expected)
+}
+
 func (s *printInfoSuite) TestBundleChannelClosed(c *gc.C) {
 	ir := getBundleInfoClosedTrack()
 	ctx := commandContextForTest(c)
-	iw := makeInfoWriter(ctx.Stdout, ctx.Warningf, &ir)
+	iw := makeInfoWriter(ctx.Stdout, ctx.Warningf, false, &ir)
 	err := iw.Print()
 	c.Assert(err, jc.ErrorIsNil)
 
@@ -73,7 +118,7 @@ channels: |
 func (s *printInfoSuite) TestBundlePrintInfo(c *gc.C) {
 	ir := getBundleInfoResponse()
 	ctx := commandContextForTest(c)
-	iw := makeInfoWriter(ctx.Stdout, ctx.Warningf, &ir)
+	iw := makeInfoWriter(ctx.Stdout, ctx.Warningf, false, &ir)
 	err := iw.Print()
 	c.Assert(err, jc.ErrorIsNil)
 
@@ -151,6 +196,20 @@ func getCharmInfoResponse() InfoResponse {
 		Series:      []string{"bionic", "xenial"},
 		Tags:        []string{"app", "seven"},
 		Charm: &Charm{
+			Config: &charm.Config{
+				Options: map[string]charm.Option{
+					"status": {
+						Type:        "string",
+						Description: "temporary string for unit status",
+						Default:     "hello",
+					},
+					"thing": {
+						Type:        "string",
+						Description: "A thing used by the charm.",
+						Default:     "🎁",
+					},
+				},
+			},
 			Subordinate: true,
 			Relations: map[string]map[string]string{
 				"provides": {