refactor: Move code from main.go to other files

* Card ID: CCT-950
* Initial step of refactoring main.go.
* Code moved from main.go to other files
* Introduced new files for connect and disconnect
  commands
* Added several other files for interactive mode,
  logging
* Some code was moved to existing files

canonical_facts_cmd.go

@@ -0,0 +1,23 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"github.com/urfave/cli/v2"
+)
+
+// canonicalFactAction tries to gather canonical facts about system,
+// and it prints JSON with facts to stdout.
+func canonicalFactAction(_ *cli.Context) error {
+	// NOTE: CLI context is not useful for anything
+	facts, err := GetCanonicalFacts()
+	if err != nil {
+		return cli.Exit(err, 1)
+	}
+	data, err := json.MarshalIndent(facts, "", "   ")
+	if err != nil {
+		return err
+	}
+	fmt.Println(string(data))
+	return nil
+}

conf.go

@@ -22,8 +22,10 @@ type Conf struct {
 	CADir    string
 }
 
-// Create a TLSConfig using the rhsm certificates
-func (conf *Conf) CreateTLSClientConfig() (*tls.Config, error) {
+var config = Conf{}
+
+// createTLSClientConfig Create a TLSConfig using the rhsm certificates
+func (conf *Conf) createTLSClientConfig() (*tls.Config, error) {
 	var certData, keyData []byte
 	var err error
 	rootCAs := make([][]byte, 0)

connect_cmd.go

@@ -0,0 +1,215 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"github.com/subpop/go-log"
+	"github.com/urfave/cli/v2"
+	"os"
+	"time"
+)
+
+// ConnectResult is structure holding information about results
+// of connect command. The result could be printed in machine-readable format.
+type ConnectResult struct {
+	Hostname              string `json:"hostname"`
+	HostnameError         string `json:"hostname_error,omitempty"`
+	UID                   int    `json:"uid"`
+	UIDError              string `json:"uid_error,omitempty"`
+	RHSMConnected         bool   `json:"rhsm_connected"`
+	RHSMConnectError      string `json:"rhsm_connect_error,omitempty"`
+	InsightsConnected     bool   `json:"insights_connected"`
+	InsightsError         string `json:"insights_connect_error,omitempty"`
+	YggdrasilStarted      bool   `json:"yggdrasil_started"`
+	YggdrasilStartedError string `json:"yggdrasil_started_error,omitempty"`
+	format                string
+}
+
+// Error implement error interface for structure ConnectResult
+func (connectResult ConnectResult) Error() string {
+	var result string
+	switch connectResult.format {
+	case "json":
+		data, err := json.MarshalIndent(connectResult, "", "    ")
+		if err != nil {
+			return err.Error()
+		}
+		result = string(data)
+	case "":
+		break
+	default:
+		result = "error: unsupported document format: " + connectResult.format
+	}
+	return result
+}
+
+// beforeConnectAction ensures that user has supplied a correct CLI options
+// and there is no conflict between provided options
+func beforeConnectAction(ctx *cli.Context) error {
+	// First check if machine-readable format is used
+	err := setupFormatOption(ctx)
+	if err != nil {
+		return err
+	}
+
+	username := ctx.String("username")
+	password := ctx.String("password")
+	organization := ctx.String("organization")
+	activationKeys := ctx.StringSlice("activation-key")
+
+	if len(activationKeys) > 0 {
+		if username != "" {
+			return fmt.Errorf("--username and --activation-key can not be used together")
+		}
+		if organization == "" {
+			return fmt.Errorf("--organization is required, when --activation-key is used")
+		}
+	}
+
+	// When machine-readable format is used, then additional requirements have to be met
+	if uiSettings.isMachineReadable {
+		if username == "" || password == "" {
+			return fmt.Errorf("--username/--password or --organization/--activation-key are required when a machine-readable format is used")
+		}
+	}
+
+	return checkForUnknownArgs(ctx)
+}
+
+// connectAction tries to register system against Red Hat Subscription Management,
+// gather the profile information that the system will configure
+// connect system to Red Hat Insights, and it also tries to start rhcd service
+func connectAction(ctx *cli.Context) error {
+	var connectResult ConnectResult
+	connectResult.format = ctx.String("format")
+
+	uid := os.Getuid()
+	if uid != 0 {
+		errMsg := "non-root user cannot connect system"
+		exitCode := 1
+		if uiSettings.isMachineReadable {
+			connectResult.UID = uid
+			connectResult.UIDError = errMsg
+			return cli.Exit(connectResult, exitCode)
+		} else {
+			return cli.Exit(fmt.Errorf("error: %s", errMsg), exitCode)
+		}
+	}
+
+	hostname, err := os.Hostname()
+	if uiSettings.isMachineReadable {
+		connectResult.Hostname = hostname
+	}
+	if err != nil {
+		exitCode := 1
+		if uiSettings.isMachineReadable {
+			connectResult.HostnameError = err.Error()
+			return cli.Exit(connectResult, exitCode)
+		} else {
+			return cli.Exit(err, exitCode)
+		}
+	}
+
+	interactivePrintf("Connecting %v to %v.\nThis might take a few seconds.\n\n", hostname, Provider)
+
+	var start time.Time
+	durations := make(map[string]time.Duration)
+	errorMessages := make(map[string]LogMessage)
+	/* 1. Register to RHSM, because we need to get consumer certificate. This blocks following action */
+	start = time.Now()
+	var returnedMsg string
+	returnedMsg, err = registerRHSM(ctx)
+	if err != nil {
+		connectResult.RHSMConnected = false
+		errorMessages["rhsm"] = LogMessage{
+			level: log.LevelError,
+			message: fmt.Errorf("cannot connect to Red Hat Subscription Management: %w",
+				err)}
+		if uiSettings.isMachineReadable {
+			connectResult.RHSMConnectError = errorMessages["rhsm"].message.Error()
+		} else {
+			fmt.Printf(
+				"%v Cannot connect to Red Hat Subscription Management\n",
+				uiSettings.iconError,
+			)
+		}
+	} else {
+		connectResult.RHSMConnected = true
+		interactivePrintf("%v %v\n", uiSettings.iconOK, returnedMsg)
+	}
+	durations["rhsm"] = time.Since(start)
+
+	/* 2. Register insights-client */
+	if errors, exist := errorMessages["rhsm"]; exist {
+		if errors.level == log.LevelError {
+			interactivePrintf(
+				"%v Skipping connection to Red Hat Insights\n",
+				uiSettings.iconError,
+			)
+		}
+	} else {
+		start = time.Now()
+		err = showProgress(" Connecting to Red Hat Insights...", registerInsights)
+		if err != nil {
+			connectResult.InsightsConnected = false
+			errorMessages["insights"] = LogMessage{
+				level:   log.LevelError,
+				message: fmt.Errorf("cannot connect to Red Hat Insights: %w", err)}
+			if uiSettings.isMachineReadable {
+				connectResult.InsightsError = errorMessages["insights"].message.Error()
+			} else {
+				fmt.Printf("%v Cannot connect to Red Hat Insights\n", uiSettings.iconError)
+			}
+		} else {
+			connectResult.InsightsConnected = true
+			interactivePrintf("%v Connected to Red Hat Insights\n", uiSettings.iconOK)
+		}
+		durations["insights"] = time.Since(start)
+	}
+
+	/* 3. Start yggdrasil (rhcd) service */
+	if rhsmErrMsg, exist := errorMessages["rhsm"]; exist && rhsmErrMsg.level == log.LevelError {
+		connectResult.YggdrasilStarted = false
+		interactivePrintf(
+			"%v Skipping activation of %v service\n",
+			uiSettings.iconError,
+			ServiceName,
+		)
+	} else {
+		start = time.Now()
+		progressMessage := fmt.Sprintf(" Activating the %v service", ServiceName)
+		err = showProgress(progressMessage, activateService)
+		if err != nil {
+			connectResult.YggdrasilStarted = false
+			errorMessages[ServiceName] = LogMessage{
+				level: log.LevelError,
+				message: fmt.Errorf("cannot activate %s service: %w",
+					ServiceName, err)}
+			if uiSettings.isMachineReadable {
+				connectResult.YggdrasilStartedError = errorMessages[ServiceName].message.Error()
+			} else {
+				fmt.Printf("%v Cannot activate the %v service\n", uiSettings.iconError, ServiceName)
+			}
+		} else {
+			connectResult.YggdrasilStarted = true
+			interactivePrintf("%v Activated the %v service\n", uiSettings.iconOK, ServiceName)
+		}
+		durations[ServiceName] = time.Since(start)
+		interactivePrintf("\nSuccessfully connected to Red Hat!\n")
+	}
+
+	if !uiSettings.isMachineReadable {
+		/* 5. Show footer message */
+		fmt.Printf("\nManage your connected systems: https://red.ht/connector\n")
+
+		/* 6. Optionally display duration time of each sub-action */
+		showTimeDuration(durations)
+	}
+
+	err = showErrorMessages("connect", errorMessages)
+	if err != nil {
+		return err
+	}
+
+	return cli.Exit(connectResult, 0)
+}