Add templateable variable parsing to launcher command

This adds templatable variable parsing to the launcher command.
Variables are defined as key/value pairs in the `tui.Update:` `case
loginMsg:` section.  Any variables defined there will be parsed and
replaced with their values if the variables are used in the user's
`terminal` or `cluster_login_command` config options in the srepd.yaml
file.

Eg: `cluster_login_command: ocm-container --cluster-id %%CLUSTER_ID%%
--launch-opts --env=INCIDENT_ID=%%INCIDENT_ID%%`

Supported variables are currently `%%CLUSTER_ID%%` and `%%INCIDENT_ID%%`

Signed-off-by: Chris Collins <[email protected]>

README.md

@@ -169,15 +169,25 @@ cluster_login_command: ocm backplane login %%CLUSTER_ID%%
 ### Automatic Login Features
 The first feature of Automatic Login is the ability to replace certain strings with their cluster-specific details. When you pass `%%VARIABLE%%` in your `terminal` or `cluster_login_command` configuration strings they will dynamically be replaced with the alert-specific variable. This allows you to be able to put the specific details of these variables inside the command. The first argument of the `terminal` setting MUST NOT BE a replaceable value.
 
-Currently, only `%%CLUSTER_ID%%` is supported. It's also important to note that if `%%CLUSTER_ID%%` does NOT appear in the `cluster_login_command` config setting that the cluster ID will be appended to the end of the cluster login command. If the replacable `%%CLUSTER_ID%%` string is present in the `cluster_login_command` setting, it will NOT be appended to the end.
+Supported Variables:
+
+* `%%CLUSTER_ID%%` - used to identify the cluster to log into. (SEE NOTE BELOW)
+* `%%INCIDENT_ID%%` - the PagerDuty Incident ID from which the cluster details have been taken.  You can, for example, use this to pass in compliance reasons, or to set a variable.
+
+Note regarding `%%CLUSTER_ID%%`: 
+
+It's also important to note that if `%%CLUSTER_ID%%` does NOT appear in the `cluster_login_command` config setting that the cluster ID will be appended to the end of the cluster login command. If the replaceable `%%CLUSTER_ID%%` string is present in the `cluster_login_command` setting, it will NOT be appended to the end.
 
 Examples:
 ```
 ## Assume the cluster ID for these examples is `abcdefg`
 
-cluster_login_command: ocm backplane login %%CLUSTER_ID%% --multi
 ## effectively runs "ocm backplane login abcdefg --multi"
+cluster_login_command: ocm backplane login %%CLUSTER_ID%% --multi
 
-cluster_login_command: ocm backplane login --multi
 ## effectively runs "ocm backplane login --multi abcdefg"
+cluster_login_command: ocm backplane login --multi
+
+## Logs into the cluster and sets the INCIDENT_ID env variable in ocm-container to the PagerDuty Incident ID
+cluster_login_command: ocm-container --cluster-id %%CLUSTER_ID --launch-opts --env=INCIDENT_ID=%%INCIDENT_ID%%
 ```

pkg/launcher/launcher.go

@@ -2,6 +2,7 @@ package launcher
 
 import (
 	"fmt"
+	"github.com/charmbracelet/log"
 	"strings"
 )
 
@@ -59,23 +60,43 @@ func (l *ClusterLauncher) validate() error {
 	return nil
 }
 
-func (l *ClusterLauncher) BuildLoginCommand(cluster string) []string {
+func (l *ClusterLauncher) BuildLoginCommand(vars map[string]string) []string {
+	///func (l *ClusterLauncher) BuildLoginCommand() []string {
 	command := []string{}
 
 	// Handle the Terminal command
 	// The first arg should not be something replaceable, as checked in the
 	// validate function
+	log.Debug("launcher.ClusterLauncher():", "Building command from terminal", "terminal", l.terminal[0])
 	command = append(command, l.terminal[0])
-	command = append(command, replaceVars(l.terminal[1:], cluster)...)
-	command = append(command, replaceVars(l.clusterLoginCommand, cluster)...)
+
+	// If there are more than one terminal arguments, replace the vars
+	// If there's not more than one terminal argument, the "replacement"
+	// nil []string{} ends up being appended as a whitespace, so don't append
+	if len(l.terminal) > 1 {
+		command = append(command, replaceVars(l.terminal[1:], vars)...)
+	}
+	command = append(command, replaceVars(l.clusterLoginCommand, vars)...)
+	log.Debug("launcher.ClusterLauncher():", "Built command", command)
+	for x, i := range command {
+		log.Debug("launcher.ClusterLauncher():", fmt.Sprintf("Built command argument [%d]", x), i)
+	}
 
 	return command
 }
 
-func replaceVars(args []string, cluster string) []string {
-	transformedArgs := []string{}
-	for _, str := range args {
-		transformedArgs = append(transformedArgs, strings.Replace(str, "%%CLUSTER_ID%%", cluster, -1))
+func replaceVars(args []string, vars map[string]string) []string {
+	if args == nil || vars == nil {
+		return []string{}
 	}
+
+	str := strings.Join(args, " ")
+
+	for k, v := range vars {
+		log.Debug("ClusterLauncher():", "Replacing vars in string", str, k, v)
+		str = strings.Replace(str, k, v, -1)
+	}
+
+	transformedArgs := strings.Split(str, " ")
 	return transformedArgs
 }

pkg/launcher/launcher_test.go

@@ -25,7 +25,7 @@ func TestClusterLauncherValidation(t *testing.T) {
 			expectErr:       true,
 		},
 		{
-			name:            "Tests terminal is nill but login args are not",
+			name:            "Tests terminal is nil but login args are not",
 			terminalArg:     "",
 			loginCommandArg: "ocm backplane session",
 			expectErr:       true,
@@ -92,6 +92,20 @@ func TestLoginCommandBuild(t *testing.T) {
 				}
 			},
 		},
+		{
+			name: "validate multiple templated replacements",
+			launcher: ClusterLauncher{
+				terminal:            []string{"gnome-terminal", "--"},
+				clusterLoginCommand: []string{"ocm-container", "--cluster-id", "%%CLUSTER_ID%%", "--launch-opts", "\"-e INCIDENT_ID=%%INCIDENT_ID%%\""},
+			},
+			expectErr: true,
+			comparisonFN: func(t *testing.T, cmd []string) {
+				expected := "gnome-terminal -- ocm-container --cluster-id abcdefg --launch-opts \"-e INCIDENT_ID=PD123456\""
+				if strings.Join(cmd, " ") != expected {
+					t.Fatalf("Expected command to be %s, got: %s", expected, strings.Join(cmd, " "))
+				}
+			},
+		},
 		{
 			name: "validate that the cluster login command can be collapsed to a single string",
 			launcher: ClusterLauncher{
@@ -134,7 +148,12 @@ func TestLoginCommandBuild(t *testing.T) {
 
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
-			cmd := test.launcher.BuildLoginCommand("abcdefg")
+			vars := map[string]string{
+				"%%CLUSTER_ID%%":    "abcdefg",
+				"%%INCIDENT_ID%%":   "PD123456",
+				"%%UNHANDLED_VAR%%": "I SHOULD NOT SHOW UP",
+			}
+			cmd := test.launcher.BuildLoginCommand(vars)
 			test.comparisonFN(t, cmd)
 		})
 	}

pkg/tui/commands.go

@@ -359,41 +359,51 @@ type loginFinishedMsg struct {
 	err error
 }
 
-func login(cluster string, launcher launcher.ClusterLauncher) tea.Cmd {
+func login(vars map[string]string, launcher launcher.ClusterLauncher) tea.Cmd {
 	// The first element of Terminal is the command to be executed, followed by args, in order
 	// This handles if folks use, eg: flatpak run <some package> as a terminal.
-	command := launcher.BuildLoginCommand(cluster)
+	command := launcher.BuildLoginCommand(vars)
 	c := exec.Command(command[0], command[1:]...)
 
 	log.Debug(fmt.Sprintf("tui.login(): %v", c.String()))
 	stderr, pipeErr := c.StderrPipe()
 	if pipeErr != nil {
-		log.Debug(fmt.Sprintf("tui.login(): %v", pipeErr.Error()))
+		log.Debug("tui.login():", "pipeErr", pipeErr.Error())
 		return func() tea.Msg {
 			return loginFinishedMsg{err: pipeErr}
 		}
 	}
 
 	err := c.Start()
 	if err != nil {
-		log.Debug(fmt.Sprintf("tui.login(): %v", err.Error()))
+		log.Debug("tui.login():", "startErr", err.Error())
 		return func() tea.Msg {
 			return loginFinishedMsg{err}
 		}
 	}
 
 	out, err := io.ReadAll(stderr)
 	if err != nil {
-		log.Debug(fmt.Sprintf("tui.login(): %v", err.Error()))
+		log.Debug("tui.login():", "loginStdErr", err.Error())
+		return func() tea.Msg {
+			return loginFinishedMsg{err}
+		}
+	}
+
+	// c.Wait() must be run after reading any output from stderrPipe
+	err = c.Wait()
+	if err != nil {
+		log.Debug("tui.login():", "waitErr", err.Error())
 		return func() tea.Msg {
 			return loginFinishedMsg{err}
 		}
 	}
 
 	if len(out) > 0 {
-		log.Debug(fmt.Sprintf("tui.login(): error: %s", out))
+		outErr := fmt.Errorf("%s", out)
+		log.Debug("tui.login():", "outErr", outErr.Error())
 		return func() tea.Msg {
-			return loginFinishedMsg{fmt.Errorf("%s", out)}
+			return loginFinishedMsg{outErr}
 		}
 	}
 

pkg/tui/tui.go

@@ -309,7 +309,14 @@ func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 			m.setStatus(fmt.Sprintf("multiple alerts found - logging into cluster %s from first alert %s", cluster, m.selectedIncidentAlerts[0].ID))
 		}
 
-		cmds = append(cmds, login(cluster, m.launcher))
+		// NOTE: It's important that **ALL** of these variables' values are NOT NIL.
+		// They can be empty strings, but the must not be nil.
+		var vars map[string]string = map[string]string{
+			"%%CLUSTER_ID%%":  cluster,
+			"%%INCIDENT_ID%%": m.selectedIncident.ID,
+		}
+
+		cmds = append(cmds, login(vars, m.launcher))
 
 	case loginFinishedMsg:
 		if msg.err != nil {