Add env ls command

Author: SimonBarendse

internals/secrethub/env.go

@@ -23,4 +23,5 @@ func NewEnvCommand(io ui.IO, newClient newClientFunc) *EnvCommand {
 func (cmd *EnvCommand) Register(r command.Registerer) {
 	clause := r.Command("env", "Manage environment variables.").Hidden() // The command is hidden, because it's still in beta.
 	NewEnvReadCommand(cmd.io, cmd.newClient).Register(clause)
+	NewEnvListCommand(cmd.io).Register(clause)
 }

internals/secrethub/env_ls.go

@@ -0,0 +1,50 @@
+package secrethub
+
+import (
+	"fmt"
+
+	"github.com/secrethub/secrethub-cli/internals/cli/ui"
+	"github.com/secrethub/secrethub-cli/internals/secrethub/command"
+)
+
+// EnvListCommand is a command to list all environment variable keys set in the process of `secrethub run`.
+type EnvListCommand struct {
+	io          ui.IO
+	environment *environment
+}
+
+// NewEnvListCommand creates a new EnvListCommand.
+func NewEnvListCommand(io ui.IO) *EnvListCommand {
+	return &EnvListCommand{
+		io:          io,
+		environment: newEnvironment(io),
+	}
+}
+
+// Register adds a CommandClause and it's args and flags to a Registerer.
+func (cmd *EnvListCommand) Register(r command.Registerer) {
+	clause := r.Command("ls", "Read the value of a single environment variable.")
+	clause.Alias("list")
+
+	cmd.environment.register(clause)
+
+	command.BindAction(clause, cmd.Run)
+}
+
+// Run handles the command with the options as specified in the command.
+func (cmd *EnvListCommand) Run() error {
+	env, err := cmd.environment.env()
+	if err != nil {
+		return err
+	}
+
+	for key, value := range env {
+		// For now only environment variables in which a secret is loaded are printed.
+		// TODO: Make this behavior configurable.
+		if value.containsSecret() {
+			fmt.Fprintln(cmd.io.Stdout(), key)
+		}
+	}
+
+	return nil
+}