Fix interface bugs for mz-debug

- Added a section in `README.md` detailing how to run the `mz-debug` tool locally with an example command.
- required_if_eq wasn't working for default values. Chaining required_unless_present fixes this
- Makes 'dump-system-catalog' a global flag

Author: SangJunBak

src/mz-debug/README.md

@@ -1,3 +1,16 @@
 # `mz-debug`
 
 This tool allows us to debug a user's self-managed environment.
+
+## Run locally:
+To run locally, an example of a command is:
+
+```bash
+./bin/bazel run \
+    --run_under="cd $PWD &&" \
+    //src/mz-debug:mz_debug self-managed -- \
+    --k8s-namespace materialize \
+    --k8s-namespace materialize-environment \
+    --auto-port-forward false \
+    --mz-connection-url 'postgres://[email protected]:6875/materialize?sslmode=disable'
+```

src/mz-debug/src/main.rs

@@ -49,7 +49,12 @@ pub struct SelfManagedDebugMode {
     #[clap(long, default_value = "true", action = clap::ArgAction::Set)]
     dump_k8s: bool,
     /// A list of namespaces to dump.
-    #[clap(long = "k8s-namespace", required_if_eq("dump_k8s", "true"), action = clap::ArgAction::Append)]
+    #[clap(
+        long = "k8s-namespace", 
+        required_unless_present = "dump_k8s", 
+        required_if_eq("dump_k8s", "true"), 
+        action = clap::ArgAction::Append
+    )]
     k8s_namespaces: Vec<String>,
     /// The kubernetes context to use.
     #[clap(long, env = "KUBERNETES_CONTEXT")]
@@ -69,8 +74,7 @@ pub struct SelfManagedDebugMode {
     port_forward_local_port: i32,
     /// The URL of the Materialize SQL connection used to dump the system catalog.
     /// An example URL is `postgres://[email protected]:6875/materialize?sslmode=disable`.
-    /// By default, we will create use the connection URL based on `port_forward_local_address` and `port_forward_local_port`.
-    /// and port_forward_local_port.
+    /// By default, we will create a connection URL based on `port_forward_local_address` and `port_forward_local_port`.
     // TODO(debug_tool3): Allow users to specify the pgconfig via separate variables
     #[clap(
         long,
@@ -86,7 +90,11 @@ pub struct EmulatorDebugMode {
     #[clap(long, default_value = "true", action = clap::ArgAction::Set)]
     dump_docker: bool,
     /// The ID of the docker container to dump.
-    #[clap(long, required_if_eq("dump_docker", "true"))]
+    #[clap(
+        long,
+        required_unless_present = "dump_docker",
+        required_if_eq("dump_docker", "true")
+    )]
     docker_container_id: Option<String>,
     /// The URL of the Materialize SQL connection used to dump the system catalog.
     /// An example URL is `postgres://[email protected]:6875/materialize?sslmode=disable`.
@@ -115,7 +123,7 @@ pub struct Args {
     #[clap(subcommand)]
     debug_mode: DebugMode,
     /// If true, the tool will dump the system catalog in Materialize.
-    #[clap(long, default_value = "true", action = clap::ArgAction::Set)]
+    #[clap(long, default_value = "true", action = clap::ArgAction::Set, global = true)]
     dump_system_catalog: bool,
 }