add expectorate tests to manage changes to API dependencies (#6831)

Author: davepacheco

Cargo.lock

@@ -18,3 +18,8 @@ petgraph.workspace = true
 serde.workspace = true
 toml.workspace = true
 omicron-workspace-hack.workspace = true
+
+[dev-dependencies]
+expectorate.workspace = true
+omicron-test-utils.workspace = true
+subprocess.workspace = true

dev-tools/ls-apis/Cargo.toml

@@ -0,0 +1,77 @@
+Bootstrap Agent (client: bootstrap-agent-client)
+    consumed by: omicron-sled-agent (omicron/sled-agent)
+    consumed by: wicketd (omicron/wicketd)
+
+Clickhouse Cluster Admin (client: clickhouse-admin-client)
+    consumed by: omicron-nexus (omicron/nexus)
+
+CockroachDB Cluster Admin (client: cockroach-admin-client)
+    consumed by: omicron-nexus (omicron/nexus)
+
+Crucible Agent (client: crucible-agent-client)
+    consumed by: omicron-nexus (omicron/nexus)
+
+Crucible Control (for testing only) (client: crucible-control-client)
+
+Crucible Pantry (client: crucible-pantry-client)
+    consumed by: omicron-nexus (omicron/nexus)
+
+Maghemite DDM Admin (client: ddm-admin-client)
+    consumed by: installinator (omicron/installinator)
+    consumed by: mgd (maghemite/mgd)
+    consumed by: omicron-sled-agent (omicron/sled-agent)
+    consumed by: wicketd (omicron/wicketd)
+
+DNS Server (client: dns-service-client)
+    consumed by: omicron-nexus (omicron/nexus)
+    consumed by: omicron-sled-agent (omicron/sled-agent)
+
+Dendrite DPD (client: dpd-client)
+    consumed by: ddmd (maghemite/ddmd)
+    consumed by: mgd (maghemite/mgd)
+    consumed by: omicron-nexus (omicron/nexus)
+    consumed by: omicron-sled-agent (omicron/sled-agent)
+    consumed by: tfportd (dendrite/tfportd)
+    consumed by: wicketd (omicron/wicketd)
+
+Downstairs Controller (debugging only) (client: dsc-client)
+
+Management Gateway Service (client: gateway-client)
+    consumed by: dpd (dendrite/dpd)
+    consumed by: omicron-nexus (omicron/nexus)
+    consumed by: omicron-sled-agent (omicron/sled-agent)
+    consumed by: wicketd (omicron/wicketd)
+
+Wicketd Installinator (client: installinator-client)
+    consumed by: installinator (omicron/installinator)
+
+Maghemite MG Admin (client: mg-admin-client)
+    consumed by: omicron-nexus (omicron/nexus)
+    consumed by: omicron-sled-agent (omicron/sled-agent)
+
+Nexus Internal API (client: nexus-client)
+    consumed by: dpd (dendrite/dpd)
+    consumed by: omicron-nexus (omicron/nexus)
+    consumed by: omicron-sled-agent (omicron/sled-agent)
+    consumed by: oximeter-collector (omicron/oximeter/collector)
+    consumed by: propolis-server (propolis/bin/propolis-server)
+
+External API (client: oxide-client)
+
+Oximeter (client: oximeter-client)
+    consumed by: omicron-nexus (omicron/nexus)
+
+Propolis (client: propolis-client)
+    consumed by: omicron-nexus (omicron/nexus)
+    consumed by: omicron-sled-agent (omicron/sled-agent)
+
+Crucible Repair (client: repair-client)
+    consumed by: crucible-downstairs (crucible/downstairs)
+
+Sled Agent (client: sled-agent-client)
+    consumed by: dpd (dendrite/dpd)
+    consumed by: omicron-nexus (omicron/nexus)
+    consumed by: omicron-sled-agent (omicron/sled-agent)
+
+Wicketd (client: wicketd-client)
+

dev-tools/ls-apis/tests/api_dependencies.out

@@ -0,0 +1,29 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at https://mozilla.org/MPL/2.0/.
+
+//! The tests here are intended help us catch cases where we're introducing new
+//! API dependencies, and particular circular API dependencies.  It's okay if
+//! API dependencies change, but it's important to make sure we're not
+//! introducing new barriers to online upgrade.
+//!
+//! This isn't (supposed to be) a test for the `ls-apis` tool itself.
+
+use omicron_test_utils::dev::test_cmds::assert_exit_code;
+use omicron_test_utils::dev::test_cmds::path_to_executable;
+use omicron_test_utils::dev::test_cmds::run_command;
+use omicron_test_utils::dev::test_cmds::EXIT_SUCCESS;
+
+/// name of the "ls-apis" executable
+const CMD_LS_APIS: &str = env!("CARGO_BIN_EXE_ls-apis");
+
+#[test]
+fn test_api_dependencies() {
+    let cmd_path = path_to_executable(CMD_LS_APIS);
+    let exec = subprocess::Exec::cmd(cmd_path).arg("apis");
+    let (exit_status, stdout_text, stderr_text) = run_command(exec);
+    assert_exit_code(exit_status, EXIT_SUCCESS, &stderr_text);
+
+    println!("stderr:\n------\n{}\n-----", stderr_text);
+    expectorate::assert_contents("tests/api_dependencies.out", &stdout_text);
+}