[6/n] [reconfigurator-cli] allow loading up an example system (#6788)

Add a new command to the reconfigurator CLI, `load-example`, that conjures up
an example system. This allows for really easy setup, both interactively and
in automated tests. Plus, having everything be seeded is really nice for
reproducibility.

Author: sunshowers

Cargo.lock

@@ -14,6 +14,7 @@ omicron-rpaths.workspace = true
 anyhow.workspace = true
 assert_matches.workspace = true
 camino.workspace = true
+chrono.workspace = true
 clap.workspace = true
 dropshot.workspace = true
 humantime.workspace = true
@@ -33,6 +34,7 @@ slog-error-chain.workspace = true
 slog.workspace = true
 swrite.workspace = true
 tabled.workspace = true
+typed-rng.workspace = true
 uuid.workspace = true
 omicron-workspace-hack.workspace = true
 

dev-tools/reconfigurator-cli/Cargo.toml

@@ -6,6 +6,7 @@
 
 use anyhow::{anyhow, bail, Context};
 use camino::Utf8PathBuf;
+use chrono::Utc;
 use clap::CommandFactory;
 use clap::FromArgMatches;
 use clap::ValueEnum;
@@ -15,6 +16,7 @@ use internal_dns_types::diff::DnsDiff;
 use nexus_inventory::CollectionBuilder;
 use nexus_reconfigurator_planning::blueprint_builder::BlueprintBuilder;
 use nexus_reconfigurator_planning::blueprint_builder::EnsureMultiple;
+use nexus_reconfigurator_planning::example::ExampleSystemBuilder;
 use nexus_reconfigurator_planning::planner::Planner;
 use nexus_reconfigurator_planning::system::{
     SledBuilder, SledHwInventory, SystemDescription,
@@ -34,6 +36,8 @@ use nexus_types::internal_api::params::DnsConfigParams;
 use nexus_types::inventory::Collection;
 use omicron_common::api::external::Generation;
 use omicron_common::api::external::Name;
+use omicron_common::policy::NEXUS_REDUNDANCY;
+use omicron_uuid_kinds::CollectionKind;
 use omicron_uuid_kinds::CollectionUuid;
 use omicron_uuid_kinds::GenericUuid;
 use omicron_uuid_kinds::OmicronZoneUuid;
@@ -45,6 +49,7 @@ use std::collections::BTreeMap;
 use std::io::BufRead;
 use swrite::{swriteln, SWrite};
 use tabled::Tabled;
+use typed_rng::TypedUuidRng;
 use uuid::Uuid;
 
 /// REPL state
@@ -76,13 +81,67 @@ struct ReconfiguratorSim {
     /// External DNS zone name configured
     external_dns_zone_name: String,
 
+    /// RNG for collection IDs
+    collection_id_rng: TypedUuidRng<CollectionKind>,
+
     /// Policy overrides
     num_nexus: Option<u16>,
 
     log: slog::Logger,
 }
 
 impl ReconfiguratorSim {
+    fn new(log: slog::Logger) -> Self {
+        Self {
+            system: SystemDescription::new(),
+            collections: IndexMap::new(),
+            blueprints: IndexMap::new(),
+            internal_dns: BTreeMap::new(),
+            external_dns: BTreeMap::new(),
+            silo_names: vec!["example-silo".parse().unwrap()],
+            external_dns_zone_name: String::from("oxide.example"),
+            collection_id_rng: TypedUuidRng::from_entropy(),
+            num_nexus: None,
+            log,
+        }
+    }
+
+    /// Returns true if the user has made local changes to the simulated
+    /// system.
+    ///
+    /// This is used when the user asks to load an example system. Doing that
+    /// basically requires a clean slate.
+    fn user_made_system_changes(&self) -> bool {
+        // Use this pattern to ensure that if a new field is added to
+        // ReconfiguratorSim, it will fail to compile until it's added here.
+        let Self {
+            system,
+            collections,
+            blueprints,
+            internal_dns,
+            external_dns,
+            // For purposes of this method, we let these policy parameters be
+            // set to any arbitrary value. This lets example systems be
+            // generated using these values.
+            silo_names: _,
+            external_dns_zone_name: _,
+            collection_id_rng: _,
+            num_nexus: _,
+            log: _,
+        } = self;
+
+        system.has_sleds()
+            || !collections.is_empty()
+            || !blueprints.is_empty()
+            || !internal_dns.is_empty()
+            || !external_dns.is_empty()
+    }
+
+    // Reset the state of the REPL.
+    fn wipe(&mut self) {
+        *self = Self::new(self.log.clone());
+    }
+
     fn blueprint_lookup(&self, id: Uuid) -> Result<&Blueprint, anyhow::Error> {
         self.blueprints
             .get(&id)
@@ -181,22 +240,12 @@ fn main() -> anyhow::Result<()> {
     let cmd = CmdReconfiguratorSim::parse();
 
     let log = dropshot::ConfigLogging::StderrTerminal {
-        level: dropshot::ConfigLoggingLevel::Debug,
+        level: dropshot::ConfigLoggingLevel::Info,
     }
     .to_logger("reconfigurator-sim")
     .context("creating logger")?;
 
-    let mut sim = ReconfiguratorSim {
-        system: SystemDescription::new(),
-        collections: IndexMap::new(),
-        blueprints: IndexMap::new(),
-        internal_dns: BTreeMap::new(),
-        external_dns: BTreeMap::new(),
-        log,
-        silo_names: vec!["example-silo".parse().unwrap()],
-        external_dns_zone_name: String::from("oxide.example"),
-        num_nexus: None,
-    };
+    let mut sim = ReconfiguratorSim::new(log);
 
     if let Some(input_file) = cmd.input_file {
         let file = std::fs::File::open(&input_file)
@@ -310,8 +359,10 @@ fn process_entry(sim: &mut ReconfiguratorSim, entry: String) -> LoopResult {
         Commands::Show => cmd_show(sim),
         Commands::Set(args) => cmd_set(sim, args),
         Commands::Load(args) => cmd_load(sim, args),
+        Commands::LoadExample(args) => cmd_load_example(sim, args),
         Commands::FileContents(args) => cmd_file_contents(args),
         Commands::Save(args) => cmd_save(sim, args),
+        Commands::Wipe => cmd_wipe(sim),
     };
 
     match cmd_result {
@@ -380,8 +431,12 @@ enum Commands {
     Save(SaveArgs),
     /// load state from a file
     Load(LoadArgs),
+    /// generate and load an example system
+    LoadExample(LoadExampleArgs),
     /// show information about what's in a saved file
     FileContents(FileContentsArgs),
+    /// reset the state of the REPL
+    Wipe,
 }
 
 #[derive(Debug, Args)]
@@ -511,6 +566,33 @@ struct LoadArgs {
     collection_id: Option<CollectionUuid>,
 }
 
+#[derive(Debug, Args)]
+struct LoadExampleArgs {
+    /// Seed for the RNG that's used to generate the example system.
+    ///
+    /// Setting this makes it possible for callers to get deterministic
+    /// results. In automated tests, the seed is typically the name of the
+    /// test.
+    #[clap(long, default_value = "reconfigurator_cli_example")]
+    seed: String,
+
+    /// The number of sleds in the example system.
+    #[clap(short = 's', long, default_value_t = ExampleSystemBuilder::DEFAULT_N_SLEDS)]
+    nsleds: usize,
+
+    /// The number of disks per sled in the example system.
+    #[clap(short = 'd', long, default_value_t = SledBuilder::DEFAULT_NPOOLS)]
+    ndisks_per_sled: u8,
+
+    /// Do not create zones in the example system.
+    #[clap(short = 'Z', long)]
+    no_zones: bool,
+
+    /// Do not create entries for disks in the blueprint.
+    #[clap(long)]
+    no_disks_in_blueprint: bool,
+}
+
 #[derive(Debug, Args)]
 struct FileContentsArgs {
     /// input file
@@ -675,7 +757,12 @@ fn cmd_inventory_generate(
             )
             .context("recording Omicron zones")?;
     }
-    let inventory = builder.build();
+
+    let mut inventory = builder.build();
+    // Assign collection IDs from the RNG. This enables consistent results when
+    // callers have explicitly seeded the RNG (e.g., in tests).
+    inventory.id = sim.collection_id_rng.next();
+
     let rv = format!(
         "generated inventory collection {} from configured sleds",
         inventory.id
@@ -848,7 +935,7 @@ fn cmd_blueprint_diff(
     // Diff'ing DNS is a little trickier.  First, compute what DNS should be for
     // each blueprint.  To do that we need to construct a list of sleds suitable
     // for the executor.
-    let sleds_by_id = make_sleds_by_id(&sim)?;
+    let sleds_by_id = make_sleds_by_id(&sim.system)?;
     let internal_dns_config1 = blueprint_internal_dns_config(
         &blueprint1,
         &sleds_by_id,
@@ -881,10 +968,9 @@ fn cmd_blueprint_diff(
 }
 
 fn make_sleds_by_id(
-    sim: &ReconfiguratorSim,
+    system: &SystemDescription,
 ) -> Result<BTreeMap<SledUuid, execution::Sled>, anyhow::Error> {
-    let collection = sim
-        .system
+    let collection = system
         .to_collection_builder()
         .context(
             "unexpectedly failed to create collection for current set of sleds",
@@ -924,7 +1010,7 @@ fn cmd_blueprint_diff_dns(
 
     let blueprint_dns_zone = match dns_group {
         CliDnsGroup::Internal => {
-            let sleds_by_id = make_sleds_by_id(sim)?;
+            let sleds_by_id = make_sleds_by_id(&sim.system)?;
             blueprint_internal_dns_config(
                 blueprint,
                 &sleds_by_id,
@@ -1003,6 +1089,11 @@ fn cmd_save(
     )))
 }
 
+fn cmd_wipe(sim: &mut ReconfiguratorSim) -> anyhow::Result<Option<String>> {
+    sim.wipe();
+    Ok(Some("wiped reconfigurator-sim state".to_string()))
+}
+
 fn cmd_show(sim: &mut ReconfiguratorSim) -> anyhow::Result<Option<String>> {
     let mut s = String::new();
     do_print_properties(&mut s, sim);
@@ -1275,6 +1366,71 @@ fn cmd_load(
     Ok(Some(s))
 }
 
+fn cmd_load_example(
+    sim: &mut ReconfiguratorSim,
+    args: LoadExampleArgs,
+) -> anyhow::Result<Option<String>> {
+    if sim.user_made_system_changes() {
+        bail!(
+            "changes made to simulated system: run `wipe system` before \
+             loading an example system"
+        );
+    }
+
+    // Generate the example system.
+    let (example, blueprint) = ExampleSystemBuilder::new(&sim.log, &args.seed)
+        .nsleds(args.nsleds)
+        .ndisks_per_sled(args.ndisks_per_sled)
+        .nexus_count(sim.num_nexus.map_or(NEXUS_REDUNDANCY, |n| n.into()))
+        .create_zones(!args.no_zones)
+        .create_disks_in_blueprint(!args.no_disks_in_blueprint)
+        .build();
+
+    // Generate the internal and external DNS configs based on the blueprint.
+    let sleds_by_id = make_sleds_by_id(&example.system)?;
+    let internal_dns = blueprint_internal_dns_config(
+        &blueprint,
+        &sleds_by_id,
+        &Default::default(),
+    )?;
+    let external_dns = blueprint_external_dns_config(
+        &blueprint,
+        &sim.silo_names,
+        sim.external_dns_zone_name.clone(),
+    );
+
+    // No more fallible operations from here on out: set the system state.
+    let collection_id = example.collection.id;
+    let blueprint_id = blueprint.id;
+    sim.system = example.system;
+    sim.collections.insert(collection_id, example.collection);
+    sim.internal_dns.insert(
+        blueprint.internal_dns_version,
+        DnsConfigParams {
+            generation: blueprint.internal_dns_version.into(),
+            time_created: Utc::now(),
+            zones: vec![internal_dns],
+        },
+    );
+    sim.external_dns.insert(
+        blueprint.external_dns_version,
+        DnsConfigParams {
+            generation: blueprint.external_dns_version.into(),
+            time_created: Utc::now(),
+            zones: vec![external_dns],
+        },
+    );
+    sim.blueprints.insert(blueprint.id, blueprint);
+    sim.collection_id_rng =
+        TypedUuidRng::from_seed(&args.seed, "reconfigurator-cli");
+
+    Ok(Some(format!(
+        "loaded example system with:\n\
+         - collection: {collection_id}\n\
+         - blueprint: {blueprint_id}",
+    )))
+}
+
 fn cmd_file_contents(args: FileContentsArgs) -> anyhow::Result<Option<String>> {
     let loaded = read_file(&args.filename)?;
 

dev-tools/reconfigurator-cli/src/main.rs

@@ -0,0 +1,26 @@
+load-example --seed test-basic
+load-example --seed test-basic
+
+show
+
+sled-list
+inventory-list
+blueprint-list
+
+sled-show 2eb69596-f081-4e2d-9425-9994926e0832
+blueprint-show ade5749d-bdf3-4fab-a8ae-00bea01b3a5a
+
+blueprint-diff-inventory 9e187896-7809-46d0-9210-d75be1b3c4d4 ade5749d-bdf3-4fab-a8ae-00bea01b3a5a
+
+inventory-generate
+blueprint-diff-inventory b32394d8-7d79-486f-8657-fd5219508181 ade5749d-bdf3-4fab-a8ae-00bea01b3a5a
+
+wipe
+load-example --seed test-basic --nsleds 1 --ndisks-per-sled 4 --no-zones
+
+sled-list
+inventory-list
+blueprint-list
+
+sled-show 89d02b1b-478c-401a-8e28-7a26f74fa41b
+blueprint-show ade5749d-bdf3-4fab-a8ae-00bea01b3a5a