zebra-state: Add support for temporary sled databases (#939)

* Test config with persistent sled database
* Test ephemeral config
* Add misconfigured ephemeral test

tower-batch/tests/ed25519.rs

@@ -123,33 +123,35 @@ where
 }
 
 #[tokio::test]
-async fn batch_flushes_on_max_items() {
+async fn batch_flushes_on_max_items() -> Result<(), Report> {
     use tokio::time::timeout;
     zebra_test::init();
 
     // Use a very long max_latency and a short timeout to check that
     // flushing is happening based on hitting max_items.
     let verifier = Batch::new(Ed25519Verifier::new(), 10, Duration::from_secs(1000));
-    assert!(
-        timeout(Duration::from_secs(1), sign_and_verify(verifier, 100, None))
-            .await
-            .is_ok()
-    );
+    timeout(Duration::from_secs(1), sign_and_verify(verifier, 100, None))
+        .await
+        .map_err(|e| eyre!(e))?
+        .map_err(|e| eyre!(e))?;
+
+    Ok(())
 }
 
 #[tokio::test]
-async fn batch_flushes_on_max_latency() {
+async fn batch_flushes_on_max_latency() -> Result<(), Report> {
     use tokio::time::timeout;
     zebra_test::init();
 
     // Use a very high max_items and a short timeout to check that
     // flushing is happening based on hitting max_latency.
     let verifier = Batch::new(Ed25519Verifier::new(), 100, Duration::from_millis(500));
-    assert!(
-        timeout(Duration::from_secs(1), sign_and_verify(verifier, 10, None))
-            .await
-            .is_ok()
-    );
+    timeout(Duration::from_secs(1), sign_and_verify(verifier, 10, None))
+        .await
+        .map_err(|e| eyre!(e))?
+        .map_err(|e| eyre!(e))?;
+
+    Ok(())
 }
 
 #[tokio::test]

zebra-state/src/lib.rs

@@ -69,6 +69,13 @@ pub struct Config {
 
     /// The maximum number of bytes to use caching data in memory.
     pub memory_cache_bytes: u64,
+
+    /// Whether to use an ephemeral database.
+    ///
+    /// Ephemeral databases are stored in memory on Linux, and in a temporary directory on other OSes.
+    ///
+    /// Set to `false` by default. If this is set to `true`, [`cache_dir`] is ignored.
+    pub ephemeral: bool,
 }
 
 impl Config {
@@ -79,12 +86,16 @@ impl Config {
             Network::Mainnet => "mainnet",
             Network::Testnet => "testnet",
         };
-        let path = self.cache_dir.join(net_dir).join("state");
 
-        sled::Config::default()
-            .path(path)
+        let config = sled::Config::default()
             .cache_capacity(self.memory_cache_bytes)
-            .mode(sled::Mode::LowSpace)
+            .mode(sled::Mode::LowSpace);
+        if self.ephemeral {
+            config.temporary(self.ephemeral)
+        } else {
+            let path = self.cache_dir.join(net_dir).join("state");
+            config.path(path)
+        }
     }
 }
 
@@ -96,6 +107,7 @@ impl Default for Config {
         Self {
             cache_dir,
             memory_cache_bytes: 512 * 1024 * 1024,
+            ephemeral: false,
         }
     }
 }

zebrad/tests/acceptance.rs

@@ -11,15 +11,25 @@ use tempdir::TempDir;
 use zebra_test::prelude::*;
 use zebrad::config::ZebradConfig;
 
-pub fn tempdir(create_config: bool) -> Result<(PathBuf, impl Drop)> {
+#[derive(PartialEq)]
+enum ConfigMode {
+    NoConfig,
+    Ephemeral,
+    Persistent,
+}
+
+fn tempdir(config_mode: ConfigMode) -> Result<(PathBuf, impl Drop)> {
     let dir = TempDir::new("zebrad_tests")?;
 
-    if create_config {
-        let cache_dir = dir.path().join("state");
-        fs::create_dir(&cache_dir)?;
-
+    if config_mode != ConfigMode::NoConfig {
         let mut config = ZebradConfig::default();
-        config.state.cache_dir = cache_dir;
+        if config_mode == ConfigMode::Ephemeral {
+            config.state.ephemeral = true;
+        } else {
+            let cache_dir = dir.path().join("state");
+            fs::create_dir(&cache_dir)?;
+            config.state.cache_dir = cache_dir;
+        }
         config.state.memory_cache_bytes = 256000000;
         config.network.listen_addr = "127.0.0.1:0".parse()?;
 
@@ -44,7 +54,7 @@ pub fn get_child(args: &[&str], tempdir: &PathBuf) -> Result<TestChild> {
 #[test]
 fn generate_no_args() -> Result<()> {
     zebra_test::init();
-    let (tempdir, _guard) = tempdir(true)?;
+    let (tempdir, _guard) = tempdir(ConfigMode::Ephemeral)?;
 
     let child = get_child(&["generate"], &tempdir)?;
     let output = child.wait_with_output()?;
@@ -59,7 +69,7 @@ fn generate_no_args() -> Result<()> {
 #[test]
 fn generate_args() -> Result<()> {
     zebra_test::init();
-    let (tempdir, _guard) = tempdir(false)?;
+    let (tempdir, _guard) = tempdir(ConfigMode::NoConfig)?;
 
     // unexpected free argument `argument`
     let child = get_child(&["generate", "argument"], &tempdir)?;
@@ -101,7 +111,7 @@ fn generate_args() -> Result<()> {
 #[test]
 fn help_no_args() -> Result<()> {
     zebra_test::init();
-    let (tempdir, _guard) = tempdir(true)?;
+    let (tempdir, _guard) = tempdir(ConfigMode::Ephemeral)?;
 
     let child = get_child(&["help"], &tempdir)?;
     let output = child.wait_with_output()?;
@@ -119,7 +129,7 @@ fn help_no_args() -> Result<()> {
 #[test]
 fn help_args() -> Result<()> {
     zebra_test::init();
-    let (tempdir, _guard) = tempdir(true)?;
+    let (tempdir, _guard) = tempdir(ConfigMode::Ephemeral)?;
 
     // The subcommand "argument" wasn't recognized.
     let child = get_child(&["help", "argument"], &tempdir)?;
@@ -137,7 +147,7 @@ fn help_args() -> Result<()> {
 #[test]
 fn revhex_args() -> Result<()> {
     zebra_test::init();
-    let (tempdir, _guard) = tempdir(true)?;
+    let (tempdir, _guard) = tempdir(ConfigMode::Ephemeral)?;
 
     // Valid
     let child = get_child(&["revhex", "33eeff55"], &tempdir)?;
@@ -152,7 +162,7 @@ fn revhex_args() -> Result<()> {
 #[test]
 fn seed_no_args() -> Result<()> {
     zebra_test::init();
-    let (tempdir, _guard) = tempdir(true)?;
+    let (tempdir, _guard) = tempdir(ConfigMode::Ephemeral)?;
 
     let mut child = get_child(&["-v", "seed"], &tempdir)?;
 
@@ -174,7 +184,7 @@ fn seed_no_args() -> Result<()> {
 #[test]
 fn seed_args() -> Result<()> {
     zebra_test::init();
-    let (tempdir, _guard) = tempdir(true)?;
+    let (tempdir, _guard) = tempdir(ConfigMode::Ephemeral)?;
 
     // unexpected free argument `argument`
     let child = get_child(&["seed", "argument"], &tempdir)?;
@@ -197,7 +207,8 @@ fn seed_args() -> Result<()> {
 #[test]
 fn start_no_args() -> Result<()> {
     zebra_test::init();
-    let (tempdir, _guard) = tempdir(true)?;
+    // start caches state, so run one of the start tests with persistent state
+    let (tempdir, _guard) = tempdir(ConfigMode::Persistent)?;
 
     let mut child = get_child(&["-v", "start"], &tempdir)?;
 
@@ -221,7 +232,7 @@ fn start_no_args() -> Result<()> {
 #[test]
 fn start_args() -> Result<()> {
     zebra_test::init();
-    let (tempdir, _guard) = tempdir(true)?;
+    let (tempdir, _guard) = tempdir(ConfigMode::Ephemeral)?;
 
     // Any free argument is valid
     let mut child = get_child(&["start", "argument"], &tempdir)?;
@@ -243,10 +254,90 @@ fn start_args() -> Result<()> {
     Ok(())
 }
 
+#[test]
+fn persistent_mode() -> Result<()> {
+    zebra_test::init();
+    let (tempdir, _guard) = tempdir(ConfigMode::Persistent)?;
+
+    let mut child = get_child(&["-v", "start"], &tempdir)?;
+
+    // Run the program and kill it at 1 second
+    std::thread::sleep(Duration::from_secs(1));
+    child.kill()?;
+    let output = child.wait_with_output()?;
+
+    // Make sure the command was killed
+    assert!(output.was_killed());
+
+    // Check that we have persistent sled database
+    let cache_dir = tempdir.join("state");
+    assert!(cache_dir.read_dir()?.count() > 0);
+
+    Ok(())
+}
+
+#[test]
+fn ephemeral_mode() -> Result<()> {
+    zebra_test::init();
+    let (tempdir, _guard) = tempdir(ConfigMode::Ephemeral)?;
+
+    // Any free argument is valid
+    let mut child = get_child(&["start", "argument"], &tempdir)?;
+    // Run the program and kill it at 1 second
+    std::thread::sleep(Duration::from_secs(1));
+    child.kill()?;
+    let output = child.wait_with_output()?;
+
+    // Make sure the command was killed
+    assert!(output.was_killed());
+
+    let cache_dir = tempdir.join("state");
+    assert!(!cache_dir.exists());
+
+    Ok(())
+}
+
+#[test]
+fn misconfigured_ephemeral_mode() -> Result<()> {
+    zebra_test::init();
+
+    let dir = TempDir::new("zebrad_tests")?;
+    let cache_dir = dir.path().join("state");
+
+    // Write a configuration that has both cache_dir and ephemeral options set
+    let mut config = ZebradConfig::default();
+    config.state.ephemeral = true;
+    // Although cache_dir has a default value, we set it a new temp directory
+    // to test that it is empty later.
+    fs::create_dir(&cache_dir)?;
+    config.state.cache_dir = cache_dir.clone();
+    config.state.memory_cache_bytes = 256000000;
+    config.network.listen_addr = "127.0.0.1:0".parse()?;
+    fs::File::create(dir.path().join("zebrad.toml"))?
+        .write_all(toml::to_string(&config)?.as_bytes())?;
+
+    let tempdir = dir.path().to_path_buf();
+
+    // Any free argument is valid
+    let mut child = get_child(&["start", "argument"], &tempdir)?;
+    // Run the program and kill it at 1 second
+    std::thread::sleep(Duration::from_secs(1));
+    child.kill()?;
+    let output = child.wait_with_output()?;
+
+    // Make sure the command was killed
+    assert!(output.was_killed());
+
+    // Check that ephemeral takes precedence over cache_dir
+    assert_eq!(cache_dir.read_dir()?.count(), 0);
+
+    Ok(())
+}
+
 #[test]
 fn app_no_args() -> Result<()> {
     zebra_test::init();
-    let (tempdir, _guard) = tempdir(true)?;
+    let (tempdir, _guard) = tempdir(ConfigMode::Ephemeral)?;
 
     let child = get_child(&[], &tempdir)?;
     let output = child.wait_with_output()?;
@@ -260,7 +351,7 @@ fn app_no_args() -> Result<()> {
 #[test]
 fn version_no_args() -> Result<()> {
     zebra_test::init();
-    let (tempdir, _guard) = tempdir(true)?;
+    let (tempdir, _guard) = tempdir(ConfigMode::Ephemeral)?;
 
     let child = get_child(&["version"], &tempdir)?;
     let output = child.wait_with_output()?;
@@ -274,7 +365,7 @@ fn version_no_args() -> Result<()> {
 #[test]
 fn version_args() -> Result<()> {
     zebra_test::init();
-    let (tempdir, _guard) = tempdir(true)?;
+    let (tempdir, _guard) = tempdir(ConfigMode::Ephemeral)?;
 
     // unexpected free argument `argument`
     let child = get_child(&["version", "argument"], &tempdir)?;
@@ -302,7 +393,7 @@ fn valid_generated_config_test() -> Result<()> {
 
 fn valid_generated_config(command: &str, expected_output: &str) -> Result<()> {
     zebra_test::init();
-    let (tempdir, _guard) = tempdir(false)?;
+    let (tempdir, _guard) = tempdir(ConfigMode::NoConfig)?;
 
     // Add a config file name to tempdir path
     let mut generated_config_path = tempdir.clone();