use dirs crate for default location of state and config (#714)

* use dirs crate for default location of state and config
* panic if a path isn't specified for zebra-state

Cargo.lock

@@ -146,6 +146,12 @@ dependencies = [
  "rustc-demangle",
 ]
 
+[[package]]
+name = "base64"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b41b7ea54a0c9d92199de89e20e58d49f02f8e699814ef3fdf266f6f748d15c7"
+
 [[package]]
 name = "bech32"
 version = "0.7.2"
@@ -525,6 +531,26 @@ dependencies = [
  "generic-array 0.14.3",
 ]
 
+[[package]]
+name = "dirs"
+version = "3.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "142995ed02755914747cc6ca76fc7e4583cd18578746716d0508ea6ed558b9ff"
+dependencies = [
+ "dirs-sys",
+]
+
+[[package]]
+name = "dirs-sys"
+version = "0.3.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e93d7f5705de3e49895a2b5e0b8855a1c27f080192ae9c32a6432d50741a57a"
+dependencies = [
+ "libc",
+ "redox_users",
+ "winapi 0.3.9",
+]
+
 [[package]]
 name = "displaydoc"
 version = "0.1.7"
@@ -1617,6 +1643,17 @@ version = "0.1.57"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "41cc0f7e4d5d4544e8861606a285bb08d3e70712ccc7d2b84d7c0ccfaf4b05ce"
 
+[[package]]
+name = "redox_users"
+version = "0.3.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "09b23093265f8d200fa7b4c2c76297f47e681c655f6f1285a8780d6a022f7431"
+dependencies = [
+ "getrandom",
+ "redox_syscall",
+ "rust-argon2",
+]
+
 [[package]]
 name = "regex"
 version = "1.3.9"
@@ -1665,6 +1702,18 @@ dependencies = [
  "opaque-debug",
 ]
 
+[[package]]
+name = "rust-argon2"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2bc8af4bda8e1ff4932523b94d3dd20ee30a87232323eda55903ffd71d2fb017"
+dependencies = [
+ "base64",
+ "blake2b_simd",
+ "constant_time_eq",
+ "crossbeam-utils",
+]
+
 [[package]]
 name = "rustc-demangle"
 version = "0.1.16"
@@ -2651,6 +2700,7 @@ name = "zebra-state"
 version = "0.1.0"
 dependencies = [
  "color-eyre",
+ "dirs",
  "futures",
  "hex",
  "lazy_static",
@@ -2697,6 +2747,7 @@ dependencies = [
  "abscissa_core",
  "chrono",
  "color-eyre",
+ "dirs",
  "futures",
  "gumdrop",
  "hyper",

zebra-consensus/src/redjubjub/tests.rs

@@ -46,6 +46,10 @@ where
 }
 
 #[tokio::test]
+async fn batch_flushes_on_max_items_test() -> Result<()> {
+    batch_flushes_on_max_items().await
+}
+
 #[spandoc::spandoc]
 async fn batch_flushes_on_max_items() -> Result<()> {
     use tokio::time::timeout;
@@ -61,6 +65,10 @@ async fn batch_flushes_on_max_items() -> Result<()> {
 }
 
 #[tokio::test]
+async fn batch_flushes_on_max_latency_test() -> Result<()> {
+    batch_flushes_on_max_latency().await
+}
+
 #[spandoc::spandoc]
 async fn batch_flushes_on_max_latency() -> Result<()> {
     use tokio::time::timeout;

zebra-state/Cargo.toml

@@ -15,6 +15,7 @@ lazy_static = "1.4.0"
 hex = "0.4.2"
 sled = "0.33.0"
 serde = { version = "1", features = ["serde_derive"] }
+dirs = "3.0.1"
 tracing = "0.1"
 tracing-futures = "0.2"
 
@@ -24,4 +25,4 @@ zebra-test = { path = "../zebra-test/" }
 spandoc = "0.2"
 tempdir = "0.3.7"
 color-eyre = "0.5"
-once_cell = "1.4"
+once_cell = "1.4"

zebra-state/src/lib.rs

@@ -30,20 +30,38 @@ pub mod on_disk;
 #[serde(deny_unknown_fields)]
 pub struct Config {
     /// The root directory for the state storage
-    pub path: PathBuf,
+    pub cache_dir: Option<PathBuf>,
 }
 
 impl Config {
+    /// Generate the appropriate `sled::Config` based on the provided
+    /// `zebra_state::Config`.
+    ///
+    /// # Details
+    ///
+    /// This function should panic if the user of `zebra-state` doesn't configure
+    /// a directory to store the state.
     pub(crate) fn sled_config(&self) -> sled::Config {
-        sled::Config::default().path(&self.path)
+        let path = self
+            .cache_dir
+            .as_ref()
+            .unwrap_or_else(|| {
+                todo!("create a nice user facing error explaining how to set the cache directory")
+            })
+            .join("state");
+
+        sled::Config::default().path(path)
     }
 }
 
 impl Default for Config {
     fn default() -> Self {
-        Self {
+        let cache_dir = std::env::var("ZEBRAD_CACHE_DIR")
-            path: PathBuf::from("./.zebra-state"),
+            .map(PathBuf::from)
-        }
+            .ok()
+            .or_else(|| dirs::cache_dir().map(|dir| dir.join("zebra")));
+
+        Self { cache_dir }
     }
 }
 
@@ -114,3 +132,17 @@ fn block_locator_heights(tip_height: BlockHeight) -> impl Iterator<Item = BlockH
         .map(BlockHeight)
         .chain(iter::once(BlockHeight(0)))
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    #[should_panic]
+    fn test_no_path() {
+        zebra_test::init();
+
+        let bad_config = Config { cache_dir: None };
+        let _unreachable = bad_config.sled_config();
+    }
+}

zebra-state/tests/basic.rs

@@ -49,6 +49,10 @@ static GET_TIP_TRANSCRIPT: Lazy<Vec<(Request, Response)>> = Lazy::new(|| {
 });
 
 #[tokio::test]
+async fn check_transcripts_test() -> Result<(), Report> {
+    check_transcripts().await
+}
+
 #[spandoc::spandoc]
 async fn check_transcripts() -> Result<(), Report> {
     zebra_test::init();
@@ -61,7 +65,7 @@ async fn check_transcripts() -> Result<(), Report> {
 
         let storage_guard = TempDir::new("")?;
         let service = on_disk::init(Config {
-            path: storage_guard.path().to_owned(),
+            cache_dir: Some(storage_guard.path().to_owned()),
         });
         let transcript = Transcript::from(transcript_data.iter().cloned());
         /// SPANDOC: check the on disk service against the transcript

zebrad/Cargo.toml

@@ -34,6 +34,7 @@ tracing-error = "0.1.2"
 
 metrics-runtime = "0.13"
 metrics = "0.12"
+dirs = "3.0.1"
 
 [dev-dependencies]
 abscissa_core = { version = "0.5", features = ["testing"] }

zebrad/src/commands.rs

@@ -91,14 +91,14 @@ impl ZebradCmd {
 impl Configurable<ZebradConfig> for ZebradCmd {
     /// Location of the configuration file
     fn config_path(&self) -> Option<PathBuf> {
-        let filename = std::env::current_dir().ok().map(|mut dir_path| {
-            dir_path.push(CONFIG_FILE);
-            dir_path
-        });
-
         let if_exists = |f: PathBuf| if f.exists() { Some(f) } else { None };
 
-        filename.and_then(if_exists)
+        dirs::preference_dir()
+            .map(|path| path.join(CONFIG_FILE))
+            .and_then(if_exists)
+            .or_else(|| std::env::current_dir().ok())
+            .map(|path| path.join(CONFIG_FILE))
+            .and_then(if_exists)
 
         // Note: Changes in how configuration is loaded may need usage
         // edits in generate.rs