* Implement Redis configuration values splitting support

* Actualize Redis main docs
* Actualize configuration docs
* Use both old & new Redis API for tests

.github/workflows/integration-tests.yml

@@ -27,7 +27,7 @@ jobs:
           name: integration-tests
           path: ./target/debug/sccache
 
-  redis:
+  redis-deprecated:
     runs-on: ubuntu-latest
     needs: build
 
@@ -75,6 +75,54 @@ jobs:
 
           ${SCCACHE_PATH} --show-stats | grep -e "Cache hits\s*[1-9]"
 
+  redis:
+    runs-on: ubuntu-latest
+    needs: build
+
+    services:
+      redis:
+        image: redis
+        ports:
+          - 6379:6379
+
+    env:
+      SCCACHE_REDIS_ENDPOINT: tcp://127.0.0.1
+      RUSTC_WRAPPER: /home/runner/.cargo/bin/sccache
+
+    steps:
+      - name: Clone repository
+        uses: actions/checkout@v4
+
+      - name: Install rust
+        uses: ./.github/actions/rust-toolchain
+        with:
+          toolchain: "stable"
+
+      - uses: actions/download-artifact@v4
+        with:
+          name: integration-tests
+          path: /home/runner/.cargo/bin/
+      - name: Chmod for binary
+        run: chmod +x ${SCCACHE_PATH}
+
+      - name: Test
+        run: cargo clean && cargo build
+
+      - name: Output
+        run: |
+          ${SCCACHE_PATH} --show-stats
+
+          ${SCCACHE_PATH} --show-stats | grep redis
+
+      - name: Test Twice for Cache Read
+        run: cargo clean && cargo build
+
+      - name: Output
+        run: |
+          ${SCCACHE_PATH} --show-stats
+
+          ${SCCACHE_PATH} --show-stats | grep -e "Cache hits\s*[1-9]"
+
   s3_minio:
     runs-on: ubuntu-latest
     needs: build

docs/Configuration.md

@@ -156,7 +156,12 @@ will default to `us-east-1`.
 
 #### redis
 
-* `SCCACHE_REDIS` full redis url, including auth and access token/passwd.
+* `SCCACHE_REDIS` full redis url, including auth and access token/passwd (deprecated).
+* `SCCACHE_REDIS_ENDPOINT` redis url without auth and access token/passwd - single node configuration.
+* `SCCACHE_REDIS_CLUSTER_ENDPOINTS` redis cluster urls, separated by comma - shared cluster configuration.
+* `SCCACHE_REDIS_USERNAME` redis username (optional).
+* `SCCACHE_REDIS_PASSWORD` redis password (optional).
+* `SCCACHE_REDIS_DB` redis database (optional, default is 0).
 * `SCCACHE_REDIS_EXPIRATION` / `SCCACHE_REDIS_TTL` ttl for redis cache, don't set for default behavior.
 * `SCCACHE_REDIS_KEY_PREFIX` key prefix (optional).
 
@@ -188,11 +193,11 @@ The full url appears then as `redis://user:passwd@1.2.3.4:6379/?db=1`.
 
 #### webdav
 
-* `SCCACHE_WEBDAV_ENDPOINT`
-* `SCCACHE_WEBDAV_KEY_PREFIX`
-* `SCCACHE_WEBDAV_USERNAME`
-* `SCCACHE_WEBDAV_PASSWORD`
-* `SCCACHE_WEBDAV_TOKEN`
+* `SCCACHE_WEBDAV_ENDPOINT` a webdav service endpoint to store cache, such as `http://127.0.0.1:8080/my/webdav.php`.
+* `SCCACHE_WEBDAV_KEY_PREFIX` specify the key prefix (subfolder) of cache (optional).
+* `SCCACHE_WEBDAV_USERNAME` a username to authenticate with webdav service (optional).
+* `SCCACHE_WEBDAV_PASSWORD` a password to authenticate with webdav service (optional).
+* `SCCACHE_WEBDAV_TOKEN` a token to authenticate with webdav service (optional) - may be used instead of login & password.
 
 #### OSS
 

docs/Redis.md

@@ -1,17 +1,32 @@
 # Redis
 
-Set `SCCACHE_REDIS` to a [Redis](https://redis.io/) url in format `redis://[[<username>]:<passwd>@]<hostname>[:port][/?db=<db>]` to store the cache in a Redis instance. Redis can be configured as a LRU (least recently used) cache with a fixed maximum cache size. Set `maxmemory` and `maxmemory-policy` according to the [Redis documentation](https://redis.io/topics/lru-cache). The `allkeys-lru` policy which discards the *least recently accessed or modified* key fits well for the sccache use case.
+If you want to use [Redis](https://redis.io/) storage for the sccache cache, you need to set the `SCCACHE_REDIS_ENDPOINT` with the single-node redis URL.
+If you want to use a Redis cluster, set `SCCACHE_REDIS_CLUSTER_ENDPOINTS` instead of `SCCACHE_REDIS_ENDPOINT` with the comma-separated list of redis node URLs.
+
+Redis endpoint URL format can be found in the [OpenDAL source code](https://github.com/apache/opendal/blob/5f1d5d1d61ed28f63d4955538b33a4d582feebef/core/src/services/redis/backend.rs#L268-L307). Some valid examples:
+* `redis://127.0.0.1:6379` or `tcp://127.0.0.1:6379` or `127.0.0.1:6379` - TCP-based Redis connection (non-secure)
+* `rediss://@1.2.3.4:6379` - TLS-based Redis connection over TCP (secure)
+* `unix:///tmp/redis.sock` or `redis+unix:///tmp/redis.sock` - Unix socket-based Redis connection
+
+Redis can be configured as a LRU (least recently used) cache with a fixed maximum cache size. Set `maxmemory` and `maxmemory-policy` according to the [Redis documentation](https://redis.io/topics/lru-cache). The `allkeys-lru` policy which discards the *least recently accessed or modified* key fits well for the sccache use case.
 
 Redis over TLS is supported. Use the [`rediss://`](https://www.iana.org/assignments/uri-schemes/prov/rediss) url scheme (note `rediss` vs `redis`). Append `#insecure` the the url to disable hostname verification and accept self-signed certificates (dangerous!). Note that this also disables [SNI](https://en.wikipedia.org/wiki/Server_Name_Indication).
 
+If you want to authenticate to Redis, set `SCCACHE_REDIS_USERNAME` and `SCCACHE_REDIS_PASSWORD` to the username and password accordingly.
+
+`SCCACHE_REDIS_DB` is the database number to use. Default is 0.
+
 Set `SCCACHE_REDIS_EXPIRATION` in seconds if you don't want your cache to live forever. This will override the default behavior of redis.
 
 `SCCACHE_REDIS_TTL` is a deprecated synonym for `SCCACHE_REDIS_EXPIRATION`.
 
 Set `SCCACHE_REDIS_KEY_PREFIX` if you want to prefix all cache keys. This can be
 useful when sharing a Redis instance with another application or cache.
 
-## Examples
+`SCCACHE_REDIS` is deprecated, use `SCCACHE_REDIS_ENDPOINT` instead.
+If you really want to use `SCCACHE_REDIS`, you should URL in format `redis://[[<username>]:<passwd>@]<hostname>[:port][/?db=<db>]`.
+
+## Deprecated API Examples
 
 Use the local Redis instance with no password:
 ```sh

src/config.rs

@@ -657,23 +657,38 @@ fn config_from_env() -> Result<EnvConfig> {
     }
 
     // ======= redis =======
-    let redis = if let Ok(url) = env::var("SCCACHE_REDIS") {
-        let ttl = number_from_env_var("SCCACHE_REDIS_EXPIRATION")
-            .or_else(|| number_from_env_var("SCCACHE_REDIS_TTL"))
-            .transpose()?
-            .unwrap_or(DEFAULT_REDIS_CACHE_TTL);
-
-        let key_prefix = key_prefix_from_env_var("SCCACHE_REDIS_KEY_PREFIX");
-
-        // TODO: add possibility to load new values from env
-        Some(RedisCacheConfig {
-            url: Some(url),
-            ttl,
-            key_prefix,
-            ..Default::default()
-        })
-    } else {
-        None
+    let redis = match (
+        env::var("SCCACHE_REDIS").ok(),
+        env::var("SCCACHE_REDIS_ENDPOINT").ok(),
+        env::var("SCCACHE_REDIS_CLUSTER_ENDPOINTS").ok(),
+    ) {
+        (None, None, None) => None,
+        (url, endpoint, cluster_endpoints) => {
+            let db = number_from_env_var("SCCACHE_REDIS_DB")
+                .transpose()?
+                .unwrap_or(DEFAULT_REDIS_DB);
+
+            let username = env::var("SCCACHE_REDIS_USERNAME").ok();
+            let password = env::var("SCCACHE_REDIS_PASSWORD").ok();
+
+            let ttl = number_from_env_var("SCCACHE_REDIS_EXPIRATION")
+                .or_else(|| number_from_env_var("SCCACHE_REDIS_TTL"))
+                .transpose()?
+                .unwrap_or(DEFAULT_REDIS_CACHE_TTL);
+
+            let key_prefix = key_prefix_from_env_var("SCCACHE_REDIS_KEY_PREFIX");
+
+            Some(RedisCacheConfig {
+                url,
+                endpoint,
+                cluster_endpoints,
+                username,
+                password,
+                db,
+                ttl,
+                key_prefix,
+            })
+        }
     };
 
     if env::var_os("SCCACHE_REDIS_EXPIRATION").is_some()