fix: set unittests dir to /tmp can explode grcov's disk (#253)

* fix: set unittests dir to /tmp can explode grcov's disk

Co-authored-by: luofucong <luofucong@greptime.com>

.github/workflows/coverage.yml

@@ -24,6 +24,10 @@ jobs:
           toolchain: ${{ env.RUST_TOOLCHAIN }}
           override: true
           profile: minimal
+      - name: Cleanup disk
+        uses: curoky/cleanup-disk-action@v2.0
+        with:
+          retain: 'rust'
       - name: Execute tests
         uses: actions-rs/cargo@v1
         with:
@@ -36,6 +40,7 @@ jobs:
           GT_S3_BUCKET: ${{ secrets.S3_BUCKET }}
           GT_S3_ACCESS_KEY_ID: ${{ secrets.S3_ACCESS_KEY_ID }}
           GT_S3_ACCESS_KEY: ${{ secrets.S3_ACCESS_KEY }}
+          UNITTEST_LOG_DIR: "__unittest_logs"
       - name: Gather coverage data
         id: coverage
         uses: actions-rs/grcov@v0.1

.github/workflows/develop.yml

@@ -46,6 +46,7 @@ jobs:
           GT_S3_BUCKET: ${{ secrets.S3_BUCKET }}
           GT_S3_ACCESS_KEY_ID: ${{ secrets.S3_ACCESS_KEY_ID }}
           GT_S3_ACCESS_KEY: ${{ secrets.S3_ACCESS_KEY }}
+          UNITTEST_LOG_DIR: "__unittest_logs"
 
   fmt:
     name: Rustfmt

src/common/telemetry/src/logging.rs

@@ -29,12 +29,17 @@ pub fn init_default_ut_logging() {
 
     START.call_once(|| {
         let mut g = GLOBAL_UT_LOG_GUARD.as_ref().lock().unwrap();
-        *g = Some(init_global_logging(
-            "unittest",
-            "/tmp/__unittest_logs",
-            "DEBUG",
-            false,
-        ));
+
+        // When running in Github's actions, env "UNITTEST_LOG_DIR" is set to a directory other
+        // than "/tmp".
+        // This is to fix the problem that the "/tmp" disk space of action runner's is small,
+        // if we write testing logs in it, actions would fail due to disk out of space error.
+        let dir =
+            env::var("UNITTEST_LOG_DIR").unwrap_or_else(|_| "/tmp/__unittest_logs".to_string());
+
+        *g = Some(init_global_logging("unittest", &dir, "DEBUG", false));
+
+        info!("logs dir = {}", dir);
     });
 }