1 files changed, 127 insertions, 0 deletions
diff --git a/jstests/watchdog/lib/charybdefs_lib.js b/jstests/watchdog/lib/charybdefs_lib.js
new file mode 100644
index 00000000000..f80246426d8
--- /dev/null
+++ b/jstests/watchdog/lib/charybdefs_lib.js
@@ -0,0 +1,127 @@
+// Exit code that the watchdog uses on exit
+const EXIT_WATCHDOG = 61;
+
+/**
+ * Control the Charybdefs file system for Fault Injectiong testing
+ *
+ * @param {string} test_name unique name for test directories
+ */
+function CharybdefsControl(test_name) {
+    'use strict';
+
+    const python = "/opt/mongodbtoolchain/v3/bin/python3";
+    let control_py = "/data/charybdefs/mongo/control.py";
+
+    // Use the minimum watchdog period
+    const wd_period_sec = 60;
+
+    // Since the watchdog can take up to (2 x period) to detect failures, stall the write for that
+    // amount of time plus a small buffer of time to account for thread scheduling, etc.
+    const fs_delay_sec = wd_period_sec * 2 + 5;
+
+    const mount_point = MongoRunner.toRealPath(test_name + '_mnt');
+    const backing_path = MongoRunner.toRealPath(test_name + '_backing');
+
+    this._runControl = function(cmd, ...args) {
+        let cmd_args = [python, control_py, cmd];
+        cmd_args = cmd_args.concat(args);
+        let ret = run.apply(null, cmd_args);
+        assert.eq(ret, 0);
+    };
+
+    /**
+     * Get the path of the mounted Charybdefs file system.
+     *
+     * @return {string} mount point
+     */
+    this.getMountPath = function() {
+        return mount_point;
+    };
+
+    /**
+     * Get the Watchdog Period.
+     *
+     * @return {number} number of sections
+     */
+    this.getWatchdogPeriodSeconds = function() {
+        return wd_period_sec;
+    };
+
+    /**
+     *  Start the Charybdefs filesystem.
+     */
+    this.start = function() {
+        this.cleanup();
+
+        this._runControl("start",
+                         "--fuse_mount=" + mount_point,
+                         "--backing_path=" + backing_path,
+                         "--log_file=foo_fs.log");
+        print("Charybdefs sucessfully started.");
+    };
+
+    // Get the current check generation
+    function _getGeneration(admin) {
+        const result = admin.runCommand({"serverStatus": 1});
+
+        assert.commandWorked(result);
+
+        return result.watchdog.checkGeneration;
+    }
+
+    /**
+     *  Wait for the watchdog to run some checks first.
+     *
+     * @param {object} MongoDB connection to admin database
+     */
+    this.waitForWatchdogToStart = function(admin) {
+        print("Waiting for MongoDB watchdog to checks run twice.");
+        assert.soon(function() {
+            return _getGeneration(admin) > 2;
+        }, "Watchdog did not start running", 5 * wd_period_sec * 1000);
+    };
+
+    /**
+     *  Inject delay on write, and wait to MongoDB to get hung.
+     *
+     * @param {string} file_name - file name to inject fault on
+     */
+    this.addWriteDelayFaultAndWait = function(file_name) {
+        // Convert seconds to microseconds for charybdefs
+        const delay_us = fs_delay_sec * 1000000;
+        this.addFault("write_buf", file_name, delay_us);
+
+        // Wait for watchdog to stop
+        print("Waiting for MongoDB to hang.");
+        sleep(fs_delay_sec * 1000);
+
+    };
+
+    /**
+     * Add a fault to inject.
+     *
+     * @param {string} method - name of fuse method to inject fault for
+     * @param {string} file_name - file name to inject fault on
+     * @param {number} delay_us - optional delay in microseconds to wait
+     */
+    this.addFault = function(method, file_name, delay_us) {
+
+        this._runControl("set_fault",
+                         "--methods=" + method,
+                         "--errno=5",
+                         "--probability=100000",
+                         "--regexp=.*" + file_name,
+                         "--delay_us=" + delay_us);
+    };
+
+    /**
+     * Shutdown and clean up the Charybdefs filesystem.
+     */
+    this.cleanup = function() {
+        this._runControl("stop_all", "--fuse_mount=" + mount_point);
+
+        // Delete any remaining files
+        resetDbpath(mount_point);
+        resetDbpath(backing_path);
+    };
+}