Command line execution works normally, but systemd service execution reports "no such host" error

**Description** When running `mongodb_exporter` directly via the command line, it connects to MongoDB successfully and exposes metrics (verifiable via `curl`). However, when starting the exporter as a `systemd` service with the same connection URI, it fails with a "no such host" error (the exporter incorrectly parses the host as `mongodb` instead of `127.0.0.1:27018`). **Version Information** - MongoDB version: 3.6.12 - mongodb_exporter version: v0.44.0 (linux-amd64) - OS: Linux (RHEL/CentOS 7, systemd-based) **Steps to Reproduce** **1. Command line execution (WORKS):** Execute the exporter directly in the terminal – it runs successfully and metrics are accessible via `curl http://localhost:9216/metrics`: > [root@mongos1 mongodb_exporter-0.44.0.linux-amd64]# ./mongodb_exporter --mongodb.uri=mongodb://dbs_admin:mypwd@127.0.0.1:27018/admin?authSource=admin --collector.dbstats **2. Systemd service configuration (FAIL):** Create `/etc/systemd/system/mongodb_exporter.service`: > [Unit] Description=Prometheus MongoDB Exporter Wants=network-online.target After=network-online.target [Service] User=mongodb_exporter Group=mongodb_exporter Type=simple Restart=on-failure ExecStart=/usr/local/bin/mongodb_exporter--collector.dbstats \ --mongodb.uri="mongodb://dbs_admin:mypwd@127.0.0.1:27018/admin?authSource=admin" \ --collector.dbstats \ --web.listen-address=:9216 CPUQuota=20% MemoryLimit=300M ExecReload=/bin/kill -HUP $MAINPID KillMode=process [Install] WantedBy=multi-user.target **3. Start systemd service:** > systemctl daemon-reload > systemctl start mongodb_exporter.service **Logs** Full error log from `journalctl -u mongodb_exporter.service`: > mongodb exporter: time="2025-12-03T16:47:30+08:00" level=error msg="Cannot connect to MongoDB: cannot connect to MongoDB: server selection error: server selection timeout, current topology: { Type: Single, Servers: [{ Addr: \"mongodb, Type: Unknown, Last error: dial tcp: lookup \"mongodb: no such host }, ] }"