"tiup cluster check --format json" does not return valid json result

[jiayang-zheng]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. What did you do?

Run "tiup cluster check" command on the console.

tiup cluster check file_beat.yaml --format json -u root -p

2. What did you expect to see?
   Get the json about the check result.
   Node Check Result Message

---

172.16.5.168 os-version Pass OS is CentOS Linux 7 (Core) 7.6.1810
172.16.5.168 cpu-cores Pass number of CPU cores / threads: 8
172.16.5.168 cpu-governor Warn Unable to determine current CPU frequency governor policy
172.16.5.168 swap Fail swap is enabled, please disable it for best performance
172.16.5.168 memory Pass memory size is 16384MB
172.16.5.168 disk Warn mount point /home does not have 'noatime' option set
172.16.5.168 disk Warn mount point /home does not have 'noatime' option set
172.16.5.168 selinux Pass SELinux is disabled
172.16.5.168 thp Pass THP is disabled
172.16.5.168 command Fail numactl not usable, bash: numactl: command not found

3. What did you see instead?
   Some useless info in json, but without the result.
   {"prefix":" - Checking node 172.16.5.168","suffix":"CheckSys: host=172.16.5.168 type=service"}
   {"prefix":" - Checking node 172.16.5.168","suffix":"CheckSys: host=172.16.5.168 type=package"}
   {"prefix":" - Checking node 172.16.5.168","mode":"done"}
   {"prefix":" - Cleanup check files on 172.16.5.168:22","suffix":"RootSSH: user=root, host=172.16.5.168, port=22"}
   {"prefix":" - Cleanup check files on 172.16.5.168:22","suffix":"Rmdir: host=172.16.5.168, directories='/tmp/tiup'"}
   {"prefix":" - Cleanup check files on 172.16.5.168:22","suffix":"RootSSH: user=root, host=172.16.5.168, port=22"}
   {"prefix":" - Cleanup check files on 172.16.5.168:22","suffix":"Rmdir: host=172.16.5.168, directories='/tmp/tiup'"}
   {"prefix":" - Cleanup check files on 172.16.5.168:22","suffix":"RootSSH: user=root, host=172.16.5.168, port=22"}
   {"prefix":" - Cleanup check files on 172.16.5.168:22","suffix":"Rmdir: host=172.16.5.168, directories='/tmp/tiup'"}
   {"prefix":" - Cleanup check files on 172.16.5.168:22","mode":"done"}
   {"prefix":" - Cleanup check files on 172.16.5.168:22","mode":"done"}
   {"prefix":" - Cleanup check files on 172.16.5.168:22","mode":"done"}
   Node Check Result Message

---

172.16.5.168 os-version Pass OS is CentOS Linux 7 (Core) 7.6.1810
172.16.5.168 cpu-cores Pass number of CPU cores / threads: 8
172.16.5.168 cpu-governor Warn Unable to determine current CPU frequency governor policy
172.16.5.168 swap Fail swap is enabled, please disable it for best performance
172.16.5.168 memory Pass memory size is 16384MB
172.16.5.168 disk Warn mount point /home does not have 'noatime' option set
172.16.5.168 disk Warn mount point /home does not have 'noatime' option set
172.16.5.168 selinux Pass SELinux is disabled
172.16.5.168 thp Pass THP is disabled
172.16.5.168 command Fail numactl not usable, bash: numactl: command not found
{"exit_code":0}

4. What version of TiUP are you using (tiup --version)?
   1.8.1 tiup
   Go Version: go1.17.5
   Git Ref: v1.8.1
   GitHash: 559b99d