Batch cert expiry scan

Loop many hosts to print notAfter dates; pipe to sort for soonest expiry

for h in $(cat hosts.txt); do echo -n "$h "; echo | openssl s_client -connect $h:443 -servername $h 2>/dev/null | openssl x509 -noout -enddate; done
tool
troubleshooting32 commands
tags
troubleshootingtlssecuritymonitoring

More troubleshooting commands

  • Decode JWT claims
    cut -d. -f2 <<<"$JWT" | tr '_-' '/+' | base64 -d 2>/dev/null | jq .

    Decode payload to inspect exp/iss/aud; note: fixes base64url, skips sig check

  • List gRPC services via reflection
    grpcurl -plaintext <host>:<port> list; grpcurl -plaintext <host>:<port> describe <svc>

    Enumerate services/methods over reflection; -plaintext skips TLS for debug

  • Per-thread CPU breakdown
    pidstat -t -p <pid> 1

    Per-thread CPU%, find the hot TID inside a busy process for jstack/perf

  • Hot thread live view
    top -H -p <pid>

    Live per-thread view; convert hot TID to hex (printf %x) to match jstack nid

  • Per-core CPU saturation
    mpstat -P ALL 1

    Per-core %usr/%sys/%iowait — spot a single saturated core vs balanced load

all 32 troubleshooting commands