zfs: introduce pkg zfs/zfscmd for command logging, status, prometheus metrics

refs #196

zfs/zfscmd/zfscmd-logging-scraper/scrape_graylog_csv.bash

@@ -0,0 +1,16 @@
+#!/usr/bin/env bash
+
+# This script converts output that was produced by zrepl and captured by Graylog
+# back to something that the scraper in this package's main can understand
+# Intended for human syslog
+# logging:
+# - type: syslog
+#   level: debug
+#   format: human
+
+
+csvfilter --skip 1 -f 0,2 -q '"' --out-quotechar=' ' /dev/stdin | sed -E 's/^\s*([^,]*), /\1 [LEVEL]/' | \
+    go run . -v \
+    --dateRE '^([^\[]+) (\[.*)' \
+    --dateFormat '2006-01-02T15:04:05.999999999Z'
+