init prometheus node exporter installation

install-node-exporter

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+#!/bin/bash
+PROM_DIR=/var/prometheus-node-exporter
+
+mkdir $PROM_DIR/
+
+apt install prometheus-node-exporter
+
+chown prometheus:prometheus $PROM_DIR
+
+echo "ARGS+= --collector.textfile.directory $PROM_DIR" \
+     >> /etc/default/prometheus-node-exporter
+
+install rdl_prometheus /usr/local/bin/

rdl_prometheus

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+#!/bin/bash
+# rdl_prometheus
+
+PROM_DIR=/var/prometheus-node-exporter
+
+help() {
+    cat -v <<EOF
+$(basename "$0") ( --help | COMMAND [ARG ...] )
+
+ Eval COMMAND with ARGs and put its exit status and timestamp into
+prometheus text file dir (default: $PROM_DIR).
+
+ COMMAND is stripped of any suffix beginning with a '.' and the result
+must only contain '_' and lowercase letters.
+
+Options
+
+ --help		print this help
+
+Environment
+
+ PROM_DIR	prometheus text file dir
+
+ RDL_PROM_LINES additional lines, can be set in COMMAND. Note:
+                RDL_PROM_LINES is not checked and prometheus might not
+                use the .prom file if it is not correct.
+
+Examples:
+
+ $ echo 'false' > test.sh; chmod 777 test.sh
+ $ $(basename "$0") ./test.sh 
+ $ cat /var/prometheus-node-exporter/test.prom 
+ test_completion_time 1757754118
+ test_status 1
+
+ $ foo() { RDL_PROM_LINES='bar 1'; return 33; }
+ $ export -f foo
+ $ $(basename "$0") foo
+ $ cat /var/prometheus-node-exporter/foo.prom 
+ foo_completion_time 1757755470
+ foo_status 33
+ bar 1
+EOF
+}
+
+test "$1" = "--help" && help
+test -z "$1" && { help; exit 1; }
+
+eval "$@"
+
+RETURN=$?
+
+NAME=$(basename "$1")
+NAME=${NAME%%.*}
+allowed_characters='^[a-z_]+$'
+
+[[ "$NAME" =~ $allowed_characters ]] || { help; exit 1; }
+
+{
+    echo "$NAME"_completion_time $(date +%s)
+    echo "$NAME"_status $RETURN
+    test -z "$RDL_PROM_LINES" || echo "$RDL_PROM_LINES"
+} > /tmp/"$NAME".prom.$$
+
+mv /tmp/"$NAME".prom.$$ "$PROM_DIR"/"$NAME".prom
+chown prometheus:prometheus "$PROM_DIR"/"$NAME".prom