From 3e3de2bd709dc881678208c487b792ff3c8ab91e Mon Sep 17 00:00:00 2001
From: "Chandan Kumar (raukadah)" <chkumar@redhat.com>
Date: Tue, 18 Feb 2025 13:15:43 +0530
Subject: [PATCH] Use prometheus api to get metrics names in check_data

Currently check_data is using prometheus metrics to check
where prometheus is working or not.

Let's use prometheus HTTP API[1] to query the list of metrics.
It will make sure, we are pushing data to the prometheus.

Links:
[1]. https://prometheus.io/docs/prometheus/latest/querying/api/

Change-Id: I9fd4e4aced915f8090afbf7e65f07aca8db64e3f
Signed-off-by: Chandan Kumar (raukadah) <chkumar@redhat.com>
---
 devstack/lib/node_exporter |  2 +-
 devstack/lib/prometheus    | 12 +++++++-----
 devstack/plugin.sh         |  4 ++--
 3 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/devstack/lib/node_exporter b/devstack/lib/node_exporter
index f84e179..d4ce1f4 100644
--- a/devstack/lib/node_exporter
+++ b/devstack/lib/node_exporter
@@ -68,7 +68,7 @@ function wait_for_data {
     # Adding sleep time so that metrics is pushed by node exporter
     sleep 60
 }
-function check_data {
+function check_data_node_exporter {
     if curl -s --head  --request  GET "http://$HOST_IP:$NODE_EXPORTER_PORT/metrics" | grep "200 OK" > /dev/null; then
         echo "#### Metrics data ####"
         curl "http://$HOST_IP:$NODE_EXPORTER_PORT/metrics"
diff --git a/devstack/lib/prometheus b/devstack/lib/prometheus
index 86a7a1a..10b325a 100644
--- a/devstack/lib/prometheus
+++ b/devstack/lib/prometheus
@@ -11,7 +11,7 @@ PROMETHEUS_PORT=${PROMETHEUS_PORT:-9090}
 
 function pre_install_prometheus {
     # Install OS packages
-    install_package wget tar
+    install_package wget tar jq
 }
 
 function install_prometheus {
@@ -94,10 +94,12 @@ function wait_for_data {
     sleep 60
 }
 
-function check_data {
-    if curl -s --head  --request  GET "http://$HOST_IP:$PROMETHEUS_PORT/metrics" | grep "200 OK" > /dev/null; then
-        echo "#### Metrics data ####"
-        curl "http://$HOST_IP:$PROMETHEUS_PORT/metrics"
+function check_data_prometheus {
+    local url="http://$HOST_IP:$PROMETHEUS_PORT/api/v1/label/__name__/values"
+
+    if curl -s --head  --request  GET "$url" | grep "200 OK" > /dev/null; then
+        echo "#### List of metrics names ####"
+        curl -s "$url" | jq -r '.data[]'
     else
         die $LINENO "Couldn't get data from prometheus"
     fi
diff --git a/devstack/plugin.sh b/devstack/plugin.sh
index 4a464db..5377c50 100644
--- a/devstack/plugin.sh
+++ b/devstack/plugin.sh
@@ -36,7 +36,7 @@ if is_service_enabled prometheus; then
         start_prometheus
         echo_summary "Give time to prometheus to scrape data"
         wait_for_data
-        check_data
+        check_data_prometheus
     fi
 
     if [[ "$1" == "unstack" ]]; then
@@ -80,7 +80,7 @@ if is_service_enabled node_exporter; then
         start_node_exporter
         echo_summary "Give time to node_exporter to push metrics"
         wait_for_data
-        check_data
+        check_data_node_exporter
     fi
 
     if [[ "$1" == "unstack" ]]; then