nixos/prometheus/pushgateway: add module and test

1 files changed, 40 insertions, 7 deletions

diff --git a/nixos/tests/prometheus-2.nix b/nixos/tests/prometheus-2.nix
index 5a4d8668cb87..d7035d49ad4d 100644
--- a/nixos/tests/prometheus-2.nix
+++ b/nixos/tests/prometheus-2.nix
@@ -3,15 +3,29 @@ import ./make-test.nix {
 
   nodes = {
     one = { pkgs, ... }: {
+      environment.systemPackages = [ pkgs.jq ];
       services.prometheus2 = {
         enable = true;
-        scrapeConfigs = [{
-          job_name = "prometheus";
-          static_configs = [{
-            targets = [ "127.0.0.1:9090" ];
-            labels = { instance = "localhost"; };
-          }];
-        }];
+        scrapeConfigs = [
+          {
+            job_name = "prometheus";
+            static_configs = [
+              {
+                targets = [ "127.0.0.1:9090" ];
+                labels = { instance = "localhost"; };
+              }
+            ];
+          }
+          {
+            job_name = "pushgateway";
+            scrape_interval = "1s";
+            static_configs = [
+              {
+                targets = [ "127.0.0.1:9091" ];
+              }
+            ];
+          }
+        ];
         rules = [
           ''
             groups:
@@ -22,6 +36,12 @@ import ./make-test.nix {
           ''
         ];
       };
+      services.prometheus.pushgateway = {
+        enable = true;
+        persistMetrics = true;
+        persistence.interval = "1s";
+        stateDir = "prometheus-pushgateway";
+      };
     };
   };
 
@@ -30,5 +50,18 @@ import ./make-test.nix {
     $one->waitForUnit("prometheus2.service");
     $one->waitForOpenPort(9090);
     $one->succeed("curl -s http://127.0.0.1:9090/metrics");
+
+    # Let's test if pushing a metric to the pushgateway succeeds
+    # and whether that metric gets ingested by prometheus.
+    $one->waitForUnit("pushgateway.service");
+    $one->succeed(
+      "echo 'some_metric 3.14' | " .
+      "curl --data-binary \@- http://127.0.0.1:9091/metrics/job/some_job");
+    $one->waitUntilSucceeds(
+      "curl -sf 'http://127.0.0.1:9090/api/v1/query?query=some_metric' " .
+      "| jq '.data.result[0].value[1]' | grep '\"3.14\"'");
+
+    # Let's test if the pushgateway persists metrics to the configured location.
+    $one->waitUntilSucceeds("test -e /var/lib/prometheus-pushgateway/metrics");
   '';
 }