Security: Authenticate to GCR for trivy scans (#72658)

* Authenticate to GCR for trivy scans

# Conflicts:
#	.drone.yml

* verify-starlark

* Change secret

# Conflicts:
#	.drone.yml

scripts/drone/events/cron.star

@@ -24,6 +24,17 @@ def cronjobs():
         grafana_com_nightly_pipeline(),
     ]
 
+def authenticate_gcr_step():
+    return {
+        "name": "authenticate-gcr",
+        "image": "docker:dind",
+        "commands": ["echo $${GCR_CREDENTIALS} | docker login -u _json_key --password-stdin https://us.gcr.io"],
+        "environment": {
+            "GCR_CREDENTIALS": from_secret("gcr_credentials"),
+        },
+        "volumes": [{"name": "docker", "path": "/var/run/docker.sock"}],
+    }
+
 def cron_job_pipeline(cronName, name, steps):
     return {
         "kind": "pipeline",
@@ -41,6 +52,14 @@ def cron_job_pipeline(cronName, name, steps):
             "retries": 3,
         },
         "steps": steps,
+        "volumes": [
+            {
+                "name": "docker",
+                "host": {
+                    "path": "/var/run/docker.sock",
+                },
+            },
+        ],
     }
 
 def scan_docker_image_pipeline(tag):
@@ -58,6 +77,7 @@ def scan_docker_image_pipeline(tag):
         cronName = "nightly",
         name = "scan-" + docker_image + "-image",
         steps = [
+            authenticate_gcr_step(),
             scan_docker_image_unknown_low_medium_vulnerabilities_step(docker_image),
             scan_docker_image_high_critical_vulnerabilities_step(docker_image),
             slack_job_failed_step("grafana-backend-ops", docker_image),
@@ -75,6 +95,7 @@ def scan_build_test_publish_docker_image_pipeline():
         cronName = "nightly",
         name = "scan-build-test-and-publish-docker-images",
         steps = [
+            authenticate_gcr_step(),
             scan_docker_image_unknown_low_medium_vulnerabilities_step("all"),
             scan_docker_image_high_critical_vulnerabilities_step("all"),
             slack_job_failed_step("grafana-backend-ops", "build-images"),
@@ -101,6 +122,8 @@ def scan_docker_image_unknown_low_medium_vulnerabilities_step(docker_image):
         "name": "scan-unknown-low-medium-vulnerabilities",
         "image": aquasec_trivy_image,
         "commands": cmds,
+        "depends_on": ["authenticate-gcr"],
+        "volumes": [{"name": "docker", "path": "/var/run/docker.sock"}],
     }
 
 def scan_docker_image_high_critical_vulnerabilities_step(docker_image):
@@ -123,6 +146,8 @@ def scan_docker_image_high_critical_vulnerabilities_step(docker_image):
         "name": "scan-high-critical-vulnerabilities",
         "image": aquasec_trivy_image,
         "commands": cmds,
+        "depends_on": ["authenticate-gcr"],
+        "volumes": [{"name": "docker", "path": "/var/run/docker.sock"}],
     }
 
 def slack_job_failed_step(channel, image):

scripts/drone/vault.star

@@ -148,4 +148,9 @@ def secrets():
             "infra/data/ci/grafana-release-eng/grafana-delivery-bot",
             "app-private-key",
         ),
+        vault_secret(
+            "gcr_credentials",
+            "secret/data/common/gcr",
+            "service-account",
+        ),
     ]