grafana: add helper script

Add a helper script and assocated README.rst to explain the
interactive development process.

Depends-On: https://review.opendev.org/c/opendev/grafyaml/+/833212
Change-Id: Ibbc2b116d0c496655a7ce6bb6971e8270ac32647

grafana/README.rst

@@ -0,0 +1,14 @@
+Developing Graphs
+=================
+
+The ``run-grafana.sh`` script in this directory will start a Docker
+container with Grafana listening on port 3000.  It will then load the
+datasources and dashboards in this directory.  Repeated runs of the
+script will re-load the scripts.
+
+You can log into the instance with the username "admin" and password
+"password".  You can then use the Grafana UI to develop graphs.
+
+The "share" icon on the graph in the UI can be used to export a JSON
+file, which your browser will download.  You can copy that to this
+directory (or update existing files) and submit a review.

grafana/run-grafana.sh

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+#!/bin/bash
+
+DOCKER=docker
+GRAFYAML_DIR=$(pwd)
+SECRETS_DIR=$(pwd)/grafana-secrets
+
+if [ ! -d ${SECRETS_DIR} ]; then
+    mkdir -p ${SECRETS_DIR}
+    echo "password" > ${SECRETS_DIR}/admin_password
+    echo "admin" > ${SECRETS_DIR}/admin_user
+    echo "key" > ${SECRETS_DIR}/secret_key
+
+fi
+
+if [[ $(${DOCKER} ps -f "name=grafana-opendev_test" --format '{{.Names}}') \
+        != 'grafana-opendev_test' ]]; then
+
+    echo "Running Grafana"
+
+    ${DOCKER} run -d --rm \
+            --name grafana-opendev_test \
+            -p 3000:3000 \
+            -v ${SECRETS_DIR}:/etc/grafana/secrets \
+            -e GF_AUTH_ANONYMOUS_ENABLED=true \
+            -e GF_USER_ALLOW_SIGN_UP=false \
+            -e GF_SECURITY_ADMIN_PASSWORD__FILE=/etc/grafana/secrets/admin_password \
+            -e GF_SECURITY_ADMIN_USER__FILE=/etc/grafana/secrets/admin_user \
+            -e GF_SECURITY_SECRET_KEY__FILE=/etc/grafana/secrets/secret_key \
+            docker.io/grafana/grafana-oss
+
+    echo "Grafana listening on :3000"
+fi
+
+echo "Reloading dashboards"
+
+${DOCKER} run --rm -t --network=host \
+          -e 'GRAFANA_URL=http://admin:password@localhost:3000' \
+          -v ${GRAFYAML_DIR}:/grafana:ro \
+          opendevorg/grafyaml