Rewrite the scripts in python

The scripts were written in bash. Using bash became quite unwieldy.

Python by nature can deal well with yaml and is thus better suited
in dealing with the yaml-based configuration files. This change
rewrites the original scripts staying as close as possible to the
original ones.

Right now, the python scripts call subprocesses a lot to work with
the tools, which were already used before. At least for yaml-
templating there may be better tools that have a python integration,
which could be used in the future.

Change-Id: Ida16318445a05dcfdada9c7a56a391e4827f02e7
19 files changed
tree: 68e494e2749f186e868c563e03954b8757bcb988
  1. .github/
  2. cfgmgr/
  3. charts/
  4. dashboards/
  5. documentation/
  6. promtail/
  7. subcommands/
  8. .gitignore
  9. .pylintrc
  10. config.yaml
  13. Pipfile
  14. Pipfile.lock

Monitoring setup for Gerrit

This project provides a setup for monitoring Gerrit instances. The setup is based on Prometheus and Grafana running in Kubernetes. In addition, logging will be provided by Grafana Loki.

The setup is provided as a helm chart. It can be installed using Helm (This README expects Helm version 3.0 or higher).

The charts used in this setup are the chart provided in the open source and can be found on GitHub:

This project just provides values.yaml-files that are already configured to work with the metrics-reporter-prometheus-plugin of Gerrit to make the setup easier.



  • Gerrit
    Gerrit requires the following plugin to be installed:

  • Promtail
    Promtail has to be installed with access to the logs-directory in the Gerrit- site. A configuration-file for Promtail will be provided in this setup. Find the documentation for Promtail here

  • Helm
    To install and configure Helm, follow the official guide.

  • ytt
    ytt is a templating tool for yaml-files. It is required for some last moment configuration. Installation instructions can be found here.

  • Pipenv
    Pipenv sets up a virtual python environment and installs required python packages based on a lock-file, ensuring a deterministic Python environment. Instruction on how Pipenv can be installed, can be found here


  • Kubernetes Cluster
    A cluster with at least 3 free CPUs and 4 GB of free memory are required. In addition persistent storage of about 30 GB will be used.

  • Ingress Controller
    The charts currently expect a Nginx ingress controller to be installed in the cluster.

  • Object store
    Loki will store the data chunks in an object store. This store has to be callable via the S3 API.

Add dashboards

To have dashboards deployed automatically during installation, export the dashboards to a JSON-file or create JSON-files describing the dashboards in another way. Put these dashboards into the ./dashboards-directory of this repository. During the installation the dashboards will be added to a configmap and with this automatically installed to Grafana.


While this project is supposed to provide a specialized and opinionated monitoring setup, some configuration is highly dependent on the specific installation. These options have to be configured in the ./config.yaml before installing and are listed here:

gerritServers.[0].hostHostname (incl. port, if required) of the Gerrit server to monitor
gerritServers.[0].usernameUsername of Gerrit user with ‘View Metrics’ capabilities
gerritServers.[0].passwordPassword of Gerrit user with ‘View Metrics’ capabilities
namespaceThe namespace the charts are installed to
tls.skipVerifyWhether to skip TLS certificate verification
tls.caCertCA certificate used for TLS certificate verification
promtail.storagePathPath to directory, where Promtail is allowed to save files (e.g. positions.yaml)
promtail.logPathPath to directory containing the Gerrit logs (e.g. /var/gerrit/logs)
prometheus.server.hostPrometheus server ingress hostname
prometheus.server.usernameUsername for Prometheus
prometheus.server.passwordPassword for Prometheus
prometheus.server.tls.certTLS certificate
prometheus.server.tls.keyTLS key
prometheus.alertmanager.slack.apiUrlAPI URL of the Slack Webhook
prometheus.alertmanager.slack.channelChannel to which the alerts should be posted
loki.hostLoki ingress hostname
loki.usernameUsername for Loki
loki.passwordPassword for Loki
loki.s3.protocolProtocol used for communicating with S3
loki.s3.hostHostname of the S3 object store
loki.s3.accessTokenThe EC2 accessToken used for authentication with S3
loki.s3.secretThe secret associated with the accessToken
loki.s3.bucketThe name of the S3 bucket
loki.s3.regionThe region in which the S3 bucket is hosted
loki.tls.certTLS certificate
loki.tls.keyTLS key
grafana.hostGrafana ingress hostname
grafana.tls.certTLS certificate
grafana.tls.keyTLS key
grafana.admin.usernameUsername for the admin user
grafana.admin.passwordPassword for the admin user
grafana.ldap.enabledWhether to enable LDAP
grafana.ldap.hostHostname of LDAP server
grafana.ldap.portPort of LDAP server (Has to be quoted!)
grafana.ldap.passwordPassword of LDAP server
grafana.ldap.bind_dnBind DN (username) of the LDAP server
grafana.ldap.accountBasesList of base DNs to discover accounts (Has to have the format "['a', 'b']")
grafana.ldap.groupBasesList of base DNs to discover groups (Has to have the format "['a', 'b']")
grafana.dashboards.editableWhether dashboards can be edited manually in the UI


The configuration file contains secrets. Thus, to be able to share the configuration, e.g. with the CI-system, it is meant to be encrypted. The encryption is explained here.

The install-command will decrypt the file before templating, if it was encrypted with sops.


Before using the script, set up a python environment using pipenv install.

The installation will use the environment of the current shell. Thus, make sure that the path for ytt, kubectland helm are set. Also the KUBECONFIG-variable has to be set to point to the kubeconfig of the target Kubernetes cluster.

This project provides a script to quickly install the monitoring setup. To use it, run:

pipenv run python ./ \
  --config config.yaml \
  install \
  [--output ./dist] \
  [--dryrun] \

The command will use the given configuration (--config/-c) to create the final files in the directory given by --output/-o (default ./dist) and install/update the Kubernetes resources and charts, if the --dryrun/-d flag is not set. If the --update-repo-flag is used, the helm repository will be updated before installing the helm charts. This is for example required, if a chart version was updated.

Configure Promtail

Promtail has to be installed with access to the directory containing the Gerrit logs, e.g. on the same host. The installation as described above will create a configuration file for Promtail, which can be found in ./dist/promtail.yaml. Use it to configure Promtail by using the -config.file=./dist/promtail.yaml- parameter, when starting Promtail. Using the Promtail binary directly this would result in the following command:

$PATH_TO_PROMTAIL/promtail \
  -config.file=./dist/promtail.yaml \

The -client.external-labels=host=$(hostname) option will add a label to each job that contains the hostname. This is useful, if multiple host are scraped for logs and only one Grafana is used to view the logs.

If TLS-verification is activated, the CA-certificate used for verification (usually the one configured for tls.caCert) has to be present in the directory configured for promtail.storagePath in the config.yaml and has to be called

The Promtail configuration provided here expects the logs to be available in JSON-format. This can be configured by setting log.jsonLogging = true in the gerrit.config.


To remove the Prometheus chart from the cluster, run

helm uninstall prometheus --namespace $NAMESPACE
helm uninstall loki --namespace $NAMESPACE
helm uninstall grafana --namespace $NAMESPACE
kubectl delete -f ./dist/configuration

To also release the volumes, run

kubectl delete -f ./dist/storage

NOTE: Doing so, all data, which was not backed up will be lost!

Remove the namespace:

kubectl delete -f ./dist/namespace.yaml

The ./ uninstall-script will automatically remove the charts installed in the configured namespace and delete the namespace as well:

pipenv run python ./ \
  --config config.yaml \