Operator Day 2022 - Slide Gist

Operator Day 2022 - Slides Gist

 ~Operator Day 2022 - Slides Gist

silde22

# Copyright 2021 Canonical Ltd.
# See LICENSE file for licensing details.
name: zinc-k8s
display-name: Zinc
description: |
  Zinc is a search engine that does full text indexing. It is a lightweight alternative to
  elasticsearch and runs in less than 100 MB of RAM. It uses bluge as the underlying indexing
  library.

  It is very simple and easy to operate as opposed to elasticsearch which requires a couple dozen
  knobs to understand and tune.

  It is a drop-in replacement for elasticsearch if you are just ingesting data using APIs and
  searching using kibana (Kibana is not supported with zinc. Zinc provides its own UI).
summary: |
  Zinc is a search engine that does full text indexing. It is a lightweight alternative to
  elasticsearch and runs in less than 100 MB of RAM. It uses bluge as the underlying indexing
  library.

containers:
  zinc:
    resource: zinc-image
    mounts:
      - storage: data
        location: /go/bin/data

resources:
  zinc-image:
    type: oci-image
    description: OCI image for zinc
    # Included for simplicity in integration tests
    upstream-source: public.ecr.aws/m5j1b6u0/zinc:latest

storage:
  data:
    type: filesystem
    location: /zinc-data

slide2

# Install/Setup MicroK8s
$ sudo snap install --classic microk8s
$ sudo usermod -aG microk8s $(whoami)
$ sudo microk8s status --wait-ready
$ sudo microk8s enable storage dns ingress
$ sudo snap alias microk8s.kubectl kubectl
$ newgrp microk8s

# Install Charmcraft
$ sudo snap install charmcraft

# Install Juju
$ sudo snap install juju --classic

# Bootstrap MicroK8s
$ juju bootstrap microk8s uk8s
$ juju add-model development

juju bootstrap microk8s micro
juju add-model development

slide23

#!/usr/bin/env python3
# Copyright 2021 Canonical Ltd.
# See LICENSE file for licensing details.
#
# Learn more at: https://juju.is/docs/sdk

"""Charmed Operator for Zinc; a lightweight elasticsearch alternative."""

import logging

from ops.charm import CharmBase
from ops.main import main
from ops.model import ActiveStatus

logger = logging.getLogger(__name__)


class ZincCharm(CharmBase):
    """Charmed Operator for Zinc; a lightweight elasticsearch alternative."""

    def __init__(self, *args):
        super().__init__(*args)
        self.framework.observe(self.on.zinc_pebble_ready, self._on_zinc_pebble_ready)

    def _on_zinc_pebble_ready(self, event):
        """Define and start a workload using the Pebble API."""
        # Get a reference the container attribute on the PebbleReadyEvent
        container = event.workload
        # Define an initial Pebble layer configuration
        pebble_layer = {
            "summary": "zinc layer",
            "description": "pebble config layer for zinc",
            "services": {
                "zinc": {
                    "override": "replace",
                    "summary": "zinc",
                    "command": "/go/bin/zinc",
                    "startup": "enabled",
                    "environment": {
                        "DATA_PATH": "/go/bin/data",
                        "FIRST_ADMIN_USER": "admin",
                        "FIRST_ADMIN_PASSWORD": "#Pa55word!",
                    },
                }
            },
        }
        container.add_layer("zinc", pebble_layer, combine=True)
        container.autostart()
        self.unit.status = ActiveStatus()


if __name__ == "__main__":
    main(ZincCharm)

slide24

# ---- BUILD & DEPLOY
# Build the charm
$ charmcraft pack
# Deploy the charm
$ juju deploy ./zinc-k8s_*.charm --resource zinc-image=public.ecr.aws/m5j1b6u0/zinc:latest

# ---- CHECK STATUS
# Check the Juju status
$ watch -n1 --color juju status --color

# ---- VERIFY
# You should then be able to browse to http://<address>:4080
# In this example http://10.1.184.215:4080

slide26

# ---- JUJU DEBUG-LOG
# Set the log level to DEBUG for the development model
$ juju model-config logging-config="<root>=WARNING;unit=DEBUG"
# Follow the debug-log
$ juju debug-log

# ---- KUBECTL
$ kubectl -n development get pods
NAME                             READY   STATUS    RESTARTS   AGE
modeloperator-6576fc7b6f-k4mb5   1/1     Running   1          22h
zinc-k8s-0    

slide28

# Copyright 2021 Canonical Ltd.
# See LICENSE file for licensing details.

get-admin-password:
  description: |
    Get the initial admin password for Zinc. This is generated at charm deployment time. If the
    password has been changed using the Zinc UI/API, this will not be valid.

slide29

#!/usr/bin/env python3
# Copyright 2021 Canonical Ltd.
# See LICENSE file for licensing details.

"""Charmed Operator for Zinc; a lightweight elasticsearch alternative."""

import logging
import secrets
import string

from charms.observability_libs.v0.kubernetes_service_patch import KubernetesServicePatch
from ops.charm import ActionEvent, CharmBase, WorkloadEvent
from ops.framework import StoredState
from ops.main import main
from ops.model import ActiveStatus
from ops.pebble import Layer

logger = logging.getLogger(__name__)


class ZincCharm(CharmBase):
    """Charmed Operator for Zinc; a lightweight elasticsearch alternative."""

    _stored = StoredState()

    def __init__(self, *args):
        super().__init__(*args)
        self._stored.set_default(initial_admin_password="")
        self.framework.observe(self.on.zinc_pebble_ready, self._on_zinc_pebble_ready)
        self.framework.observe(self.on.get_admin_password_action, self._on_get_admin_password)

        self._service_patcher = KubernetesServicePatch(self, [(self.app.name, 4080, 4080)])

    def _on_zinc_pebble_ready(self, event: WorkloadEvent):
        """Define and start a workload using the Pebble API."""
        # Get a reference the container attribute on the PebbleReadyEvent
        container = event.workload

        # If we've not got an initial admin password, then generate one
        if not self._stored.initial_admin_password:
            self._stored.initial_admin_password = self._generate_password()

        # Define an initial Pebble layer configuration
        container.add_layer("zinc", self._pebble_layer, combine=True)
        container.autostart()
        self.unit.status = ActiveStatus()

    def _on_get_admin_password(self, event: ActionEvent) -> None:
        """Returns the initial generated password for the admin user as an action response."""
        if not self._stored.initial_admin_password:
            self._stored.initial_admin_password = self._generate_password()
        event.set_results({"admin-password": self._stored.initial_admin_password})

    @property
    def _pebble_layer(self) -> Layer:
        return Layer(
            {
                "services": {
                    "zinc": {
                        "override": "replace",
                        "summary": "zinc",
                        "command": "/go/bin/zinc",
                        "startup": "enabled",
                        "environment": {
                            "DATA_PATH": "/go/bin/data",
                            "FIRST_ADMIN_USER": "admin",
                            "FIRST_ADMIN_PASSWORD": self._stored.initial_admin_password,
                        },
                    }
                },
            }
        )

    def _generate_password(self) -> str:
        """Generates a random 24 character password."""
        chars = string.ascii_letters + string.digits
        return "".join(secrets.choice(chars) for _ in range(24))


if __name__ == "__main__":  # pragma: nocover
    main(ZincCharm, use_juju_for_storage=True)

slide3

# canonical/template-operator
https://github.com/canonical/template-operator

# zinc-k8s-operator
https://github.com/jnsgruk/zinc-k8s-operator

slide30

# ---- BUILD AGAIN
# Build the charm
$ charmcraft pack
# Remove old charm (cannot refresh -- storage)
$ juju remove-application zinc-k8s –destroy-storage
# Refresh the deployment
$ juju deploy ./zinc-k8s_*.charm --resource zinc-image=public.ecr.aws/m5j1b6u0/zinc:v0.1.1
# Check the juju status
$ watch -n1 --color juju status --color

# ---- RUN ACTION
# Run the action
$ juju run-action zinc-k8s/0 get-admin-password --wait
unit-zinc-k8s-0:
  UnitId: zinc-k8s/0
  id: "4"
  results:
    admin-password: axGqZeFWJGlLZH7OpQXCRPM8
  status: completed
# ...