Add charm tracing

[mmkay]

Issue

This PR adds charm tracing support to Grafana charm.

Solution

Use charm_tracing library with OTLP/HTTP(S) protocol.

Testing Instructions

Use the following bundles to test: Without TLS:

bundle: kubernetes
applications:
  alertmanager:
    charm: alertmanager-k8s
    channel: stable
    revision: 96
    series: focal
    resources:
      alertmanager-image: 84
    scale: 1
    constraints: arch=amd64
    storage:
      data: kubernetes,1,1024M
    trust: true
  catalogue:
    charm: catalogue-k8s
    channel: stable
    revision: 33
    series: focal
    resources:
      catalogue-image: 32
    scale: 1
    options:
      description: "Canonical Observability Stack Lite, or COS Lite, is a light-weight,
        highly-integrated, \nJuju-based observability suite running on Kubernetes.\n"
      tagline: Model-driven Observability Stack deployed with a single command.
      title: Canonical Observability Stack
    constraints: arch=amd64
    trust: true
  grafana-k8s:
    charm: local:grafana-k8s-0
    series: focal
    scale: 1
    constraints: arch=amd64
    storage:
      database: kubernetes,1,1024M
    trust: true
  loki:
    charm: loki-k8s
    channel: stable
    revision: 105
    series: focal
    resources:
      loki-image: 88
    scale: 1
    constraints: arch=amd64
    storage:
      active-index-directory: kubernetes,1,1024M
      loki-chunks: kubernetes,1,1024M
    trust: true
  prometheus:
    charm: prometheus-k8s
    channel: stable
    revision: 159
    series: focal
    resources:
      prometheus-image: 134
    scale: 1
    constraints: arch=amd64
    storage:
      database: kubernetes,1,1024M
    trust: true
  tempo-k8s:
    charm: tempo-k8s
    channel: candidate
    revision: 22
    resources:
      tempo-image: 14
    scale: 1
    constraints: arch=amd64
    storage:
      data: kubernetes,1,1024M
  traefik:
    charm: traefik-k8s
    channel: stable
    revision: 166
    series: focal
    resources:
      traefik-image: 155
    scale: 1
    constraints: arch=amd64
    storage:
      configurations: kubernetes,1,1024M
    trust: true
relations:
- - traefik:ingress-per-unit
  - prometheus:ingress
- - traefik:ingress-per-unit
  - loki:ingress
- - traefik:ingress
  - alertmanager:ingress
- - prometheus:alertmanager
  - alertmanager:alerting
- - loki:alertmanager
  - alertmanager:alerting
- - prometheus:metrics-endpoint
  - traefik:metrics-endpoint
- - prometheus:metrics-endpoint
  - alertmanager:self-metrics-endpoint
- - prometheus:metrics-endpoint
  - loki:metrics-endpoint
- - catalogue:ingress
  - traefik:ingress
- - catalogue:catalogue
  - prometheus:catalogue
- - catalogue:catalogue
  - alertmanager:catalogue
- - tempo-k8s:tracing
  - grafana-k8s:tracing
- - tempo-k8s:grafana-source
  - grafana-k8s:grafana-source
- - traefik:traefik-route
  - grafana-k8s:ingress

With TLS:

bundle: kubernetes
applications:
  alertmanager:
    charm: alertmanager-k8s
    channel: stable
    revision: 96
    series: focal
    resources:
      alertmanager-image: 84
    scale: 1
    constraints: arch=amd64
    storage:
      data: kubernetes,1,1024M
    trust: true
  catalogue:
    charm: catalogue-k8s
    channel: stable
    revision: 33
    series: focal
    resources:
      catalogue-image: 32
    scale: 1
    options:
      description: "Canonical Observability Stack Lite, or COS Lite, is a light-weight,
        highly-integrated, \nJuju-based observability suite running on Kubernetes.\n"
      tagline: Model-driven Observability Stack deployed with a single command.
      title: Canonical Observability Stack
    constraints: arch=amd64
    trust: true
  grafana-k8s:
    charm: local:grafana-k8s-0
    series: focal
    scale: 1
    constraints: arch=amd64
    storage:
      database: kubernetes,1,1024M
    trust: true
  loki:
    charm: loki-k8s
    channel: stable
    revision: 105
    series: focal
    resources:
      loki-image: 88
    scale: 1
    constraints: arch=amd64
    storage:
      active-index-directory: kubernetes,1,1024M
      loki-chunks: kubernetes,1,1024M
    trust: true
  prometheus:
    charm: prometheus-k8s
    channel: stable
    revision: 159
    series: focal
    resources:
      prometheus-image: 134
    scale: 1
    constraints: arch=amd64
    storage:
      database: kubernetes,1,1024M
    trust: true
  self-signed-certificates:
    charm: self-signed-certificates
    channel: stable
    revision: 72
    scale: 1
    constraints: arch=amd64
  tempo-k8s:
    charm: tempo-k8s
    channel: candidate
    revision: 22
    resources:
      tempo-image: 14
    scale: 1
    constraints: arch=amd64
    storage:
      data: kubernetes,1,1024M
  traefik:
    charm: traefik-k8s
    channel: stable
    revision: 166
    series: focal
    resources:
      traefik-image: 155
    scale: 1
    constraints: arch=amd64
    storage:
      configurations: kubernetes,1,1024M
    trust: true
relations:
- - traefik:ingress-per-unit
  - prometheus:ingress
- - traefik:ingress-per-unit
  - loki:ingress
- - traefik:ingress
  - alertmanager:ingress
- - prometheus:alertmanager
  - alertmanager:alerting
- - loki:alertmanager
  - alertmanager:alerting
- - prometheus:metrics-endpoint
  - traefik:metrics-endpoint
- - prometheus:metrics-endpoint
  - alertmanager:self-metrics-endpoint
- - prometheus:metrics-endpoint
  - loki:metrics-endpoint
- - catalogue:ingress
  - traefik:ingress
- - catalogue:catalogue
  - prometheus:catalogue
- - catalogue:catalogue
  - alertmanager:catalogue
- - self-signed-certificates:certificates
  - grafana-k8s:certificates
- - tempo-k8s:tracing
  - grafana-k8s:tracing
- - tempo-k8s:grafana-source
  - grafana-k8s:grafana-source
- - traefik:traefik-route
  - grafana-k8s:ingress
- - traefik:certificates
  - self-signed-certificates:certificates

Release Notes