Add refresh v3 implementation (#411)

Does not include migration for refreshing from v2 (currently on stable)

This PR branch only supports refreshing to/from mysql-router-k8s charm
code with refresh v3

Uses `charm-refresh` Python package:
https://github.com/canonical/charm-refresh

Discussed with @paulomach—we will merge this & release to edge to enable
mysql-router monorepo migration, but we will not promote to
beta/candidate/stable until the v2 to v3 migration is implemented (once
a decision on specification DA202 is made)

Mostly the same as
canonical/mysql-router-operator#241 (plus
canonical/mysql-router-operator#279)

Author: carlcsaposs-canonical

.github/workflows/integration_test.yaml

@@ -84,10 +84,10 @@ jobs:
     needs:
       - collect-integration-tests
     runs-on: ${{ matrix.job.runner }}
-    timeout-minutes: 217  # Sum of steps `timeout-minutes` + 5
+    timeout-minutes: 226  # Sum of steps `timeout-minutes` + 5
     steps:
       - name: Free up disk space
-        timeout-minutes: 1
+        timeout-minutes: 10
         run: |
           printf '\nDisk usage before cleanup\n'
           df --human-readable

.github/workflows/release.yaml

@@ -1,6 +1,6 @@
 # Copyright 2023 Canonical Ltd.
 # See LICENSE file for licensing details.
-name: Release to Charmhub
+name: Release to Charmhub edge
 
 on:
   push:
@@ -13,18 +13,29 @@ on:
       - '.github/workflows/sync_docs.yaml'
 
 jobs:
+  tag:
+    name: Create charm refresh compatibility version git tag
+    uses: canonical/data-platform-workflows/.github/workflows/[email protected]
+    with:
+      track: '8.0'
+    permissions:
+      contents: write  # Needed to create git tag
+
   ci-tests:
+    needs:
+      - tag
     uses: ./.github/workflows/ci.yaml
     permissions:
       contents: write  # Needed for Allure Report
 
   release:
     name: Release charm
     needs:
+      - tag
       - ci-tests
     uses: canonical/data-platform-workflows/.github/workflows/[email protected]
     with:
-      track: '8.0'
+      track: ${{ needs.tag.outputs.track }}
       artifact-prefix: ${{ needs.ci-tests.outputs.artifact-prefix }}
     secrets:
       charmhub-token: ${{ secrets.CHARMHUB_TOKEN }}

actions.yaml

@@ -1,21 +1,61 @@
 # Copyright 2023 Canonical Ltd.
 # See LICENSE file for licensing details.
 
-resume-upgrade:
-  description: Upgrade remaining units (after you manually verified that upgraded units are healthy).
+pre-refresh-check:
+  description: Check if charm is ready to refresh
+  additionalProperties: false
+force-refresh-start:
+  description: |
+    Potential of data loss and downtime
+
+    Force refresh of first unit
+
+    Must run with at least one of the parameters `=false`
   params:
-    force:
+    check-compatibility:
+      type: boolean
+      default: true
+      description: |
+        Potential of data loss and downtime
+
+        If `false`, force refresh if new version of Router and/or charm is not compatible with previous version
+    run-pre-refresh-checks:
       type: boolean
-      default: false
+      default: true
       description: |
-        Potential of *data loss* and *downtime*
-        
-        Force upgrade of next unit.
-        
-        Use to
-        - force incompatible upgrade and/or
-        - continue upgrade if 1+ upgraded units have non-active status
-  required: []
+        Potential of data loss and downtime
+
+        If `false`, force refresh if app is unhealthy or not ready to refresh (and unit status shows "Pre-refresh check failed")
+    check-workload-container:
+      type: boolean
+      default: true
+      description: |
+        Potential of data loss and downtime during and after refresh
+
+        If `false`, allow refresh to Router container version that has not been validated to work with the charm revision
+  additionalProperties: false
+resume-refresh:
+  description: |
+    Refresh next unit(s) (after you have manually verified that refreshed units are healthy)
+
+    If the `pause-after-unit-refresh` config is set to `all`, this action will refresh the next unit.
+
+    If `pause-after-unit-refresh` is set to `first`, this action will refresh all remaining units.
+    Exception: if automatic health checks fail after a unit has refreshed, the refresh will pause.
+
+    If `pause-after-unit-refresh` is set to `none`, this action will have no effect unless it is called with `check-health-of-refreshed-units` as `false`.
+  params:
+    check-health-of-refreshed-units:
+      type: boolean
+      default: true
+      description: |
+        Potential of data loss and downtime
+
+        If `false`, force refresh (of next unit) if 1 or more refreshed units are unhealthy
+
+        Warning: if first unit to refresh is unhealthy, consider running `force-refresh-start` action on that unit instead of using this parameter.
+        If first unit to refresh is unhealthy because compatibility checks, pre-refresh checks, or workload container checks are failing, this parameter is more destructive than the `force-refresh-start` action.
+  additionalProperties: false
 
 set-tls-private-key:
   description:

charm_version

@@ -84,19 +84,21 @@ parts:
   files:
     plugin: dump
     source: .
+    after:
+      - poetry-deps  # Ensure poetry is installed
     build-packages:
       - git
     override-build: |
-      # Workaround to add unique identifier (git hash) to charm version while specification
-      # DA053 - Charm versioning
-      # (https://docs.google.com/document/d/1Jv1jhWLl8ejK3iJn7Q3VbCIM9GIhp8926bgXpdtx-Sg/edit?pli=1)
-      # is pending review.
-      python3 -c 'import pathlib; import shutil; import subprocess; git_hash=subprocess.run(["git", "describe", "--always", "--dirty"], capture_output=True, check=True, encoding="utf-8").stdout; file = pathlib.Path("charm_version"); shutil.copy(file, pathlib.Path("charm_version.backup")); version = file.read_text().strip(); file.write_text(f"{version}+{git_hash}")'
+      # Set `charm_version` in refresh_versions.toml from git tag
+      # Create venv in `..` so that git working tree is not dirty
+      python3 -m venv ../refresh-version-venv
+      source ../refresh-version-venv/bin/activate
+      poetry install --only build-refresh-version
+      write-charm-version
 
       craftctl default
     stage:
       - LICENSE
-      - charm_version
-      - workload_version
+      - refresh_versions.toml
       - scripts
       - templates

charmcraft.yaml

@@ -15,3 +15,11 @@ options:
       and managed by the charm.
     type: string
     default: "{}"
+
+  pause-after-unit-refresh:
+    description: |
+      Wait for manual confirmation to resume refresh after these units refresh
+
+      Allowed values: "all", "first", "none"
+    type: string
+    default: first

config.yaml

@@ -49,11 +49,8 @@ requires:
 peers:
   cos:
     interface: cos
-  upgrade-version-a:
-    # Relation versioning scheme:
-    # DA056 - Upgrading in-place upgrade protocol
-    # https://docs.google.com/document/d/1H7qy5SAwLiCOKO9xMQJbbQP5_-jGV6Lhi-mJOk4gZ08/edit
-    interface: upgrade
+  refresh-v-three:
+    interface: refresh
   mysql-router-peers:
     interface: mysql_router_peers
 resources:

metadata.yaml

@@ -14,6 +14,7 @@ tenacity = "^9.1.2"
 jinja2 = "^3.1.6"
 poetry-core = "^2.1.3"
 requests = "^2.32.4"
+charm-refresh = "^3.1.0.2"
 
 [tool.poetry.group.charm-libs.dependencies]
 # data_platform_libs/v0/data_interfaces.py
@@ -58,6 +59,14 @@ pyyaml = "^6.0.2"
 tenacity = "^9.1.2"
 allure-pytest = "^2.14.3"
 allure-pytest-default-results = "^0.1.3"
+tomli = "^2.2.1"
+tomli-w = "^1.2.0"
+
+[tool.poetry.group.build-refresh-version]
+optional = true
+
+[tool.poetry.group.build-refresh-version.dependencies]
+charm-refresh-build-version = "^0.4.0"
 
 [tool.coverage.run]
 branch = true

poetry.lock

@@ -0,0 +1,4 @@
+# https://canonical-charm-refresh.readthedocs-hosted.com/latest/refresh-versions-toml/
+
+charm_major = 1
+workload = "8.0.42"