monitor.status-page

def status_page(components: Sequence[Component]) -> StatusSummary

@dataclass(frozen=True)
class Component:
    """One row of a status page."""

    name: str
    state: ComponentState

@dataclass(frozen=True)
class StatusSummary:
    """The banner at the top of the page."""

    #: the worst component state
    state: ComponentState
    #: "All systems operational", "Degraded performance", "Partial outage", "Major outage" or "Scheduled maintenance"
    headline: str
    #: names of the components not operational, in input order
    affected: List[str]

from fune.monitor.status_page import status_page  # monitor.status-page@^1

from typing import List, Sequence, Set

from .monitor_status_page_types import Component, StatusSummary

# Worst last. Maintenance ranks below every real problem: an outage elsewhere
# during planned work is still the headline.
_RANK = ["operational", "maintenance", "degraded", "partial-outage", "major-outage"]
_HEADLINE = {
    "operational": "All systems operational",
    "maintenance": "Scheduled maintenance",
    "degraded": "Degraded performance",
    "partial-outage": "Partial outage",
    "major-outage": "Major outage",
}


def status_page(components: Sequence[Component]) -> StatusSummary:
    """The banner for a whole status page: the worst component state wins."""
    if len(components) == 0:
        raise ValueError("components must not be empty")
    seen: Set[str] = set()
    worst = 0
    affected: List[str] = []
    for c in components:
        if c.name == "":
            raise ValueError("component name must not be empty")
        if c.name in seen:
            raise ValueError("duplicate component name: %s" % (c.name,))
        seen.add(c.name)
        if c.state not in _RANK:
            raise ValueError("unknown component state: %s" % (c.state,))
        rank = _RANK.index(c.state)
        worst = max(worst, rank)
        if rank > 0:
            affected.append(c.name)
    state = _RANK[worst]
    return StatusSummary(state=state, headline=_HEADLINE[state], affected=affected)

Install

fune build

With that line in your source, in a Python project (language python in fune.project), fune build resolves it and its 1 dependency, pins them in fune.lock, downloads only the Python package of each, and builds the code above into your project’s .fune/build, one readable file per capability with a header linking back here. Or pin a range in fune.project and build in one step:

fune add monitor.status-page

The manifest, vectors and README with only the Python implementation. Install it without the registry with fune add ./monitor.status-page-1.0.0-python.fune, or fetch it from a terminal with fune pull monitor.status-page@1.0.0:python.

The whole function, every language, is one file too: monitor.status-page-1.0.0.fune, 13,298 bytes, sha256 d9db4b93cf50e564dd970817a68ff904dff2740c164187a2bb320660670351ae. It installs into a project of any language.

# fune: before monitor.status-page

# fune: after monitor.status-page

# fune: replace monitor.component-state in monitor.status-page

# fune: step monitor.status-page after <n|label>

More from the author

major-outage > partial-outage > degraded > maintenance > operational

| state | headline | | --- | --- | | `major-outage` | Major outage | | `partial-outage` | Partial outage | | `degraded` | Degraded performance | | `maintenance` | Scheduled maintenance | | `operational` | All systems operational |

Maintenance ranks below every real problem: a component that is degraded while another is under planned maintenance is the news. It still ranks above operational, and a component under maintenance is listed in `affected`, so readers know it may be unavailable.

`affected` is in input order (the order the page lists its components), not sorted by severity, so it matches the page.

## Decisions

- **No components is an error**, not "All systems operational": a page with nothing on it is a configuration mistake, and claiming all is well would hide it. - **Names must be unique and non-empty.** Duplicates would make `affected` ambiguous. Names are compared exactly, so `api` and `API` are different. - States use the registry's kebab-case (`major-outage`); Statuspage's API spelling (`major_outage`) is refused rather than guessed at.

## Errors

- `components must not be empty` - `component name must not be empty` - `duplicate component name: X` - `unknown component state: X`

## Sources

- Atlassian Support, "Show service status with components": https://support.atlassian.com/statuspage/docs/show-service-status-with-components/ - Statuspage Status API, page status and component statuses: https://metastatuspage.com/api. Statuspage's own overall indicator is `none | minor | major | critical`; this capability reports the worst component state instead, which says more and maps onto it directly.

Files