coal-mine 0.1

Example commands

$ coal-mine &
[1] 7564
$ curl 'http://coal-mine-server/coal-mine/v1/canary/create?name=My+First+Canary&periodicity=3600'
{
    "status": "ok",
    "canary": {
        "deadline": "2015-03-19T02:08:44.885182",
        "id": "fbkvlsby",
        "paused": false,
        "description": "",
        "periodicity": 3600,
        "name": "My First Canary",
        "slug": "my-first-canary",
        "emails": [],
        "history": [
            [
                "2015-03-19T01:08:44.885182",
                "Snitch created"
            ]
        ],
        "late": false
    }
}
$ curl 'http://coal-mine-server/fbkvlsby?comment=short+form+trigger+url'
{
    "recovered": false,
    "unpaused": false,
    "status": "ok"
}
$ curl 'http://coal-mine-server/coal-mine/v1/canary/trigger?slug=my-first-canary&comment=long+form+trigger+url'
{
    "recovered": false,
    "unpaused": false,
    "status": "ok"
}
$ curl 'http://coal-mine-server/coal-mine/v1/canary/get?name=My+First+Canary'
{
    "canary": {
        "paused": false,
        "name": "My First Canary",
        "history": [
            [
                "2015-03-19T01:11:56.408000",
                "Triggered (long form trigger url)"
            ],
            [
                "2015-03-19T01:10:42.608000",
                "Triggered (short form trigger url)"
            ],
            [
                "2015-03-19T01:08:44.885000",
                "Snitch created"
            ]
        ],
        "emails": [],
        "id": "fbkvlsby",
        "late": false,
        "slug": "my-first-canary",
        "deadline": "2015-03-19T02:11:56.408000",
        "periodicity": 3600,
        "description": ""
    },
    "status": "ok"
}

All API endpoints are fully documented below.

Watching a cron job

0 0 * * * my-backup-script.sh && (curl http://coal-mine-server/fbkvlsby &>/dev/null)

Create canary

Endpoint: /coal-mine/v1/canary/create

Side effects:

Adds canary to database. Creates history record at current time with “Canary created” as its comment. Sets deadline to current time plus periodicity, unless “paused” was specified.

Required parameters:

• name

• periodicity

• auth_key (if authentication is enabled in the server)

Optional parameters:

• description - empty if unspecified

• email - specify multiple times for multiple addresses; no notifications if unspecified

• paused - allows canary to be created already in paused state

Response is the same as shown for get().

Delete canary

Endpoint: /coal-mine/v1/canary/delete

Required parameters:

• name, id, or slug

• auth_key

Response:

{'status': 'ok'}

Update canary

Endpoint: /coal-mine/v1/canary/update

Side effects:

Updates the specified canary attributes. Updates deadline to latest history timestamp plus periodicity if periodicity is updated and canary is unpaused, and sets late state if new deadline is before now. Sends notification if canary goes from not late to late or vice versa.

Required parameters:

• id or slug (not name, which should only be specified to update the name and slug)

• auth_key

Optional parameters:

• name

• periodicity

• description

• email

Response is the same as shown for get().

Get canary

Endpoint: /coal-mine/v1/canary/get

Required parameters:

• name, id, or slug

• auth_key

Response:

{'status': 'ok',
 'canary': {'name': name,
           'description': description,
           'id': identifier,
           'slug': slug,
           'periodicity': seconds,
           'emails': [address, ...],
           'late': boolean,
           'paused': boolean,
           'deadline': 'YYYY-MM-DDTHH:MM:SSZ',
           'history': [['YYYY-MM-DDTHH:MM:SSZ', comment], ...]}}

List canaries

Endpoint: /coal-mine/v1/canary/list

Required parameters:

• auth_key

Optional parameters:

• verbose - include all query output for each canary

• paused - boolean, whether to list paused / unpaused canaries only

• late - boolean, whether to list late / timely canaries only

Response:

{'status': 'ok',
 'canaries': [{'name': name,
             'id': identifier},
            ...]}

If “verbose” is true, then the JSON for each canary includes all the fields shown above, not just the name and identifier.

Trigger canary

Endpoint: /coal-mine/v1/canary/trigger

Also: /identifier, in which case the “id” parameter is implied

Side effects:

Sets late state to false. Sets deadline to now plus periodicity. Adds history record. Prunes history records. Unpauses canary. Generates notification email if canary was previously late.

Required parameters:

• name, id, or slug

• auth_key

Optional parameters:

• comment - stored in history with trigger record

Response:

{'status': 'ok', 'recovered': boolean, 'unpaused': boolean}

• recovered - indicates whether the canary was previously late before this trigger

• unpaused - indicates whether the canary was previously paused before this trigger

Pause canary

Endpoint: /coal-mine/v1/canary/pause

Side effects:

Clears deadline. Sets late state to false if necessary. Pauses canary. Adds history record about pause. Prunes history records.

Required parameters:

• name, id, or slug

• auth_key

Optional parameters:

• comment

Response is the same as shown for get().

Unpause canary

Endpoint /coal-mine/v1/canary/unpause

Side effects:

Sets deadline to now plus periodicity. Unpauses canary. Adds history record about unpause. Prunes history records.

Required parameters:

• name, id, or slug

• auth_key

Optional parameters:

• comment

Response is the same as shown for get().

Development philosophy

Use Python.

Do one, simple thing well. There are several similar projects out there that do more than this project attempts to do.

Make the implementation as simple and straightforward as possible. The code should be small. What everything does should be obvious from reading it.

Minimize external dependencies. If something is simple and straightforward to do ourselves, don’t use a third-party package just for the sake of using a third-party package.

Data model

For each canary, we store:

• name

• description

• slug - the name, lower-cased, with spaces and underscores converted to hyphens and other non-alphanumeric characters removed

• random identifier, guaranteed unique

• periodicity - maximum number of seconds that can elapse before a canary is late.

• notification email address(es)

• late state (boolean)

• paused state (boolean)

• deadline for next update

• history of triggers, pruned when (>1000 or (>100 and older than one week)

Timestamps in database are UTC.

To Do

(Pull requests welcome!)

Other storage engines.

Other notification mechanisms.

More smtplib configuration options in INI file.

Unit tests would be nice.

Web UI.

Links to Web UI in email notifications.

Repeat notifications if a canary remains late for an extended period of time? Not even sure I want this.

Better authentication?

Support time-zone localization of displayed timestamps.

SSL support in server