GitHub - nzsambo/gatus: ⛑ Gatus

Gatus is a health dashboard that gives you the ability to monitor your services using HTTP, ICMP, TCP, and even DNS queries as well as evaluate the result of said queries by using a list of conditions on values like the status code, the response time, the certificate expiration, the body and many others. The icing on top is that each of these health checks can be paired with alerting via Slack, PagerDuty, Discord, Twilio and more.

I personally deploy it in my Kubernetes cluster and let it monitor the status of my core applications: https://status.twin.sh/

Quick start

docker run -p 8080:8080 --name gatus twinproduction/gatus

For more details, see Usage

Have any feedback or want to share your good/bad experience with Gatus? Feel free to email me at feedback@gatus.io

Why Gatus?

Before getting into the specifics, I want to address the most common question:

Why would I use Gatus when I can just use Prometheus’ Alertmanager, Cloudwatch or even Splunk?

Neither of these can tell you that there’s a problem if there are no clients actively calling the endpoint. In other words, it's because monitoring metrics mostly rely on existing traffic, which effectively means that unless your clients are already experiencing a problem, you won't be notified.

Gatus, on the other hand, allows you to configure health checks for each of your features, which in turn allows it to monitor these features and potentially alert you before any clients are impacted.

A sign you may want to look into Gatus is by simply asking yourself whether you'd receive an alert if your load balancer was to go down right now. Will any of your existing alerts be triggered? Your metrics won’t report an increase in errors if no traffic makes it to your applications. This puts you in a situation where your clients are the ones that will notify you about the degradation of your services rather than you reassuring them that you're working on fixing the issue before they even know about it.

Features

The main features of Gatus are:

Highly flexible health check conditions: While checking the response status may be enough for some use cases, Gatus goes much further and allows you to add conditions on the response time, the response body and even the IP address.
Ability to use Gatus for user acceptance tests: Thanks to the point above, you can leverage this application to create automated user acceptance tests.
Very easy to configure: Not only is the configuration designed to be as readable as possible, it's also extremely easy to add a new service or a new endpoint to monitor.
Alerting: While having a pretty visual dashboard is useful to keep track of the state of your application(s), you probably don't want to stare at it all day. Thus, notifications via Slack, Mattermost, Messagebird, PagerDuty, Twilio, Google chat and Teams are supported out of the box with the ability to configure a custom alerting provider for any needs you might have, whether it be a different provider or a custom application that manages automated rollbacks.
Metrics
Low resource consumption: As with most Go applications, the resource footprint that this application requires is negligibly small.
Badges:
Dark mode

Usage

By default, the configuration file is expected to be at config/config.yaml.

You can specify a custom path by setting the GATUS_CONFIG_FILE environment variable.

Here's a simple example:

endpoints:
  - name: website                 # Name of your endpoint, can be anything
    url: "https://twin.sh/health"
    interval: 5m                  # Duration to wait between every status check (default: 60s)
    conditions:
      - "[STATUS] == 200"         # Status must be 200
      - "[BODY].status == UP"     # The json path "$.status" must be equal to UP
      - "[RESPONSE_TIME] < 300"   # Response time must be under 300ms
  - name: example
    url: "https://example.org/"
    interval: 60s
    conditions:
      - "[STATUS] == 200"

This example would look similar to this:

Note that you can also use environment variables in the configuration file (e.g. $DOMAIN, ${DOMAIN})

If you want to test it locally, see Docker.

Configuration

Parameter	Description	Default
`debug`	Whether to enable debug logs.	`false`
`metrics`	Whether to expose metrics at /metrics.	`false`
`storage`	Storage configuration	`{}`
`endpoints`	List of endpoints to monitor.	Required `[]`
`endpoints[].enabled`	Whether to monitor the endpoint.	`true`
`endpoints[].name`	Name of the endpoint. Can be anything.	Required `""`
`endpoints[].group`	Group name. Used to group multiple endpoints together on the dashboard. See Endpoint groups.	`""`
`endpoints[].url`	URL to send the request to.	Required `""`
`endpoints[].method`	Request method.	`GET`
`endpoints[].conditions`	Conditions used to determine the health of the endpoint. See Conditions.	`[]`
`endpoints[].interval`	Duration to wait between every status check.	`60s`
`endpoints[].graphql`	Whether to wrap the body in a query param (`{"query":"$body"}`).	`false`
`endpoints[].body`	Request body.	`""`
`endpoints[].headers`	Request headers.	`{}`
`endpoints[].dns`	Configuration for an endpoint of type DNS. See Monitoring an endpoint using DNS queries.	`""`
`endpoints[].dns.query-type`	Query type (e.g. MX)	`""`
`endpoints[].dns.query-name`	Query name (e.g. example.com)	`""`
`endpoints[].alerts[].type`	Type of alert. Valid types: `slack`, `discord`, `email`, `googlechat`, `pagerduty`, `twilio`, `mattermost`, `messagebird`, `teams` `custom`.	Required `""`
`endpoints[].alerts[].enabled`	Whether to enable the alert.	`false`
`endpoints[].alerts[].failure-threshold`	Number of failures in a row needed before triggering the alert.	`3`
`endpoints[].alerts[].success-threshold`	Number of successes in a row before an ongoing incident is marked as resolved.	`2`
`endpoints[].alerts[].send-on-resolved`	Whether to send a notification once a triggered alert is marked as resolved.	`false`
`endpoints[].alerts[].description`	Description of the alert. Will be included in the alert sent.	`""`
`endpoints[].client`	Client configuration.	`{}`
`endpoints[].ui`	UI configuration at the endpoint level.	`{}`
`endpoints[].ui.hide-hostname`	Whether to include the hostname in the result.	`false`
`endpoints[].ui.dont-resolve-failed-conditions`	Whether to resolve failed conditions for the UI.	`false`
`alerting`	Alerting configuration.	`{}`
`security`	Security configuration.	`{}`
`disable-monitoring-lock`	Whether to disable the monitoring lock.	`false`
`skip-invalid-config-update`	Whether to ignore invalid configuration update. See Reloading configuration on the fly.	`false`
`web`	Web configuration.	`{}`
`web.address`	Address to listen on.	`0.0.0.0`
`web.port`	Port to listen on.	`8080`
`ui`	UI configuration.	`{}`
`ui.title`	Title of the document.	`Health Dashboard ǀ Gatus`
`ui.header`	Header at the top of the dashboard.	`Health Status`
`ui.logo`	URL to the logo to display.	`""`
`ui.link`	Link to open when the logo is clicked.	`""`
`maintenance`	Maintenance configuration.	`{}`

Conditions

Here are some examples of conditions you can use:

Condition	Description	Passing values	Failing values
`[STATUS] == 200`	Status must be equal to 200	200	201, 404, ...
`[STATUS] < 300`	Status must lower than 300	200, 201, 299	301, 302, ...
`[STATUS] <= 299`	Status must be less than or equal to 299	200, 201, 299	301, 302, ...
`[STATUS] > 400`	Status must be greater than 400	401, 402, 403, 404	400, 200, ...
`[STATUS] == any(200, 429)`	Status must be either 200 or 429	200, 429	201, 400, ...
`[CONNECTED] == true`	Connection to host must've been successful	true	false
`[RESPONSE_TIME] < 500`	Response time must be below 500ms	100ms, 200ms, 300ms	500ms, 501ms
`[IP] == 127.0.0.1`	Target IP must be 127.0.0.1	127.0.0.1	0.0.0.0
`[BODY] == 1`	The body must be equal to 1	1	`{}`, `2`, ...
`[BODY].user.name == john`	JSONPath value of `$.user.name` is equal to `john`	`{"user":{"name":"john"}}`
`[BODY].data[0].id == 1`	JSONPath value of `$.data[0].id` is equal to 1	`{"data":[{"id":1}]}`
`[BODY].age == [BODY].id`	JSONPath value of `$.age` is equal JSONPath `$.id`	`{"age":1,"id":1}`
`len([BODY].data) < 5`	Array at JSONPath `$.data` has less than 5 elements	`{"data":[{"id":1}]}`
`len([BODY].name) == 8`	String at JSONPath `$.name` has a length of 8	`{"name":"john.doe"}`	`{"name":"bob"}`
`has([BODY].errors) == false`	JSONPath `$.errors` does not exist	`{"name":"john.doe"}`	`{"errors":[]}`
`has([BODY].users) == true`	JSONPath `$.users` exists	`{"users":[]}`	`{}`
`[BODY].name == pat(john*)`	String at JSONPath `$.name` matches pattern `john*`	`{"name":"john.doe"}`	`{"name":"bob"}`
`[BODY].id == any(1, 2)`	Value at JSONPath `$.id` is equal to `1` or `2`	1, 2	3, 4, 5
`[CERTIFICATE_EXPIRATION] > 48h`	Certificate expiration is more than 48h away	49h, 50h, 123h	1h, 24h, ...

Placeholders

Placeholder	Description	Example of resolved value
`[STATUS]`	Resolves into the HTTP status of the request	404
`[RESPONSE_TIME]`	Resolves into the response time the request took, in ms	10
`[IP]`	Resolves into the IP of the target host	192.168.0.232
`[BODY]`	Resolves into the response body. Supports JSONPath.	`{"name":"john.doe"}`
`[CONNECTED]`	Resolves into whether a connection could be established	`true`
`[CERTIFICATE_EXPIRATION]`	Resolves into the duration before certificate expiration	`24h`, `48h`, 0 (if not protocol with certs)
`[DNS_RCODE]`	Resolves into the DNS status of the response	NOERROR

Functions

Function	Description	Example
`len`	Returns the length of the object/slice. Works only with the `[BODY]` placeholder.	`len([BODY].username) > 8`
`has`	Returns `true` or `false` based on whether a given path is valid. Works only with the `[BODY]` placeholder.	`has([BODY].errors) == false`
`pat`	Specifies that the string passed as parameter should be evaluated as a pattern. Works only with `==` and `!=`.	`[IP] == pat(192.168.*)`
`any`	Specifies that any one of the values passed as parameters is a valid value. Works only with `==` and `!=`.	`[BODY].ip == any(127.0.0.1, ::1)`

NOTE: Use pat only when you need to. [STATUS] == pat(2*) is a lot more expensive than [STATUS] < 300.

Storage

Parameter	Description	Default
`storage`	Storage configuration	`{}`
`storage.path`	Path to persist the data in. Only supported for types `sqlite` and `postgres`.	`""`
`storage.type`	Type of storage. Valid types: `memory`, `sqlite`, `postgres`.	`"memory"`

If storage.type is memory (default):

# Note that this is the default value, and you can omit the storage configuration altogether to achieve the same result.
# Because the data is stored in memory, the data will not survive a restart.
storage:
  type: memory

If storage.type is sqlite, storage.path must not be blank:

storage:
  type: sqlite
  path: data.db

See examples/docker-compose-sqlite-storage for an example.

If storage.type is postgres, storage.path must be the connection URL:

storage:
  type: postgres
  path: "postgres://user:password@127.0.0.1:5432/gatus?sslmode=disable"

See examples/docker-compose-postgres-storage for an example.

Client configuration

In order to support a wide range of environments, each monitored endpoint has a unique configuration for the client used to send the request.

Parameter	Description	Default
`client.insecure`	Whether to skip verifying the server's certificate chain and host name.	`false`
`client.ignore-redirect`	Whether to ignore redirects (true) or follow them (false, default).	`false`
`client.timeout`	Duration before timing out.	`10s`
`client.oauth2`	OAuth2 client configuration.	`{}`
`client.oauth2.token-url`	The token endpoint URL	required `""`
`client.oauth2.client-id`	The client id which should be used for the `Client credentials flow`	required `""`
`client.oauth2.client-secret`	The client secret which should be used for the `Client credentials flow`	required `""`
`client.oauth2.scopes[]`	A list of `scopes` which should be used for the `Client credentials flow`.	required `[""]`

Note that some of these parameters are ignored based on the type of endpoint. For instance, there's no certificate involved in ICMP requests (ping), therefore, setting client.insecure to true for an endpoint of that type will not do anything.

This default configuration is as follows:

client:
  insecure: false
  ignore-redirect: false
  timeout: 10s

Note that this configuration is only available under endpoints[], alerting.mattermost and alerting.custom.

Here's an example with the client configuration under endpoints[]:

endpoints:
  - name: website
    url: "https://twin.sh/health"
    client:
      insecure: false
      ignore-redirect: false
      timeout: 10s
    conditions:
      - "[STATUS] == 200"

This example shows how you can use the client.oauth2 configuration to query a backend API with Bearer token:

endpoints:
  - name: website
    url: "https://your.health.api/getHealth"
    client:
      oauth2:
        token-url: https://your-token-server/token
        client-id: 00000000-0000-0000-0000-000000000000
        client-secret: your-client-secret
        scopes: ['https://your.health.api/.default']
    conditions:
      - "[STATUS] == 200"

Alerting

Gatus supports multiple alerting providers, such as Slack and PagerDuty, and supports different alerts for each individual endpoints with configurable descriptions and thresholds.

Note that if an alerting provider is not properly configured, all alerts configured with the provider's type will be ignored.

Parameter	Description	Default
`alerting.discord`	Configuration for alerts of type `discord`. See Configuring Discord alerts.	`{}`
`alerting.email`	Configuration for alerts of type `email`. See Configuring Email alerts.	`{}`
`alerting.googlechat`	Configuration for alerts of type `googlechat`. See Configuring Google Chat alerts.	`{}`
`alerting.mattermost`	Configuration for alerts of type `mattermost`. See Configuring Mattermost alerts.	`{}`
`alerting.messagebird`	Configuration for alerts of type `messagebird`. See Configuring Messagebird alerts.	`{}`
`alerting.opsgenie`	Configuration for alerts of type `opsgenie`. See Configuring Opsgenie alerts.	`{}`
`alerting.pagerduty`	Configuration for alerts of type `pagerduty`. See Configuring PagerDuty alerts.	`{}`
`alerting.slack`	Configuration for alerts of type `slack`. See Configuring Slack alerts.	`{}`
`alerting.teams`	Configuration for alerts of type `teams`. See Configuring Teams alerts.	`{}`
`alerting.telegram`	Configuration for alerts of type `telegram`. See Configuring Telegram alerts.	`{}`
`alerting.twilio`	Settings for alerts of type `twilio`. See Configuring Twilio alerts.	`{}`
`alerting.custom`	Configuration for custom actions on failure or alerts. See Configuring Custom alerts.	`{}`

Configuring Discord alerts

Parameter	Description	Default
`alerting.discord`	Configuration for alerts of type `discord`	`{}`
`alerting.discord.webhook-url`	Discord Webhook URL	Required `""`
`alerting.discord.default-alert`	Default alert configuration. See Setting a default alert	N/A

alerting:
  discord: 
    webhook-url: "https://discord.com/api/webhooks/**********/**********"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 30s
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: discord
        enabled: true
        description: "healthcheck failed"
        send-on-resolved: true

Configuring Email alerts

Parameter	Description	Default
`alerting.email`	Configuration for alerts of type `email`	`{}`
`alerting.email.from`	Email used to send the alert	Required `""`
`alerting.email.username`	Username of the SMTP server used to send the alert. If empty, uses `alerting.email.from`.	`""`
`alerting.email.password`	Password of the SMTP server used to send the alert	Required `""`
`alerting.email.host`	Host of the mail server (e.g. `smtp.gmail.com`)	Required `""`
`alerting.email.port`	Port the mail server is listening to (e.g. `587`)	Required `0`
`alerting.email.to`	Email(s) to send the alerts to	Required `""`
`alerting.email.default-alert`	Default alert configuration. See Setting a default alert	N/A

alerting:
  email:
    from: "from@example.com"
    username: "from@example.com"
    password: "hunter2"
    host: "mail.example.com"
    port: 587
    to: "recipient1@example.com,recipient2@example.com"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: email
        enabled: true
        description: "healthcheck failed"
        send-on-resolved: true

NOTE: Some mail servers are painfully slow.

Configuring Google Chat alerts

Parameter	Description	Default
`alerting.googlechat`	Configuration for alerts of type `googlechat`	`{}`
`alerting.googlechat.webhook-url`	Google Chat Webhook URL	Required `""`
`alerting.googlechat.client`	Client configuration. See Client configuration.	`{}`
`alerting.googlechat.default-alert`	Default alert configuration. See Setting a default alert.	N/A

alerting:
  googlechat: 
    webhook-url: "https://chat.googleapis.com/v1/spaces/*******/messages?key=**********&token=********"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 30s
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: googlechat
        enabled: true
        description: "healthcheck failed"
        send-on-resolved: true

Configuring Mattermost alerts

Parameter	Description	Default
`alerting.mattermost`	Configuration for alerts of type `mattermost`	`{}`
`alerting.mattermost.webhook-url`	Mattermost Webhook URL	Required `""`
`alerting.mattermost.client`	Client configuration. See Client configuration.	`{}`
`alerting.mattermost.default-alert`	Default alert configuration. See Setting a default alert.	N/A

alerting:
  mattermost: 
    webhook-url: "http://**********/hooks/**********"
    client:
      insecure: true

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 30s
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: mattermost
        enabled: true
        description: "healthcheck failed"
        send-on-resolved: true

Here's an example of what the notifications look like:

Configuring Messagebird alerts

Parameter	Description	Default
`alerting.messagebird`	Settings for alerts of type `messagebird`	`{}`
`alerting.messagebird.access-key`	Messagebird access key	Required `""`
`alerting.messagebird.originator`	The sender of the message	Required `""`
`alerting.messagebird.recipients`	The recipients of the message	Required `""`
`alerting.messagebird.default-alert`	Default alert configuration. See Setting a default alert	N/A

Example of sending SMS text message alert using Messagebird:

alerting:
  messagebird:
    access-key: "..."
    originator: "31619191918"
    recipients: "31619191919,31619191920"

endpoints:
  - name: website
    interval: 30s
    url: "https://twin.sh/health"
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: messagebird
        enabled: true
        failure-threshold: 3
        send-on-resolved: true
        description: "healthcheck failed"

Configuring Opsgenie alerts

Parameter	Description	Default
`alerting.opsgenie`	Configuration for alerts of type `opsgenie`	`{}`
`alerting.opsgenie.api-key`	Opsgenie API Key	Required `""`
`alerting.opsgenie.priority`	Priority level of the alert.	`P1`
`alerting.opsgenie.source`	Source field of the alert.	`gatus`
`alerting.opsgenie.entity-prefix`	Entity field prefix.	`gatus-`
`alerting.opsgenie.alias-prefix`	Alias field prefix.	`gatus-healthcheck-`
`alerting.opsgenie.tags`	Tags of alert.	`[]`
`alerting.opsgenie.default-alert`	Default alert configuration. See Setting a default alert	N/A

Opsgenie provider will automatically open and close alerts.

alerting:
  opsgenie:
    api-key: "00000000-0000-0000-0000-000000000000"

Configuring PagerDuty alerts

Parameter	Description	Default
`alerting.pagerduty`	Configuration for alerts of type `pagerduty`	`{}`
`alerting.pagerduty.integration-key`	PagerDuty Events API v2 integration key	`""`
`alerting.pagerduty.overrides`	List of overrides that may be prioritized over the default configuration	`[]`
`alerting.pagerduty.overrides[].group`	Endpoint group for which the configuration will be overridden by this configuration	`""`
`alerting.pagerduty.overrides[].integration-key`	PagerDuty Events API v2 integration key	`""`
`alerting.pagerduty.default-alert`	Default alert configuration. See Setting a default alert	N/A

It is highly recommended to set endpoints[].alerts[].send-on-resolved to true for alerts of type pagerduty, because unlike other alerts, the operation resulting from setting said parameter to true will not create another incident but mark the incident as resolved on PagerDuty instead.

Behavior:

By default, alerting.pagerduty.integration-key is used as the integration key
If the endpoint being evaluated belongs to a group (endpoints[].group) matching the value of alerting.pagerduty.overrides[].group, the provider will use that override's integration key instead of alerting.pagerduty.integration-key's

alerting:
  pagerduty: 
    integration-key: "********************************"
    # You can also add group-specific integration keys, which will 
    # override the integration key above for the specified groups
    overrides:
     - group: "core"
       integration-key: "********************************"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 30s
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: pagerduty
        enabled: true
        failure-threshold: 3
        success-threshold: 5
        send-on-resolved: true
        description: "healthcheck failed"

  - name: back-end
    group: core
    url: "https://example.org/"
    interval: 5m
    conditions:
      - "[STATUS] == 200"
      - "[CERTIFICATE_EXPIRATION] > 48h"
    alerts:
      - type: pagerduty
        enabled: true
        failure-threshold: 3
        success-threshold: 5
        send-on-resolved: true
        description: "healthcheck failed"

Configuring Slack alerts

Parameter	Description	Default
`alerting.slack`	Configuration for alerts of type `slack`	`{}`
`alerting.slack.webhook-url`	Slack Webhook URL	Required `""`
`alerting.slack.default-alert`	Default alert configuration. See Setting a default alert	N/A

alerting:
  slack: 
    webhook-url: "https://hooks.slack.com/services/**********/**********/**********"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 30s
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: slack
        enabled: true
        description: "healthcheck failed 3 times in a row"
        send-on-resolved: true
      - type: slack
        enabled: true
        failure-threshold: 5
        description: "healthcheck failed 5 times in a row"
        send-on-resolved: true

Here's an example of what the notifications look like:

Configuring Teams alerts

Parameter	Description	Default
`alerting.teams`	Configuration for alerts of type `teams`	`{}`
`alerting.teams.webhook-url`	Teams Webhook URL	Required `""`
`alerting.teams.default-alert`	Default alert configuration. See Setting a default alert	N/A

alerting:
  teams:
    webhook-url: "https://********.webhook.office.com/webhookb2/************"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 30s
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: teams
        enabled: true
        description: "healthcheck failed"
        send-on-resolved: true

Here's an example of what the notifications look like:

Configuring Telegram alerts

Parameter	Description	Default
`alerting.telegram`	Configuration for alerts of type `telegram`	`{}`
`alerting.telegram.token`	Telegram Bot Token	Required `""`
`alerting.telegram.id`	Telegram User ID	Required `""`
`alerting.telegram.api-url`	Telegram API URL	`https://api.telegram.org`
`alerting.telegram.default-alert`	Default alert configuration. See Setting a default alert	N/A

alerting:
  telegram: 
    token: "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11"
    id: "0123456789"

endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 30s
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
    alerts:
      - type: telegram
        enabled: true
        send-on-resolved: true

Here's an example of what the notifications look like:

Configuring Twilio alerts

Parameter	Description	Default
`alerting.twilio`	Settings for alerts of type `twilio`	`{}`
`alerting.twilio.sid`	Twilio account SID	Required `""`
`alerting.twilio.token`	Twilio auth token	Required `""`
`alerting.twilio.from`	Number to send Twilio alerts from	Required `""`
`alerting.twilio.to`	Number to send twilio alerts to	Required `""`
`alerting.twilio.default-alert`	Default alert configuration. See Setting a default alert	N/A

alerting:
  twilio:
    sid: "..."
    token: "..."
    from: "+1-234-567-8901"
    to: "+1-234-567-8901"

endpoints:
  - name: website
    interval: 30s
    url: "https://twin.sh/health"
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: twilio
        enabled: true
        failure-threshold: 5
        send-on-resolved: true
        description: "healthcheck failed"

Configuring custom alerts

Parameter	Description	Default
`alerting.custom`	Configuration for custom actions on failure or alerts	`{}`
`alerting.custom.url`	Custom alerting request url	Required `""`
`alerting.custom.method`	Request method	`GET`
`alerting.custom.body`	Custom alerting request body.	`""`
`alerting.custom.headers`	Custom alerting request headers	`{}`
`alerting.custom.client`	Client configuration. See Client configuration.	`{}`
`alerting.custom.default-alert`	Default alert configuration. See Setting a default alert	N/A

While they're called alerts, you can use this feature to call anything.

For instance, you could automate rollbacks by having an application that keeps tracks of new deployments, and by leveraging Gatus, you could have Gatus call that application endpoint when an endpoint starts failing. Your application would then check if the endpoint that started failing was part of the recently deployed application, and if it was, then automatically roll it back.

The placeholders [ALERT_DESCRIPTION] and [ENDPOINT_NAME] are automatically substituted for the alert description and the endpoint name. These placeholders can be used in the body (alerting.custom.body) and in the url (alerting.custom.url).

If you have an alert using the custom provider with send-on-resolved set to true, you can use the [ALERT_TRIGGERED_OR_RESOLVED] placeholder to differentiate the notifications. The aforementioned placeholder will be replaced by TRIGGERED or RESOLVED accordingly, though it can be modified (details at the end of this section).

For all intents and purposes, we'll configure the custom alert with a Slack webhook, but you can call anything you want.

alerting:
  custom:
    url: "https://hooks.slack.com/services/**********/**********/**********"
    method: "POST"
    body: |
      {
        "text": "[ALERT_TRIGGERED_OR_RESOLVED]: [ENDPOINT_NAME] - [ALERT_DESCRIPTION]"
      }
endpoints:
  - name: website
    url: "https://twin.sh/health"
    interval: 30s
    conditions:
      - "[STATUS] == 200"
      - "[BODY].status == UP"
      - "[RESPONSE_TIME] < 300"
    alerts:
      - type: custom
        enabled: true
        failure-threshold: 10
        success-threshold: 3
        send-on-resolved: true
        description: "health check failed"

Note that you can customize the resolved values for the [ALERT_TRIGGERED_OR_RESOLVED] placeholder like so:

alerting:
  custom:
    placeholders:
      ALERT_TRIGGERED_OR_RESOLVED:
        TRIGGERED: "partial_outage"
        RESOLVED: "operational"

As a result, the [ALERT_TRIGGERED_OR_RESOLVED] in the body of first example of this section would be replaced by partial_outage when an alert is triggered and operational when an alert is resolved.

Setting a default alert

Parameter	Description	Default
`alerting.*.default-alert.enabled`	Whether to enable the alert	N/A
`alerting.*.default-alert.failure-threshold`	Number of failures in a row needed before triggering the alert	N/A
`alerting.*.default-alert.success-threshold`	Number of successes in a row before an ongoing incident is marked as resolved	N/A
`alerting.*.default-alert.send-on-resolved`	Whether to send a notification once a triggered alert is marked as resolved	N/A
`alerting.*.default-alert.description`	Description of the alert. Will be included in the alert sent	N/A

While you can specify the alert configuration directly in the endpoint definition, it's tedious and may lead to a very long configuration file.

To avoid such problem, you can use the default-alert parameter present in each provider configuration:

alerting:
  slack: 
    webhook-url: "https://hooks.slack.com/services/**********/**********/**********"
    default-alert:
      enabled: true
      description: "health check failed"
      send-on-resolved: true
      failure-threshold: 5
      success-threshold: 5

As a result, your Gatus configuration looks a lot tidier:

endpoints:
  - name: example
    url: "https://example.org"
    conditions:
      - "[STATUS] == 200"
    alerts:
      - type: slack

  - name: other-example
    url: "https://example.com"
    conditions:
      - "[STATUS] == 200"
    alerts:
      - type: slack

It also allows you to do things like this:

endpoints:
  - name: example
    url: "https://example.org"
    conditions:
      - "[STATUS] == 200"
    alerts:
      - type: slack
        failure-threshold: 5
      - type: slack
        failure-threshold: 10
      - type: slack
        failure-threshold: 15

Of course, you can also mix alert types:

alerting:
  slack:
    webhook-url: "https://hooks.slack.com/services/**********/**********/**********"
    default-alert:
      enabled: true
      failure-threshold: 3
  pagerduty:
    integration-key: "********************************"
    default-alert:
      enabled: true
      failure-threshold: 5

endpoints:
  - name: endpoint-1
    url: "https://example.org"
    conditions:
      - "[STATUS] == 200"
    alerts:
      - type: slack
      - type: pagerduty

  - name: endpoint-2
    url: "https://example.org"
    conditions:
      - "[STATUS] == 200"
    alerts:
      - type: slack
      - type: pagerduty

Maintenance

If you have maintenance windows, you may not want to be annoyed by alerts. To do that, you'll have to use the maintenance configuration:

Parameter	Description	Default
`maintenance.enabled`	Whether the maintenance period is enabled	`true`
`maintenance.start`	Time at which the maintenance window starts in `hh:mm` format (e.g. `23:00`)	Required `""`
`maintenance.duration`	Duration of the maintenance window (e.g. `1h`, `30m`)	Required `""`
`maintenance.every`	Days on which the maintenance period applies (e.g. `[Monday, Thursday]`). If left empty, the maintenance window applies every day	`[]`

Note that the maintenance configuration uses UTC.

Here's an example:

maintenance:
  start: 23:00
  duration: 1h
  every: [Monday, Thursday]

Note that you can also specify each day on separate lines:

maintenance:
  start: 23:00
  duration: 1h
  every:
    - Monday
    - Thursday

Security

Parameter	Description	Default
`security`	Security configuration	`{}`
`security.basic`	HTTP Basic configuration	`{}`
`security.oidc`	OpenID Connect configuration	`{}`

Basic

Parameter	Description	Default
`security.basic`	HTTP Basic configuration	`{}`
`security.basic.username`	Username for Basic authentication.	Required `""`
`security.basic.password-bcrypt-base64`	Password hashed with Bcrypt and then encoded with base64 for Basic authentication.	Required `""`

The example below will require that you authenticate with the username john.doe and the password hunter2:

security:
  basic:
    username: "john.doe"
    password-bcrypt-base64: "JDJhJDEwJHRiMnRFakxWazZLdXBzRERQazB1TE8vckRLY05Yb1hSdnoxWU0yQ1FaYXZRSW1McmladDYu"

WARNING: Make sure to carefully select to cost of the bcrypt hash. The higher the cost, the longer it takes to compute the hash, and basic auth verifies the password against the hash on every request. As of 2022-01-08, I suggest a cost of 8.

OIDC (ALPHA)

Parameter	Description	Default
`security.oidc`	OpenID Connect configuration	`{}`
`security.oidc.issuer-url`	Issuer URL	Required `""`
`security.oidc.redirect-url`	Redirect URL. Must end with `/authorization-code/callback`	Required `""`
`security.oidc.client-id`	Client id	Required `""`
`security.oidc.client-secret`	Client secret	Required `""`
`security.oidc.scopes`	Scopes to request. The only scope you need is `openid`.	Required `[]`
`security.oidc.allowed-subjects`	List of subjects to allow. If empty, all subjects are allowed.	`[]`

security:
  oidc:
    issuer-url: "https://example.okta.com"
    redirect-url: "https://status.example.com/authorization-code/callback"
    client-id: "123456789"
    client-secret: "abcdefghijk"
    scopes: ["openid"]
    # You may optionally specify a list of allowed subjects. If this is not specified, all subjects will be allowed.
    #allowed-subjects: ["johndoe@example.com"]

NOTE: The OIDC feature is currently in Alpha. Breaking changes may occur. Use this feature at your own risk.

Deployment

Many examples can be found in the .examples folder, but this section will focus on the most popular ways of deploying Gatus.

Docker

To run Gatus locally with Docker:

docker run -p 8080:8080 --name gatus twinproduction/gatus

Other than using one of the examples provided in the .examples folder, you can also try it out locally by creating a configuration file, we'll call it config.yaml for this example, and running the following command:

docker run -p 8080:8080 --mount type=bind,source="$(pwd)"/config.yaml,target=/config/config.yaml --name gatus twinproduction/gatus

If you're on Windows, replace "$(pwd)" by the absolute path to your current directory, e.g.:

docker run -p 8080:8080 --mount type=bind,source=C:/Users/Chris/Desktop/config.yaml,target=/config/config.yaml --name gatus twinproduction/gatus

To build the image locally:

docker build . -t twinproduction/gatus

Helm Chart

Helm must be installed to use the chart. Please refer to Helm's documentation to get started.

Once Helm is set up properly, add the repository as follows:

helm repo add gatus https://avakarev.github.io/gatus-chart

To get more details, please check chart's configuration and helmfile example

Terraform

Gatus can be deployed on Terraform by using the following module: terraform-kubernetes-gatus.

Running the tests

go test ./... -mod vendor

Using in Production

See the Deployment section.

FAQ

Sending a GraphQL request

By setting endpoints[].graphql to true, the body will automatically be wrapped by the standard GraphQL query parameter.

For instance, the following configuration:

endpoints:
  - name: filter-users-by-gender
    url: http://localhost:8080/playground
    method: POST
    graphql: true
    body: |
      {
        users(gender: "female") {
          id
          name
          gender
          avatar
        }
      }
    conditions:
      - "[STATUS] == 200"
      - "[BODY].data.users[0].gender == female"

will send a POST request to http://localhost:8080/playground with the following body:

{"query":"      {\n        users(gender: \"female\") {\n          id\n          name\n          gender\n          avatar\n        }\n      }"}

Recommended interval

NOTE: This does not apply if disable-monitoring-lock is set to true, as the monitoring lock is what tells Gatus to only evaluate one endpoint at a time.

To ensure that Gatus provides reliable and accurate results (i.e. response time), Gatus only evaluates one endpoint at a time In other words, even if you have multiple endpoints with the same interval, they will not execute at the same time.

You can test this yourself by running Gatus with several endpoints configured with a very short, unrealistic interval, such as 1ms. You'll notice that the response time does not fluctuate - that is because while endpoints are evaluated on different goroutines, there's a global lock that prevents multiple endpoints from running at the same time.

Unfortunately, there is a drawback. If you have a lot of endpoints, including some that are very slow or prone to timing out (the default timeout is 10s), then it means that for the entire duration of the request, no other endpoint can be evaluated.

The interval does not include the duration of the request itself, which means that if an endpoint has an interval of 30s and the request takes 2s to complete, the timestamp between two evaluations will be 32s, not 30s.

While this does not prevent Gatus' from performing health checks on all other endpoints, it may cause Gatus to be unable to respect the configured interval, for instance:

Endpoint A has an interval of 5s, and times out after 10s to complete
Endpoint B has an interval of 5s, and takes 1ms to complete
Endpoint B will be unable to run every 5s, because endpoint A's health evaluation takes longer than its interval

To sum it up, while Gatus can handle any interval you throw at it, you're better off having slow requests with higher interval.

As a rule of thumb, I personally set the interval for more complex health checks to 5m (5 minutes) and simple health checks used for alerting (PagerDuty/Twilio) to 30s.

Default timeouts

Endpoint type	Timeout
HTTP	10s
TCP	10s
ICMP	10s

To modify the timeout, see Client configuration.

Monitoring a TCP endpoint

By prefixing endpoints[].url with tcp:\\, you can monitor TCP endpoints at a very basic level:

endpoints:
  - name: redis
    url: "tcp://127.0.0.1:6379"
    interval: 30s
    conditions:
      - "[CONNECTED] == true"

Placeholders [STATUS] and [BODY] as well as the fields endpoints[].body, endpoints[].headers, endpoints[].method and endpoints[].graphql are not supported for TCP endpoints.

NOTE: [CONNECTED] == true does not guarantee that the endpoint itself is healthy - it only guarantees that there's something at the given address listening to the given port, and that a connection to that address was successfully established.

Monitoring an endpoint using ICMP

By prefixing endpoints[].url with icmp:\\, you can monitor endpoints at a very basic level using ICMP, or more commonly known as "ping" or "echo":

endpoints:
  - name: ping-example
    url: "icmp://example.com"
    conditions:
      - "[CONNECTED] == true"

Only the placeholders [CONNECTED], [IP] and [RESPONSE_TIME] are supported for endpoints of type ICMP. You can specify a domain prefixed by icmp://, or an IP address prefixed by icmp://.

Monitoring an endpoint using DNS queries

Defining a dns configuration in an endpoint will automatically mark said endpoint as an endpoint of type DNS:

endpoints:
  - name: example-dns-query
    url: "8.8.8.8" # Address of the DNS server to use
    interval: 30s
    dns:
      query-name: "example.com"
      query-type: "A"
    conditions:
      - "[BODY] == 93.184.216.34"
      - "[DNS_RCODE] == NOERROR"

There are two placeholders that can be used in the conditions for endpoints of type DNS:

The placeholder [BODY] resolves to the output of the query. For instance, a query of type A would return an IPv4.
The placeholder [DNS_RCODE] resolves to the name associated to the response code returned by the query, such as NOERROR, FORMERR, SERVFAIL, NXDOMAIN, etc.

Monitoring an endpoint using STARTTLS

If you have an email server that you want to ensure there are no problems with, monitoring it through STARTTLS will serve as a good initial indicator:

endpoints:
  - name: starttls-smtp-example
    url: "starttls://smtp.gmail.com:587"
    interval: 30m
    client:
      timeout: 5s
    conditions:
      - "[CONNECTED] == true"
      - "[CERTIFICATE_EXPIRATION] > 48h"

Monitoring an endpoint using TLS

Monitoring endpoints using SSL/TLS encryption, such as LDAP over TLS, can help detect certificate expiration:

endpoints:
  - name: tls-ldaps-example
    url: "tls://ldap.example.com:636"
    interval: 30m
    client:
      timeout: 5s
    conditions:
      - "[CONNECTED] == true"
      - "[CERTIFICATE_EXPIRATION] > 48h"

disable-monitoring-lock

Setting disable-monitoring-lock to true means that multiple endpoints could be monitored at the same time.

While this behavior wouldn't generally be harmful, conditions using the [RESPONSE_TIME] placeholder could be impacted by the evaluation of multiple endpoints at the same time, therefore, the default value for this parameter is false.

There are three main reasons why you might want to disable the monitoring lock:

You're using Gatus for load testing (each endpoint are periodically evaluated on a different goroutine, so technically, if you create 100 endpoints with a 1 seconds interval, Gatus will send 100 requests per second)
You have a lot of endpoints to monitor
You want to test multiple endpoints at very short intervals (< 5s)

Reloading configuration on the fly

For the sake of convenience, Gatus automatically reloads the configuration on the fly if the loaded configuration file is updated while Gatus is running.

By default, the application will exit if the updating configuration is invalid, but you can configure Gatus to continue running if the configuration file is updated with an invalid configuration by setting skip-invalid-config-update to true.

Keep in mind that it is in your best interest to ensure the validity of the configuration file after each update you apply to the configuration file while Gatus is running by looking at the log and making sure that you do not see the following message:

The configuration file was updated, but it is not valid. The old configuration will continue being used.

Failure to do so may result in Gatus being unable to start if the application is restarted for whatever reason.

I recommend not setting skip-invalid-config-update to true to avoid a situation like this, but the choice is yours to make.

If you are not using a file storage, updating the configuration while Gatus is running is effectively the same as restarting the application.

NOTE: Updates may not be detected if the config file is bound instead of the config folder. See #151.

Endpoint groups

Endpoint groups are used for grouping multiple endpoints together on the dashboard.

endpoints:
  - name: frontend
    group: core
    url: "https://example.org/"
    interval: 5m
    conditions:
      - "[STATUS] == 200"

  - name: backend
    group: core
    url: "https://example.org/"
    interval: 5m
    conditions:
      - "[STATUS] == 200"

  - name: monitoring
    group: internal
    url: "https://example.org/"
    interval: 5m
    conditions:
      - "[STATUS] == 200"

  - name: nas
    group: internal
    url: "https://example.org/"
    interval: 5m
    conditions:
      - "[STATUS] == 200"

  - name: random endpoint that isn't part of a group
    url: "https://example.org/"
    interval: 5m
    conditions:
      - "[STATUS] == 200"

The configuration above will result in a dashboard that looks like this:

Exposing Gatus on a custom port

By default, Gatus is exposed on port 8080, but you may specify a different port by setting the web.port parameter:

web:
  port: 8081

If you're using a PaaS like Heroku that doesn't let you set a custom port and exposes it through an environment variable instead, you can use that environment variable directly in the configuration file:

web:
  port: ${PORT}

Badges

Uptime

Gatus can automatically generate an SVG badge for one of your monitored endpoints. This allows you to put badges in your individual applications' README or even create your own status page if you desire.

The path to generate a badge is the following:

/api/v1/endpoints/{key}/uptimes/{duration}/badge.svg

Where:

{duration} is 7d, 24h or 1h
{key} has the pattern <GROUP_NAME>_<ENDPOINT_NAME> in which both variables have , /, _, , and . replaced by -.

For instance, if you want the uptime during the last 24 hours from the endpoint frontend in the group core, the URL would look like this:

https://example.com/api/v1/endpoints/core_frontend/uptimes/7d/badge.svg

If you want to display an endpoint that is not part of a group, you must leave the group value empty:

https://example.com/api/v1/endpoints/_frontend/uptimes/7d/badge.svg

Example:

![Uptime 24h](https://status.twin.sh/api/v1/endpoints/core_blog-external/uptimes/24h/badge.svg)

If you'd like to see a visual example of each badge available, you can simply navigate to the endpoint's detail page.

Response time

The endpoint to generate a badge is the following:

/api/v1/endpoints/{key}/response-times/{duration}/badge.svg

Where:

{duration} is 7d, 24h or 1h
{key} has the pattern <GROUP_NAME>_<ENDPOINT_NAME> in which both variables have , /, _, , and . replaced by -.

API

Gatus provides a simple read-only API that can be queried in order to programmatically determine endpoint status and history.

All endpoints are available via a GET request to the following endpoint:

/api/v1/endpoints/statuses

Example: https://status.twin.sh/api/v1/endpoints/statuses

Specific endpoints can also be queried by using the following pattern:

/api/v1/endpoints/{group}_{endpoint}/statuses

Example: https://status.twin.sh/api/v1/endpoints/core_blog-home/statuses

Gzip compression will be used if the Accept-Encoding HTTP header contains gzip.

The API will return a JSON payload with the Content-Type response header set to application/json. No such header is required to query the API.

Name		Name	Last commit message	Last commit date
Latest commit History 871 Commits
.examples		.examples
.github		.github
alerting		alerting
client		client
config		config
controller		controller
core		core
docs		docs
jsonpath		jsonpath
metric		metric
pattern		pattern
security		security
storage		storage
test		test
util		util
vendor		vendor
watchdog		watchdog
web		web
.dockerignore		.dockerignore
.gitattributes		.gitattributes
.gitignore		.gitignore
Dockerfile		Dockerfile
LICENSE		LICENSE
Makefile		Makefile
README.md		README.md
config.yaml		config.yaml
go.mod		go.mod
go.sum		go.sum
main.go		main.go

License

nzsambo/gatus

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Table of Contents

Why Gatus?

Features

Usage

Configuration

Conditions

Placeholders

Functions

Storage

Client configuration

Alerting

Configuring Discord alerts

Configuring Email alerts

Configuring Google Chat alerts

Configuring Mattermost alerts

Configuring Messagebird alerts

Configuring Opsgenie alerts

Configuring PagerDuty alerts

Configuring Slack alerts

Configuring Teams alerts

Configuring Telegram alerts

Configuring Twilio alerts

Configuring custom alerts

Setting a default alert

Maintenance

Security

Basic

OIDC (ALPHA)

Deployment

Docker

Helm Chart

Terraform

Running the tests

Using in Production

FAQ

Sending a GraphQL request

Recommended interval

Default timeouts

Monitoring a TCP endpoint

Monitoring an endpoint using ICMP

Monitoring an endpoint using DNS queries

Monitoring an endpoint using STARTTLS

Monitoring an endpoint using TLS

disable-monitoring-lock

Reloading configuration on the fly

Endpoint groups

Exposing Gatus on a custom port

Badges

Uptime

Response time

API

High level design overview

Sponsors

About

Resources

License

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