Services Health Check

Light application to run HTTP tests and evaluate expressions with results.

How It Works?

The application parse all tests inside the test file. After that, it executes the test, saves the value inside the Redis database and evaluates the expression, if the expression is false or the request fails, the application going to create an incident inside the PargerDuty.

Setup

Quick start

Deploy it in less than 30 seconds!

Prerequisite

• GO 1.13+
• Locally running Redis or URL to remote instance (required for Observer only).

From Source

go get -u github.com/Pantani/healthcheck
cd $GOPATH/src/github.com/Pantani/healthcheck

Make commands

- install     Install missing dependencies. Runs `go get` internally. e.g.; make install get=github.com/foo/bar
- start       Start API in development mode.
- stop        Stop development mode.
- restart     Restart in development mode.
- compile     Compile the binary.
- exec        Run given command. e.g.; make exec run="go test ./..."
- clean       Clean build files. Runs `go clean` internally.
- test        Run all unit tests.
- fmt         Run `go fmt` for all go files.
- goreleaser  Release the last tag version with GoReleaser.
- govet       Run go vet.
- golint      Run golint.

Environment Variables

All environment variables for developing are set inside the .env file.

REDIS_URL=Redis Database URL
PAGERDUTY_KEY=PargerDuty Access Key
PAGERDUTY_ESCALATION_POLICY=PagerDuty Escalation Policy ID
PAGERDUTY_SERVICE=PagerDuty Service ID

Create Tests

To create a new test, do you need to edit the file config/fixtures.json.

Test Structure

[
  {
    "namespace": string, # test namespace.
    "host": string, # the host to be reached.
    "tests": [ # Array of tests to be executed in the current namespace.
      {
        "name": string, # test name.
        "method": string, # HTTP method type.
        "url_path": string, # URL path to the test.
        "json_path": string, # path inside JSON to get the information to be saved.
        "body": any, # body for POST tests.
        "expression": string, # expression used to evaluate the test.
        "update_time": string # test update time.
      }
      ...
    ]
  },
  ...
]

Test Example

[
  {
    "namespace": "bitcoin",
    "host": "https://btc1.trezor.io",
    "tests": [
      {
        "name": "block_height",
        "method": "GET",
        "url_path": "api",
        "json_path": "blockbook.bestHeight",
        "expression": "lastValue <= newValue",
        "update_time": "5s"
      },
      {
        "name": "host",
        "method": "GET",
        "url_path": "api",
        "json_path": "blockbook.host",
        "expression": "len(newValue) > 0",
        "update_time": "10s"
      }
    ]
  },
  {
    "namespace": "ethereum",
    "host": "https://infura.io",
    "tests": [
      {
        "name": "eth_getBlockByNumber",
        "method": "POST",
        "json_path": "result.hash",
        "body": {"jsonrpc":"2.0","method":"eth_getBlockByNumber","params":["0x1b4", true],"id":1},
        "expression": "newValue matches lastValue",
        "update_time": "10s"
      }
    ]
  }
]

Expressions

We are using expr to evaluate the expressions. You can find the expression language here

Default Variables

The Default variables give you a convenient way to evaluate expressions in your tests. These variables are automatically set by the application:

Variable	Description
lastValue	The result value from the last test executed
newValue	The result value from the current tests

Tools

• Setup Redis:

brew install redis

• Running in the IDE ( GoLand ):

1. Run;
2. Edit configuration;
3. New Go build configuration;
4. Select directory as configuration type;
5. Set metrics as program argument and -i as Go tools argument;

Unit Tests

To run the unit tests: make test.