Configuration

The Ioto Agent is controlled via several JSON/5 configuration files that are that are read at startup by Ioto.

The configuration files are are copied from the select appplication ./app/NAME/config directory into the top-level ./state directory.

File	Description
device.json5	Device registration configuration.
ioto.json5	Primary Ioto configuration file. Configures enabled services, logging and log file ingestion
ioto.crt	Allocated Ioto certificate for cloud communications.
ioto.key	Allocated Ioto certificate key for cloud communications.
local.json5	Local configuration for development.
provision.json5	Device and cloud provisioning configuration.
schema.json5	Database data schema.
signature.json5	REST API signatures.
shadow.json5	Local copy of the AWS IoT shadow state.
state.db	Saved database.
web.json5	Web server configuration file.

JSON/5

Ioto uses a human-readable JSON/5 for configuration. JSON/5 an extension of JSON that makes it easier to create, read and maintain configuration files in JSON.

JSON/5 adds the following JavaScript features to JSON.

• Object keys may be JavaScript identifiers without quotes.
• Objects or arrays may have a trailing comma.
• Strings may be single quoted.
• Strings may span multiple lines (single, double or back-tick quotes).
• Numbers may have a leading or trailing decimal point, can be hexadecimal, and may begin with a plus.
• Values may be regular expressions.
• The undefined value may be used.
• Single and multiline comments are allowed and preserved.

{
    // single-comment
    /*
        Multi-line comment
    */
    unquotedKey: 42,
    singleQuoteString: 'The "lazy brown fox" jumped...',
    multiLine: "Line one
        line two
    ",
    hex: 0x42,
    trailingComma: {
        one: 1,
        two: 2,
    },
}

Some Ioto configuration properties accept numeric values as human-readable string with unit suffixes. In this case, the value must be string. The limits and timeouts properties in the web.json5 file support the suffixes: unlimited, infinite, kb, k, mb, m, gb, g, byte, bytes, infinite, never, sec, secs, seconds, min, mins, minute, minutes, hr, hrs, hour, hours, day, days, week, weeks, month, months, year and years.

Profiles

Configuration files can provide multiple property profiles that can be selected at runtime. When Ioto is run, it executes with selected profile. This is typically prod for production and dev for development. However, you can create your own profiles for any desired execution configuration such as qa or test.

The Ioto profile is defined via the PROFILE environment variable or via the --profile command line option.

Configuration profiles are defined under the conditional.profile property in any configuration file. The relevant configuration properties are selected by the current Ioto profile. When selected, the relevant set are copied to overwrite properties of the same name at the top level. This allows a single configuration file to apply different settings based on the current values of the profile property.

conditional: {
    profile: {
        dev: {
            limits: {
                //  Override the default stack size
                stack: '64k',
            }
        },
        prod: {
            log: {
                //  Send trace to a specific output file
                path: 'ioto.log',
            }
        }
    }
}

Ioto Configuration

The primary Ioto configuration file is called ioto.json5.

Here is a sample ioto.json5:

{
    services: {
        database: true,
        keys: true,
        logs: false,
        mqtt: true,
        provision: true,
        serialize: 'auto',
        shadow: false,
        sync: true,
        update: true,
        url: true,
        web: false,
    },
    files: [
        {path: '/var/log/sys*log', group: 'ioto', stream: '{hostname}' }
    ],
    limits: {
        stack: '16k',
    },
    log: {
        path: 'aws',
        format: '%D %H %A[%P] %T %S %M',
        types: 'error,info',
        sources: 'all',
    }
}

The configuration file defines the following items:

• The services to enable.
• The files files to capture and send to CloudWatch logs.
• The Ioto execution limits that defines the default stack size
• The Ioto log log configuration.

The configuration properties are defined in the Configuration Properties.

The ioto.json5 services property collection defines which services to build and enable when running Ioto.

The selectable Ioto services are:

• database -- Enable the embedded database
• demo -- Demonstrate sending data to the cloud
• keys -- Get AWS IAM keys for local AWS API invocation (dedicated clouds only)
• logs -- Capture log files and send to AWS CloudWatch logs (dedicated clouds only)
• mqtt -- Enable MQTT protocol
• provision -- Dynamically provision keys and certificates for cloud based management
• register -- Register with the Ioto Builder
• serialize -- Run a serialization service when making the device
• shadow -- Enable AWS IoT shadow state storage
• sync -- Enable transparent database synchronization with the cloud
• url -- Enable client HTTP request support
• web -- Enable the local embedded web server