interface description of iptb TestbedNode

node.go

package testbedi

import (
        "context"
        "io"
        "time"

        "github.com/ipfs/go-cid"
        "github.com/multiformats/go-multiaddr"
)

type NewNodeFunc func(dir string, extras map[string]interface{}) (TestbedNode, error)
type GetAttrListFunc func() []string
type GetAttrDescFunc func(attr string) (string, error)

type TestbedNode interface {
        Libp2p
        Config
        Attributes
        Metrics
        Core
}

type Libp2p interface {
        // PeerID returns the peer id
        PeerID() (*cid.Cid, error)
        // APIAddr returns the multiaddr for the api
        APIAddr() (multiaddr.Multiaddr, error)
        // SwarmAddrs returns the swarm addrs for the node
        SwarmAddrs() ([]multiaddr.Multiaddr, error)
}

type Config interface {
        // GetConfig returns the configuration of the node
        GetConfig() (interface{}, error)
        // WriteConfig writes the configuration of the node
        WriteConfig(interface{}) error
}

// Attributes are ways to shape process execution and additional information that alters the
// environment the process executes in
type Attributes interface {
        // GetAttr returns the value of attr
        GetAttr(attr string) (string, error)
        // SetAttr sets the attr to val
        SetAttr(attr string, val string) error
        // GetAttrList returns a list of attrs that can be retrieved
        GetAttrList() []string
        // GetAttrDesc returns the description of attr
        GetAttrDesc(attr string) (string, error)
        /* Example:

        * Network:
        - Bandwidth
        - Jitter
        - Latency
        - Packet_Loss

        * CPU
        - Limit

        * RAM
        - Limit

        */
}

// Metrics are ways to gather information during process execution
type Metrics interface {
        // Events returns reader for events
        Events() (io.ReadCloser, error)
        // Logs returns reader for logs
        Logs() (io.ReadCloser, error)

        // Heartbeat returns key values pairs of a defined set of metrics
        Heartbeat() (map[string]interface{}, error)
        // Metric returns metric value at key
        Metric(key string) (interface{}, error)
        /* Examples:

        * Filesystem:
        - device_name
        - swap
        - mount_point
        - total
        - pct_used

        * CPU
        - cores
        - iowait
        - pct_used

        * RAM
        - total
        - pct_used

        * Network
        - bwout
        - bwin
        - ping

        */
}

// TestbedNode specifies the interface to a process controlled by iptb
type Core interface {
        // Allows a node to run an initialization it may require
        // Ex: Installing additional dependencies / setting up configuration
        Init(ctx context.Context, agrs ...string) (TBOutput, error)
        // Starts the node
        Start(ctx context.Context, args ...string) error
        // Stops the node
        Stop(ctx context.Context, wait bool) error
        // Runs a command in the context of the node
        RunCmd(ctx context.Context, args ...string) (TBOutput, error)
        // Connect the node to another
        Connect(ctx context.Context, tbn TestbedNode, timeout time.Duration) error
        // Starts a shell in the context of the node
        Shell(ctx context.Context, nodes []TestbedNode) error

        // Writes a log line to stdout
        Infof(format string, args ...interface{})
        // Writes a log line to stderr
        Errorf(format string, args ...interface{})
        // StderrReader returns reader of stderr for the node
        StderrReader() (io.ReadCloser, error)
        // StdoutReader returns reader of stdout for the node
        StdoutReader() (io.ReadCloser, error)

        // Dir returns the iptb directory assigned to the node
        Dir() string
        // Type returns the type of node
        Type() string
        // Type returns the deployment
        Deployment() string
        // String returns a unique identify
        String() string
}

possible inspiration for attribute types: https://github.com/uber-go/zap/blob/master/zapcore/field.go#L97-L103