@ably/cli
Version:
Ably CLI for Pub/Sub, Chat and Spaces
170 lines (169 loc) • 8.11 kB
JavaScript
import { Args, Flags } from "@oclif/core";
import chalk from "chalk";
import { AblyBaseCommand } from "../../../base-command.js";
import { waitUntilInterruptedOrTimeout } from "../../../utils/long-running.js";
export default class ChannelsOccupancySubscribe extends AblyBaseCommand {
static args = {
channel: Args.string({
description: "Channel name to subscribe to occupancy events",
required: true,
}),
};
static description = "Subscribe to occupancy events on a channel";
static examples = [
"$ ably channels occupancy subscribe my-channel",
'$ ably channels occupancy subscribe my-channel --api-key "YOUR_API_KEY"',
'$ ably channels occupancy subscribe my-channel --token "YOUR_ABLY_TOKEN"',
"$ ably channels occupancy subscribe my-channel --json",
"$ ably channels occupancy subscribe my-channel --pretty-json",
"$ ably channels occupancy subscribe my-channel --duration 30",
];
static flags = {
...AblyBaseCommand.globalFlags,
duration: Flags.integer({
description: "Automatically exit after the given number of seconds (0 = run indefinitely)",
char: "D",
required: false,
}),
};
cleanupInProgress = false;
client = null;
async properlyCloseAblyClient() {
if (!this.client || this.client.connection.state === 'closed' || this.client.connection.state === 'failed') {
return;
}
return new Promise((resolve) => {
const timeout = setTimeout(() => {
resolve();
}, 2000);
const onClosedOrFailed = () => {
clearTimeout(timeout);
resolve();
};
this.client.connection.once('closed', onClosedOrFailed);
this.client.connection.once('failed', onClosedOrFailed);
this.client.close();
});
}
// Override finally to ensure resources are cleaned up
async finally(err) {
await this.properlyCloseAblyClient();
return super.finally(err);
}
async run() {
const { args, flags } = await this.parse(ChannelsOccupancySubscribe);
let channel = null;
try {
this.client = await this.createAblyRealtimeClient(flags);
if (!this.client)
return;
const client = this.client;
const channelName = args.channel;
// Get channel with occupancy option enabled
channel = client.channels.get(channelName, {
params: {
occupancy: 'metrics'
}
});
// Set up connection state logging
this.setupConnectionStateLogging(client, flags, {
includeUserFriendlyMessages: true
});
// Set up channel state logging
this.setupChannelStateLogging(channel, flags, {
includeUserFriendlyMessages: true
});
// Subscribe to occupancy events - these are delivered as channel events
// According to docs, occupancy updates come as [meta]occupancy events
const occupancyEventName = "[meta]occupancy";
this.logCliEvent(flags, "occupancy", "subscribing", `Subscribing to occupancy events on channel: ${channelName}`, { channel: channelName });
if (!this.shouldOutputJson(flags)) {
this.log(`${chalk.green("Subscribing to occupancy events on channel:")} ${chalk.cyan(channelName)}`);
}
channel.subscribe(occupancyEventName, (message) => {
const timestamp = message.timestamp
? new Date(message.timestamp).toISOString()
: new Date().toISOString();
const event = {
channel: channelName,
event: occupancyEventName,
data: message.data,
timestamp,
};
this.logCliEvent(flags, "occupancy", "occupancyUpdate", `Occupancy update received for channel ${channelName}`, event);
if (this.shouldOutputJson(flags)) {
this.log(this.formatJsonOutput(event, flags));
}
else {
this.log(`${chalk.gray(`[${timestamp}]`)} ${chalk.cyan(`Channel: ${channelName}`)} | ${chalk.yellow("Occupancy Update")}`);
if (message.data !== null && message.data !== undefined) {
this.log(`${chalk.green("Occupancy Data:")} ${JSON.stringify(message.data, null, 2)}`);
}
this.log(""); // Empty line for better readability
}
});
this.logCliEvent(flags, "occupancy", "listening", "Listening for occupancy events. Press Ctrl+C to exit.");
if (!this.shouldOutputJson(flags)) {
this.log("Listening for occupancy events. Press Ctrl+C to exit.");
}
// Wait until the user interrupts or the optional duration elapses
const effectiveDuration = typeof flags.duration === "number" && flags.duration > 0
? flags.duration
: process.env.ABLY_CLI_DEFAULT_DURATION
? Number(process.env.ABLY_CLI_DEFAULT_DURATION)
: undefined;
const exitReason = await waitUntilInterruptedOrTimeout(effectiveDuration);
this.logCliEvent(flags, "occupancy", "runComplete", "Exiting wait loop", { exitReason });
this.cleanupInProgress = exitReason === "signal";
}
catch (error) {
const errorMsg = error instanceof Error ? error.message : String(error);
this.logCliEvent(flags, "occupancy", "fatalError", `Error during occupancy subscription: ${errorMsg}`, { channel: args.channel, error: errorMsg });
if (this.shouldOutputJson(flags)) {
this.log(this.formatJsonOutput({ channel: args.channel, error: errorMsg, success: false }, flags));
}
else {
this.error(`Error: ${errorMsg}`);
}
}
finally {
// Wrap all cleanup in a timeout to prevent hanging
await Promise.race([
this.performCleanup(flags || {}, channel),
new Promise((resolve) => {
setTimeout(() => {
this.logCliEvent(flags || {}, "occupancy", "cleanupTimeout", "Cleanup timed out after 5s, forcing completion");
resolve();
}, 5000);
})
]);
if (!this.shouldOutputJson(flags || {})) {
if (this.cleanupInProgress) {
this.log(chalk.green("Graceful shutdown complete (user interrupt)."));
}
else {
this.log(chalk.green("Duration elapsed – command finished cleanly."));
}
}
}
}
async performCleanup(flags, channel) {
// Unsubscribe from occupancy events with timeout
if (channel) {
try {
await Promise.race([
Promise.resolve(channel.unsubscribe("[meta]occupancy")),
new Promise((resolve) => setTimeout(resolve, 1000))
]);
this.logCliEvent(flags, "occupancy", "unsubscribedOccupancy", "Unsubscribed from occupancy events");
}
catch (error) {
this.logCliEvent(flags, "occupancy", "unsubscribeError", `Error unsubscribing from occupancy: ${error instanceof Error ? error.message : String(error)}`);
}
}
// Close Ably client (already has internal timeout)
this.logCliEvent(flags, "connection", "closingClientFinally", "Closing Ably client.");
await this.properlyCloseAblyClient();
this.logCliEvent(flags, "connection", "clientClosedFinally", "Ably client close attempt finished.");
}
}