Function readMappedHostPort

packages/container/src/dev.ts:308–328

Read the host port Docker mapped for `containerPort` on a running container.

(
  containerName: string,
  containerPort: number,
  out: DevOutput
)

/** Read the host port Docker mapped for `containerPort` on a running container. */
async function readMappedHostPort(
  containerName: string,
  containerPort: number,
  out: DevOutput
): Promise<number> {
  const { stdout } = await runForwarded(
    'docker',
    ['port', containerName, `${containerPort}/tcp`],
    out,
    { quiet: true }
  );
  // Output like "0.0.0.0:54321" (possibly multiple lines for ipv4/ipv6).
  const match = stdout.match(/:(\d+)\s*$/m);
  if (!match) {
    throw new Error(
      `Could not determine mapped host port for ${containerName} ` +
        `(${containerPort}/tcp). Got: ${stdout.trim()}`
    );
  }
  return Number(match[1]);
}

function uniqueContainerName(serviceName: string): string {
  const safe = serviceName.toLowerCase().replace(/[^a-z0-9-_.]/g, '-');