File upload

Most Selenium clients implement the WebDriver /file endpoint, so uploading usually works out of the box — the client zips the local file and pushes it to the hub, and the browser sees it on its own filesystem.

Client snippets

Java

WebElement input = driver.findElement(By.cssSelector("input[type='file']"));

// Make sure the element is visible
((JavascriptExecutor) driver).executeScript(
    "arguments[0].style.display = 'block';", input);

// Configure the client to upload local files to the remote Selenium instance
driver.setFileDetector(new LocalFileDetector());

// Local path on the machine running the tests — not inside the container!
input.sendKeys("/path/to/file/on/machine/which/runs/tests");

Python

from selenium.webdriver.remote.file_detector import LocalFileDetector

input = driver.find_element(By.CSS_SELECTOR, "input[type='file']")
driver.execute_script("arguments[0].style.display = 'block';", input)
driver.file_detector = LocalFileDetector()
input.send_keys("/path/to/file/on/machine/which/runs/tests")

WebdriverIO

const remoteFilePath = browser.uploadFile('/path/to/local/file');
$("input[type='file']").setValue(remoteFilePath);

How it works

Not every driver implements the WebDriver upload endpoint — geckodriver, IEDriver and WebKitWebDriver do not. WebSummoner fills that gap itself, so upload behaves the same on every browser it ships.

In Docker mode, the hub unpacks the uploaded archive and copies the file straight into the browser container, then hands the driver the resulting in-container path. Nothing has to be shared between the hub and the container, and the driver never needs its own upload support.

Files land in /opt/websummoner/uploads inside the container and disappear with it. The file is written by a process running in the container, so it is owned by the browser’s own user and readable only by it (0600), and the directory behaves like /tmp — sticky and world-writable. You may mount a tmpfs over it if you want uploads to stay in memory.

The directory does not have to exist in the image — it is created on first upload — so this works with custom and older browser images too. Images without tar fall back to the Docker copy API automatically; the only thing that mode cannot do is write into a mounted destination. Start the hub with:

./websummoner -enable-file-upload

In drivers mode there is no container, so the hub writes the file to its own filesystem and returns that path:

./websummoner -disable-docker -enable-file-upload