What causes "Password should be at least 8 characters long" in testcontainers/testcontainers-java?

Use a password of at least 8 characters that also meets the 3-of-4 category rule

testcontainers/testcontainers-java · error · IllegalArgumentException

Password should be at least 8 characters long

Error message

Password should be at least 8 characters long

What it means

checkPasswordStrength() enforces a minimum password length of 8 characters, matching SQL Server's policy. Shorter passwords would be rejected by the SQL Server container at startup, so testcontainers throws IllegalArgumentException early. It is raised from withPassword().

Solutions

Use a password of at least 8 characters that also meets the 3-of-4 category rule
Generate a strong test password, e.g. "yourStrong(!)Password"
Check length before calling withPassword()

Example fix

// before
container.withPassword("pass123");
// after
container.withPassword("pass1234!");

Defensive patterns

Strategy: validation

Validate before calling

if (password == null || password.length() < 8) { throw new IllegalArgumentException("Password must be at least 8 characters"); }

Try / catch

try { container.withPassword(pw); } catch (IllegalArgumentException e) { throw new IllegalStateException("Weak SA password: " + e.getMessage(), e); }

Prevention

Use a shared constant strong test password across the test suite
Add a length assert in test setup before container construction

When it happens

Trigger: Calling withPassword() with a String shorter than 8 characters, e.g. withPassword("pass123") (7 chars).

Common situations: Using weak test passwords like "admin" or "sa123" in test configs; shortened passwords generated by tooling; copying examples without strengthening the sample password.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

AI-assisted analysis of testcontainers/testcontainers-java@8e549514e3 (2026-09-12). Data as JSON: /api/errors/1f1309830ba779f1. Report an issue: GitHub.

Appendix: source

Thrown at modules/mssqlserver/src/main/java/org/testcontainers/containers/MSSQLServerContainer.java:146

    @Override
    public String getTestQueryString() {
        return "SELECT 1";
    }

    @Override
    public SELF withPassword(final String password) {
        checkPasswordStrength(password);
        this.password = password;
        return self();
    }

    private void checkPasswordStrength(String password) {
        if (password == null) {
            throw new IllegalArgumentException("Null password is not allowed");
        }

        if (password.length() < 8) {
            throw new IllegalArgumentException("Password should be at least 8 characters long");
        }

        if (password.length() > 128) {
            throw new IllegalArgumentException("Password can be up to 128 characters long");
        }

        long satisfiedCategories = Stream
            .of(PASSWORD_CATEGORY_VALIDATION_PATTERNS)
            .filter(p -> p.matcher(password).find())
            .count();

        if (satisfiedCategories < 3) {
            throw new IllegalArgumentException(
                "Password must contain characters from three of the following four categories:\n" +
                " - Latin uppercase letters (A through Z)\n" +
                " - Latin lowercase letters (a through z)\n" +
                " - Base 10 digits (0 through 9)\n" +
                " - Non-alphanumeric characters such as: exclamation point (!), dollar sign ($), number sign (#), " +

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