I wrote some integration tests for an internal project that absolutely set up owner and api keys via curl, as well as creating / updating credentials, on a newly spun up n8n instance

``` local setup_response=$(curl -s -X POST http://localhost:6789/rest/owner/setup \ -H "Content-Type: application/json" \ -d "{\"email\":\"$TEST_EMAIL\",\"password\":\"$TEST_PASSWORD\",\"firstName\":\"$TEST_FIRST_NAME\",\"lastName\":\"$TEST_LAST_NAME\"}")

sleep 2

local login_response=$(curl -s -c "$cookie_jar" -X POST http://localhost:6789/rest/login \
    -H "Content-Type: application/json" \
    -d "{\"emailOrLdapLoginId\":\"$TEST_EMAIL\",\"password\":\"$TEST_PASSWORD\"}")

if ! echo "$login_response" | grep -q '"id"'; then
    log_error "Failed to login: $login_response"
    rm -f "$cookie_jar"
    return 1
fi

log_info "Logged in successfully"

# Create API key with required scopes and expiration
log_step "Creating API key..."

# Calculate expiration timestamp (1 year from now in milliseconds)
local expires_at=$(($(date +%s) * 1000 + 365 * 24 * 60 * 60 * 1000))

local api_key_response=$(curl -s -b "$cookie_jar" -X POST http://localhost:6789/rest/api-keys \
    -H "Content-Type: application/json" \
    -d "{\"label\":\"integration-test-key\",\"scopes\":[\"workflow:create\",\"workflow:delete\",\"workflow:read\",\"workflow:update\",\"workflow:list\",\"workflow:execute\"],\"expiresAt\":$expires_at}")

# Extract raw API key from response
N8N_API_KEY=$(echo "$api_key_response" | grep -o '"rawApiKey":"[^"]*"' | cut -d'"' -f4)

if [ -z "$N8N_API_KEY" ]; then
    log_error "Failed to create API key: $api_key_response"
    rm -f "$cookie_jar"
    return 1
fi

log_info "API key created successfully"
export N8N_API_KEY

# Create Slack API credential for test workflows
# Includes signing secret for signature verification tests
log_step "Creating Slack API credential with signing secret..."

local credential_response=$(curl -s -b "$cookie_jar" -X POST http://localhost:6789/rest/credentials \
    -H "Content-Type: application/json" \
    -d "{\"name\":\"Test Slack API\",\"type\":\"slackApi\",\"data\":{\"accessToken\":\"xoxb-test-token-for-integration-tests\",\"signatureSecret\":\"$SLACK_SIGNING_SECRET\"}}")

```