Using LTS to Configure Block Alarms for WAF Rules

Application Scenarios

After you authorize WAF to access Log Tank Service (LTS), you can use the attack logs recorded by LTS for quick and efficient real-time analysis, device O&M management, and analysis of service trends.

This topic walks you through how to enable LTS quick analysis for WAF attack logs and configure alarm rules to analyze WAF attack logs and generate alarms. In this way, you can gain insight into the protection status of your workloads in WAF in real time and make informed decisions.

Resource and Cost Planning

Step 1: Buy the Standard Edition Cloud WAF

The following describes how to buy the standard edition cloud WAF.

1. Log in to the WAF console.
2. In the upper right corner of the page, click Buy WAF. On the purchase page displayed, select Cloud Mode for WAF Mode.
   • Region: Select the region nearest to your services WAF will protect.
   • Edition: Select Standard.
   • Expansion Package and Required Duration: Set them based on site requirements.

3. Confirm the product details and click Buy Now in the lower right corner of the page.
4. Check the order details and read the WAF Disclaimer. Then, select the box and click Pay Now.
5. On the payment page, select a payment method and pay for your order.

   After the order is paid, click Access Console to go to the Dashboard page. Hover over the Product Details area to view the purchased instance edition and its specifications.

Step 2: Add Website Information to WAF

The following example shows how to add a website to WAF in cloud CNAME access mode.

• For details about the cloud load balancer access mode, see Connecting a Website to WAF (Cloud Mode - ELB Access).
• For details about the dedicated mode, see Connecting a Website to WAF (Dedicated Mode).

1. In the navigation pane on the left, choose Website Settings.
2. In the upper left corner of the website list, click Add Website.
3. Select Cloud - CNAME and click Configure Now.
4. Configure website information as prompted.
   Figure 1 Configuring basic information
   

   Table 2 Key parameters

   Parameter	Description	Example Value
   Domain Name	Domain name you want to add to WAF for protection. The domain name has an ICP license. You can enter a single domain name (for example, top-level domain name example.com or level-2 domain name www.example.com) or a wildcard domain name (*.example.com).	www.example.com
   Protected Port	The port over which the website traffic goes	Standard ports
   Server Configuration	Web server address settings. You need to configure the client protocol, server protocol, server weights, server address, and server port. Client Protocol: protocol used by a client to access a server. The options are HTTP and HTTPS. Server Protocol: protocol used by WAF to forward client requests. The options are HTTP and HTTPS. Server Address: public IP address (generally corresponding to the A record of the domain name configured on the DNS) or domain name (generally corresponding to the CNAME record of the domain name configured on the DNS) of the web server that a client accesses. Server Port: service port over which the WAF instance forwards client requests to the origin server. Weight: Requests are distributed across backend origin servers based on the load balancing algorithm you select and the weight you assign to each server.	Client Protocol: Select HTTP. Server Protocol: HTTP Server Address: IPv4 XXX.XXX.1.1 Server Port: 80
   Use Layer-7 Proxy	You need to configure whether you deploy layer-7 proxies in front of WAF. Set this parameter based on your website deployment.	Yes

5. Click Next and complete the basic information about the website to be protected. Perform the following operations as prompted on the Add Website page:
   Figure 2 Domain name added to WAF
   
   1. Whitelist back-to-source IP addresses.
   2. Test WAF.

   After the preceding steps are complete, you can check the Access Status of the added domain name in the domain name list. The Access Status of the domain name is Inaccessible at first. You need to modify the DNS record.

Step 3: Enable LTS for Protection Logs

1. Log in to the WAF console.
2. Click in the upper left corner and select a region or project.
3. (Optional) If you have enabled the enterprise project function, in the upper part of the navigation pane on the left, select your enterprise project from the Filter by enterprise project drop-down list. Then, WAF will display the related security data in the enterprise project on the page.
4. In the navigation pane on the left, choose Events.
5. Click Connect to LTS on the Log Settings tab if needed.

   Table 3 LTS configuration parameters

   Parameter	Description	Example Value
   Log Types	Select the log types you want to transfer to LTS. You can transfer WAF access logs and WAF attack logs. Attack logs and access logs are in different formats. If you select both log types, you need to configure two different log streams.	WAF access logs and WAF attack logs
   Log Group	Select the log group for log transfer. You can also click Create Log Group to create a log group. A log group is the basic unit for LTS to manage logs. It comprises log streams and categorizes them. A log group does not store any log data. It only helps with log stream management. You can create up to 100 log groups for each account. For more details, see Managing Log Groups.	lts-group-waf
   WAF Access Log Stream	If you select WAF access logs for Log Types, you need to configure a WAF access log stream. You can also click Create Log Stream to create a WAF access log stream. This stream logs key information about each HTTP access, including the access time, client IP address, and requested resource URL.	lts-topic-waf-access
   WAF Attack Log Stream	If you select WAF attack logs for Log Types, you need to configure a WAF attack log stream. You can also click Create Log Stream to create a WAF attack log stream. This stream logs key information about each attack, including the attack type, protective action, and attack source IP address.	lts-topic-waf-attack

   The configuration takes about 10 minutes to take effect. After the configuration takes effect, LTS is billed by traffic. For details about LTS pricing, see LTS Pricing Details.

6. Check or analyze logs.

   After WAF is connected to LTS, created log groups (① in Figure 3) and log streams (② in Figure 3) for attack and access logs will be automatically displayed on the Log Settings tab. You can click WAF access log stream or WAF attack log stream to check, search, or analyze WAF logs. For more details, see Searching and Analyzing Logs.

   Figure 3 Log Settings
   

7. After selecting a log stream, on the Log Search tab (③ in Figure 3), choose > Download Logs (④ in Figure 3) to download the reported logs in the log stream.
   • Frontend download: You can directly save log query results to a local PC. Download records will not appear in your log download history. Each time you can download up to 5,000 log records. You can download logs in .csv or .txt format.
   • Offline backend download: You can download log files to a temporary OBS bucket via a backend task. Your browser must have public network access to download these files from your log download history. Each time you can download up to 20 million log records. You can download logs in .csv, .txt, or .json format.

   You can also download log files through an OBS transfer task. For details, see Transferring Logs to OBS.

Step 4: Quickly Analyze Block Logs Generated by Protection Rules

1. Log in to the LTS console.
2. In the log group list, expand the WAF log group and choose log stream attack.
3. On the log stream details page, click in the upper right corner. On the page displayed, click the Cloud Structured Parsing tab.
4. Select JSON for log structuring. Then, click Select from existing events and select a log in the dialog box displayed on the right.
5. Click Intelligent Extraction to find the fields you want to analyze quickly. Enable these fields in the Quick Analysis column. After this, you can collect and analyze periodic logs.
   Figure 4 Log extraction field
   

6. Find the category field, click in the Alias column, change the field name, and click to save the settings.
   

   There is already a built-in category field in the system so you need to change the alias name of the category field, or your settings cannot be saved.

7. In the lower right corner of the list, click Save. LTS quickly analyzes and collects statistics on logs in the specified period.
8. In the navigation pane, choose Visualization. On the right pane, select a log query time range, enter an SQL statement in the search box, and click Query.

   You can group logs by rule and URI. Enter the following SQL statement in the search box to query logs of a specified rule:

   select rule, uri, count(*) as cnt where action = 'block' group by rule, uri order by cnt desc

Step 5: Configure Alarm Rules

1. Log in to the LTS console.
2. In the navigation pane on the left, choose Alarms > Alarm Rules.
3. Click Create. In the dialog box displayed on the right, specify related parameters. Table 4 describes the parameters. Figure 5 shows an example.
   Figure 5 Create Alarm Rule
   

   Table 4 Parameter description

   Parameter	Description	Example Value
   Rule Name	Name of the custom rule.	WAF alarms
   Statistics	Select By SQL.	By SQL
   Charts	Click Configure from Scratch. Specify Log Group Name and Log Stream Name. Query Time Range: Time range for log statistics Query Statement: Enter the SQL statement configured in Step 8, for example, select rule,uri,count(*) as cnt where action='block' group by rule,uri order by cnt desc.	None
   Query Frequency	Frequency that triggers alarms. Generally, a fixed custom interval of 5 minutes is selected.	Custom interval 5 minutes
   Conditional Expression	Alarm threshold.	cnt>5
   Alarm Severity	Select an alarm severity based on the blocking emergency of the rule. The options are critical, major, minor, and info.	Major
   Send Notification	Select Yes.	Yes
   SMN Topic	Select a topic from the drop-down list or create a topic. If there are no topics, click View Topic and perform the following steps to create a topic: Create a topic. For details, see Creating a Topic. Add one or more subscriptions to the topic. You will need to provide a phone number, email address, function, platform application endpoint, DMS endpoint, or HTTP/HTTPS endpoint for receiving alarm notifications. For details, see Adding a Subscription. Confirm the subscription. After the subscription is added, confirm the subscription. For details about topics and subscriptions, see the Simple Message Notification User Guide.	None
   Time Zone/Language	You can modify the language and time zone for receiving messages.	None
   Message Templates	Select an existing template from the drop-down list box or click Create Message Template and create a template.	sql_template

4. Confirm all parameters and click OK. The alarm rule is configured. When the alarm rule is triggered, you will receive an alarm email or SMS message.