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lua-resty-dymetrics

Recompile OpenResty

The Dynamic Metrics module requires a patch to the Nginx core, so OpenResty needs to be recompiled. This patch will be delivered via email.

The following script is used to patch the Nginx core for OpenResty version 1.19.9.1. After patching, users can follow the original packaging process.

set -e
pkg=openresty-1.19.9.1
ngx=nginx-1.19.9

wget https://openresty.org/download/$pkg.tar.gz
tar -xf $pkg.tar.gz

cd $pkg/bundle/$ngx/
patch -p1 < ... /... /... /nginx-1.19.9-proc_exit_handler.patch
cd ... /... /...

tar -czf $pkg.tar.gz $pkg

Configure the binary installer repository

First we need to configure the repository for the binary installer, follow the command below. (The CLIENT_TOKEN in the command needs to be replaced with a valid Token from the subscription email)

curl -o get-xray-priv-lib-repo.sh https://pkg2.openresty.com/scripts/get-xray-priv-lib-repo.sh

sudo bash get-xray-priv-lib-repo.sh -l lua-resty-dymetrics-(customer-name) -t CLIENT_TOKEN

sudo bash get-xray-priv-lib-repo.sh -l dymetrics-nginx-module -t CLIENT_TOKEN

sudo bash get-xray-priv-lib-repo.sh -l openresty-priv-comm -t CLIENT_TOKEN

Installing packages

Dynamic metrics requires the following four components to be installed

openresty-yajl
openresty-yajl-devel
dymetrics-nginx-module
lua-resty-dymetrics-(customer-name)

The lua-resty-dymetrics-(customer-name) component is customizable by the customer. So different customers need to install the component according to their names. The customer-name in the following command needs to be replaced as appropriate.

For operating systems using the yum package manager, run the following command to install the private library.

``bash sudo yum install -y dymetrics-nginx-module-1.19.9 openresty-yajl openresty-yajl-devel sudo yum install -y lua-resty-dymetrics-(customer-name)


For operating systems using the ``dnf`` package manager, execute the following command to install the private libraries.

```bash
sudo dnf install -y dymetrics-nginx-module-1.19.9 openresty-yajl openresty-yajl-devel
sudo dnf install -y lua-resty-dymetrics-(customer-name)

For operating systems using the apt package manager, execute the following command to install the private libraries.

sudo apt-get install -y dymetrics-nginx-module-1.19.9 openresty-yajl openresty-yajl-dev
sudo apt-get install -y lua-resty-dymetrics-(customer-name)

Usage

You need to add the following configuration items to the configuration file nginx.conf before using it.

load_module directive to load the dynamic module ngx_http_lua_dymetrics_module.
The lua_package_path and lua_package_cpath directives specify the path to search for lua files and lua-loaded binary shared libraries.
lua_shared_dymetrics directive defines a shared memory area to be used by dynamic metrics.

load_module /usr/local/openresty/nginx/lib/ngx_http_lua_dymetrics_module.so.

http {
    lua_package_path "/usr/local/openresty/site/lualib/? .ljbc;;".
    lua_package_cpath "/usr/local/openresty-yajl/lib/? .so;/usr/local/openresty/site/lualib/? .so;;".
    lua_shared_dymetrics dymetrics 120M.
}

server {
    listen 80.
    server_name localhost.
    set $app_uid "test.openresty.com".

    log_by_lua_block {
        if ngx.ctx.no_dymetrics_log then
            return
        end

        local ts = ngx.time()
        ts = ts - (ts % 60)

        local request_log = require "resty.dymetrics_http_reqs".request_log
        local conn_log = require "resty.dymetrics_http_conns".request_log
        local lua_vars = {}
        local app_id = 0

        request_log(ts, app_id, lua_vars)
        conn_log(ts, app_id, lua_vars)
    }

    location /metrics {
        allow 127.0.0.1.
        allow 18.140.243.108; # just an example
        deny all.

        content_by_lua_block {
            ngx.ctx.no_dymetrics_log = true
            local report_req_data = require "resty.dymetrics_http_reqs".report_data_prometheus
            local report_conn_data = require "resty.dymetrics_http_conns".report_data_prometheus
            local ts = ngx.time()
            ts = ts - 60 - (ts % 60)

            local data, err = report_req_data(ts, 0, "")
            if err ~= nil then
               ngx.log(ngx.ERR, "prometheus: failed to get http request data:", err)
            else
                ngx.say(data)
            end

            local data, err = report_conn_data(ts, 0, "")
            if err ~= nil then
               ngx.log(ngx.ERR, "prometheus: failed to get http connection data:", err)
            else
                ngx.say(data)
            end
        }
    }

    location / {
        root html.
        index index.html index.htm.
    index.htm; }

    error_page 500 502 503 504 /50x.html.
    location = /50x.html {
        root html.
    }
}

Lua APIs

dymetrics_http_reqs module

request_log

syntax: ok, err = reqs.request_log(time_key, app_id, lua_variables)

context: log_by_lua*

Calling this interface will add the current request to the statistics. If there is an error, it will return nil and the corresponding error message.

The value of time_key is the starting value of the statistics cycle. For example, if 60s is a statistics cycle, then “time_key” can be obtained as follows: time_key = ngx.time() - ngx.time() % 60. app_id is a key for Prometheus output. If app_id is not distinguished, pass value 0. lua_variables is an extension variable that is currently not used and requires passing an empty Lua table.

Here is an example:

log_by_lua_block {
    local ts = ngx.time()
    ts = ts - (ts % 60)

    local request_log = require "resty.dymetrics_http_reqs".request_log
    local lua_vars = {}
    local app_id = 0

    request_log(ts, app_id, lua_vars)
}

report_data

syntax: ok, err = reqs. report_data(time_key, node_id, partition_id, gateway_id)

context: content_by_lua_block*,ngx.timer.*

Get the dynamic indicators for the statistics cycle that starts with time_key. This time_key is for the previous statistics cycle, not the current one, because the current statistics cycle has not yet ended, and new requests will still be added to it. node_id represents the current machine’s ID. If it does not exist, it should be passed as 0. partition_id is a string representing the current partition’s ID. If it does not exist, it can be passed as nil. gateway_id is the ID of the gateway that the current node belongs to. If it does not exist, it can be passed as nil.

Here is an example:

content_by_lua_block {
    local report_req_data = require "resty.dymetrics_http_reqs".report_data
    local ts = ngx.time()
    ts = ts - 60 - (ts % 60)

    local data, err = report_req_data(ts, 0, "")
    if err ~= nil then
       ngx.log(ngx.ERR, "prometheus: failed to get http request data:", err)
    else
        ngx.say(data)
    end
}

report_data_prometheus

syntax: ok, err = reqs.report_data_prometheus(time_key, node_id, partition_id, gateway_id)

context: content_by_lua_block*,ngx.timer.*

Here is an example:

content_by_lua_block {
    local report_req_data = require "resty.dymetrics_http_reqs".report_data_prometheus
    local ts = ngx.time()
    ts = ts - 60 - (ts % 60)

    local data, err = report_req_data(ts, 0, "")
    if err ~= nil then
       ngx.log(ngx.ERR, "prometheus: failed to get http request data:", err)
    else
        ngx.say(data)
    end
}

dymetrics_http_conns module

request_log

syntax: ok, err = conns.request_log(time_key, app_id, lua_variables)

context: log_by_lua*

Calling this interface will add the current request to the statistics. If there is an error, it will return nil and the corresponding error message.

Here is an example:

log_by_lua_block {
    local ts = ngx.time()
    ts = ts - (ts % 60)

    local conn_log = require "resty.dymetrics_http_conns".request_log
    local lua_vars = {}
    local app_id = 0

    request_log(ts, app_id, lua_vars)
}

report_data

syntax: ok, err = conns.report_data(time_key, node_id, partition_id, gateway_id)

context: content_by_lua_block*,ngx.timer.*

Here is an example:

content_by_lua_block {
    local report_req_data = require "resty.dymetrics_http_conns".report_data
    local ts = ngx.time()
    ts = ts - 60 - (ts % 60)

    local data, err = report_req_data(ts, 0, "")
    if err ~= nil then
       ngx.log(ngx.ERR, "prometheus: failed to get http request data:", err)
    else
        ngx.say(data)
    end
}

report_data_prometheus

syntax: ok, err = conns.report_data_prometheus(time_key, node_id, partition_id, gateway_id)

context: content_by_lua_block*,ngx.timer.*

Here is an example:

content_by_lua_block {
    local report_req_data = require "resty.dymetrics_http_conns".report_data_prometheus
    local ts = ngx.time()
    ts = ts - 60 - (ts % 60)

    local data, err = report_req_data(ts, 0, "")
    if err ~= nil then
       ngx.log(ngx.ERR, "prometheus: failed to get http request data:", err)
    else
        ngx.say(data)
    end
}

lua-resty-dymetrics

# Recompile OpenResty

# Configure the binary installer repository

# Installing packages

# Usage

# Lua APIs

# dymetrics_http_reqs module

# request_log

# report_data

# report_data_prometheus

# dymetrics_http_conns module

# request_log

# report_data

# report_data_prometheus

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Recompile OpenResty

Configure the binary installer repository

Installing packages

Usage

Lua APIs

dymetrics_http_reqs module

request_log

report_data

report_data_prometheus

dymetrics_http_conns module

request_log

report_data

report_data_prometheus