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- <h1>Attaching Logs</h1>
- <p>SITE_NAME ping endpoints accept HTTP HEAD, GET and POST request methods.</p>
- <p>When using HTTP POST, <strong>you can include arbitrary payload in the request body</strong>.
- If the request body looks like a UTF-8 string, SITE_NAME will log the
- first 10 kilobytes (10 000 bytes) of the request body, so you can inspect it later.</p>
- <h2>Logging Command Output</h2>
- <p>In this example, we run <code>certbot renew</code>, capture its output, and submit
- the captured output to SITE_NAME:</p>
- <div class="bash highlight"><pre><span></span><code><span class="ch">#!/bin/sh</span>
-
- <span class="nv">m</span><span class="o">=</span><span class="k">$(</span>/usr/bin/certbot renew <span class="m">2</span>><span class="p">&</span><span class="m">1</span><span class="k">)</span>
- curl -fsS -m <span class="m">10</span> --retry <span class="m">5</span> --data-raw <span class="s2">"</span><span class="nv">$m</span><span class="s2">"</span> PING_URL
- </code></pre></div>
-
-
- <h2>In Combination with the <code>/fail</code> Endpoint</h2>
- <p>We can extend the previous example and signal either success or failure
- depending on the exit code:</p>
- <div class="bash highlight"><pre><span></span><code><span class="ch">#!/bin/sh</span>
-
- <span class="nv">url</span><span class="o">=</span>PING_URL
-
- <span class="nv">m</span><span class="o">=</span><span class="k">$(</span>/usr/bin/certbot renew <span class="m">2</span>><span class="p">&</span><span class="m">1</span><span class="k">)</span>
-
- <span class="k">if</span> <span class="o">[</span> <span class="nv">$?</span> -ne <span class="m">0</span> <span class="o">]</span><span class="p">;</span> <span class="k">then</span> <span class="nv">url</span><span class="o">=</span><span class="nv">$url</span>/fail<span class="p">;</span> <span class="k">fi</span>
- curl -fsS -m <span class="m">10</span> --retry <span class="m">5</span> --data-raw <span class="s2">"</span><span class="nv">$m</span><span class="s2">"</span> <span class="nv">$url</span>
- </code></pre></div>
-
-
- <p>The above script can be packaged in a single line. The one-line
- version sacrifices some readability, but it can be used directly in crontab,
- without using a wrapper script:</p>
- <div class="bash highlight"><pre><span></span><code><span class="nv">m</span><span class="o">=</span><span class="k">$(</span>/usr/bin/certbot renew <span class="m">2</span>><span class="p">&</span><span class="m">1</span><span class="k">)</span><span class="p">;</span> curl -fsS --data-raw <span class="s2">"</span><span class="nv">$m</span><span class="s2">"</span> <span class="s2">"PING_URL</span><span class="k">$(</span><span class="o">[</span> <span class="nv">$?</span> -ne <span class="m">0</span> <span class="o">]</span> <span class="o">&&</span> <span class="nb">echo</span> -n /fail<span class="k">)</span><span class="s2">"</span>
- </code></pre></div>
-
-
- <h2>Using Runitor</h2>
- <p><a href="https://github.com/bdd/runitor">Runitor</a> is a third party utility that runs the
- supplied command, captures its output and and reports to SITE_NAME.
- It also measures the execution time, and retries HTTP requests on transient errors.
- Best of all, the syntax is simple and clean:</p>
- <div class="bash highlight"><pre><span></span><code>runitor -uuid your-uuid-here -- /usr/bin/certbot renew
- </code></pre></div>
-
-
- <h2>Handling More Than 10KB of Logs</h2>
- <p>While SITE_NAME can store a small amount of logs in a pinch, it is not specifically
- designed for that. If you run into the issue of logs getting cut off, consider
- the following options:</p>
- <ul>
- <li>See if the logs can be made less verbose. For example, if you have a batch job
- that outputs a line of text per item processed, perhaps it can output a short
- summary with the totals instead.</li>
- <li>If the important content is usually at the end, submit the <strong>last 10KB</strong> instead
- of the first. Here is an example that submits the last 10KB of <code>dmesg</code> output:</li>
- </ul>
- <div class="bash highlight"><pre><span></span><code><span class="ch">#!/bin/sh</span>
-
- <span class="nv">m</span><span class="o">=</span><span class="k">$(</span>dmesg <span class="p">|</span> tail --bytes<span class="o">=</span><span class="m">10000</span><span class="k">)</span>
- curl -fsS -m <span class="m">10</span> --retry <span class="m">5</span> --data-raw <span class="s2">"</span><span class="nv">$m</span><span class="s2">"</span> PING_URL
- </code></pre></div>
-
-
- <ul>
- <li>Finally, if for your use case it is critical to capture the entire log output,
- consider using a dedicated log aggregation service for capturing the logs.</li>
- </ul>
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