user91279: I want to use multiple nodes with the same remote bitcoind. E.g. my node on my desktop, my node on digital ocean, my node on Google cloud ...
I don't want to run everywhere a full bitcoind and pay for the disk space. 
I currently check the option to use btcpayserver (docker) on Google cloud as well. Again, it would need bitcoind. 
Any hints welcome.

user120: c-lightning internally calls bitcoin-cli and will pass a couple of commandline arguments to it. These arguments are all prefixed with --bitcoin-* and will match the ones that bitcoin-cli accepts.
So for your use-case you first need to make sure that bitcoin-cli is available on the machine that you will be running the c-lightning instances on. If it isn't you can simply use the Bitcoin PPA to install (but not run) bitcoind which will also install bitcoin-cli (assuming you're using a debian based OS):
sudo add-apt-repository ppa:bitcoin/bitcoin
sudo apt-get update

For a remote bitcoind you need to specify the following arguments:

--bitcoin-rpcconnect=<bitcoind-ip:port> this tells bitcoin-cli to connect to a remote bitcoind instance instead of trying localhost:8332 (make sure bitcoind is configured with -rpcallowip=<ip>, where <ip> is the machine you'll be running c-lightning on)
--bitcoin-rpcuser=<username> the username configured with bitcoind
--bitcoin-rpcpassword=<password> the password configured with bitcoind

In any case I'd suggest running bitcoin-cli --bitcoin-rpcconnect=<bitcoind-ip:port> --bitcoin-rpcuser=<username> --bitcoin-rpcpassword=<password> from the command line on the c-lightning machine to verify that bitcoind and bitcoin-cli are configured correctly.

91279: <p>I want to use multiple nodes with the same remote bitcoind. E.g. my node on my desktop, my node on digital ocean, my node on Google cloud ...</p>

<p>I don't want to run everywhere a full bitcoind and pay for the disk space. 
I currently check the option to use btcpayserver (docker) on Google cloud as well. Again, it would need bitcoind. </p>

<p>Any hints welcome.</p>
 120: <p>c-lightning internally calls <code>bitcoin-cli</code> and will pass a couple of commandline arguments to it. These arguments are all prefixed with <code>--bitcoin-*</code> and will match the ones that <code>bitcoin-cli</code> accepts.</p>

<p>So for your use-case you first need to make sure that <code>bitcoin-cli</code> is available on the machine that you will be running the c-lightning instances on. If it isn't you can simply use the Bitcoin PPA to install (but not run) <code>bitcoind</code> which will also install <code>bitcoin-cli</code> (assuming you're using a debian based OS):</p>

<pre><code>sudo add-apt-repository ppa:bitcoin/bitcoin
sudo apt-get update
</code></pre>

<p>For a remote <code>bitcoind</code> you need to specify the following arguments:</p>

<ul>
<li><code>--bitcoin-rpcconnect=&lt;bitcoind-ip:port&gt;</code> this tells <code>bitcoin-cli</code> to connect to a remote <code>bitcoind</code> instance instead of trying <code>localhost:8332</code> (make sure <code>bitcoind</code> is configured with <code>-rpcallowip=&lt;ip&gt;</code>, where <code>&lt;ip&gt;</code> is the machine you'll be running c-lightning on)</li>
<li><code>--bitcoin-rpcuser=&lt;username&gt;</code> the username configured with <code>bitcoind</code></li>
<li><code>--bitcoin-rpcpassword=&lt;password&gt;</code> the password configured with <code>bitcoind</code></li>
</ul>

<p>In any case I'd suggest running <code>bitcoin-cli --bitcoin-rpcconnect=&lt;bitcoind-ip:port&gt; --bitcoin-rpcuser=&lt;username&gt; --bitcoin-rpcpassword=&lt;password&gt;</code> from the command line on the c-lightning machine to verify that <code>bitcoind</code> and <code>bitcoin-cli</code> are configured correctly.</p>
