add explicit information for the Rapsberry pi

docs/alternative-architectures.md

@@ -10,6 +10,11 @@ Currently supported architectures are the following:
 - `arm64`
 - `arm32`
 
+so for the Raspberry Pi the following should be in your `vars.yaml` file:
+```
+matrix_architecture = "arm32"
+```
+
 ## Implementation details
 This subsection is used for a reminder, how the different roles implement architecture differenes. This is **not** aimed at the users, so one does not have to do anything based on this subsection.
 

docs/prerequisites.md

@@ -1,6 +1,6 @@
 # Prerequisites
 
-- An x86 server running **CentOS** (7 only for now; [8 is not yet supported](https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/300)), **Debian** (9/Stretch+), **Ubuntu** (16.04+), or **Archlinux**. This playbook doesn't support running on ARM ([see](https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/299)), however a minimal subset of the tools can be built on the host, which may result in a working configuration, even on a Raspberry pi (see [Self-Building](self-building.md)). We only strive to support released stable versions of distributions, not betas or pre-releases. This playbook can take over your whole server or co-exist with other services that you have there.
+- An x86 server running **CentOS** (7 only for now; [8 is not yet supported](https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/300)), **Debian** (9/Stretch+), **Ubuntu** (16.04+), or **Archlinux**. This playbook doesn't support running on ARM ([see](https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/299)), however a minimal subset of the tools can be built on the host, which may result in a working configuration, even on a Raspberry pi (see [Alternative Architectures](alternative-architectures.md)). We only strive to support released stable versions of distributions, not betas or pre-releases. This playbook can take over your whole server or co-exist with other services that you have there.
 
 - `root` access to your server (or a user capable of elevating to `root` via `sudo`).
 

docs/self-building.md

@@ -1,5 +1,7 @@
 # Self-building
 
+**Caution: self-building does not have to be used on its own. See the [Alternative Architectures](alternative-architectures.md) page.**
+
 The playbook supports the self-building of some of its components. This may be useful for architectures besides x86_64, which have no Docker images right now (e g. the armv7 for the Raspberry Pi). Some playbook roles have been updated, so they build the necessary image on the host. It needs more space, as some build tools need to be present (like Java, for ma1sd).
 
 To use these modification there is a variable that needs to be switched to enable this functionality. Add this to your `vars.yaml` file: