Add all the remaining sections to Switching to OTP releases

docs/installation/migrating_from_source_otp_en.md

@@ -2,17 +2,140 @@
 ## Why would one want to switch?
 Benefits of OTP releases over from-source installs include:
 * **Less space used.** OTP releases come without source code, build tools, have docs and debug symbols stripped from the compiled bytecode and do not cointain tests, docs, revision history.
-* **Minimal system dependencies.** Excluding the database and reverse proxy, all you need to download and run a release is `curl`, `unzip` and `ncurses`. Because Erlang runtime and Elixir are shipped with Pleroma, one can use the latest BEAM optimizations and Pleroma features, without having to worry about outdated system repos or a missing `erlang-*` package.
+* **Minimal system dependencies.** Excluding the database and reverse proxy, only `curl`, `unzip` and `ncurses` are needed to download and run the release. Because Erlang runtime and Elixir are shipped with Pleroma, one can use the latest BEAM optimizations and Pleroma features, without having to worry about outdated system repos or a missing `erlang-*` package.
 * **Potentially less bugs and better performance.** This extends on the previous point, because we have control over exactly what gets shipped, we can tweak the VM arguments and forget about weird bugs due to Erlang/Elixir version mismatches.
-* **Faster and less bug-prone mix tasks.** On a from-source install one has to wait untill a new Pleroma node is started for each mix task and they execute outside of the instance context (for example if you deleted a user via a mix task, the instance will have no knowledge of that and continue to display status count and follows before the cache expires). Mix tasks in OTP releases are executed by calling into a running instance via RPC, which solves both of these problems.
+* **Faster and less bug-prone mix tasks.** On a from-source install one has to wait untill a new Pleroma node is started for each mix task and they execute outside of the instance context (for example if a user was deleted via a mix task, the instance will have no knowledge of that and continue to display status count and follows before the cache expires). Mix tasks in OTP releases are executed by calling into a running instance via RPC, which solves both of these problems.
 
 ### Sounds great, how do I switch?
-Currently we support Linux machines with GNU (e.g. Debian, Ubuntu) or musl (e.g. Alpine) libc and `x86_64`, `aarch64` or `armv7l` CPUs. If you are unsure you can check the [Detecting flavour](otp_en.html#detecting-flavour) section in OTP install guide. If your platform is supported, proceed with the guide, if not check the [My platform is not supported](#my-platform-is-not-supported) section.
+Currently we support Linux machines with GNU (e.g. Debian, Ubuntu) or musl (e.g. Alpine) libc and `x86_64`, `aarch64` or `armv7l` CPUs. If you are unsure, check the [Detecting flavour](otp_en.html#detecting-flavour) section in OTP install guide. If your platform is supported, proceed with the guide, if not check the [My platform is not supported](#my-platform-is-not-supported) section.
 ### I don't think it is worth the effort, can I stay on a from-source install?
 Yes, currently there are no plans to deprecate them.
+
 ### My platform is not supported
-If you believe your platform is a popular choice for running Pleroma instances, or has the potential to become one you can [file an issue on our Gitlab](https://git.pleroma.social/pleroma/pleroma/issues/new). If not, guides on how to build and update releases by yourself will be available soon.
+If you think your platform is a popular choice for running Pleroma instances, or has the potential to become one, you can [file an issue on our Gitlab](https://git.pleroma.social/pleroma/pleroma/issues/new). If not, guides on how to build and update releases by yourself will be available soon.
-## Moving uploads/instance static directory
+## Pre-requisites
-## Moving emoji
+You will be running commands as root. If you aren't root already, please elevate your priviledges by executing `sudo su`/`su`.
-## Moving the config
+
+The system needs to have `curl` and `unzip` installed for downloading and unpacking release builds.
+
+Debian/Ubuntu:
+```sh
+apt install curl unzip
+```
+Alpine:
+```
+apk add curl unzip
+
+```
+## Moving content out of the application directory
+When using OTP releases the application directory changes with every version so it would be a bother to keep content there (and also dangerous unless `--no-rm` option is used when updating). Fortunately almost all paths in Pleroma are configurable, so it is possible to move them out of there.
+
+Pleroma should be stopped before proceeding.
+
+### Moving uploads/custom public files directory
+```sh
+# Create uploads directory and set proper permissions (skip if using a remote uploader)
+# Note: It does not have to be `/var/lib/pleroma/uploads`, you can configure it to be something else later
+mkdir -p /var/lib/pleroma/uploads
+chown -R pleroma /var/lib/pleroma
+
+# Create custom public files directory
+# Note: It does not have to be `/var/lib/pleroma/static`, you can configure it to be something else later
+mkdir -p /var/lib/pleroma/static
+chown -R pleroma /var/lib/pleroma
+
+# If you use the local uploader with default settings your uploads should be located in `~pleroma/uploads`
+mv ~pleroma/uploads /var/lib/pleroma/uploads
+
+# If you have created the custom public files directory with default settings it should be located in `~pleroma/instance/static`
+mv ~pleroma/instance/static /var/lib/pleroma/static
+```
+
+### Moving emoji
+Assuming you have all emojis in subdirectories of `priv/static/emoji` moving them can be done with
+```sh
+mkdir /var/lib/pleroma/static/emoji
+ls -d ~pleroma/priv/static/emoji/*/ | xargs -i sh -c 'mv "{}" "/var/lib/pleroma/static/emoji/$(basename {})"'
+```
+
+But, if for some reason you have custom emojis in the root directory you should copy the whole directory instead.
+```sh
+mv ~pleroma/priv/static/emoji /var/lib/pleroma/static/emoji
+```
+and then copy custom emojis to `/var/lib/pleroma/static/emoji/custom`. 
+
+This is needed because storing custom emojis in the root directory is deprecated, but if you just move them to `/var/lib/pleroma/static/emoji/custom` it will break emoji urls on old posts.
+
+Note that globs have been replaced with `pack_extensions`, so if your emojis are not in png/gif you should [modify the default value](config.html#emoji).
+
+### Moving the config
+```sh
+# Create the config directory
+# The default path for Pleroma config is /etc/pleroma/config.exs
+# but it can be set via PLEROMA_CONFIG_PATH environment variable
+mkdir -p /etc/pleroma
+
+# Move the config file
+mv ~pleroma/config/prod.secret.exs /etc/pleroma/config.exs
+
+# Change `use Mix.Config` at the top to `import Config`
+$EDITOR /etc/pleroma/config.exs
+```
 ## Installing the release
+```sh
+# Delete all files in pleroma user's directory
+rm -r ~pleroma/*
+
+# Clone the release build into a temporary directory and unpack it
+su pleroma -s $SHELL -lc "
+curl 'https://git.pleroma.social/api/v4/projects/2/jobs/artifacts/master/download?job=$FLAVOUR' -o /tmp/pleroma.zip
+unzip /tmp/pleroma.zip -d /tmp/
+"
+
+# Move the release to the home directory and delete temporary files
+su pleroma -s $SHELL -lc "
+mv /tmp/release/* /opt/pleroma
+rmdir /tmp/release
+rm /tmp/pleroma.zip
+"
+
+# Start the instance to verify that everything is working as expected
+su pleroma -s $SHELL -lc "./bin/pleroma daemon"
+
+# Wait for about 20 seconds and query the instance endpoint, if it shows your uri, name and email correctly, you are configured correctly
+sleep 20 && curl http://localhost:4000/api/v1/instance
+
+# Stop the instance
+su pleroma -s $SHELL -lc "./bin/pleroma stop"
+```
+
+## Setting up a system service
+OTP releases have different service files than from-source installs so they need to be copied over again.
+
+Debian/Ubuntu:
+```sh
+# Copy the service into a proper directory
+cp ~pleroma/installation/pleroma.service /etc/systemd/system/pleroma.service
+
+# Reload service files
+systemctl reload-daemon
+
+# Reenable pleroma to start on boot
+systemctl reenable pleroma
+
+# Start pleroma
+systemctl start pleroma
+```
+
+Alpine:
+```sh
+# Copy the service into a proper directory
+cp -f ~pleroma/installation/init.d/pleroma /etc/init.d/pleroma
+
+# Start pleroma
+rc-service pleroma start
+```
+## Running mix tasks
+Refer to [Running mix tasks](otp_en.html#running-mix-tasks) section from OTP release installation guide.
+## Updating
+Refer to [Updating](otp_en.html#updating) section from OTP release installation guide.