If you decided to use dynamic linking, you will also need to install the library ([7.8.3 release](https://github.com/facebook/rocksdb/releases/tag/v7.8.3) is required).
On [Debian 12 (bookworm)](https://packages.debian.org/bookworm/librocksdb-dev) and [Ubuntu 23.04 (lunar)](https://packages.ubuntu.com/lunar/librocksdb-dev):
*Note: Unless you run into the below mentioned libc (GLIBC) version issue, avoiding the approach described in this section is faster and requires less disk space on the build host. You may want to try the above cross compilation approach first and only use this one here as the last resort.*
If your build system runs on a different OS distribution and/or release than the target system electrs is going to run on, you may run into `GLIBC` version issues like:
```
$ ./electrs --help
./electrs: /lib/arm-linux-gnueabihf/libm.so.6: version `GLIBC_2.29' not found (required by ./electrs)
```
To cross-compile electrs for a different (Debian based) target distribution you can use a [debootstrap](https://wiki.debian.org/Debootstrap) based approach. For example your build system may be a 64-bit Debian `stable` (bullseye) system and you want to cross-compile for an armv7l (32-bit) Debian `oldstable` (buster) target, like an Odroid HC1/HC2.
Install and setup debootstrap:
```
sudo apt install debootstrap
```
Next, create working directory for a `buster` based system and set it up:
Next, mount proc, sys and dev to the target system:
```
sudo mount -t proc /proc debootstrap-buster/proc
sudo mount --rbind /sys debootstrap-buster/sys
sudo mount --rbind /dev debootstrap-buster/dev
```
If you have checked out the electrs git reposity somewhere already and don't want to have a duplicate copy inside the debootstrap working directory, just mount bind the exiting directory into the chroot:
```
sudo mkdir -p debootstrap-buster/mnt/electrs
sudo mount --rbind ./electrs debootstrap-buster/mnt/electrs
```
chroot into the `buster` system and install the required dependencies to build electrs with a statically linked rocksdb:
```
sudo chroot debootstrap-buster /bin/bash
apt install curl
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
source "$HOME/.cargo/env"
apt install clang cmake build-essential
# install target specific cross compiler (armhf/gnueabihf)
Cross-compile `electrs` release with a statically linked rocksdb for armv7l (armhf) with libatomic inside `buster` chroot: *(bindgen needs an include path to the sources (header files) provided by the libc6-dev-armhf-cross package)*
The built electrs binary will be in `/mnt/electrs/target/arm-unknown-linux-gnueabihf/release` within the chroot or can be accessed from outside the chroot respectively.
Run one of the commands above (depending on linking type) with argument `--target aarch64-unknown-linux-gnu` and prepended with env vars: `BINDGEN_EXTRA_CLANG_ARGS="-target gcc-aarch64-linux-gnu" RUSTFLAGS="-C linker=aarch64-linux-gnu-gcc"`
It's a bit long but sufficient! You will find the resulting binary in `target/aarch64-unknown-linux-gnu/release/electrs` - copy it to your target machine.
#### Generating man pages
If you installed `cfg_me` to generate man page, you can run `cfg_me man` to see it right away or `cfg_me -o electrs.1 man` to save it into a file (`electrs.1`).
## Docker-based installation from source
**Important**: The `Dockerfile` is provided for demonstration purposes and may NOT be suitable for production use.
The maintainers of electrs are not deeply familiar with Docker, so you should DYOR.
If you are not familiar with Docker either it's probably be safer to NOT use it.
Note: currently Docker installation links statically
Note: health check only works if Prometheus is running on port 4224 inside container
```bash
$ docker build -t electrs-app .
$ mkdir db
$ docker run --network host \
--volume $HOME/.bitcoin:/home/user/.bitcoin:ro \
--volume $PWD/db:/home/user/db \
--env ELECTRS_DB_DIR=/home/user/db \
--rm -i -t electrs-app
```
If not using the host-network, you probably want to expose the ports for electrs and Prometheus like so:
```bash
$ docker run --volume $HOME/.bitcoin:/home/user/.bitcoin:ro \
--volume $PWD/db:/home/user/db \
--env ELECTRS_DB_DIR=/home/user/db \
--env ELECTRS_ELECTRUM_RPC_ADDR=0.0.0.0:50001 \
--env ELECTRS_MONITORING_ADDR=0.0.0.0:4224 \
--rm -i -t electrs-app
```
To access the server from outside Docker, add `-p 50001:50001 -p 4224:4224` but be aware of the security risks. Good practice is to group containers that needs access to the server inside the same Docker network and not expose the ports to the outside world.
