# Building `librocksdb`

Instructions for building rocksdb prior to creating a Mitto Debian
package.  Assumes that the Mitto repo is located in `~/mitto` and the
rocksdb repo is located in `~/rocksdb`.

On the build machine, get and build rocksdb.

```
$ cd ~
$ ROCKSDB_VER=v6.17.3
$ git clone -b ${ROCKSDB_VER} --depth 1 https://github.com/facebook/rocksdb.git
$ cd rocksdb \

# If PORTABLE isn't set, one runs the risk of creating a library with
# instructions using CPU features that may not be present in the
# target systems.
$ PORTABLE=1 make shared_lib

# Not necessary to build, but necessary to actually run Mitto
$ sudo make INSTALL_PATH=/usr install-shared
```

The above will create the following files/links:
```
$ cd ~
$ ls -ltr rocksdb/librocksdb*
-rwxr-xr-x 1 khe khe 169760472 Mar 18 08:58 rocksdb/librocksdb.so.6.17.3*
lrwxrwxrwx 1 khe khe        20 Mar 18 08:58 rocksdb/librocksdb.so.6.17 -> librocksdb.so.6.17.3*
lrwxrwxrwx 1 khe khe        20 Mar 18 08:58 rocksdb/librocksdb.so.6 -> librocksdb.so.6.17.3*
lrwxrwxrwx 1 khe khe        20 Mar 18 08:58 rocksdb/librocksdb.so -> librocksdb.so.6.17.3*
```
The `.so` file and related links are included in the Mitto Debian
package when it is built.  Their exact location and path must be
correct for packaging and package installation to work.

## Mitto

### Update Mitto

1. `mitto/DEBIAN/Makefile`
2. Possibly `mitto/DEBIAN/debian/postinst`

### Build Mitto Debian Package

Once rocksdb is built, Mitto can be built.
```
$ cd ~/mitto
$ make all       # will eventually 'make DEBIAN'
```

## CircleCI Repo

If the version of rocksdb has changed, the following must be updated:
1. `Dockerfile` in `circleci` repo.

Build and push a new Docker image to CircleCI.