Let's clone this repo:
git clone https://github.com/supabase/postgres $HOME/supabase-postgres
cd $HOME/supabase-postgresBut how do we build stuff within it? With nix build, of course! For example,
the following command will, when completed, create a symlink named result that
points to a path which contains an entire PostgreSQL 15 installation —
extensions and all:
nix build .#psql_15/bin
$ readlink result
/nix/store/ybf48481x033649mgdzk5dyaqv9dppzx-postgresql-and-plugins-15.3
$ ls result
bin include lib share
$ ll result/bin/
total 9928
dr-xr-xr-x 2 root root 4096 Dec 31 1969 ./
dr-xr-xr-x 5 root root 4096 Dec 31 1969 ../
lrwxrwxrwx 1 root root 79 Dec 31 1969 .initdb-wrapped -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/.initdb-wrapped*
-r-xr-xr-x 1 root root 9829624 Dec 31 1969 .postgres-wrapped*
lrwxrwxrwx 1 root root 73 Dec 31 1969 clusterdb -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/clusterdb*
lrwxrwxrwx 1 root root 72 Dec 31 1969 createdb -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/createdb*
lrwxrwxrwx 1 root root 74 Dec 31 1969 createuser -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/createuser*
lrwxrwxrwx 1 root root 70 Dec 31 1969 dropdb -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/dropdb*
lrwxrwxrwx 1 root root 72 Dec 31 1969 dropuser -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/dropuser*
lrwxrwxrwx 1 root root 68 Dec 31 1969 ecpg -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/ecpg*
lrwxrwxrwx 1 root root 70 Dec 31 1969 initdb -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/initdb*
lrwxrwxrwx 1 root root 72 Dec 31 1969 oid2name -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/oid2name*
lrwxrwxrwx 1 root root 74 Dec 31 1969 pg_amcheck -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/pg_amcheck*
lrwxrwxrwx 1 root root 81 Dec 31 1969 pg_archivecleanup -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/pg_archivecleanup*
lrwxrwxrwx 1 root root 77 Dec 31 1969 pg_basebackup -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/pg_basebackup*
lrwxrwxrwx 1 root root 76 Dec 31 1969 pg_checksums -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/pg_checksums*
-r-xr-xr-x 1 root root 53432 Dec 31 1969 pg_config*
lrwxrwxrwx 1 root root 78 Dec 31 1969 pg_controldata -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/pg_controldata*
-r-xr-xr-x 1 root root 82712 Dec 31 1969 pg_ctl*
lrwxrwxrwx 1 root root 71 Dec 31 1969 pg_dump -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/pg_dump*
lrwxrwxrwx 1 root root 74 Dec 31 1969 pg_dumpall -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/pg_dumpall*
lrwxrwxrwx 1 root root 74 Dec 31 1969 pg_isready -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/pg_isready*
lrwxrwxrwx 1 root root 77 Dec 31 1969 pg_receivewal -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/pg_receivewal*
lrwxrwxrwx 1 root root 78 Dec 31 1969 pg_recvlogical -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/pg_recvlogical*
lrwxrwxrwx 1 root root 73 Dec 31 1969 pg_repack -> /nix/store/bi9i5ns4cqxk235qz3srs9p4x1qfxfna-pg_repack-1.4.8/bin/pg_repack*
lrwxrwxrwx 1 root root 75 Dec 31 1969 pg_resetwal -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/pg_resetwal*
lrwxrwxrwx 1 root root 74 Dec 31 1969 pg_restore -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/pg_restore*
lrwxrwxrwx 1 root root 73 Dec 31 1969 pg_rewind -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/pg_rewind*
lrwxrwxrwx 1 root root 77 Dec 31 1969 pg_test_fsync -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/pg_test_fsync*
lrwxrwxrwx 1 root root 78 Dec 31 1969 pg_test_timing -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/pg_test_timing*
lrwxrwxrwx 1 root root 74 Dec 31 1969 pg_upgrade -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/pg_upgrade*
lrwxrwxrwx 1 root root 79 Dec 31 1969 pg_verifybackup -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/pg_verifybackup*
lrwxrwxrwx 1 root root 74 Dec 31 1969 pg_waldump -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/pg_waldump*
lrwxrwxrwx 1 root root 71 Dec 31 1969 pgbench -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/pgbench*
lrwxrwxrwx 1 root root 71 Dec 31 1969 pgsql2shp -> /nix/store/4wwzd3c136g6j7aqva2gyiqgwy784qjv-postgis-3.3.3/bin/pgsql2shp*
lrwxrwxrwx 1 root root 77 Dec 31 1969 pgsql2shp-3.3.3 -> /nix/store/4wwzd3c136g6j7aqva2gyiqgwy784qjv-postgis-3.3.3/bin/pgsql2shp-3.3.3*
lrwxrwxrwx 1 root root 75 Dec 31 1969 pgtopo_export -> /nix/store/4wwzd3c136g6j7aqva2gyiqgwy784qjv-postgis-3.3.3/bin/pgtopo_export*
lrwxrwxrwx 1 root root 81 Dec 31 1969 pgtopo_export-3.3.3 -> /nix/store/4wwzd3c136g6j7aqva2gyiqgwy784qjv-postgis-3.3.3/bin/pgtopo_export-3.3.3*
lrwxrwxrwx 1 root root 75 Dec 31 1969 pgtopo_import -> /nix/store/4wwzd3c136g6j7aqva2gyiqgwy784qjv-postgis-3.3.3/bin/pgtopo_import*
lrwxrwxrwx 1 root root 81 Dec 31 1969 pgtopo_import-3.3.3 -> /nix/store/4wwzd3c136g6j7aqva2gyiqgwy784qjv-postgis-3.3.3/bin/pgtopo_import-3.3.3*
-r-xr-xr-x 1 root root 286 Dec 31 1969 postgres*
lrwxrwxrwx 1 root root 74 Dec 31 1969 postmaster -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/postmaster*
lrwxrwxrwx 1 root root 68 Dec 31 1969 psql -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/psql*
lrwxrwxrwx 1 root root 74 Dec 31 1969 raster2pgsql -> /nix/store/4wwzd3c136g6j7aqva2gyiqgwy784qjv-postgis-3.3.3/bin/raster2pgsql*
lrwxrwxrwx 1 root root 80 Dec 31 1969 raster2pgsql-3.3.3 -> /nix/store/4wwzd3c136g6j7aqva2gyiqgwy784qjv-postgis-3.3.3/bin/raster2pgsql-3.3.3*
lrwxrwxrwx 1 root root 73 Dec 31 1969 reindexdb -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/reindexdb*
lrwxrwxrwx 1 root root 71 Dec 31 1969 shp2pgsql -> /nix/store/4wwzd3c136g6j7aqva2gyiqgwy784qjv-postgis-3.3.3/bin/shp2pgsql*
lrwxrwxrwx 1 root root 77 Dec 31 1969 shp2pgsql-3.3.3 -> /nix/store/4wwzd3c136g6j7aqva2gyiqgwy784qjv-postgis-3.3.3/bin/shp2pgsql-3.3.3*
lrwxrwxrwx 1 root root 72 Dec 31 1969 vacuumdb -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/vacuumdb*
lrwxrwxrwx 1 root root 72 Dec 31 1969 vacuumlo -> /nix/store/kdjdxnyhpwpvb11da8s99ylqilspcmzl-postgresql-15.3/bin/vacuumlo*
As we can see, these files all point to paths under /nix/store. We're actually
looking at a "farm" of symlinks to various paths, but collectively they form an
entire installation directory we can reuse as much as we want.
The path
/nix/store/ybf48481x033649mgdzk5dyaqv9dppzx-postgresql-and-plugins-15.3
ultimately is a cryptographically hashed, unique name for our installation of
PostgreSQL with those plugins. This hash includes everything used to build it,
so even a single change anywhere to any extension or version would result in a
new hash.
The ability to refer to a piece of data by its hash, by some notion of content, is a very powerful primitive, as we'll see later.
What if we wanted PostgreSQL 16 and plugins? Just replace _15 with _16:
nix build .#psql_16/bin
You're done:
$ readlink result
/nix/store/p7ziflx0000s28bfb213jsghrczknkc4-postgresql-and-plugins-14.8
nix develop . will just drop you in a subshell with
tools you need ready to go instantly. That's all you need to do! And once that
shell goes away, nix installed tools will be removed from your $PATH as well.
There's an even easier way to do this that is completely transparent to you, as well.