devtools/docker: allow custom db port

Instead of hardcoding the DB port, set it using
GO_DISCOVERY_DATABASE_PORT.

Change-Id: Ib2f4dcf0fdcde1ce4401281ae2094627103328af
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/329491
Trust: Julie Qiu <julie@golang.org>
Run-TryBot: Julie Qiu <julie@golang.org>
TryBot-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jamal Carvalho <jamal@golang.org>
diff --git a/devtools/docker/docker-compose.yaml b/devtools/docker/docker-compose.yaml
index 9d39f9a..6b8d108 100644
--- a/devtools/docker/docker-compose.yaml
+++ b/devtools/docker/docker-compose.yaml
@@ -27,6 +27,7 @@
       - GOMODCACHE=/gomodcache
       # TERM is set to xterm-256color for use by devtools/lib.sh.
       - TERM=xterm-256color
+      - WAITFORIT_TIMEOUT=300
     entrypoint: "./third_party/wait-for-it/wait-for-it.sh db:5432 -- ./all.bash"
     volumes:
       - ../../:/pkgsite
@@ -126,7 +127,7 @@
       - POSTGRES_USER=postgres
       - POSTGRES_DB=discovery_e2e_test
     ports:
-        - 5428:5432
+        - ${GO_DISCOVERY_DATABASE_PORT:-5432}:5432
   nodejs:
     image: node:14.17.0
     environment: