Go for the postdeploy.sh approach

Dockerfile

@@ -2,4 +2,7 @@ FROM gitea/gitea:1.11.2
 
 COPY . ${WORKDIR}
 
+RUN mkdir -p /app/
+COPY postdeploy.sh /app/
+
 EXPOSE 80:3000

app.json

@@ -1,5 +1,6 @@
 {
   "name": "gitea",
   "description": "Gitea is a painless self-hosted Git service.",
-  "repository": "https://gitlab.com/autonomic-cooperative/gitea-dokku"
+  "repository": "https://gitlab.com/autonomic-cooperative/gitea-dokku",
+  "scripts": { "dokku": { "postdeploy": "bash /app/postdeploy.sh" } }
 }

postdeploy.sh

@@ -0,0 +1,44 @@
+#!/bin/bash
+
+set -eu -o pipefail
+
+setup_root_user() {
+    set -eu
+
+    # TODO(decentral1se): fix to use sqlite3 database for now
+    user_count=$(mysql -u"${DB_USER}" -p"${DB_PASS}" -h mysql --database="${DB_NAME}" -N -B -e "SELECT count(*) FROM user;")
+
+    if [[ "${user_count}" == "0" ]]; then
+        echo "==> Setting up root user for first run"
+
+        if gitea create-admin --name "$ADMIN_USER" --password "$ADMIN_PASS" --email "$ADMIN_MAIL"; then
+            echo "==> root user added"
+        else
+            echo "==> Failed to add root user"
+            exit 1
+        fi
+    fi
+}
+
+do_healthcheck() {
+    set -eu
+
+    echo "==> Running Gitea healthcheck"
+
+    while ! curl --fail "https://${DOMAIN}/healthcheck"; do
+        echo "==> Waiting for Gitea to come up"
+        sleep 1
+    done
+
+    echo "==> Gitea is up"
+}
+
+main() {
+    set -eu
+
+    do_healthcheck
+    setup_root_user
+}
+
+# TODO(decentral1se): test manually for now...
+# main