Allow db host, name user and password to be configurable

app/config.template.json

@@ -23,7 +23,7 @@
     },
     "SqlSettings": {
         "DriverName": "postgres",
-        "DataSource": "postgres://mmuser:mmuser_password@db:DB_PORT/mattermost?sslmode=disable&connect_timeout=10",
+        "DataSource": "postgres://MM_USERNAME:MM_PASSWORD@DB_HOST:DB_PORT/MM_DBNAME?sslmode=disable&connect_timeout=10",
         "DataSourceReplicas": [],
         "MaxIdleConns": 10,
         "MaxOpenConns": 10,

app/docker-entry.sh

@@ -1,17 +1,26 @@
 #!/bin/bash
 config=/mattermost/config/config.json
+DB_HOST=${DB_HOST:-db}
+DB_PORT_5432_TCP_PORT=${DB_PORT_5432_TCP_PORT:-5432}
+MM_USERNAME=${MM_USERNAME:-mmuser}
+MM_PASSWORD=${MM_PASSWORD:-mmuser_password}
+MM_DBNAME=${MM_DBNAME:-mattermost}
 echo -ne "Configure database connection..."
 if [ ! -f $config ]
 then
     cp /config.template.json $config
+    sed -Ei "s/DB_HOST/$DB_HOST/" $config
     sed -Ei "s/DB_PORT/$DB_PORT_5432_TCP_PORT/" $config
+    sed -Ei "s/MM_USERNAME/$MM_USERNAME/" $config
+    sed -Ei "s/MM_PASSWORD/$MM_PASSWORD/" $config
+    sed -Ei "s/MM_DBNAME/$MM_DBNAME/" $config
     echo OK
 else
     echo SKIP
 fi
 
 echo "Wait until database is ready..."
-until nc -z db $DB_PORT_5432_TCP_PORT
+until nc -z $DB_HOST $DB_PORT_5432_TCP_PORT
 do
     sleep 1
 done