Merge pull request ckan#6244 from Gauravp-NEC/Fix-for-issue-4845

 Hardcoded references to db host and users removed

contrib/docker/.env.template

@@ -34,12 +34,18 @@ CKAN_SMTP_MAIL_FROM=ckan@localhost
 # Image: db
 POSTGRES_PASSWORD=ckan
 #
+# POSTGRES_USER must be set to the database user used by CKAN, typically named ckan
+POSTGRES_USER=ckan
+#
 # POSTGRES_PORT must be available on the host: sudo netstat -na | grep 5432
 # To apply change: docker-compose down && docker rmi docker_db docker_ckan && docker-compose build
 POSTGRES_PORT=5432
 #
 # The datastore database will be created in the db container as docs
-# Readwrite user/pass will be ckan:POSTGRES_PASSWORD
-# Readonly user/pass will be datastore_ro:DATASTORE_READONLY_PASSWORD
+# Readwrite user/pass will be POSTGRES_USER:POSTGRES_PASSWORD
+# Readonly user/pass will be DATASTORE_READONLY_USER:DATASTORE_READONLY_PASSWORD
 DATASTORE_READONLY_PASSWORD=datastore
-
+DATASTORE_READONLY_USER=datastore_ro
+# POSTGRES_HOST must be set to the host for the postgres server.
+# As a default 'db' will point to the postgres running in the docker container specified by the docker-compose.yml file.
+POSTGRES_HOST=db

contrib/docker/ckan-entrypoint.sh

@@ -42,7 +42,7 @@ write_config () {
 }
 
 # Wait for PostgreSQL
-while ! pg_isready -h db -U ckan; do
+while ! pg_isready -h "${POSTGRES_HOST}" -U "${POSTGRES_USER}"; do
   sleep 1;
 done
 

contrib/docker/docker-compose.yml

@@ -24,16 +24,17 @@ services:
       - "0.0.0.0:${CKAN_PORT}:5000"
     environment:
       # Defaults work with linked containers, change to use own Postgres, SolR, Redis or Datapusher
-      - CKAN_SQLALCHEMY_URL=postgresql://ckan:${POSTGRES_PASSWORD}@db/ckan
-      - CKAN_DATASTORE_WRITE_URL=postgresql://ckan:${POSTGRES_PASSWORD}@db/datastore
-      - CKAN_DATASTORE_READ_URL=postgresql://datastore_ro:${DATASTORE_READONLY_PASSWORD}@db/datastore
+      - CKAN_SQLALCHEMY_URL=postgresql://${POSTGRES_USER}:${POSTGRES_PASSWORD}@${POSTGRES_HOST}/ckan
+      - CKAN_DATASTORE_WRITE_URL=postgresql://${POSTGRES_USER}:${POSTGRES_PASSWORD}@${POSTGRES_HOST}/datastore
+      - CKAN_DATASTORE_READ_URL=postgresql://${DATASTORE_READONLY_USER}:${DATASTORE_READONLY_PASSWORD}@${POSTGRES_HOST}/datastore
       - CKAN_SOLR_URL=http://solr:8983/solr/ckan
       - CKAN_REDIS_URL=redis://redis:6379/1
       - CKAN_DATAPUSHER_URL=http://datapusher:8800
       - CKAN_SITE_URL=${CKAN_SITE_URL}
       - CKAN_MAX_UPLOAD_SIZE_MB=${CKAN_MAX_UPLOAD_SIZE_MB}
       - POSTGRES_PASSWORD=${POSTGRES_PASSWORD}
       - DS_RO_PASS=${DATASTORE_READONLY_PASSWORD}
+      - POSTGRES_HOST=${POSTGRES_HOST}
     restart: unless-stopped
 
     volumes:
@@ -49,7 +50,7 @@ services:
     restart: unless-stopped
 
   db:
-    container_name: db
+    container_name: ${POSTGRES_HOST}
     build:
       context: ../../
       dockerfile: contrib/docker/postgresql/Dockerfile  

doc/maintaining/installing/install-from-docker-compose.rst

@@ -142,6 +142,19 @@ The location of these named volumes needs to be backed up in a production enviro
 To migrate CKAN data between different hosts, simply transfer the content of the named volumes.
 A detailed use case of data transfer will be discussed in step 5.
 
+You have the option of using environment variables rather than hard coding the actual docker
+container name. For example, if you want to remove the "db" container name replace "db" with
+name of your environment variable in docker-compose.yml:
+
+     links:
+      - db
+
+     depends_on:
+      - db
+
+     db:
+       container_name: ${POSTGRES_HOST}
+
 c. Convenience: paths to named volumes
 
 The files inside named volumes reside on a long-ish path on the host.