can not connect to postgres from Docker - postgresql

Question

I have a docker image in which i have hadoop cluster composed fo one master and two slaves. On this cluster, I have HBase.
I'm trying to migrate my postgres Database which is installed on my local machine to HBase Database which is on the Docker image using scoop .
For postgres, this is my postgresql.conf configuration file:
#------------------------------------------------------------------------------
# CONNECTIONS AND AUTHENTICATION
#------------------------------------------------------------------------------
# - Connection Settings -
listen_addresses = '*' # what IP address(es) to listen on;
# comma-separated list of addresses;
# defaults to 'localhost'; use '*' for all
# (change requires restart) port = 5432 # (change requires restart)
max_connections = 100 # (change requires restart)
#superuser_reserved_connections = 3 # (change requires restart) unix_socket_directories = '/var/run/postgresql' # comma-separated list
of directories
# (change requires restart)
#unix_socket_group = '' # (change requires restart)
#unix_socket_permissions = 0777 # begin with 0 to use octal notation
# (change requires restart)
#bonjour = off # advertise server via Bonjour
# (change requires restart)
#bonjour_name = '' # defaults to the computer name
# - Security and Authentication -
#authentication_timeout = 1min # 1s-600s ssl = on
#ssl_ciphers = 'HIGH:MEDIUM:+3DES:!aNULL' # allowed SSL ciphers
#ssl_prefer_server_ciphers = on
#ssl_ecdh_curve = 'prime256v1'
#ssl_dh_params_file = '' ssl_cert_file = '/etc/ssl/certs/ssl-cert-snakeoil.pem' ssl_key_file =
'/etc/ssl/private/ssl-cert-snakeoil.key'
#ssl_ca_file = ''
#ssl_crl_file = ''
#password_encryption = md5 # md5 or scram-sha-256
#db_user_namespace = off
#row_security = on
# GSSAPI using Kerberos
#krb_server_keyfile = ''
#krb_caseins_users = off
# - TCP Keepalives -
# see "man 7 tcp" for details
#tcp_keepalives_idle = 0 # TCP_KEEPIDLE, in seconds;
# 0 selects the system default
#tcp_keepalives_interval = 0 # TCP_KEEPINTVL, in seconds;
# 0 selects the system default
#tcp_keepalives_count = 0 # TCP_KEEPCNT;
# 0 selects the system default
Also this is the content of pg_hba.conf file:
# Database administrative login by Unix domain socket local all postgres peer
# TYPE DATABASE USER ADDRESS METHOD
# "local" is for Unix domain socket connections only local all all trust
# IPv4 local connections: host all all 127.0.0.1/32 trust
# IPv6 local connections: host all all ::1/128 trust
# Allow replication connections from localhost, by a user with the
# replication privilege.
local replication all trust
host replication all 127.0.0.1/32 trust
host replication all ::1/128
my problem is when I try to connect to postgres from docker image using scoop using this command:
sqoop import --connect jdbc:postgresql://localhost:5432/mimic --username postgres --password 0000 --table admission_ids --hbase-table mimic --column-family admission_ids --hbase-row-key id -m 1
I just have this problem:
Check that the hostname and port are correct and that the postmaster
is accepting TCP/IP connections. org.postgresql.util.PSQLException:
Connection refused. Check that the hostname and port are correct and
that the postmaster is accepting TCP/IP connections.
After a search, I jsut understand that docker is the origin of this issue, and to confirm that, I just try to connect to postgres using tenlnet from my local machine in the first time and this is the result :
telnet localhost 5432
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
and from the docker for the second time :
telnet localhost 5432
Trying 127.0.0.1...
Trying ::1...
telnet: Unable to connect to remote host: Cannot assign requested address
my docker image is named spark-hadoop.
I tried to trun this command but always not working:
docker run -d --name bridgeToHadoop --publish=127.0.0.1:5432:5432 -p 172.18.0.2:5432:5432 spark-hadoop

Answer 1

Postgresql running on host machine and you are trying to connect it from docker container. When you do this, host shouldn't be localhost in connection string. Here localhost means docker container.
Replace localhost with IP address, it should be following
sqoop import --connect jdbc:postgresql://host-pi-addr:5432/mimic --username postgres --password 0000 --table admission_ids --hbase-table mimic --column-family admission_ids --hbase-row-key id -m 1

Answer 2

Docker uses a default 172.17.0.0/16 subnet IP range for container networking. You need to allow non-local connections because your container network is no longer seen as local with respect to the postgres server. To permit external connections in the appropriate range add the following to pg_hba.conf (with appropriate choices for DATABASE, USER AND METHOD).
#TYPE DATABASE USER ADDRESS METHOD
host all all 172.17.0.0/16 scram-sha-256`
Also, by default the postgres server only listens on localhost, so you also need to tell postgres to listen on other IP addresses by adding the following to postgresql.conf.
listen_addresses = '*'