pg_hba.confについて
設定ファイルについてちょっとみる
19.1. pg_hba.confファイル以下がinitdbした直後のファイルの中身。
# PostgreSQL Client Authentication Configuration File # =================================================== # # Refer to the "Client Authentication" section in the PostgreSQL # documentation for a complete description of this file. A short # synopsis follows. # # This file controls: which hosts are allowed to connect, how clients # are authenticated, which PostgreSQL user names they can use, which # databases they can access. Records take one of these forms: # # local DATABASE USER METHOD [OPTIONS] # host DATABASE USER ADDRESS METHOD [OPTIONS] # hostssl DATABASE USER ADDRESS METHOD [OPTIONS] # hostnossl DATABASE USER ADDRESS METHOD [OPTIONS] # # (The uppercase items must be replaced by actual values.) # # The first field is the connection type: "local" is a Unix-domain # socket, "host" is either a plain or SSL-encrypted TCP/IP socket, # "hostssl" is an SSL-encrypted TCP/IP socket, and "hostnossl" is a # plain TCP/IP socket. # # DATABASE can be "all", "sameuser", "samerole", "replication", a # database name, or a comma-separated list thereof. The "all" # keyword does not match "replication". Access to replication # must be enabled in a separate record (see example below). # # USER can be "all", a user name, a group name prefixed with "+", or a # comma-separated list thereof. In both the DATABASE and USER fields # you can also write a file name prefixed with "@" to include names # from a separate file. # # ADDRESS specifies the set of hosts the record matches. It can be a # host name, or it is made up of an IP address and a CIDR mask that is # an integer (between 0 and 32 (IPv4) or 128 (IPv6) inclusive) that # specifies the number of significant bits in the mask. A host name # that starts with a dot (.) matches a suffix of the actual host name. # Alternatively, you can write an IP address and netmask in separate # columns to specify the set of hosts. Instead of a CIDR-address, you # can write "samehost" to match any of the server's own IP addresses, # or "samenet" to match any address in any subnet that the server is # directly connected to. # # METHOD can be "trust", "reject", "md5", "password", "gss", "sspi", # "krb5", "ident", "peer", "pam", "ldap", "radius" or "cert". Note that # "password" sends passwords in clear text; "md5" is preferred since # it sends encrypted passwords. # # OPTIONS are a set of options for the authentication in the format # NAME=VALUE. The available options depend on the different # authentication methods -- refer to the "Client Authentication" # section in the documentation for a list of which options are # available for which authentication methods. # # Database and user names containing spaces, commas, quotes and other # special characters must be quoted. Quoting one of the keywords # "all", "sameuser", "samerole" or "replication" makes the name lose # its special character, and just match a database or username with # that name. # # This file is read on server startup and when the postmaster receives # a SIGHUP signal. If you edit the file on a running system, you have # to SIGHUP the postmaster for the changes to take effect. You can # use "pg_ctl reload" to do that. # Put your actual configuration here # ---------------------------------- # # If you want to allow non-local connections, you need to add more # "host" records. In that case you will also need to make PostgreSQL # listen on a non-local interface via the listen_addresses # configuration parameter, or via the -i or -h command line switches. # TYPE DATABASE USER ADDRESS METHOD # "local" is for Unix domain socket connections only local all all peer # IPv4 local connections: host all all 127.0.0.1/32 ident # IPv6 local connections: host all all ::1/128 ident # Allow replication connections from localhost, by a user with the # replication privilege. #local replication postgres peer #host replication postgres 127.0.0.1/32 ident #host replication postgres ::1/128 ident
メモ
hba=host-based authentication: ホストベース認証の略。postgresqlデータベースアクセス時に認証が必要で、その認証がここのファイルが決めているってことだと思われる。
# TYPE DATABASE USER ADDRESS METHOD # "local" is for Unix domain socket connections only local all all md5 # IPv4 local connections: host all all 127.0.0.1/32 md5 # IPv6 local connections: host all all ::1/128 md5 # Allow replication connections from localhost, by a user with the # replication privilege. #local replication postgres peer #host replication postgres 127.0.0.1/32 ident #host replication postgres ::1/128 ident
自分が気になるのはpg_hba.confのMETHODを上記のようにmd5に変更してから以下の一連のコマンドを実行することができなくなった。linuxのユーザ変更は可能だけれどもbashの状態でpsqlにエラーが出る。localからssh接続でサーバ上のpostgresqlに接続すっる場合はどこを戻せばよいのか?
su postgres
psql
結果が以下の通り。
psql: could not connect to server: No such file or directory Is the server running locally and accepting connections on Unix domain socket "/var/run/postgresql/.s.PGSQL.5432"?
このようにしたらpsqlのコマンドが通ったんだけど理由がわからない。もしかしてvar/runが関係している?centos7の場合、再起動するとvar/run以下のファイルが削除される事があるらしい。
# systemctl enable postgresql
Created symlink from /etc/systemd/system/multi-user.target.wants/postgresql.service to /usr/lib/systemd/system/postgresql.service.
# su postgres bash-4.2$ psql psql (9.2.24) Type "help" for help. postgres=# \dt