Using GraphQL with Ruby on Rails: 作業ログ

https://www.apollographql.com/blog/community/backend/using-graphql-with-ruby-on-rails/

apollo blogが一番わかりやすかったので見ながら作成

まずはpostgresqlをインストール。

sudo port install postgresql14

  postgresql14 has the following notes:
    To use the postgresql server, install the postgresql14-server port

sudo port install postgresql14-server

--->  Some of the ports you installed have notes:
  postgresql14-server has the following notes:
    To create a database instance, after install do
     sudo mkdir -p /opt/local/var/db/postgresql14/defaultdb
     sudo chown postgres:postgres /opt/local/var/db/postgresql14/defaultdb
     sudo su postgres -c 'cd /opt/local/var/db/postgresql14 && /opt/local/lib/postgresql14/bin/initdb -D /opt/local/var/db/postgresql14/defaultdb'

    A startup item has been generated that will aid in starting postgresql14-server with launchd. It is disabled by default. Execute the following
    command to start it, and to cause it to launch at startup:
    
        sudo port load postgresql14-server

上記のコマンドを上から流す。そうすると最後のコマンドのログはこんな感じ

$ sudo su postgres -c 'cd /opt/local/var/db/postgresql14 && /opt/local/lib/postgresql14/bin/initdb -D /opt/local/var/db/postgresql14/defaultdb'
The files belonging to this database system will be owned by user "postgres".
This user must also own the server process.

The database cluster will be initialized with locale "ja_JP.UTF-8".
The default database encoding has accordingly been set to "UTF8".
initdb: could not find suitable text search configuration for locale "ja_JP.UTF-8"
The default text search configuration will be set to "simple".

Data page checksums are disabled.

fixing permissions on existing directory /opt/local/var/db/postgresql14/defaultdb ... ok
creating subdirectories ... ok
selecting dynamic shared memory implementation ... posix
selecting default max_connections ... 100
selecting default shared_buffers ... 128MB
selecting default time zone ... Asia/Tokyo
creating configuration files ... ok
running bootstrap script ... ok
performing post-bootstrap initialization ... ok
syncing data to disk ... ok

initdb: warning: enabling "trust" authentication for local connections
You can change this by editing pg_hba.conf or using the option -A, or
--auth-local and --auth-host, the next time you run initdb.

Success. You can now start the database server using:

    /opt/local/lib/postgresql14/bin/pg_ctl -D /opt/local/var/db/postgresql14/defaultdb -l logfile start

最後のコマンドを実行してみる

$ /opt/local/lib/postgresql14/bin/pg_ctl -D /opt/local/var/db/postgresql14/defaultdb -l logfile start
pg_ctl: could not open PID file "/opt/local/var/db/postgresql14/defaultdb/postmaster.pid": Permission denied
$ sudo /opt/local/lib/postgresql14/bin/pg_ctl -D /opt/local/var/db/postgresql14/defaultdb -l logfile start
Password:
pg_ctl: cannot be run as root
Please log in (using, e.g., "su") as the (unprivileged) user that will
own the server process.

Permission deniedなのにsudoをつけるとエラーになる。

さっきやってなかったコマンド

~ takayuki$ sudo port load postgresql14-server
Password:
--->  Loading startupitem 'postgresql14-server' for postgresql14-server

$ sudo ls -l /opt/local/var/db/postgresql14/defaultdb/postmaster.pid
-rw-------  1 postgres  postgres  107 11 30 22:19 /opt/local/var/db/postgresql14/defaultdb/postmaster.pid

pidファイルはpostgresユーザなのは当たり前

~ takayuki$ /opt/local/lib/postgresql14/bin/psql -U postgres
psql (14.0)
Type "help" for help.

postgres=#

接続はできるので、とりあえず、先に進む。

やっとここでrails new。とりあえず今回はかなり単純に実行 rails new rails_graphql_practice -d postgresql

こんなエラーが出て失敗

checking for pg_config... no
No pg_config... trying anyway. If building fails, please try again with
 --with-pg-config=/path/to/pg_config
checking for libpq-fe.h... no
Can't find the 'libpq-fe.h header

https://stackoverflow.com/questions/6040583/cant-find-the-libpq-fe-h-header-when-trying-to-install-pg-gem

古い記事ですが、これのMacPortsを参考にするとこんな感じ

$ sudo gem install pg -- --with-pg-config=/opt/local/lib/postgresql14/bin/pg_config
Password:
Building native extensions with: '--with-pg-config=/opt/local/lib/postgresql14/bin/pg_config'
This could take a while...
Successfully installed pg-1.2.3
Parsing documentation for pg-1.2.3
Installing ri documentation for pg-1.2.3
Done installing documentation for pg after 0 seconds
1 gem installed

成功

bundle installも成功

ここから先は先ほどの記事の内容を上からなぞっていきます。

models作成

rails g model Artist first_name last_name email
rails g model Item title description:text image_url artist:references

そして、seedsの追記やdb:migrateなど、なんやかんやありまして、 rails g graphql:object itemするところでエラー。

bundle add graphqlでGemfileにgraphiql-railsも追加されるが、別途bundle installしないとgemが追加されてなかったです。

また、rails g graphql:object -hすると最後の行に

Create a GraphQL::ObjectType with the given name and fields.If the given type name matches an existing ActiveRecord model, the generated type will automatically include fields for the models database columns.

と表示されるので、databaseの内容を直接読み出してくれてるみたいです。