add postgres & pgbouncer notes

notes/postgres.md

@@ -0,0 +1,87 @@
+# Postgres
+
+## Optimization
+
+- https://pgtune.leopard.in.ua/#/
+
+### PgBouncer
+
+- https://docs.joinmastodon.org/admin/scaling/#pgbouncer
+- https://masto.host/mastodon-pgbouncer-guide/
+
+#### Installation
+
+creating the pgbouncer admin user:
+
+```bash
+DB_PASSWORD=$(< /dev/urandom tr -dc A-Za-z0-9 | head -c32; echo)
+echo "pgbouncer password (save this securely): $DB_PASSWORD"
+echo "CREATE USER pgbouncer WITH PASSWORD '$DB_PASSWORD' CREATEDB" | sudo -u postgres psql -f -
+```
+
+#### Config
+
+.env.production:
+
+```sh
+DB_HOST=localhost
+DB_USER=mastodon
+DB_NAME=mastodon_production
+DB_PASS=
+
+# change from postgres port (default: 5432) to pgbouncer (default: 6432)
+DB_PORT=6432
+# add this:
+PREPARED_STATEMENTS=false
+```
+
+---
+
+/etc/pgbouncer/pgbouncer.ini:
+
+```ini
+[databases]
+mastodon_production = host=127.0.0.1 port=5432 dbname=mastodon_production user=mastodon password=
+
+[pgbouncer]
+listen_addr = localhost
+listen_port = 6432
+auth_type = md5
+auth_file = /etc/pgbouncer/userlist.txt
+admin_users = pgbouncer
+pool_mode = transaction
+max_client_conn = 100
+default_pool_size = 20
+```
+
+---
+
+/etc/pgbouncer/userlist.txt:
+
+generate md5 hash of postgres passwords with `echo -n "pass" | md5sum`
+
+```
+"mastodon" "md5xxxxxxxx"
+"pgbouncer" "md5xxxxxxxx"
+```
+
+## Connecting from TablePlus.app via Tailscale
+
+/etc/postgresql/15/main/postgres.conf
+
+```
+listen_addresses = '*'
+```
+
+---
+
+/etc/postgresql/15/main/pg_hba.conf:
+
+```
+# tailscale
+host   all              all             100.64.0.0/10           md5
+```
+
+---
+
+![](https://user-images.githubusercontent.com/1703673/206910912-1dea1173-7090-47db-b964-1b4bbe0d197e.png)

notes/prometheus.md

@@ -36,7 +36,7 @@ systemctl status redis-exporter.service
 
 /home/mastodon/live/.env.production:
 
-```
+```sh
 STATSD_ADDR=localhost:9125
 ```
 
@@ -129,7 +129,7 @@ scrape_configs:
 
 ---
 
-json-config.yml:
+/etc/prometheus/json-config.yml:
 
 ```yml
 modules:

scripts/upgrade.sh

@@ -40,7 +40,7 @@ sudo -u mastodon "$RBENV_ROOT/bin/rbenv" global "$RUBY_VERSION"
 # run migrations:
 # https://docs.joinmastodon.org/admin/upgrading/
 echo "Running pre-deploy database migrations..."
-sudo -u mastodon SKIP_POST_DEPLOYMENT_MIGRATIONS=true RAILS_ENV=production "$RBENV_ROOT/shims/bundle" exec rails db:migrate
+sudo -u mastodon SKIP_POST_DEPLOYMENT_MIGRATIONS=true RAILS_ENV=production DB_PORT=5432 "$RBENV_ROOT/shims/bundle" exec rails db:migrate
 
 # restart mastodon
 echo "Restarting services (round 1/2)..."
@@ -50,7 +50,7 @@ sudo systemctl restart mastodon-web mastodon-sidekiq mastodon-streaming
 echo "Clearing cache..."
 sudo -u mastodon RAILS_ENV=production "$RBENV_ROOT/shims/ruby" "$APP_ROOT/bin/tootctl" cache clear
 echo "Running post-deploy database migrations..."
-sudo -u mastodon RAILS_ENV=production "$RBENV_ROOT/shims/bundle" exec rails db:migrate
+sudo -u mastodon RAILS_ENV=production DB_PORT=5432 "$RBENV_ROOT/shims/bundle" exec rails db:migrate
 
 # restart mastodon again
 echo "Restarting services (round 2/2)..."