matrix-synapse: Add support for extra postgresql args

Allows passing extra arguments to the pqlib library upon connection, for
instance to set keepalive settings, as documented in:
https://github.com/matrix-org/synapse/blob/develop/docs/postgres.md#synapse-config

charts/matrix-synapse/Chart.yaml

@@ -6,7 +6,7 @@ icon: https://matrix.org/images/matrix-logo.svg
 appVersion: 1.38.1
 
 type: application
-version: 2.1.4
+version: 2.1.5
 maintainers:
   - name: Alexander Olofsson
     email: ace@haxalot.com

charts/matrix-synapse/templates/_helpers.tpl

@@ -197,6 +197,25 @@ Set postgresql sslmode
 {{- end -}}
 {{- end -}}
 
+
+{{/*
+Set postgresql extra args
+Refer to https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-PARAMKEYWORDS
+for a list of options that can be passed.
+*/}}
+{{- define "matrix-synapse.postgresql.extraArgs" -}}
+{{- if .Values.postgresql.enabled -}}
+{{- with .Values.postgresql.extraArgs }}
+  {{- . | toYaml }}
+{{- end }}
+{{- else -}}
+{{- with .Values.externalPostgresql.extraArgs }}
+  {{- . | toYaml }}
+{{- end }}
+{{- end -}}
+{{- end -}}
+
+
 {{/*
 Set redis host
 */}}

charts/matrix-synapse/templates/secrets.yaml

@@ -36,6 +36,7 @@ stringData:
 {{- $postgresPort := include "matrix-synapse.postgresql.port" . }}
 {{- $postgresPass := include "matrix-synapse.postgresql.password" . }}
 {{- $postgresSSLMode := include "matrix-synapse.postgresql.sslmode" . }}
+{{- $postgresExtraArgs := include "matrix-synapse.postgresql.extraArgs" . }}
 
     ## Database configuration ##
 
@@ -54,6 +55,7 @@ stringData:
         sslmode: {{ $postgresSSLMode | quote }}
         cp_min: 5
         cp_max: 10
+        {{- $postgresExtraArgs | nindent 8 }}
 
 {{- $redisHost := include "matrix-synapse.redis.host" . }}
 {{- $redisPort := include "matrix-synapse.redis.port" . }}

charts/matrix-synapse/values.yaml

@@ -597,6 +597,21 @@ postgresql:
     # storageClass: "-"
     size: 16Gi
 
+  ## Extra arguments for the database connection
+  ## ref: https://github.com/matrix-org/synapse/blob/develop/docs/postgres.md#synapse-config
+  ##
+  extraArgs: {}
+  #  # seconds of inactivity after which TCP should send a keepalive message to the server
+  #  keepalives_idle: 10
+  #
+  #  # the number of seconds after which a TCP keepalive message that is not
+  #  # acknowledged by the server should be retransmitted
+  #  keepalives_interval: 10
+  #
+  #  # the number of TCP keepalives that can be lost before the client's connection
+  #  # to the server is considered dead
+  #  keepalives_count: 3
+
 ## An externally configured Postgres server to use for Synapse's database, note
 ## that the database needs to have both COLLATE and CTYPE set to "C".
 ##
@@ -608,6 +623,21 @@ externalPostgresql:
   database: synapse
   # sslmode: prefer
 
+  ## Extra arguments for the database connection
+  ## ref: https://github.com/matrix-org/synapse/blob/develop/docs/postgres.md#synapse-config
+  ##
+  extraArgs: {}
+  #  # seconds of inactivity after which TCP should send a keepalive message to the server
+  #  keepalives_idle: 10
+  #
+  #  # the number of seconds after which a TCP keepalive message that is not
+  #  # acknowledged by the server should be retransmitted
+  #  keepalives_interval: 10
+  #
+  #  # the number of TCP keepalives that can be lost before the client's connection
+  #  # to the server is considered dead
+  #  keepalives_count: 3
+
 ## This configuration is for the internal Redis that's deployed for use with
 ## workers/sharding, for an external Redis server you want to set enabled to
 ## false and configure the externalRedis block.