postgres-release
This is a BOSH release for PostgreSQL.
Contents
Deploying
In order to deploy the postgres-release you must follow the standard steps for deploying software with BOSH.
-
Deploy and run a BOSH director. Please refer to BOSH documentation for instructions on how to do that. Bosh-lite specific instructions can be found here.
-
Install the BOSH command line Interface (CLI) v2+. Please refer to BOSH CLI documentation. Use the CLI to target your director.
-
Upload the desired stemcell directly to bosh. bosh.io provides a resource to find and download stemcells.
# Example for bosh-lite bosh upload-stemcell https://bosh.io/d/stemcells/bosh-warden-boshlite-ubuntu-xenial-go_agent
-
Upload the latest release from bosh.io:
bosh upload-release https://bosh.io/d/github.com/cloudfoundry/postgres-release
or create and upload a development release:
cd ~/workspace/postgres-release bosh -n create-release --force && bosh -n upload-release
-
Generate the manifest. You can provide in input an operation file to customize the manifest:
~/workspace/postgres-release/scripts/generate-deployment-manifest \ -o OPERATION-FILE-PATH > OUTPUT_MANIFEST_PATH
You can use the operation file to specify
postgres
job properties or to override the configuration if your BOSH director cloud-config is not compatible.This example operation file is a great starting point. Note: when using this operation file, you will need to inject
pgadmin_database_password
atbosh deploy
-time, which is a good pattern for keeping credentials out of manifests.You are also provided with options to enable TLS in the PostgreSQL server or to use static ips.
-
Deploy:
bosh -d DEPLOYMENT_NAME deploy OUTPUT_MANIFEST_PATH
Example, injecting the
pgadmin_database_password
variable:bosh -d DEPLOYMENT_NAME deploy -v pgadmin_database_password=foobarbaz OUTPUT_MANIFEST_PATH
Customizing
The table below shows the most significant properties you can use to customize your PostgreSQL installation. The complete list of available properties can be found in the spec.
Property | Description |
---|---|
databases.port | The database port. Default: 5432 |
databases.databases | A list of databases and associated properties to create when Postgres starts |
databases.databases[n].name | Database name |
databases.databases[n].citext | If true the citext extension is created for the db |
databases.roles | A list of database roles and associated properties to create |
databases.roles[n].name | Role name |
databases.roles[n].password | Login password for the role. If not provided, TLS certificate authentication is assumed for the user. |
databases.roles[n].common_name | The cn attribute of the certificate for the user. It only applies to TLS certificate authentication. |
databases.roles[n].permissions | A list of attributes for the role. For the complete list of attributes, refer to ALTER ROLE command options. |
databases.tls.certificate | PEM-encoded certificate for secure TLS communication |
databases.tls.private_key | PEM-encoded key for secure TLS communication |
databases.tls.ca | PEM-encoded certification authority for secure TLS communication. Only needed to let users authenticate with TLS certificate. |
databases.max_connections | Maximum number of database connections |
databases.log_line_prefix | The postgres printf style string that is output at the beginning of each log line. Default: %m: |
databases.collect_statement_statistics | Enable the pg_stat_statements extension and collect statement execution statistics. Default: false |
databases.additional_config | A map of additional key/value pairs to include as extra configuration properties |
databases.monit_timeout | Monit timout in seconds for the postgres job start. Default: 90 . |
databases.trust_local_connection | Whether or not postgres must trust local connections. vcap is always trusted. It defaults to true . |
databases.skip_data_copy_in_minor | Whether or not a copy of the data directory is created during PostgreSQL minor upgrades. A copy is created by default. |
databases.hooks.timeout | Time limit in seconds for the hook script. By default, it's set to 0 that means no time limit. |
databases.hooks.pre-start | Script to run before starting PostgreSQL. |
databases.hooks.post-start | Script to run after PostgreSQL has started. |
databases.hooks.pre-stop | Script to run before stopping PostgreSQL. |
databases.hooks.post-stop | Script to run after PostgreSQL has stopped. |
janitor.script | If specified, this script would be run periodically. This would be useful for running house-keeping tasks. |
janitor.interval | Interval in seconds between two invocations of the janitor script. By default it's set to 1 day. |
janitor.timeout | Time limit in seconds for the janitor script. By default it's set to 0 that means no time limit. |
Note
- Removing a database from
databases.databases
list and deploying again does not trigger a physical deletion of the database in PostgreSQL. - Removing a role from
databases.roles
list and deploying again does not trigger a physical deletion of the role in PostgreSQL.
Enabling TLS on the PostgreSQL server
PostgreSQL has native support for using TLS connections to encrypt client/server communications for increased security.
You can enable it by setting the databases.tls.certificate
and the databases.tls.private_key
properties.
A script is provided that creates a CA, generates a key pair, and signs it with the CA:
./scripts/generate-postgres-certs -n HOSTNAME_OR_IP_ADDRESS
The common name for the server certificate must be set to the DNS hostname if any or to the ip address of the PostgreSQL server. This because in TLS mode verify-full
, the hostname is matched against the common-name. Refer to PostgreSQL documentation for more details.
You can also use BOSH variables to generate the certificates. See by way of example the operation file used by the manifest generation script.
~/workspace/postgres-release/scripts/generate-deployment-manifest \
-s -h HOSTNAME_OR_IP_ADDRESS \
-o OPERATION-FILE-PATH > OUTPUT_MANIFEST_PATH
Enabling TLS certificate authentication
In order to perform authentication using TLS client certificates, you must not specify a user password and you must configure the following properties:
databases.tls.certificate
databases.tls.private_key
databases.tls.ca
The cn (Common Name) attribute of the certificate will be compared to the requested database user name, and if they match the login will be allowed.
Optionally you can map the common_name to a different database user by specifying property databases.roles[n].common_name
.
A script is provided that creates a client certificates:
./scripts/generate-postgres-client-certs --ca-cert <PATH-TO-CA-CERT> --ca-key <PATH-TO-CA-KEY> --client-name <USER_NAME>
Hooks
You can run custom code before or after PostgreSQL starts or stops or periodically. For details, see hooks documentation.
Backup and Restore
You can enable backup and restore through bbr by adding the bbr-postgres-db
job with the postgres
job and by setting its release_level_backup
option to true
. If enabled, a backup is collected using pg_dump
for each database specified in the databases.databases
property.
If you don't colocate the bbr-postgres-db
with postgres
then you must specify in the postgres.dbuser
property a database user with enough permissions to run backup and restore.
If your PostgreSQL is configured with TLS, by default backup and restore are run with sslmode=verify-full
. You can change it to sslmode=verify-ca
by setting postgres.ssl_verify_hostname
to false
.
Caveats:
- Restore does not drop the database, the extensions, or the schema; therefore the schema of the restored and existing databases must be the same.
- If a backup is not present for one of the configured databases in the
databases.databases
property, the restore issues a message and continues.
Contributing
Contributor License Agreement
Contributors must sign the Contributor License Agreement before their contributions can be merged. Follow the directions here to complete that process.
Developer Workflow
-
Create a feature branch from the development branch
cd postgres-release git checkout develop git checkout -b feature-branch
-
Make changes on your branch
-
Test your changes by running acceptance tests
-
Push to your fork (
git push origin feature-branch
) and submit a pull request selectingdevelop
as the target branch. PRs submitted against other branches will need to be resubmitted with the correct branch targeted.
Known Limitations
The postgres-release does not directly support high availability. Even if you deploy more instances, no replication is configured.
Upgrading
Refer to versions.yml in order to assess if a postgres-release version upgrades the PostgreSQL version.
Upgrade Test Policy
The maintainers of the postgres-release test the following upgrade paths:
- From the previous postgres-release
- From the latest postgres-release that bumps the previous PostgreSQL version
- From the latest cf-deployment that bumps the previous PostgreSQL version
Considerations before deploying
- A copy of the database is made for the upgrade, you may need to adjust the persistent disk capacity of the
postgres
job.- For major upgrades the copy is always created
- For minor upgrades the copy is created unless the
databases.skip_data_copy_in_minor
is set totrue
.
- The upgrade happens as part of the pre-start and its duration may vary basing on your env.
- In case of a PostgreSQL minor upgrade a simple copy of the old data directory is made.
- In case of a PostgreSQL major upgrade the
pg_upgrade
utility is used.
- Postgres will be unavailable during this upgrade.
Considerations after a successful deployment
In case a copy of the old database is kept (see considerations above), the old database is moved to /var/vcap/store/postgres/postgres-previous
. The postgres-previous directory will be kept until the next postgres upgrade is performed in the future. You are free to remove this if you have verified the new database works and you want to reclaim the space.
Recovering a failure during deployment
In case of a long upgrade, the deployment may time out; anyway, bosh would not stop the actual upgrade process. In this case you can just wait for the upgrade to complete and, only when postgres is up and running, rerun the bosh deploy.
If the upgrade fails:
- The old data directory is still available at
/var/vcap/store/postgres/postgres-x.x.x
wherex.x.x
is the old PostgreSQL version - The new data directory is at
/var/vcap/store/postgres/postgres-y.y.y
wherey.y.y
is the new PostgreSQL version - If the upgrade is a PostgreSQL major upgrade:
- A marker file is kept at
/var/vcap/store/postgres/POSTGRES_UPGRADE_LOCK
to prevent the upgrade from happening again. pg_upgrade
logs that may have details of why the migration failed can be found in/var/vcap/sys/log/postgres/postgres_ctl.log
- A marker file is kept at
If you want to attempt the upgrade again or to roll back to the previous release, you should remove the new data directory and, if present, the marker file.