Merge pull request percona#30 from percona/PMM-7344-Update-to-0.8.0

PMM-7344 update to 0.8.0

Author: askomorokhov

.gitignore

@@ -18,3 +18,4 @@
 /.assets-branch
 /.metrics.*.added
 /.metrics.*.removed
+/tools/src

Gopkg.lock

@@ -18,6 +18,9 @@ docker run --net=host -e DATA_SOURCE_NAME="postgresql://postgres:password@localh
 
 ### Flags
 
+* `help`
+  Show context-sensitive help (also try --help-long and --help-man).
+
 * `web.listen-address`
   Address to listen on for web interface and telemetry. Default is `:9187`.
 
@@ -30,6 +33,9 @@ docker run --net=host -e DATA_SOURCE_NAME="postgresql://postgres:password@localh
 * `disable-settings-metrics`
   Use the flag if you don't want to scrape `pg_settings`.
 
+* `auto-discover-databases`
+  Enable discovering databases automatically.
+
 * `extend.query-path`
   Path to a YAML file containing custom queries to run. Check out [`queries.yaml`](queries.yaml)
   for examples of the format.
@@ -38,16 +44,22 @@ docker run --net=host -e DATA_SOURCE_NAME="postgresql://postgres:password@localh
   Do not run - print the internal representation of the metric maps. Useful when debugging a custom
   queries file.
 
+* `constantLabels`
+  Labels to set in all metrics. A list of `label=value` pairs, separated by commas.
+
+* `version`
+  Show application version.
+
+* `exclude-databases`
+  A list of databases to remove when autoDiscoverDatabases is enabled.
+
 * `log.level`
   Set logging level: one of `debug`, `info`, `warn`, `error`, `fatal`
 
 * `log.format`
   Set the log output target and format. e.g. `logger:syslog?appname=bob&local=7` or `logger:stdout?json=true`
   Defaults to `logger:stderr`.
 
-* `constantLabels`
-  Labels to set in all metrics. A list of `label=value` pairs, separated by commas.
-
 ### Environment Variables
 
 The following environment variables configure the exporter:
@@ -60,6 +72,9 @@ The following environment variables configure the exporter:
    an alternative to `DATA_SOURCE_NAME` which exclusively accepts the raw URI
    without a username and password component.
 
+* `DATA_SOURCE_URI_FILE`
+   The same as above but reads the URI from a file.
+
 * `DATA_SOURCE_USER`
   When using `DATA_SOURCE_URI`, this environment variable is used to specify
   the username.
@@ -86,13 +101,19 @@ The following environment variables configure the exporter:
 * `PG_EXPORTER_DISABLE_SETTINGS_METRICS`
   Use the flag if you don't want to scrape `pg_settings`. Value can be `true` or `false`. Defauls is `false`.
 
+* `PG_EXPORTER_AUTO_DISCOVER_DATABASES`
+  Enable discovering databases automatically. Value can be `true` or `false`. Defauls is `false`.
+
 * `PG_EXPORTER_EXTEND_QUERY_PATH`
   Path to a YAML file containing custom queries to run. Check out [`queries.yaml`](queries.yaml)
   for examples of the format.
 
 * `PG_EXPORTER_CONSTANT_LABELS`
   Labels to set in all metrics. A list of `label=value` pairs, separated by commas.
 
+* `PG_EXPORTER_EXCLUDE_DATABASES`
+  A comma-separated list of databases to remove when autoDiscoverDatabases is enabled. Default is empty string.
+
 Settings set by environment variables starting with `PG_` will be overwritten by the corresponding CLI flag if given.
 
 ### Setting the Postgres server's data source name
@@ -138,9 +159,11 @@ flag. This removes all built-in metrics, and uses only metrics defined by querie
 
 ### Automatically discover databases
 To scrape metrics from all databases on a database server, the database DSN's can be dynamically discovered via the 
-`--auto-discover-databases` flag. When true, `SELECT datname FROM pg_database` is run for all configured DSN's. From the 
+`--auto-discover-databases` flag. When true, `SELECT datname FROM pg_database WHERE datallowconn = true AND datistemplate = false and datname != current_database()` is run for all configured DSN's. From the 
 result a new set of DSN's is created for which the metrics are scraped.
 
+In addition, the option `--exclude-databases` adds the possibily to filter the result from the auto discovery to discard databases you do not need.
+
 ### Running as non-superuser
 
 To be able to collect metrics from `pg_stat_activity` and `pg_stat_replication`
@@ -181,6 +204,7 @@ ALTER USER postgres_exporter SET SEARCH_PATH TO postgres_exporter,pg_catalog;
 -- GRANT postgres_exporter TO <MASTER_USER>;
 CREATE SCHEMA IF NOT EXISTS postgres_exporter;
 GRANT USAGE ON SCHEMA postgres_exporter TO postgres_exporter;
+GRANT CONNECT ON DATABASE postgres TO postgres_exporter;
 
 CREATE OR REPLACE FUNCTION get_pg_stat_activity() RETURNS SETOF pg_stat_activity AS
 $$ SELECT * FROM pg_catalog.pg_stat_activity; $$
@@ -212,3 +236,10 @@ GRANT SELECT ON postgres_exporter.pg_stat_replication TO postgres_exporter;
 > ```
 > DATA_SOURCE_NAME=postgresql://postgres_exporter:password@localhost:5432/postgres?sslmode=disable
 > ```
+
+# Hacking
+* To build a copy for your current architecture run `go run mage.go binary`.
+  This will create a symlink to the just built binary in the root directory.
+* To build release tar balls run `go run mage.go release`.
+* Build system is a bit temperamental at the moment since the conversion to mage - I am working on getting it
+  to be a perfect out of the box experience, but am time-constrained on it at the moment.