[+] add a SystemD service template (#704)

* Add a SystemD service template to DEB / RPM / Tar
* move samples to a special `contrib` folder
* fix tests
* fix linter warnings

---------

Co-authored-by: Pavlo Golub <pavlo.golub@gmail.com>

Author: kmoppel

.goreleaser.yml

@@ -28,12 +28,14 @@ archives:
     - goos: windows
       formats: ['zip']
   files:
-    - ./grafana/**/*
-    - ./README.md
-    - src: ./internal/sources/sample.sources.yaml
-      dst: sample.sources.yaml
-    - src: ./internal/metrics/metrics.yaml
-      dst: metrics.yaml
+    - "./grafana/**/*"
+    - "./README.md"
+    - src: "./internal/metrics/metrics.yaml"
+      dst: "metrics.yaml"
+    - src: "./contrib/sample.sources.yaml"
+      dst: "sample.sources.yaml"
+    - src: "./contrib/sample.systemd.service"
+      dst: "/etc/pgwatch/sample.systemd.service"
 
 
 checksum:
@@ -63,9 +65,11 @@ nfpms:
     contents:
       - src: "./grafana/*"
         dst: "/etc/pgwatch/grafana"
-      - src: "./internal/sources/sample.sources.yaml"
+      - src: "./contrib/sample.sources.yaml"
         dst: "/etc/pgwatch/sample.sources.yaml"
       - src: "./internal/metrics/metrics.yaml"
         dst: "/etc/pgwatch/metrics.yaml"
       - src: "./README.md"
         dst: "/etc/pgwatch/README.md"
+      - src: "./contrib/sample.systemd.service"
+        dst: "/etc/pgwatch/sample.systemd.service"

internal/sources/sample.sources.yaml contrib/sample.sources.yamlinternal/sources/sample.sources.yaml renamed to contrib/sample.sources.yaml

@@ -1,5 +1,5 @@
 - name: test1       # An arbitrary unique name for the monitored source
-  conn_str: postgresql://pgwatch:pgwatchadmin@somehost/mydb
+  conn_str: postgresql://postgres@localhost/postgres
   kind: postgres              # One of the:
                               # - postgres
                               # - postgres-continuous-discovery

contrib/sample.systemd.service

@@ -0,0 +1,20 @@
+# This is an example of a systemD config file for pgwatch.
+# You can copy it to "/etc/systemd/system/pgwatch.service", adjust as necessary and then call
+# systemctl daemon-reload && systemctl start pgwatch && systemctl enable pgwatch
+# to start and also enable auto-start after reboot.
+
+[Unit]
+Description=Pgwatch Gathering Daemon
+After=network-online.target
+# When on the monitored node then it's a good idea to only launch after Postgres
+# After=postgresql
+
+[Service]
+User=postgres
+Type=simple
+ExecStart=/usr/bin/pgwatch --sources /etc/pgwatch/sample.sources.yaml --sink=prometheus://0.0.0.0:9187
+Restart=on-failure
+TimeoutStartSec=0
+
+[Install]
+WantedBy=multi-user.target

docs/concept/installation_options.md

@@ -23,7 +23,7 @@ The default Docker demo image `cybertecpostgresql/pgwatch-demo` uses this approa
 One can deploy the gatherer daemon(s) decentralized with
 *sources to be monitored* defined in simple YAML files. In that case there
 is no need for the central Postgres configuration database. See the
-[sample.sources.yaml](https://github.com/cybertec-postgresql/pgwatch/blob/master/internal/sources/sample.sources.yaml)
+[sample.sources.yaml](https://github.com/cybertec-postgresql/pgwatch/blob/master/contrib/sample.sources.yaml)
 config file for an example.
 
 !!! Note

docs/reference/advanced_features.md

@@ -34,7 +34,7 @@ config (for Config DB based setups) looks like:
 ```
 
 For YAML based setups an example can be found from the
-[instances.yaml](https://github.com/cybertec-postgresql/pgwatch/blob/master/internal/sources/sample.sources.yaml#L21)
+[instances.yaml](https://github.com/cybertec-postgresql/pgwatch/blob/master/contrib/sample.sources.yaml#L21)
 file.
 
 If Patroni is powered by *etcd*, then also username, password, ca_file,
@@ -65,7 +65,7 @@ the whole instance. The metric name to enable log parsing is
 destination / setting to work, the monitoring user needs superuser /
 pg_monitor privileges - if this is not possible then log settings need
 to be specified manually under "Host config" as seen for example
-[here](https://github.com/cybertec-postgresql/pgwatch/blob/master/internal/sources/sample.sources.yaml#L25).
+[here](https://github.com/cybertec-postgresql/pgwatch/blob/master/contrib/sample.sources.yaml#L25).
 
 **Sample configuration if not using CSVLOG logging:**
 

internal/sources/yaml_test.go

@@ -3,7 +3,6 @@ package sources_test
 import (
 	"os"
 	"path/filepath"
-	"runtime"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -14,24 +13,14 @@ import (
 // the number of entries in the sample.sources.yaml file
 const sampleEntriesNumber = 4
 
-var (
-	currentDir string
-	sampleFile string
+const (
+	contribDir = "../../contrib/"
+	sampleFile = "../../contrib/sample.sources.yaml"
 )
 
-func init() {
-	// setup the test environment
-	_, filename, _, ok := runtime.Caller(0)
-	if !ok {
-		panic("Cannot get the current file path")
-	}
-	currentDir = filepath.Dir(filename)
-	sampleFile = filepath.Join(currentDir, "sample.sources.yaml")
-}
-
 func TestNewYAMLSourcesReaderWriter(t *testing.T) {
 	a := assert.New(t)
-	yamlrw, err := sources.NewYAMLSourcesReaderWriter(ctx, "../sample.sources.yaml")
+	yamlrw, err := sources.NewYAMLSourcesReaderWriter(ctx, sampleFile)
 	a.NoError(err)
 	a.NotNil(t, yamlrw)
 }
@@ -49,7 +38,7 @@ func TestYAMLGetMonitoredDatabases(t *testing.T) {
 	})
 
 	t.Run("folder with yaml files", func(*testing.T) {
-		yamlrw, err := sources.NewYAMLSourcesReaderWriter(ctx, currentDir)
+		yamlrw, err := sources.NewYAMLSourcesReaderWriter(ctx, contribDir)
 		a.NoError(err)
 
 		dbs, err := yamlrw.GetSources()
@@ -66,7 +55,7 @@ func TestYAMLGetMonitoredDatabases(t *testing.T) {
 	})
 
 	t.Run("garbage file", func(*testing.T) {
-		yamlrw, err := sources.NewYAMLSourcesReaderWriter(ctx, filepath.Join(currentDir, "yaml.go"))
+		yamlrw, err := sources.NewYAMLSourcesReaderWriter(ctx, filepath.Join(contribDir, "yaml.go"))
 		a.NoError(err)
 		dbs, err := yamlrw.GetSources()
 		a.Error(err)