Fix link to coreos/go-systemd/tree/main/sdjournal

README.md

@@ -65,14 +65,14 @@ The following configuration settings are supported:
 
 * `aws_region`: (Optional) The AWS region whose CloudWatch Logs API will be written to. If not provided,
   this defaults to the region where the host EC2 instance is running.
-  
+
 * `ec2_instance_id`: (Optional) The id of the EC2 instance on which the tool is running. There is very
   little reason to set this, since it will be automatically set to the id of the host EC2 instance.
 
 * `journal_dir`: (Optional) Override the directory where the systemd journal can be found. This is
   useful in conjunction with remote log aggregation, to work with journals synced from other systems.
   The default is to use the local system's journal.
-  
+
 * `log_group`: (Required) The name of the cloudwatch log group to write logs into. This log group must
   be created before running the program.
 
@@ -84,14 +84,18 @@ The following configuration settings are supported:
     log level are read and pushed to CloudWatch. For more information about priority levels, look at
     https://www.freedesktop.org/software/systemd/man/journalctl.html
 
+* `log_unit`: (Optional) The `journalctl` unit to filter. By default,
+  not filter. Replicates the behaviour of use the command `journalctl
+  -u <log_unit>`. Multiple values can be provided, separated by "`,`".
+
 * `log_stream`: (Optional) The name of the cloudwatch log stream to write logs into. This defaults to
   the EC2 instance id. Each running instance of this application (along with any other applications
   writing logs into the same log group) must have a unique `log_stream` value. If the given log stream
   doesn't exist then it will be created before writing the first set of journal events.
-  
+
 * `state_file`: (Required) Path to a location where the program can write, and later read, some
   state it needs to preserve between runs. (The format of this file is an implementation detail.)
-  
+
 * `buffer_size`: (Optional) The size of the local event buffer where journal events will be kept
   in order to write batches of events to the CloudWatch Logs API. The default is 100. A batch of
   new events will be written to CloudWatch Logs every second even if the buffer does not fill, but
@@ -116,7 +120,7 @@ At the time of writing, in early 2017, the supported InstanceIdentityDocument va
 * `${instance.KernelID}`: The kernel ID used to launch the instance (PV instances only)
 * `${instance.RamdiskID}`: The ramdisk ID used to launch the instance (PV instances only)
 * `${instance.Architecture}`: The CPU architecture of the instance, eg `x86_64`
-  
+
 ### AWS API access
 
 This program requires access to call some of the Cloudwatch API functions. The recommended way to

config.go

@@ -16,40 +16,42 @@ import (
 	"github.com/hashicorp/hcl"
 )
 
-type Config struct {
+type config struct {
 	AWSCredentials *awsCredentials.Credentials
 	AWSRegion      string
-	EC2InstanceId  string
+	EC2InstanceID  string
 	LogGroupName   string
 	LogStreamName  string
-	LogPriority    Priority
+	LogPriority    priorityType
+	LogUnit        string
 	StateFilename  string
 	JournalDir     string
 	BufferSize     int
 }
 
 type fileConfig struct {
 	AWSRegion     string `hcl:"aws_region"`
-	EC2InstanceId string `hcl:"ec2_instance_id"`
+	EC2InstanceID string `hcl:"ec2_instance_id"`
 	LogGroupName  string `hcl:"log_group"`
 	LogStreamName string `hcl:"log_stream"`
 	LogPriority   string `hcl:"log_priority"`
+	LogUnit       string `hcl:"log_unit"`
 	StateFilename string `hcl:"state_file"`
 	JournalDir    string `hcl:"journal_dir"`
 	BufferSize    int    `hcl:"buffer_size"`
 }
 
-func getLogLevel(priority string) (Priority, error) {
-
-	logLevels := map[Priority][]string{
-		EMERGENCY: {"0", "emerg"},
-		ALERT:     {"1", "alert"},
-		CRITICAL:  {"2", "crit"},
-		ERROR:     {"3", "err"},
-		WARNING:   {"4", "warning"},
-		NOTICE:    {"5", "notice"},
-		INFO:      {"6", "info"},
-		DEBUG:     {"7", "debug"},
+func getLogLevel(priority string) (priorityType, error) {
+
+	logLevels := map[priorityType][]string{
+		emergencyP: {"0", "emerg"},
+		alertP:     {"1", "alert"},
+		criticalP:  {"2", "crit"},
+		errorP:     {"3", "err"},
+		warningP:   {"4", "warning"},
+		noticeP:    {"5", "notice"},
+		infoP:      {"6", "info"},
+		debugP:     {"7", "debug"},
 	}
 
 	for i, s := range logLevels {
@@ -58,10 +60,10 @@ func getLogLevel(priority string) (Priority, error) {
 		}
 	}
 
-	return DEBUG, fmt.Errorf("'%s' is unsupported log priority", priority)
+	return debugP, fmt.Errorf("'%s' is unsupported log priority", priority)
 }
 
-func LoadConfig(filename string) (*Config, error) {
+func loadConfig(filename string) (*config, error) {
 	configBytes, err := ioutil.ReadFile(filename)
 	if err != nil {
 		return nil, err
@@ -84,7 +86,7 @@ func LoadConfig(filename string) (*Config, error) {
 
 	expandFileConfig(&fConfig, metaClient)
 
-	config := &Config{}
+	config := &config{}
 
 	if fConfig.AWSRegion != "" {
 		config.AWSRegion = fConfig.AWSRegion
@@ -96,33 +98,34 @@ func LoadConfig(filename string) (*Config, error) {
 		config.AWSRegion = region
 	}
 
-	if fConfig.EC2InstanceId != "" {
-		config.EC2InstanceId = fConfig.EC2InstanceId
+	if fConfig.EC2InstanceID != "" {
+		config.EC2InstanceID = fConfig.EC2InstanceID
 	} else {
-		instanceId, err := metaClient.GetMetadata("instance-id")
+		instanceID, err := metaClient.GetMetadata("instance-id")
 		if err != nil {
 			return nil, fmt.Errorf("unable to detect EC2 instance id: %s", err)
 		}
-		config.EC2InstanceId = instanceId
+		config.EC2InstanceID = instanceID
 	}
 
 	if fConfig.LogPriority == "" {
 		// Log everything
-		config.LogPriority = DEBUG
+		config.LogPriority = debugP
 	} else {
 		config.LogPriority, err = getLogLevel(fConfig.LogPriority)
 		if err != nil {
-			return nil, fmt.Errorf("The provided log filtering '%s' is unsupported by systemd!", fConfig.LogPriority)
+			return nil, fmt.Errorf("The provided log filtering '%s' is unsupported by systemd", fConfig.LogPriority)
 		}
 	}
 
+	config.LogUnit = fConfig.LogUnit
 	config.LogGroupName = fConfig.LogGroupName
 
 	if fConfig.LogStreamName != "" {
 		config.LogStreamName = fConfig.LogStreamName
 	} else {
 		// By default we use the instance id as the stream name.
-		config.LogStreamName = config.EC2InstanceId
+		config.LogStreamName = config.EC2InstanceID
 	}
 
 	config.StateFilename = fConfig.StateFilename
@@ -144,7 +147,7 @@ func LoadConfig(filename string) (*Config, error) {
 	return config, nil
 }
 
-func (c *Config) NewAWSSession() *awsSession.Session {
+func (c *config) newAWSSession() *awsSession.Session {
 	config := &aws.Config{
 		Credentials: c.AWSCredentials,
 		Region:      aws.String(c.AWSRegion),
@@ -153,7 +156,6 @@ func (c *Config) NewAWSSession() *awsSession.Session {
 	return awsSession.New(config)
 }
 
-
 /*
  * Expand variables of the form $Foo or ${Foo} in the user provided config
  * from the EC2Metadata Instance Identity Document
@@ -167,12 +169,12 @@ func expandFileConfig(config *fileConfig, metaClient *ec2metadata.EC2Metadata) {
 	// struct extracting the string fields and their values into the vars map
 	data, err := metaClient.GetInstanceIdentityDocument()
 	if err == nil {
-		metadata := reflect.ValueOf( data )
+		metadata := reflect.ValueOf(data)
 
 		for i := 0; i < metadata.NumField(); i++ {
 			field := metadata.Field(i)
 			ftype := metadata.Type().Field(i)
-			if (field.Type() != reflect.TypeOf("")) {
+			if field.Type() != reflect.TypeOf("") {
 				continue
 			}
 			vars[ftype.Name] = fmt.Sprintf("%v", field.Interface())
@@ -199,8 +201,8 @@ func expandFileConfig(config *fileConfig, metaClient *ec2metadata.EC2Metadata) {
 								return val
 							}
 							// Unknown key => empty string
-							return "" 
-						} else if (strings.HasPrefix(varname, "env.")) {
+							return ""
+						} else if strings.HasPrefix(varname, "env.") {
 							return os.Getenv(strings.TrimPrefix(varname, "env."))
 						} else {
 							// Unknown prefix => empty string
@@ -213,7 +215,6 @@ func expandFileConfig(config *fileConfig, metaClient *ec2metadata.EC2Metadata) {
 	}
 }
 
-
 // Modified version of os.Expand() that only expands ${name} and not $name
 func expandBraceVars(s string, mapping func(string) string) string {
 	buf := make([]byte, 0, 2*len(s))
@@ -223,10 +224,10 @@ func expandBraceVars(s string, mapping func(string) string) string {
 		if s[j] == '$' && j+3 < len(s) && s[j+1] == '{' {
 			buf = append(buf, s[i:j]...)
 			idx := strings.Index(s[j+2:], "}")
-			if (idx >= 0) {
+			if idx >= 0 {
 				// We have a full ${name} string
 				buf = append(buf, mapping(s[j+2:j+2+idx])...)
-				j += 2+idx
+				j += 2 + idx
 			} else {
 				// We ran out of string (unclosed ${)
 				return string(buf)
@@ -236,6 +237,3 @@ func expandBraceVars(s string, mapping func(string) string) string {
 	}
 	return string(buf) + s[i:]
 }
-
-
-

go.mod

@@ -0,0 +1,12 @@
+module github.com/boryskova/journald-cloudwatch-logs
+
+go 1.19
+
+require (
+        github.com/aws/aws-sdk-go v1.4.11-0.20160915231818-d54f7c6d021d
+        github.com/coreos/go-systemd v0.0.0-20160907121635-2f344660b11f
+        github.com/coreos/pkg v0.0.0-20160727233714-3ac0863d7acf
+        github.com/go-ini/ini v1.21.1
+        github.com/hashicorp/hcl v0.0.0-20160902165219-99df0eb941dd
+        github.com/jmespath/go-jmespath v0.0.0-20160803190731-bd40a432e4c7
+)

go.sum

@@ -0,0 +1,36 @@
+github.com/aws/aws-sdk-go v1.4.11-0.20160915231818-d54f7c6d021d h1:bmLH3/SXrvYSoLHOPA0AzaD3HyAr1gL/d3TR3dzo0kA=
+github.com/aws/aws-sdk-go v1.4.11-0.20160915231818-d54f7c6d021d/go.mod h1:ZRmQr0FajVIyZ4ZzBYKG5P3ZqPz9IHG41ZoMu1ADI3k=
+github.com/coreos/go-systemd v0.0.0-20160907121635-2f344660b11f h1:CjKZ1H3olidJYTH3q4CKOfR/uTuXweso6sfbOB3/CKQ=
+github.com/coreos/go-systemd v0.0.0-20160907121635-2f344660b11f/go.mod h1:F5haX7vjVVG0kc13fIWeqUViNPyEJxv/OmvnBo0Yme4=
+github.com/coreos/pkg v0.0.0-20160727233714-3ac0863d7acf h1:CAKfRE2YtTUIjjh1bkBtyYFaUT/WmOqsJjgtihT0vMI=
+github.com/coreos/pkg v0.0.0-20160727233714-3ac0863d7acf/go.mod h1:E3G3o1h8I7cfcXa63jLwjI0eiQQMgzzUDFVpN/nH/eA=
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/go-ini/ini v1.21.1 h1:+QXUYsI7Tfxc64oD6R5BxU/Aq+UwGkyjH4W/hMNG7bg=
+github.com/go-ini/ini v1.21.1/go.mod h1:ByCAeIL28uOIIG0E3PJtZPDL8WnHpFKFOtgjp+3Ies8=
+github.com/gopherjs/gopherjs v0.0.0-20181017120253-0766667cb4d1 h1:EGx4pi6eqNxGaHF6qqu48+N2wcFQ5qg5FXgOdqsJ5d8=
+github.com/gopherjs/gopherjs v0.0.0-20181017120253-0766667cb4d1/go.mod h1:wJfORRmW1u3UXTncJ5qlYoELFm8eSnnEO6hX4iZ3EWY=
+github.com/hashicorp/hcl v0.0.0-20160902165219-99df0eb941dd h1:84QdurP28/GTPuAXatiouvNyhN9dflZY9KtMbatmupI=
+github.com/hashicorp/hcl v0.0.0-20160902165219-99df0eb941dd/go.mod h1:oZtUIOe8dh44I2q6ScRibXws4Ajl+d+nod3AaR9vL5w=
+github.com/jmespath/go-jmespath v0.0.0-20160803190731-bd40a432e4c7 h1:SMvOWPJCES2GdFracYbBQh93GXac8fq7HeN6JnpduB8=
+github.com/jmespath/go-jmespath v0.0.0-20160803190731-bd40a432e4c7/go.mod h1:Nht3zPeWKUH0NzdCt2Blrr5ys8VGpn0CEB0cQHVjt7k=
+github.com/jtolds/gls v4.20.0+incompatible h1:xdiiI2gbIgH/gLH7ADydsJ1uDOEzR8yvV7C0MuV77Wo=
+github.com/jtolds/gls v4.20.0+incompatible/go.mod h1:QJZ7F/aHp+rZTRtaJ1ow/lLfFfVYBRgL+9YlvaHOwJU=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d h1:zE9ykElWQ6/NYmHa3jpm/yHnI4xSofP+UP6SpjHcSeM=
+github.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d/go.mod h1:OnSkiWE9lh6wB0YB77sQom3nweQdgAjqCqsofrRNTgc=
+github.com/smartystreets/goconvey v1.6.4 h1:fv0U8FUIMPNf1L9lnHLvLhgicrIVChEkdzIKYqbNC9s=
+github.com/smartystreets/goconvey v1.6.4/go.mod h1:syvi0/a8iFYH4r/RixwvyeAJjdLS9QV7WQ/tjFTllLA=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.5.1 h1:nOGnQDM7FYENwehXlg/kFVnos3rEvtKTjRvOWSzb6H4=
+github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/tools v0.0.0-20190328211700-ab21143f2384/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
+gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

journal.go

@@ -3,17 +3,32 @@ package main
 import (
 	"github.com/coreos/go-systemd/sdjournal"
 	"strconv"
+	"strings"
 )
 
-func AddLogFilters(journal *sdjournal.Journal, config *Config) {
+func addLogFilters(journal *sdjournal.Journal, config *config) {
 
 	// Add Priority Filters
-	if config.LogPriority < DEBUG {
-		for p, _ := range PriorityJSON {
+	if config.LogPriority < debugP {
+		for p := range priorityJSON {
 			if p <= config.LogPriority {
 				journal.AddMatch("PRIORITY=" + strconv.Itoa(int(p)))
 			}
 		}
 		journal.AddDisjunction()
 	}
+
+	// Add unit filter (multiple values possible, separate by ",")
+	if config.LogUnit != "" {
+		unitsRaw := strings.Split(config.LogUnit, ",")
+
+		for _, unitRaw := range unitsRaw {
+			unit := strings.TrimSpace(unitRaw)
+			if unit != "" {
+				journal.AddMatch("SYSLOG_IDENTIFIER=" + unit)
+				journal.AddDisjunction()
+			}
+		}
+
+	}
 }