config: restructure in 'jobs' and 'global' section

cmd/config.go

@@ -8,7 +8,16 @@ import (
 )
 
 type Config struct {
-	Jobs map[string]Job
+	Global Global
+	Jobs   map[string]Job
+}
+
+type Global struct {
+	Serve struct {
+		Stdinserver struct {
+			SockDir string
+		}
+	}
 }
 
 type RPCConnecter interface {

cmd/config_parse.go

@@ -3,10 +3,10 @@ package cmd
 import (
 	"io/ioutil"
 
+	"fmt"
 	"github.com/mitchellh/mapstructure"
 	"github.com/pkg/errors"
 	yaml "gopkg.in/yaml.v2"
-	"fmt"
 )
 
 func ParseConfig(path string) (config *Config, err error) {
@@ -30,43 +30,76 @@ func ParseConfig(path string) (config *Config, err error) {
 
 func parseConfig(i interface{}) (c *Config, err error) {
 
-	var jm map[string]map[string]interface{}
-	if err := mapstructure.Decode(i, &jm); err != nil {
-		return nil, errors.Wrap(err, "config must be a dict with job name as key and jobs as values")
+	var asMap struct {
+		Global map[string]interface{}
+		Jobs   []map[string]interface{}
+	}
+	if err := mapstructure.Decode(i, &asMap); err != nil {
+		return nil, errors.Wrap(err, "config root must be a dict")
 	}
 
-	c = &Config{
-		Jobs: make(map[string]Job, len(jm)),
+	c = &Config{}
+
+	// Parse global with defaults
+	c.Global.Serve.Stdinserver.SockDir = "/var/run/zrepl/stdinserver"
+	err = mapstructure.Decode(asMap.Global, &c.Global)
+	if err != nil {
+		err = errors.Wrap(err, "cannot parse global section: %s")
+		return
 	}
 
-	for name := range jm {
-
-		c.Jobs[name], err = parseJob(name, jm[name])
+	// Parse Jobs
+	c.Jobs = make(map[string]Job, len(asMap.Jobs))
+	for i := range asMap.Jobs {
+		job, err := parseJob(asMap.Jobs[i])
 		if err != nil {
-			err = errors.Wrapf(err, "cannot parse job '%s'", name)
+			// Try to find its name
+			namei, ok := asMap.Jobs[i]["name"]
+			if !ok {
+				namei = fmt.Sprintf("<no name, %i in list>", i)
+			}
+			err = errors.Wrapf(err, "cannot parse job '%v'", namei)
 			return nil, err
 		}
-
+		c.Jobs[job.JobName()] = job
 	}
 
 	return c, nil
 
 }
 
-func parseJob(name string, i map[string]interface{}) (j Job, err error) {
-
-	jobtype_i, ok := i["type"]
+func extractStringField(i map[string]interface{}, key string, notempty bool) (field string, err error) {
+	vi, ok := i[key]
 	if !ok {
-		err = errors.New("must have field 'type'")
-		return nil, err
+		err = errors.Errorf("must have field '%s'", key)
+		return "", err
 	}
-	jobtype_str, ok := jobtype_i.(string)
+	field, ok = vi.(string)
 	if !ok {
-		err = errors.New("'type' field must have type string")
-		return nil, err
+		err = errors.Errorf("'%s' field must have type string", key)
+		return "", err
+	}
+	if notempty && len(field) <= 0 {
+		err = errors.Errorf("'%s' field must not be empty", key)
+		return "", err
+	}
+	return
+}
+
+func parseJob(i map[string]interface{}) (j Job, err error) {
+
+	name, err := extractStringField(i, "name", true)
+	if err != nil {
+		return
 	}
 
-	switch jobtype_str {
+	jobtype, err := extractStringField(i, "type", true)
+	if err != nil {
+		return
+
+	}
+
+	switch jobtype {
 	case "pull":
 		return parsePullJob(name, i)
 	case "source":
@@ -74,7 +107,7 @@ func parseJob(name string, i map[string]interface{}) (j Job, err error) {
 	case "local":
 		return parseLocalJob(name, i)
 	default:
-		return nil, errors.Errorf("unknown job type '%s'", jobtype_str)
+		return nil, errors.Errorf("unknown job type '%s'", jobtype)
 	}
 
 	panic("implementation error")
@@ -83,22 +116,17 @@ func parseJob(name string, i map[string]interface{}) (j Job, err error) {
 }
 
 func parseConnect(i map[string]interface{}) (c RPCConnecter, err error) {
-	type_i, ok := i["type"]
-	if !ok {
-		err = errors.New("must have field 'type'")
-		return
-	}
-	type_str, ok := type_i.(string)
-	if !ok {
-		err = errors.New("'type' field must have type string")
+
+	t, err := extractStringField(i, "type", true)
+	if err != nil {
 		return nil, err
 	}
 
-	switch type_str {
+	switch t {
 	case "ssh+stdinserver":
 		return parseSSHStdinserverConnecter(i)
 	default:
-		return nil, errors.Errorf("unknown connection type '%s'", type_str)
+		return nil, errors.Errorf("unknown connection type '%s'", t)
 	}
 
 	panic("implementation error")
@@ -131,9 +159,8 @@ err:
 
 func parsePrunePolicy(v map[string]interface{}) (p PrunePolicy, err error) {
 
-	policyName, ok := v["policy"]
-	if !ok {
-		err = errors.Errorf("policy name not specified")
+	policyName, err := extractStringField(v, "policy", true)
+	if err != nil {
 		return
 	}
 
@@ -152,22 +179,16 @@ func parsePrunePolicy(v map[string]interface{}) (p PrunePolicy, err error) {
 
 func parseAuthenticatedChannelListenerFactory(v map[string]interface{}) (p AuthenticatedChannelListenerFactory, err error) {
 
-	t, ok := v["type"]
-	if !ok {
-		err = errors.Errorf("must specify 'type' field")
-		return
-	}
-	s, ok := t.(string)
-	if !ok {
-		err = errors.Errorf("'type' must be a string")
-		return
+	t, err := extractStringField(v, "type", true)
+	if err != nil {
+		return nil, err
 	}
 
-	switch s{
+	switch t {
 	case "stdinserver":
 		return parseStdinserverListenerFactory(v)
 	default:
-		err = errors.Errorf("unknown type '%s'", s)
+		err = errors.Errorf("unknown type '%s'", t)
 		return
 	}
 

cmd/sampleconf/localbackup/host1.yml

@@ -1,5 +1,5 @@
-mirror_local:
-
+jobs:
+- name: mirror_local
   type: local
 
   # snapshot the filesystems matched by the left-hand-side of the mapping

cmd/sampleconf/pullbackup/backuphost.yml

@@ -1,7 +1,7 @@
-fullbackup_prod1:
-
-  # connect to remote using ssh / stdinserver command
+jobs:
+- name: fullbackup_prod1
   type: pull
+  # connect to remote using ssh / stdinserver command
   connect:
     type: ssh+stdinserver
     host: prod1.example.com

cmd/sampleconf/pullbackup/productionhost.yml

@@ -1,14 +1,30 @@
-fullbackup_prod1:
+global:
+  serve:
+    stdinserver:
+      # Directory where AF_UNIX sockets for stdinserver command are placed.
+      #
+      # `zrepl stdinserver CLIENT_IDENTITY`
+      #   * connects to the socket in $sockdir/CLIENT_IDENTITY
+      #   * sends its stdin / stdout file descriptors to the `zrepl daemon` process (see cmsg(3))
+      #   * does nothing more
+      #
+      # This enables a setup where `zrepl daemon` is not directly exposed to the internet
+      # but instead all traffic is tunnelled through SSH.
+      # The server with the source job has an authorized_keys file entry for the public key
+      # used by the corresponding pull job
+      #
+      #   command="/mnt/zrepl stdinserver CLIENT_IDENTITY" ssh-ed25519 AAAAC3NzaC1E... zrepl@pullingserver
+      #
+      # Below is the default value.
+      sockdir: /var/run/zrepl/stdinserver
 
+jobs:
+
+- name: fullbackup_prod1
   # expect remote to connect via ssh+stdinserver with fullbackup_prod1 as client_identity
   type: source
   serve:
-    # Creates an AF_UNIX socket with name client_identity in a well-known directory
-    # private to the zrepl user (which runs both the zrepld and the stdinserver command via authorized_keys)
-    # The stdinserver command connects to that socket and sends its stdin and stdout
-    # file descriptors over that UNIX socket to the zrepld.
-    # This avoids additional memory-to-memory copies and is more portable than splice(2) on Linux.
-    type: stdinserver
+    type: stdinserver # see global.serve.stdinserver for explanation
     client_identity: fullbackup_prod1
 
   # snapshot these filesystems every 10m with zrepl_ as prefix

cmd/sampleconf/pushbackup/backuphost.yml

@@ -1,4 +1,5 @@
-fullbackup_prod1:
+jobs:
+- name: fullbackup_prod1
 
   # expect remote to connect via ssh+stdinserver with fullbackup_prod1 as client_identity
   type: push-sink

cmd/sampleconf/pushbackup/productionhost.yml

@@ -1,4 +1,5 @@
-fullbackup_prod1:
+jobs:
+- name: fullbackup_prod1
 
   # connect to remote using ssh / stdinserver command
   type: push