From 289f53d38674a76e666aac30342eba60837466e4 Mon Sep 17 00:00:00 2001 From: Michael Richmond Date: Thu, 7 Jul 2016 01:40:58 -0700 Subject: k8s middleware cleanup, testcases, basic SRV (#181) * Removing unnecessary gitignore pattern * Updating Makefile to run unittests for subpackages * Adding Corefile validation to ignore overlapping zones * Fixing SRV query handling * Updating README.md now that SRV works * Fixing debug message, adding code comment * Clarifying implementation of zone normalization * "Overlapping zones" is ill-defined. Reimplemented zone overlap/subzone checking to contain these functions in k8s middleware and provide better code comments explaining the normalization. * Separate build verbosity from test verbosity * Cleaning up comments to match repo code style * Merging warning messages into single message * Moving function docs to before function declaration * Adding test cases for k8sclient connector * Tests cover connector create and setting base url * Fixed bugs in connector create and setting base url functions * Updaing README to group and order development work * Priority focused on achieving functional parity with SkyDNS. * Adding work items to README and cleaning up formatting * More README format cleaning * List formating * Refactoring k8s API call to allow dependency injection * Add test cases for data parsing from k8s into dataobject structures * URL is dependency-injected to allow replacement with a mock http server during test execution * Adding more data validation for JSON parsing tests * Adding test case for GetResourceList() * Adding notes about SkyDNS embedded IP and port record names * Marked test case implemented. * Fixing formatting for example command. * Fixing formatting * Adding notes about Docker image building. * Adding SkyDNS work item * Updating TODO list * Adding name template to Corefile to specify how k8s record names are assembled * Adding template support for multi-segment zones * Updating example CoreFile for k8s with template comment * Misc whitespace cleanup * Adding SkyDNS naming notes * Adding namespace filtering to CoreFile config * Updating example k8sCoreFile to specify namespaces * Removing unused codepath * Adding check for valid namespace * More README TODO restructuring to focus effort * Adding template validation while parsing CoreFile * Record name template is considered invalid if it contains a symbol of the form ${bar} where the symbol "${bar}" is not an accepted template symbol. * Refactoring generation of answer records * Parse typeName out of query string * Refactor answer record creation as operation over list of ServiceItems * Moving k8s API caching into SkyDNS equivalency segment * Adding function to assemble record names from template * Warning: This commit may be broken. Syncing to get laptop code over to dev machine. * More todo notes * Adding comment describing sample test data. * Update k8sCorefile * Adding comment * Adding filtering support for kubernetes "type" * Required refactoring to support reuse of the StringInSlice function. * Cleaning up formatting * Adding note about SkyDNS supporting word "any". * baseUrl -> baseURL * Also removed debug statement from core/setup/kubernetes.go * Fixing test breaking from Url -> URL naming changes * Changing record name template language ${...} -> {...} * Fix formatting with go fmt * Updating all k8sclient data getters to return error value * Adding error message to k8sclient data accessors * Cleaning up setup for kubernetes * Removed verbose nils in initial k8s middleware instance * Set reasonable defaults if CoreFile has no parameters in the kubernetes block. (k8s endpoint, and name template) * Formatting cleanup -- go fmt --- middleware/kubernetes/kubernetes.go | 203 +++++++++++++++++++++--------------- 1 file changed, 120 insertions(+), 83 deletions(-) (limited to 'middleware/kubernetes/kubernetes.go') diff --git a/middleware/kubernetes/kubernetes.go b/middleware/kubernetes/kubernetes.go index 25c8cab3c..d6d93f809 100644 --- a/middleware/kubernetes/kubernetes.go +++ b/middleware/kubernetes/kubernetes.go @@ -2,111 +2,148 @@ package kubernetes import ( - "fmt" - "strings" + "errors" + "fmt" "time" "github.com/miekg/coredns/middleware" - "github.com/miekg/coredns/middleware/kubernetes/msg" k8sc "github.com/miekg/coredns/middleware/kubernetes/k8sclient" + "github.com/miekg/coredns/middleware/kubernetes/msg" + "github.com/miekg/coredns/middleware/kubernetes/nametemplate" + "github.com/miekg/coredns/middleware/kubernetes/util" "github.com/miekg/coredns/middleware/proxy" -// "github.com/miekg/coredns/middleware/singleflight" + // "github.com/miekg/coredns/middleware/singleflight" - "github.com/miekg/dns" + "github.com/miekg/dns" "golang.org/x/net/context" ) type Kubernetes struct { - Next middleware.Handler - Zones []string - Proxy proxy.Proxy // Proxy for looking up names during the resolution process - Ctx context.Context -// Inflight *singleflight.Group - APIConn *k8sc.K8sConnector + Next middleware.Handler + Zones []string + Proxy proxy.Proxy // Proxy for looking up names during the resolution process + Ctx context.Context + // Inflight *singleflight.Group + APIConn *k8sc.K8sConnector + NameTemplate *nametemplate.NameTemplate + Namespaces *[]string } - +// getZoneForName returns the zone string that matches the name and a +// list of the DNS labels from name that are within the zone. +// For example, if "coredns.local" is a zone configured for the +// Kubernetes middleware, then getZoneForName("a.b.coredns.local") +// will return ("coredns.local", ["a", "b"]). func (g Kubernetes) getZoneForName(name string) (string, []string) { - /* - * getZoneForName returns the zone string that matches the name and a - * list of the DNS labels from name that are within the zone. - * For example, if "coredns.local" is a zone configured for the - * Kubernetes middleware, then getZoneForName("a.b.coredns.local") - * will return ("coredns.local", ["a", "b"]). - */ - var zone string - var serviceSegments []string - - for _, z := range g.Zones { - if dns.IsSubDomain(z, name) { - zone = z - - serviceSegments = dns.SplitDomainName(name) - serviceSegments = serviceSegments[:len(serviceSegments) - dns.CountLabel(zone)] - break - } - } - - return zone, serviceSegments -} + var zone string + var serviceSegments []string + for _, z := range g.Zones { + if dns.IsSubDomain(z, name) { + zone = z + + serviceSegments = dns.SplitDomainName(name) + serviceSegments = serviceSegments[:len(serviceSegments)-dns.CountLabel(zone)] + break + } + } + + return zone, serviceSegments +} // Records looks up services in kubernetes. // If exact is true, it will lookup just // this name. This is used when find matches when completing SRV lookups // for instance. func (g Kubernetes) Records(name string, exact bool) ([]msg.Service, error) { + var ( + serviceName string + namespace string + typeName string + ) + + fmt.Println("enter Records('", name, "', ", exact, ")") + zone, serviceSegments := g.getZoneForName(name) + + /* + // For initial implementation, assume namespace is first serviceSegment + // and service name is remaining segments. + serviceSegLen := len(serviceSegments) + if serviceSegLen >= 2 { + namespace = serviceSegments[serviceSegLen-1] + serviceName = strings.Join(serviceSegments[:serviceSegLen-1], ".") + } + // else we are looking up the zone. So handle the NS, SOA records etc. + */ + + // TODO: Implementation above globbed together segments for the serviceName if + // multiple segments remained. Determine how to do similar globbing using + // the template-based implementation. + namespace = g.NameTemplate.GetNamespaceFromSegmentArray(serviceSegments) + serviceName = g.NameTemplate.GetServiceFromSegmentArray(serviceSegments) + typeName = g.NameTemplate.GetTypeFromSegmentArray(serviceSegments) + + fmt.Println("[debug] exact: ", exact) + fmt.Println("[debug] zone: ", zone) + fmt.Println("[debug] servicename: ", serviceName) + fmt.Println("[debug] namespace: ", namespace) + fmt.Println("[debug] typeName: ", typeName) + fmt.Println("[debug] APIconn: ", g.APIConn) + + // TODO: Implement wildcard support to allow blank namespace value + if namespace == "" { + err := errors.New("Parsing query string did not produce a namespace value") + fmt.Printf("[ERROR] %v\n", err) + return nil, err + } - fmt.Println("enter Records('", name, "', ", exact, ")") - - zone, serviceSegments := g.getZoneForName(name) + // Abort if the namespace is not published per CoreFile + if g.Namespaces != nil && !util.StringInSlice(namespace, *g.Namespaces) { + return nil, nil + } - var serviceName string - var namespace string + k8sItems, err := g.APIConn.GetServiceItemsInNamespace(namespace, serviceName) + fmt.Println("[debug] k8s items:", k8sItems) - // For initial implementation, assume namespace is first serviceSegment - // and service name is remaining segments. - serviceSegLen := len(serviceSegments) - if serviceSegLen >= 2 { - namespace = serviceSegments[serviceSegLen-1] - serviceName = strings.Join(serviceSegments[:serviceSegLen-1], ".") - } - // else we are looking up the zone. So handle the NS, SOA records etc. + if err != nil { + fmt.Printf("[ERROR] Got error while looking up ServiceItems. Error is: %v\n", err) + return nil, err + } + if k8sItems == nil { + // Did not find item in k8s + return nil, nil + } - fmt.Println("[debug] zone: ", zone) - fmt.Println("[debug] servicename: ", serviceName) - fmt.Println("[debug] namespace: ", namespace) - fmt.Println("[debug] APIconn: ", g.APIConn) + // test := g.NameTemplate.GetRecordNameFromNameValues(nametemplate.NameValues{ServiceName: serviceName, TypeName: typeName, Namespace: namespace, Zone: zone}) + // fmt.Printf("[debug] got recordname %v\n", test) - k8sItem := g.APIConn.GetServiceItemInNamespace(namespace, serviceName) - fmt.Println("[debug] k8s item:", k8sItem) + records := g.getRecordsForServiceItems(k8sItems, name) - switch { - case exact && k8sItem == nil: - fmt.Println("here2") - return nil, nil - } + return records, nil +} - if k8sItem == nil { - // Did not find item in k8s - return nil, nil - } +// TODO: assemble name from parts found in k8s data based on name template rather than reusing query string +func (g Kubernetes) getRecordsForServiceItems(serviceItems []*k8sc.ServiceItem, name string) []msg.Service { + var records []msg.Service - fmt.Println("[debug] clusterIP:", k8sItem.Spec.ClusterIP) + for _, item := range serviceItems { + fmt.Println("[debug] clusterIP:", item.Spec.ClusterIP) + for _, p := range item.Spec.Ports { + fmt.Println("[debug] port:", p.Port) + } - for _, p := range k8sItem.Spec.Ports { - fmt.Println("[debug] host:", name) - fmt.Println("[debug] port:", p.Port) - } + clusterIP := item.Spec.ClusterIP - clusterIP := k8sItem.Spec.ClusterIP - var records []msg.Service - for _, p := range k8sItem.Spec.Ports{ - s := msg.Service{Host: clusterIP, Port: p.Port} - records = append(records, s) - } + s := msg.Service{Host: name} + records = append(records, s) + for _, p := range item.Spec.Ports { + s := msg.Service{Host: clusterIP, Port: p.Port} + records = append(records, s) + } + } - return records, nil + fmt.Printf("[debug] records from getRecordsForServiceItems(): %v\n", records) + return records } /* @@ -121,13 +158,13 @@ func (g Kubernetes) Get(path string, recursive bool) (bool, error) { */ func (g Kubernetes) splitDNSName(name string) []string { - l := dns.SplitDomainName(name) + l := dns.SplitDomainName(name) - for i, j := 0, len(l)-1; i < j; i, j = i+1, j-1 { - l[i], l[j] = l[j], l[i] - } + for i, j := 0, len(l)-1; i < j; i, j = i+1, j-1 { + l[i], l[j] = l[j], l[i] + } - return l + return l } // skydns/local/skydns/east/staging/web @@ -215,9 +252,9 @@ func isKubernetesNameError(err error) bool { } const ( - priority = 10 // default priority when nothing is set - ttl = 300 // default ttl when nothing is set - minTtl = 60 - hostmaster = "hostmaster" + priority = 10 // default priority when nothing is set + ttl = 300 // default ttl when nothing is set + minTtl = 60 + hostmaster = "hostmaster" k8sTimeout = 5 * time.Second ) -- cgit v1.2.3