diff options
Diffstat (limited to 'vendor/github.com/armon/consul-api/api.go')
-rw-r--r-- | vendor/github.com/armon/consul-api/api.go | 323 |
1 files changed, 323 insertions, 0 deletions
diff --git a/vendor/github.com/armon/consul-api/api.go b/vendor/github.com/armon/consul-api/api.go new file mode 100644 index 00000000..e1335769 --- /dev/null +++ b/vendor/github.com/armon/consul-api/api.go @@ -0,0 +1,323 @@ +package consulapi + +import ( + "bytes" + "encoding/json" + "fmt" + "io" + "net/http" + "net/url" + "strconv" + "time" +) + +// QueryOptions are used to parameterize a query +type QueryOptions struct { + // Providing a datacenter overwrites the DC provided + // by the Config + Datacenter string + + // AllowStale allows any Consul server (non-leader) to service + // a read. This allows for lower latency and higher throughput + AllowStale bool + + // RequireConsistent forces the read to be fully consistent. + // This is more expensive but prevents ever performing a stale + // read. + RequireConsistent bool + + // WaitIndex is used to enable a blocking query. Waits + // until the timeout or the next index is reached + WaitIndex uint64 + + // WaitTime is used to bound the duration of a wait. + // Defaults to that of the Config, but can be overriden. + WaitTime time.Duration + + // Token is used to provide a per-request ACL token + // which overrides the agent's default token. + Token string +} + +// WriteOptions are used to parameterize a write +type WriteOptions struct { + // Providing a datacenter overwrites the DC provided + // by the Config + Datacenter string + + // Token is used to provide a per-request ACL token + // which overrides the agent's default token. + Token string +} + +// QueryMeta is used to return meta data about a query +type QueryMeta struct { + // LastIndex. This can be used as a WaitIndex to perform + // a blocking query + LastIndex uint64 + + // Time of last contact from the leader for the + // server servicing the request + LastContact time.Duration + + // Is there a known leader + KnownLeader bool + + // How long did the request take + RequestTime time.Duration +} + +// WriteMeta is used to return meta data about a write +type WriteMeta struct { + // How long did the request take + RequestTime time.Duration +} + +// HttpBasicAuth is used to authenticate http client with HTTP Basic Authentication +type HttpBasicAuth struct { + // Username to use for HTTP Basic Authentication + Username string + + // Password to use for HTTP Basic Authentication + Password string +} + +// Config is used to configure the creation of a client +type Config struct { + // Address is the address of the Consul server + Address string + + // Scheme is the URI scheme for the Consul server + Scheme string + + // Datacenter to use. If not provided, the default agent datacenter is used. + Datacenter string + + // HttpClient is the client to use. Default will be + // used if not provided. + HttpClient *http.Client + + // HttpAuth is the auth info to use for http access. + HttpAuth *HttpBasicAuth + + // WaitTime limits how long a Watch will block. If not provided, + // the agent default values will be used. + WaitTime time.Duration + + // Token is used to provide a per-request ACL token + // which overrides the agent's default token. + Token string +} + +// DefaultConfig returns a default configuration for the client +func DefaultConfig() *Config { + return &Config{ + Address: "127.0.0.1:8500", + Scheme: "http", + HttpClient: http.DefaultClient, + } +} + +// Client provides a client to the Consul API +type Client struct { + config Config +} + +// NewClient returns a new client +func NewClient(config *Config) (*Client, error) { + // bootstrap the config + defConfig := DefaultConfig() + + if len(config.Address) == 0 { + config.Address = defConfig.Address + } + + if len(config.Scheme) == 0 { + config.Scheme = defConfig.Scheme + } + + if config.HttpClient == nil { + config.HttpClient = defConfig.HttpClient + } + + client := &Client{ + config: *config, + } + return client, nil +} + +// request is used to help build up a request +type request struct { + config *Config + method string + url *url.URL + params url.Values + body io.Reader + obj interface{} +} + +// setQueryOptions is used to annotate the request with +// additional query options +func (r *request) setQueryOptions(q *QueryOptions) { + if q == nil { + return + } + if q.Datacenter != "" { + r.params.Set("dc", q.Datacenter) + } + if q.AllowStale { + r.params.Set("stale", "") + } + if q.RequireConsistent { + r.params.Set("consistent", "") + } + if q.WaitIndex != 0 { + r.params.Set("index", strconv.FormatUint(q.WaitIndex, 10)) + } + if q.WaitTime != 0 { + r.params.Set("wait", durToMsec(q.WaitTime)) + } + if q.Token != "" { + r.params.Set("token", q.Token) + } +} + +// durToMsec converts a duration to a millisecond specified string +func durToMsec(dur time.Duration) string { + return fmt.Sprintf("%dms", dur/time.Millisecond) +} + +// setWriteOptions is used to annotate the request with +// additional write options +func (r *request) setWriteOptions(q *WriteOptions) { + if q == nil { + return + } + if q.Datacenter != "" { + r.params.Set("dc", q.Datacenter) + } + if q.Token != "" { + r.params.Set("token", q.Token) + } +} + +// toHTTP converts the request to an HTTP request +func (r *request) toHTTP() (*http.Request, error) { + // Encode the query parameters + r.url.RawQuery = r.params.Encode() + + // Get the url sring + urlRaw := r.url.String() + + // Check if we should encode the body + if r.body == nil && r.obj != nil { + if b, err := encodeBody(r.obj); err != nil { + return nil, err + } else { + r.body = b + } + } + + // Create the HTTP request + req, err := http.NewRequest(r.method, urlRaw, r.body) + + // Setup auth + if err == nil && r.config.HttpAuth != nil { + req.SetBasicAuth(r.config.HttpAuth.Username, r.config.HttpAuth.Password) + } + + return req, err +} + +// newRequest is used to create a new request +func (c *Client) newRequest(method, path string) *request { + r := &request{ + config: &c.config, + method: method, + url: &url.URL{ + Scheme: c.config.Scheme, + Host: c.config.Address, + Path: path, + }, + params: make(map[string][]string), + } + if c.config.Datacenter != "" { + r.params.Set("dc", c.config.Datacenter) + } + if c.config.WaitTime != 0 { + r.params.Set("wait", durToMsec(r.config.WaitTime)) + } + if c.config.Token != "" { + r.params.Set("token", r.config.Token) + } + return r +} + +// doRequest runs a request with our client +func (c *Client) doRequest(r *request) (time.Duration, *http.Response, error) { + req, err := r.toHTTP() + if err != nil { + return 0, nil, err + } + start := time.Now() + resp, err := c.config.HttpClient.Do(req) + diff := time.Now().Sub(start) + return diff, resp, err +} + +// parseQueryMeta is used to help parse query meta-data +func parseQueryMeta(resp *http.Response, q *QueryMeta) error { + header := resp.Header + + // Parse the X-Consul-Index + index, err := strconv.ParseUint(header.Get("X-Consul-Index"), 10, 64) + if err != nil { + return fmt.Errorf("Failed to parse X-Consul-Index: %v", err) + } + q.LastIndex = index + + // Parse the X-Consul-LastContact + last, err := strconv.ParseUint(header.Get("X-Consul-LastContact"), 10, 64) + if err != nil { + return fmt.Errorf("Failed to parse X-Consul-LastContact: %v", err) + } + q.LastContact = time.Duration(last) * time.Millisecond + + // Parse the X-Consul-KnownLeader + switch header.Get("X-Consul-KnownLeader") { + case "true": + q.KnownLeader = true + default: + q.KnownLeader = false + } + return nil +} + +// decodeBody is used to JSON decode a body +func decodeBody(resp *http.Response, out interface{}) error { + dec := json.NewDecoder(resp.Body) + return dec.Decode(out) +} + +// encodeBody is used to encode a request body +func encodeBody(obj interface{}) (io.Reader, error) { + buf := bytes.NewBuffer(nil) + enc := json.NewEncoder(buf) + if err := enc.Encode(obj); err != nil { + return nil, err + } + return buf, nil +} + +// requireOK is used to wrap doRequest and check for a 200 +func requireOK(d time.Duration, resp *http.Response, e error) (time.Duration, *http.Response, error) { + if e != nil { + return d, resp, e + } + if resp.StatusCode != 200 { + var buf bytes.Buffer + io.Copy(&buf, resp.Body) + return d, resp, fmt.Errorf("Unexpected response code: %d (%s)", resp.StatusCode, buf.Bytes()) + } + return d, resp, e +} |