@@ -11,13 +11,16 @@ import (
1111 "time"
1212
1313 cloudevents "github.com/cloudevents/sdk-go/v2"
14+ cehttp "github.com/cloudevents/sdk-go/v2/protocol/http"
15+
1416 "github.com/google/uuid"
1517)
1618
1719const (
1820 DefaultInvokeSource = "/boson/fn"
1921 DefaultInvokeType = "boson.fn"
2022 DefaultInvokeContentType = "application/json"
23+ DefaultInvokeRequestType = "POST"
2124 DefaultInvokeData = `{"message":"Hello World"}`
2225 DefaultInvokeFormat = "http"
2326)
@@ -30,6 +33,7 @@ type InvokeMessage struct {
3033 Type string
3134 ContentType string
3235 Data []byte
36+ RequestType string // HTTP Request GET/POST (defaults to POST)
3337 Format string // optional override for function-defined message format
3438}
3539
@@ -40,6 +44,7 @@ func NewInvokeMessage() InvokeMessage {
4044 Source : DefaultInvokeSource ,
4145 Type : DefaultInvokeType ,
4246 ContentType : DefaultInvokeContentType ,
47+ RequestType : DefaultInvokeRequestType ,
4348 Data : []byte (DefaultInvokeData ),
4449 // Format override not set by default: value from function being preferred.
4550 }
@@ -63,6 +68,11 @@ func invoke(ctx context.Context, c *Client, f Function, target string, m InvokeM
6368 // set. Once decided, codify in a test.
6469 format := DefaultInvokeFormat
6570
71+ // RequestType is expected GET or POST
72+ if m .RequestType == "" {
73+ m .RequestType = DefaultInvokeRequestType
74+ }
75+
6676 if verbose {
6777 fmt .Printf ("Invoking '%v' function at %v\n " , f .Invoke , route )
6878 }
@@ -79,19 +89,27 @@ func invoke(ctx context.Context, c *Client, f Function, target string, m InvokeM
7989 }
8090 }
8191
92+ if m .RequestType != "POST" && m .RequestType != "GET" {
93+ err = fmt .Errorf ("http request type '%v' not supported, expected GET or POST" , m .RequestType )
94+ return
95+ }
96+
8297 switch format {
8398 case "http" :
84- return sendPost (ctx , route , m , c .transport , verbose )
99+ return sendHttp (ctx , route , m , c .transport , verbose )
85100 case "cloudevent" :
86- // CouldEvents return a string which always includes a fairly verbose
87- // summation of fields, so metadata is not applicable
88- meta := make (map [string ][]string )
89- body , err = sendEvent (ctx , route , m , c .transport , verbose )
90- return meta , body , err
101+ switch m .RequestType {
102+ case "POST" :
103+ body , err = sendEvent (ctx , route , m , c .transport , verbose )
104+ case "GET" :
105+ // Construct a special CloudEvents GET request.
106+ // This will be used most likely only for very special cases
107+ body , err = sendGetEvent (ctx , route , m , c .transport , verbose )
108+ }
91109 default :
92110 err = fmt .Errorf ("format '%v' not supported" , format )
93- return
94111 }
112+ return
95113}
96114
97115// invocationRoute returns a route to the named target instance of a func:
@@ -176,30 +194,84 @@ func sendEvent(ctx context.Context, route string, m InvokeMessage, t http.RoundT
176194 return
177195}
178196
197+ // sendGetEvent sends a GET event as a cloudEvent. Normally, this is not the
198+ // way CEs are intended to be sent exactly.
199+ // In CloudEvents specification it reads:
200+ //
201+ // "Events can be transferred with all standard or application-defined HTTP request
202+ // methods that support payload body transfers"
203+ //
204+ // Since this is not the case for GET request, we need to specify custom protocol
205+ // and use a slightly different client resulting in a slightly different
206+ // function all together.
207+ func sendGetEvent (ctx context.Context , route string , m InvokeMessage , t http.RoundTripper , verbose bool ) (resp string , err error ) {
208+ if m .ID == "" {
209+ // we're using a different Client function, we need to create an ID.
210+ // ce.NewClientHTTP() sets ID if not present, ce.NewClient() doesn't
211+ m .ID = uuid .NewString ()
212+ }
213+
214+ // construct the event
215+ event := cloudevents .NewEvent ()
216+ event .SetID (m .ID )
217+ event .SetSource (m .Source )
218+ event .SetType (m .Type )
219+ event .SetDataContentType (m .ContentType )
220+
221+ if verbose {
222+ fmt .Println ("Constructing a GET request CloudEvent:" )
223+ fmt .Printf ("Event: %+v\n " , event )
224+ }
225+ // create http protocol with GET method
226+ protocol , err := cehttp .New (cehttp .WithRoundTripper (t ), cehttp .WithMethod ("GET" ))
227+ if err != nil {
228+ return
229+ }
230+
231+ c , err := cloudevents .NewClient (protocol )
232+ if err != nil {
233+ return
234+ }
235+
236+ if verbose {
237+ fmt .Printf ("Sending event\n %v" , event )
238+ }
239+
240+ evt , result := c .Request (cloudevents .ContextWithTarget (ctx , route ), event )
241+ if cloudevents .IsUndelivered (result ) {
242+ err = fmt .Errorf ("unable to invoke: %v" , result )
243+ } else if evt != nil { // Check for nil in case no event is returned
244+ resp = evt .String ()
245+ }
246+ return
247+ }
248+
179249// sendPost to the route populated with data in the invoke message.
180- func sendPost (ctx context.Context , route string , m InvokeMessage , t http.RoundTripper , verbose bool ) (map [string ][]string , string , error ) {
250+ func sendHttp (ctx context.Context , route string , m InvokeMessage , t http.RoundTripper , verbose bool ) (map [string ][]string , string , error ) {
181251 client := http.Client {
182252 Transport : t ,
183253 Timeout : time .Minute ,
184254 }
185- values := url.Values {
186- "ID" : {m .ID },
187- "Source" : {m .Source },
188- "Type" : {m .Type },
189- "ContentType" : {m .ContentType },
190- "Data" : {string (m .Data )},
191- }
255+
192256 if verbose {
257+ values := url.Values {
258+ "ID" : {m .ID },
259+ "Source" : {m .Source },
260+ "Type" : {m .Type },
261+ "ContentType" : {m .ContentType },
262+ "Data" : {string (m .Data )},
263+ }
193264 fmt .Println ("Sending values" )
194265 for k , v := range values {
195266 fmt .Printf (" %v: %v\n " , k , v [0 ]) // NOTE len==1 value slices assumed
196267 }
197268 }
198269
199- req , err := http .NewRequestWithContext (ctx , "POST" , route , bytes .NewReader (m .Data ))
270+ req , err := http .NewRequestWithContext (ctx , m . RequestType , route , bytes .NewReader (m .Data ))
200271 if err != nil {
201272 return nil , "" , fmt .Errorf ("failure to create request: %w" , err )
202273 }
274+
203275 req .Header .Add ("Content-Type" , m .ContentType )
204276
205277 resp , err := client .Do (req )
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