parent
3e9a17abb9
commit
9343d2ea69
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// Package apiutils contains utilities which are useful for implementing api
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// endpoints.
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package apiutils |
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import ( |
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"context" |
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"crypto/rand" |
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"encoding/hex" |
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"encoding/json" |
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"errors" |
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"fmt" |
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"net/http" |
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"strconv" |
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"github.com/mediocregopher/mediocre-go-lib/v2/mlog" |
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) |
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type loggerCtxKey int |
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// SetRequestLogger sets the given Logger onto the given Request's Context,
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// returning a copy.
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func SetRequestLogger(r *http.Request, logger *mlog.Logger) *http.Request { |
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ctx := r.Context() |
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ctx = context.WithValue(ctx, loggerCtxKey(0), logger) |
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return r.WithContext(ctx) |
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} |
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// GetRequestLogger returns the Logger which was set by SetRequestLogger onto
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// this Request, or nil.
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func GetRequestLogger(r *http.Request) *mlog.Logger { |
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ctx := r.Context() |
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logger, _ := ctx.Value(loggerCtxKey(0)).(*mlog.Logger) |
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if logger == nil { |
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logger = mlog.Null |
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} |
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return logger |
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} |
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// JSONResult writes the JSON encoding of the given value as the response body.
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func JSONResult(rw http.ResponseWriter, r *http.Request, v interface{}) { |
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b, err := json.Marshal(v) |
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if err != nil { |
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InternalServerError(rw, r, err) |
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return |
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} |
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b = append(b, '\n') |
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rw.Header().Set("Content-Type", "application/json") |
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rw.Write(b) |
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} |
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// BadRequest writes a 400 status and a JSON encoded error struct containing the
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// given error as the response body.
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func BadRequest(rw http.ResponseWriter, r *http.Request, err error) { |
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GetRequestLogger(r).Warn(r.Context(), "bad request", err) |
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rw.WriteHeader(400) |
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JSONResult(rw, r, struct { |
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Error string `json:"error"` |
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}{ |
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Error: err.Error(), |
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}) |
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} |
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// InternalServerError writes a 500 status and a JSON encoded error struct
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// containing a generic error as the response body (though it will log the given
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// one).
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func InternalServerError(rw http.ResponseWriter, r *http.Request, err error) { |
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GetRequestLogger(r).Error(r.Context(), "internal server error", err) |
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rw.WriteHeader(500) |
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JSONResult(rw, r, struct { |
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Error string `json:"error"` |
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}{ |
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Error: "internal server error", |
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}) |
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} |
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// StrToInt parses the given string as an integer, or returns the given default
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// integer if the string is empty.
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func StrToInt(str string, defaultVal int) (int, error) { |
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if str == "" { |
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return defaultVal, nil |
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} |
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return strconv.Atoi(str) |
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} |
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// GetCookie returns the namd cookie's value, or the given default value if the
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// cookie is not set.
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//
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// This will only return an error if there was an unexpected error parsing the
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// Request's cookies.
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func GetCookie(r *http.Request, cookieName, defaultVal string) (string, error) { |
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c, err := r.Cookie(cookieName) |
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if errors.Is(err, http.ErrNoCookie) { |
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return defaultVal, nil |
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} else if err != nil { |
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return "", fmt.Errorf("reading cookie %q: %w", cookieName, err) |
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} |
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return c.Value, nil |
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} |
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// RandStr returns a human-readable random string with the given number of bytes
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// of randomness.
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func RandStr(numBytes int) string { |
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b := make([]byte, numBytes) |
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if _, err := rand.Read(b); err != nil { |
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panic(err) |
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} |
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return hex.EncodeToString(b) |
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} |
@ -1,91 +0,0 @@ |
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package api |
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import ( |
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"context" |
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"crypto/rand" |
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"encoding/hex" |
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"encoding/json" |
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"errors" |
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"fmt" |
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"net/http" |
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"strconv" |
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"github.com/mediocregopher/mediocre-go-lib/v2/mlog" |
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) |
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type loggerCtxKey int |
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func setRequestLogger(r *http.Request, logger *mlog.Logger) *http.Request { |
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ctx := r.Context() |
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ctx = context.WithValue(ctx, loggerCtxKey(0), logger) |
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return r.WithContext(ctx) |
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} |
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func getRequestLogger(r *http.Request) *mlog.Logger { |
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ctx := r.Context() |
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logger, _ := ctx.Value(loggerCtxKey(0)).(*mlog.Logger) |
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if logger == nil { |
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logger = mlog.Null |
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} |
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return logger |
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} |
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func jsonResult(rw http.ResponseWriter, r *http.Request, v interface{}) { |
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b, err := json.Marshal(v) |
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if err != nil { |
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internalServerError(rw, r, err) |
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return |
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} |
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b = append(b, '\n') |
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rw.Header().Set("Content-Type", "application/json") |
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rw.Write(b) |
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} |
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func badRequest(rw http.ResponseWriter, r *http.Request, err error) { |
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getRequestLogger(r).Warn(r.Context(), "bad request", err) |
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rw.WriteHeader(400) |
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jsonResult(rw, r, struct { |
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Error string `json:"error"` |
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}{ |
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Error: err.Error(), |
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}) |
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} |
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func internalServerError(rw http.ResponseWriter, r *http.Request, err error) { |
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getRequestLogger(r).Error(r.Context(), "internal server error", err) |
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rw.WriteHeader(500) |
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jsonResult(rw, r, struct { |
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Error string `json:"error"` |
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}{ |
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Error: "internal server error", |
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}) |
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} |
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func strToInt(str string, defaultVal int) (int, error) { |
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if str == "" { |
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return defaultVal, nil |
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} |
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return strconv.Atoi(str) |
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} |
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func getCookie(r *http.Request, cookieName, defaultVal string) (string, error) { |
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c, err := r.Cookie(cookieName) |
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if errors.Is(err, http.ErrNoCookie) { |
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return defaultVal, nil |
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} else if err != nil { |
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return "", fmt.Errorf("reading cookie %q: %w", cookieName, err) |
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} |
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return c.Value, nil |
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} |
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func randStr(numBytesEntropy int) string { |
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b := make([]byte, numBytesEntropy) |
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if _, err := rand.Read(b); err != nil { |
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panic(err) |
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} |
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return hex.EncodeToString(b) |
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} |
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