Add sliceutils.ContainsFunc

Builder offers option to add extra fields to log messages

LICENSE

@@ -1,373 +1,21 @@
-Mozilla Public License Version 2.0
-==================================
-
-1. Definitions
---------------
-
-1.1. "Contributor"
-    means each individual or legal entity that creates, contributes to
-    the creation of, or owns Covered Software.
-
-1.2. "Contributor Version"
-    means the combination of the Contributions of others (if any) used
-    by a Contributor and that particular Contributor's Contribution.
-
-1.3. "Contribution"
-    means Covered Software of a particular Contributor.
-
-1.4. "Covered Software"
-    means Source Code Form to which the initial Contributor has attached
-    the notice in Exhibit A, the Executable Form of such Source Code
-    Form, and Modifications of such Source Code Form, in each case
-    including portions thereof.
-
-1.5. "Incompatible With Secondary Licenses"
-    means
-
-    (a) that the initial Contributor has attached the notice described
-        in Exhibit B to the Covered Software; or
-
-    (b) that the Covered Software was made available under the terms of
-        version 1.1 or earlier of the License, but not also under the
-        terms of a Secondary License.
-
-1.6. "Executable Form"
-    means any form of the work other than Source Code Form.
-
-1.7. "Larger Work"
-    means a work that combines Covered Software with other material, in
-    a separate file or files, that is not Covered Software.
-
-1.8. "License"
-    means this document.
-
-1.9. "Licensable"
-    means having the right to grant, to the maximum extent possible,
-    whether at the time of the initial grant or subsequently, any and
-    all of the rights conveyed by this License.
-
-1.10. "Modifications"
-    means any of the following:
-
-    (a) any file in Source Code Form that results from an addition to,
-        deletion from, or modification of the contents of Covered
-        Software; or
-
-    (b) any new file in Source Code Form that contains any Covered
-        Software.
-
-1.11. "Patent Claims" of a Contributor
-    means any patent claim(s), including without limitation, method,
-    process, and apparatus claims, in any patent Licensable by such
-    Contributor that would be infringed, but for the grant of the
-    License, by the making, using, selling, offering for sale, having
-    made, import, or transfer of either its Contributions or its
-    Contributor Version.
-
-1.12. "Secondary License"
-    means either the GNU General Public License, Version 2.0, the GNU
-    Lesser General Public License, Version 2.1, the GNU Affero General
-    Public License, Version 3.0, or any later versions of those
-    licenses.
-
-1.13. "Source Code Form"
-    means the form of the work preferred for making modifications.
-
-1.14. "You" (or "Your")
-    means an individual or a legal entity exercising rights under this
-    License. For legal entities, "You" includes any entity that
-    controls, is controlled by, or is under common control with You. For
-    purposes of this definition, "control" means (a) the power, direct
-    or indirect, to cause the direction or management of such entity,
-    whether by contract or otherwise, or (b) ownership of more than
-    fifty percent (50%) of the outstanding shares or beneficial
-    ownership of such entity.
-
-2. License Grants and Conditions
---------------------------------
-
-2.1. Grants
-
-Each Contributor hereby grants You a world-wide, royalty-free,
-non-exclusive license:
-
-(a) under intellectual property rights (other than patent or trademark)
-    Licensable by such Contributor to use, reproduce, make available,
-    modify, display, perform, distribute, and otherwise exploit its
-    Contributions, either on an unmodified basis, with Modifications, or
-    as part of a Larger Work; and
-
-(b) under Patent Claims of such Contributor to make, use, sell, offer
-    for sale, have made, import, and otherwise transfer either its
-    Contributions or its Contributor Version.
-
-2.2. Effective Date
-
-The licenses granted in Section 2.1 with respect to any Contribution
-become effective for each Contribution on the date the Contributor first
-distributes such Contribution.
-
-2.3. Limitations on Grant Scope
-
-The licenses granted in this Section 2 are the only rights granted under
-this License. No additional rights or licenses will be implied from the
-distribution or licensing of Covered Software under this License.
-Notwithstanding Section 2.1(b) above, no patent license is granted by a
-Contributor:
-
-(a) for any code that a Contributor has removed from Covered Software;
-    or
-
-(b) for infringements caused by: (i) Your and any other third party's
-    modifications of Covered Software, or (ii) the combination of its
-    Contributions with other software (except as part of its Contributor
-    Version); or
-
-(c) under Patent Claims infringed by Covered Software in the absence of
-    its Contributions.
-
-This License does not grant any rights in the trademarks, service marks,
-or logos of any Contributor (except as may be necessary to comply with
-the notice requirements in Section 3.4).
-
-2.4. Subsequent Licenses
-
-No Contributor makes additional grants as a result of Your choice to
-distribute the Covered Software under a subsequent version of this
-License (see Section 10.2) or under the terms of a Secondary License (if
-permitted under the terms of Section 3.3).
-
-2.5. Representation
-
-Each Contributor represents that the Contributor believes its
-Contributions are its original creation(s) or it has sufficient rights
-to grant the rights to its Contributions conveyed by this License.
-
-2.6. Fair Use
-
-This License is not intended to limit any rights You have under
-applicable copyright doctrines of fair use, fair dealing, or other
-equivalents.
-
-2.7. Conditions
-
-Sections 3.1, 3.2, 3.3, and 3.4 are conditions of the licenses granted
-in Section 2.1.
-
-3. Responsibilities
--------------------
-
-3.1. Distribution of Source Form
-
-All distribution of Covered Software in Source Code Form, including any
-Modifications that You create or to which You contribute, must be under
-the terms of this License. You must inform recipients that the Source
-Code Form of the Covered Software is governed by the terms of this
-License, and how they can obtain a copy of this License. You may not
-attempt to alter or restrict the recipients' rights in the Source Code
-Form.
-
-3.2. Distribution of Executable Form
-
-If You distribute Covered Software in Executable Form then:
-
-(a) such Covered Software must also be made available in Source Code
-    Form, as described in Section 3.1, and You must inform recipients of
-    the Executable Form how they can obtain a copy of such Source Code
-    Form by reasonable means in a timely manner, at a charge no more
-    than the cost of distribution to the recipient; and
-
-(b) You may distribute such Executable Form under the terms of this
-    License, or sublicense it under different terms, provided that the
-    license for the Executable Form does not attempt to limit or alter
-    the recipients' rights in the Source Code Form under this License.
-
-3.3. Distribution of a Larger Work
-
-You may create and distribute a Larger Work under terms of Your choice,
-provided that You also comply with the requirements of this License for
-the Covered Software. If the Larger Work is a combination of Covered
-Software with a work governed by one or more Secondary Licenses, and the
-Covered Software is not Incompatible With Secondary Licenses, this
-License permits You to additionally distribute such Covered Software
-under the terms of such Secondary License(s), so that the recipient of
-the Larger Work may, at their option, further distribute the Covered
-Software under the terms of either this License or such Secondary
-License(s).
-
-3.4. Notices
-
-You may not remove or alter the substance of any license notices
-(including copyright notices, patent notices, disclaimers of warranty,
-or limitations of liability) contained within the Source Code Form of
-the Covered Software, except that You may alter any license notices to
-the extent required to remedy known factual inaccuracies.
-
-3.5. Application of Additional Terms
-
-You may choose to offer, and to charge a fee for, warranty, support,
-indemnity or liability obligations to one or more recipients of Covered
-Software. However, You may do so only on Your own behalf, and not on
-behalf of any Contributor. You must make it absolutely clear that any
-such warranty, support, indemnity, or liability obligation is offered by
-You alone, and You hereby agree to indemnify every Contributor for any
-liability incurred by such Contributor as a result of warranty, support,
-indemnity or liability terms You offer. You may include additional
-disclaimers of warranty and limitations of liability specific to any
-jurisdiction.
-
-4. Inability to Comply Due to Statute or Regulation
----------------------------------------------------
-
-If it is impossible for You to comply with any of the terms of this
-License with respect to some or all of the Covered Software due to
-statute, judicial order, or regulation then You must: (a) comply with
-the terms of this License to the maximum extent possible; and (b)
-describe the limitations and the code they affect. Such description must
-be placed in a text file included with all distributions of the Covered
-Software under this License. Except to the extent prohibited by statute
-or regulation, such description must be sufficiently detailed for a
-recipient of ordinary skill to be able to understand it.
-
-5. Termination
---------------
-
-5.1. The rights granted under this License will terminate automatically
-if You fail to comply with any of its terms. However, if You become
-compliant, then the rights granted under this License from a particular
-Contributor are reinstated (a) provisionally, unless and until such
-Contributor explicitly and finally terminates Your grants, and (b) on an
-ongoing basis, if such Contributor fails to notify You of the
-non-compliance by some reasonable means prior to 60 days after You have
-come back into compliance. Moreover, Your grants from a particular
-Contributor are reinstated on an ongoing basis if such Contributor
-notifies You of the non-compliance by some reasonable means, this is the
-first time You have received notice of non-compliance with this License
-from such Contributor, and You become compliant prior to 30 days after
-Your receipt of the notice.
-
-5.2. If You initiate litigation against any entity by asserting a patent
-infringement claim (excluding declaratory judgment actions,
-counter-claims, and cross-claims) alleging that a Contributor Version
-directly or indirectly infringes any patent, then the rights granted to
-You by any and all Contributors for the Covered Software under Section
-2.1 of this License shall terminate.
-
-5.3. In the event of termination under Sections 5.1 or 5.2 above, all
-end user license agreements (excluding distributors and resellers) which
-have been validly granted by You or Your distributors under this License
-prior to termination shall survive termination.
-
-************************************************************************
-*                                                                      *
-*  6. Disclaimer of Warranty                                           *
-*  -------------------------                                           *
-*                                                                      *
-*  Covered Software is provided under this License on an "as is"       *
-*  basis, without warranty of any kind, either expressed, implied, or  *
-*  statutory, including, without limitation, warranties that the       *
-*  Covered Software is free of defects, merchantable, fit for a        *
-*  particular purpose or non-infringing. The entire risk as to the     *
-*  quality and performance of the Covered Software is with You.        *
-*  Should any Covered Software prove defective in any respect, You     *
-*  (not any Contributor) assume the cost of any necessary servicing,   *
-*  repair, or correction. This disclaimer of warranty constitutes an   *
-*  essential part of this License. No use of any Covered Software is   *
-*  authorized under this License except under this disclaimer.         *
-*                                                                      *
-************************************************************************
-
-************************************************************************
-*                                                                      *
-*  7. Limitation of Liability                                          *
-*  --------------------------                                          *
-*                                                                      *
-*  Under no circumstances and under no legal theory, whether tort      *
-*  (including negligence), contract, or otherwise, shall any           *
-*  Contributor, or anyone who distributes Covered Software as          *
-*  permitted above, be liable to You for any direct, indirect,         *
-*  special, incidental, or consequential damages of any character      *
-*  including, without limitation, damages for lost profits, loss of    *
-*  goodwill, work stoppage, computer failure or malfunction, or any    *
-*  and all other commercial damages or losses, even if such party      *
-*  shall have been informed of the possibility of such damages. This   *
-*  limitation of liability shall not apply to liability for death or   *
-*  personal injury resulting from such party's negligence to the       *
-*  extent applicable law prohibits such limitation. Some               *
-*  jurisdictions do not allow the exclusion or limitation of           *
-*  incidental or consequential damages, so this exclusion and          *
-*  limitation may not apply to You.                                    *
-*                                                                      *
-************************************************************************
-
-8. Litigation
--------------
-
-Any litigation relating to this License may be brought only in the
-courts of a jurisdiction where the defendant maintains its principal
-place of business and such litigation shall be governed by laws of that
-jurisdiction, without reference to its conflict-of-law provisions.
-Nothing in this Section shall prevent a party's ability to bring
-cross-claims or counter-claims.
-
-9. Miscellaneous
-----------------
-
-This License represents the complete agreement concerning the subject
-matter hereof. If any provision of this License is held to be
-unenforceable, such provision shall be reformed only to the extent
-necessary to make it enforceable. Any law or regulation which provides
-that the language of a contract shall be construed against the drafter
-shall not be used to construe this License against a Contributor.
-
-10. Versions of the License
----------------------------
-
-10.1. New Versions
-
-Mozilla Foundation is the license steward. Except as provided in Section
-10.3, no one other than the license steward has the right to modify or
-publish new versions of this License. Each version will be given a
-distinguishing version number.
-
-10.2. Effect of New Versions
-
-You may distribute the Covered Software under the terms of the version
-of the License under which You originally received the Covered Software,
-or under the terms of any subsequent version published by the license
-steward.
-
-10.3. Modified Versions
-
-If you create software not governed by this License, and you want to
-create a new license for such software, you may create and use a
-modified version of this License if you rename the license and remove
-any references to the name of the license steward (except to note that
-such modified license differs from this License).
-
-10.4. Distributing Source Code Form that is Incompatible With Secondary
-Licenses
-
-If You choose to distribute Source Code Form that is Incompatible With
-Secondary Licenses under the terms of this version of the License, the
-notice described in Exhibit B of this License must be attached.
-
-Exhibit A - Source Code Form License Notice
--------------------------------------------
-
-  This Source Code Form is subject to the terms of the Mozilla Public
-  License, v. 2.0. If a copy of the MPL was not distributed with this
-  file, You can obtain one at http://mozilla.org/MPL/2.0/.
-
-If it is not possible or desirable to put the notice in a particular
-file, then You may include the notice in a location (such as a LICENSE
-file in a relevant directory) where a recipient would be likely to look
-for such a notice.
-
-You may add additional accurate notices of copyright ownership.
-
-Exhibit B - "Incompatible With Secondary Licenses" Notice
----------------------------------------------------------
-
-  This Source Code Form is "Incompatible With Secondary Licenses", as
-  defined by the Mozilla Public License, v. 2.0.
+MIT License
+
+Copyright (c) 2024 mStar
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

go.mod

@@ -1,3 +1,12 @@
-module gitlab.com/mstarongitlab/goutils
+module git.mstar.dev/mstar/goutils
 
 go 1.19
+
+require github.com/rs/zerolog v1.33.0
+
+require (
+	github.com/mattn/go-colorable v0.1.13 // indirect
+	github.com/mattn/go-isatty v0.0.19 // indirect
+	github.com/rs/xid v1.5.0 // indirect
+	golang.org/x/sys v0.12.0 // indirect
+)

go.sum

@@ -0,0 +1,16 @@
+github.com/coreos/go-systemd/v22 v22.5.0/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=
+github.com/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
+github.com/mattn/go-colorable v0.1.13 h1:fFA4WZxdEF4tXPZVKMLwD8oUnCTTo08duU7wxecdEvA=
+github.com/mattn/go-colorable v0.1.13/go.mod h1:7S9/ev0klgBDR4GtXTXX8a3vIGJpMovkB8vQcUbaXHg=
+github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
+github.com/mattn/go-isatty v0.0.19 h1:JITubQf0MOLdlGRuRq+jtsDlekdYPia9ZFsB8h/APPA=
+github.com/mattn/go-isatty v0.0.19/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/rs/xid v1.5.0 h1:mKX4bl4iPYJtEIxp6CYiUuLQ/8DYMoz0PUdtGgMFRVc=
+github.com/rs/xid v1.5.0/go.mod h1:trrq9SKmegXys3aeAKXMUTdJsYXVwGY3RLcfgqegfbg=
+github.com/rs/zerolog v1.33.0 h1:1cU2KZkvPxNyfgEmhHAz/1A9Bz+llsdYzklWFzgp0r8=
+github.com/rs/zerolog v1.33.0/go.mod h1:/7mN4D5sKwJLZQ2b/znpjC3/GQWY/xaDXUM0kKWRHss=
+golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.12.0 h1:CM0HF96J0hcLAwsHPJZjfdNzs0gftsLfgKt57wWHJ0o=
+golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=

http/chain.go

@@ -0,0 +1,16 @@
+package webutils
+
+import (
+	"net/http"
+	"slices"
+)
+
+type HandlerBuilder func(http.Handler) http.Handler
+
+func ChainMiddlewares(base http.Handler, links ...HandlerBuilder) http.Handler {
+	slices.Reverse(links)
+	for _, f := range links {
+		base = f(base)
+	}
+	return base
+}

http/context.go

@@ -0,0 +1,19 @@
+package webutils
+
+import (
+	"context"
+	"net/http"
+)
+
+func ContextValsMiddleware(pairs map[any]any) HandlerBuilder {
+	return func(h http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			ctx := r.Context()
+			for key, val := range pairs {
+				ctx = context.WithValue(ctx, key, val)
+			}
+			newRequest := r.WithContext(ctx)
+			h.ServeHTTP(w, newRequest)
+		})
+	}
+}

http/httpErr.go

@@ -0,0 +1,72 @@
+package webutils
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+)
+
+// Return an error over an http connection.
+// The error will have the given return code `code`
+// and a json encoded body with the field "id" set to `errId`
+// and a field "message" set to the `message`
+//
+// Deprecated: Use ProblemDetails or ProblemDetailsStatusOnly instead
+func HttpErr(w http.ResponseWriter, errId int, message string, code int) {
+	w.WriteHeader(code)
+	w.Header().Add("Content-Type", "application/json")
+	fmt.Fprintf(w, "{\"id\": %d, \"message\": \"%s\"}", errId, message)
+}
+
+// Write an RFC 9457 compliant problem details response
+// If details is not nil, it will be included.
+// If extras is not nil, each key-value pair will be included at
+// the root layer.
+// Keys in extras that would overwrite the default elements will be ignored.
+// Those would be "type", "status", "title" and "detail"
+func ProblemDetails(
+	w http.ResponseWriter,
+	statusCode int,
+	errorType string,
+	errorTitle string,
+	details *string,
+	extras map[string]any,
+) {
+	w.Header().Add("Content-Type", "application/problem+json")
+	w.WriteHeader(statusCode)
+	data := map[string]any{
+		"type":   errorType,
+		"status": statusCode,
+		"title":  errorTitle,
+	}
+	if details != nil {
+		data["detail"] = *details
+	}
+	if extras != nil {
+		for k, v := range extras {
+			if _, ok := data[k]; ok {
+				// Don't overwrite default fields
+				continue
+			}
+			data[k] = v
+		}
+	}
+	enc := json.NewEncoder(w)
+	enc.Encode(data)
+}
+
+// Write a simple problem details response.
+// It only provides the status code, as defined in RFC 9457, section 4.2.1
+func ProblemDetailsStatusOnly(w http.ResponseWriter, statusCode int) {
+	w.Header().Add("Content-Type", "application/problem+json")
+	w.WriteHeader(statusCode)
+	data := map[string]any{
+		"type":      "about:blank",
+		"title":     http.StatusText(statusCode),
+		"status":    statusCode,
+		"reference": "RFC 9457",
+	}
+
+	enc := json.NewEncoder(w)
+	enc.Encode(data)
+}

http/json.go

@@ -0,0 +1,17 @@
+package webutils
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+)
+
+func SendJson(w http.ResponseWriter, data any) error {
+	encoded, err := json.Marshal(data)
+	if err != nil {
+		return err
+	}
+	w.Header().Add("Content-Type", "application/json")
+	fmt.Fprint(w, string(encoded))
+	return nil
+}

http/zerolog.go

@@ -0,0 +1,59 @@
+package webutils
+
+import (
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/rs/zerolog/hlog"
+	"github.com/rs/zerolog/log"
+)
+
+func BuildLoggingMiddleware(extras map[string]string) HandlerBuilder {
+	return func(h http.Handler) http.Handler {
+		return ChainMiddlewares(h,
+			hlog.NewHandler(log.Logger),
+			hlog.AccessHandler(func(r *http.Request, status, size int, duration time.Duration) {
+				if strings.HasPrefix(r.URL.Path, "/assets") {
+					return
+				}
+				logger := hlog.FromRequest(r).Info().
+					Str("method", r.Method).
+					Stringer("url", r.URL).
+					Int("status", status).
+					Int("size", size).
+					Dur("duration", duration)
+				for k, v := range extras {
+					logger = logger.Str(k, v)
+				}
+				logger.Send()
+			}),
+			hlog.RemoteAddrHandler("ip"),
+			hlog.UserAgentHandler("user_agent"),
+			hlog.RefererHandler("referer"),
+			hlog.RequestIDHandler("req_id", "Request-Id"),
+		)
+	}
+}
+
+func LoggingMiddleware(handler http.Handler) http.Handler {
+	return ChainMiddlewares(handler,
+		hlog.NewHandler(log.Logger),
+		hlog.AccessHandler(func(r *http.Request, status, size int, duration time.Duration) {
+			if strings.HasPrefix(r.URL.Path, "/assets") {
+				return
+			}
+			hlog.FromRequest(r).Info().
+				Str("method", r.Method).
+				Stringer("url", r.URL).
+				Int("status", status).
+				Int("size", size).
+				Dur("duration", duration).
+				Send()
+		}),
+		hlog.RemoteAddrHandler("ip"),
+		hlog.UserAgentHandler("user_agent"),
+		hlog.RefererHandler("referer"),
+		hlog.RequestIDHandler("req_id", "Request-Id"),
+	)
+}

logrotate/logrotate.go

@@ -0,0 +1,67 @@
+// File wrapper for rotating log files
+// Copied from https://stackoverflow.com/a/28797984
+package logrotate
+
+import (
+	"os"
+	"path"
+	"sync"
+	"time"
+)
+
+type RotateWriter struct {
+	lock     sync.Mutex
+	filename string // should be set to the actual filename
+	fp       *os.File
+}
+
+// Make a new RotateWriter. Return nil if error occurs during setup.
+func New(filename string) (*RotateWriter, error) {
+	w := &RotateWriter{filename: filename}
+	err := w.Rotate()
+	if err != nil {
+		return nil, err
+	}
+	return w, nil
+}
+
+// Write satisfies the io.Writer interface.
+func (w *RotateWriter) Write(output []byte) (int, error) {
+	w.lock.Lock()
+	defer w.lock.Unlock()
+	return w.fp.Write(output)
+}
+
+// Perform the actual act of rotating and reopening file.
+func (w *RotateWriter) Rotate() (err error) {
+	w.lock.Lock()
+	defer w.lock.Unlock()
+
+	// Close existing file if open
+	if w.fp != nil {
+		err = w.fp.Close()
+		w.fp = nil
+		if err != nil {
+			return
+		}
+	}
+	// Rename dest file if it already exists
+	_, err = os.Stat(w.filename)
+	if err == nil {
+		err = os.Rename(w.filename, w.filename+"."+time.Now().Format(time.RFC3339))
+		if err != nil {
+			return
+		}
+	}
+
+	// Create a file.
+	dir := path.Dir(w.filename)
+	_, err = os.Stat(dir)
+	if err != nil {
+		if err = os.Mkdir(dir, os.ModeDir); err != nil {
+			return
+		}
+	}
+	w.fp, err = os.Create(w.filename)
+	return
+}

maputils/mapUtils.go

@@ -1,6 +1,6 @@
 package maputils
 
-import "gitlab.com/mstarongitlab/goutils/sliceutils"
+import "git.mstar.dev/mstar/goutils/sliceutils"
 
 // MapSameKeys applies a given function to every key-value pair of a map.
 // The returned map's value type may be different from the type of the inital map's value
@@ -71,3 +71,15 @@ func CompareMap[K, V comparable](a, b map[K]V) bool {
 	}
 	return true
 }
+
+func Compact[K comparable, V any](
+	m map[K]V,
+	compactor func(accK K, accV V, nextK K, nextV V) (K, V),
+) (K, V) {
+	var accK K
+	var accV V
+	for k, v := range m {
+		accK, accV = compactor(accK, accV, k, v)
+	}
+	return accK, accV
+}

math/math.go

@@ -0,0 +1,13 @@
+package mathutils
+
+type SignedNumber interface {
+	~int | ~int8 | ~int16 | ~int32 | ~int64 | ~float32 | ~float64
+}
+
+func Abs[T SignedNumber](num T) T {
+	if num > 0 {
+		return num
+	} else {
+		return num * -1
+	}
+}

other/other.go

@@ -1,5 +1,7 @@
 package other
 
+import "fmt"
+
 // OutputIntoChannel takes a singular return value and sends it into the target channel.
 // This is a wrapper for functions where a value can't be collected from directly.
 // Example: goroutines
@@ -7,6 +9,10 @@ func OutputIntoChannel[T any](out T, target chan T) {
 	target <- out
 }
 
+// Must is a quick wrapper to ensure that a function exits without error.
+// If err is not nil, it panics. Otherwise val is returned.
+// The intended use is something like Must(someFunc()), where someFunc
+// has the signature someFunc() (T, error), with T being whatever type needed
 func Must[T any](val T, err error) T {
 	if err != nil {
 		panic(err)
@@ -14,6 +20,13 @@ func Must[T any](val T, err error) T {
 	return val
 }
 
+// IntoPointer returns a pointer to the given value
 func IntoPointer[T any](val T) *T {
 	return &val
 }
+
+// Error formats error messages to follow a common convention of
+// "source: message: wrapped error"
+func Error(source, message string, err error) error {
+	return fmt.Errorf("%s: %s: %w", source, message, err)
+}

other/zerolog.go

@@ -0,0 +1,76 @@
+package other
+
+import (
+	"flag"
+	"io"
+	"os"
+	"strings"
+
+	"github.com/rs/zerolog"
+	"github.com/rs/zerolog/log"
+)
+
+var cliFlagLogLevel = "info"
+var cliFlagLogJson = false
+
+func SetupFlags() {
+	flag.StringVar(
+		&cliFlagLogLevel,
+		"loglevel",
+		"info",
+		"Set the logging level. Valid values (case insensitive) are: debug, info, warn, error, fatal",
+	)
+	flag.BoolVar(
+		&cliFlagLogJson,
+		"logjson",
+		false,
+		"Log json objects to stderr instead of nicely formatted ones",
+	)
+}
+
+// Configure logging. Utilises the flags setup in [SetupFlags].
+// If logWriter is not nil, will also write logs, as json objects,
+// to the given writer
+func ConfigureLogging(logWriter io.Writer) {
+	configOutputs(logWriter)
+	configLevel()
+}
+
+func configLevel() {
+	switch strings.ToLower(cliFlagLogLevel) {
+	case "trace":
+		zerolog.SetGlobalLevel(zerolog.TraceLevel)
+	case "debug":
+		zerolog.SetGlobalLevel(zerolog.DebugLevel)
+	case "info":
+		zerolog.SetGlobalLevel(zerolog.InfoLevel)
+	case "warn":
+		zerolog.SetGlobalLevel(zerolog.WarnLevel)
+	case "error":
+		zerolog.SetGlobalLevel(zerolog.ErrorLevel)
+	case "fatal":
+		zerolog.SetGlobalLevel(zerolog.FatalLevel)
+	default:
+		zerolog.SetGlobalLevel(zerolog.InfoLevel)
+	}
+	log.Info().Str("new-level", cliFlagLogLevel).Msg("New logging level set")
+}
+
+func configOutputs(logWriter io.Writer) {
+	console := zerolog.ConsoleWriter{Out: os.Stderr}
+	extraLogWriters := []io.Writer{console}
+	if logWriter != nil {
+		extraLogWriters = append(extraLogWriters, logWriter)
+	}
+	if !cliFlagLogJson {
+		log.Logger = zerolog.New(zerolog.MultiLevelWriter(extraLogWriters...)).
+			With().
+			Timestamp().
+			Logger()
+	} else {
+		log.Logger = zerolog.New(zerolog.MultiLevelWriter(
+			append([]io.Writer{log.Logger}, extraLogWriters...)...,
+		)).With().Timestamp().Logger()
+	}
+	return
+}

sliceutils/sliceUtils.go

@@ -80,3 +80,20 @@ func Contains[T comparable](a []T, b T) bool {
 	}
 	return false
 }
+
+func ContainsFunc[T any](a []T, f func(t T) bool) bool {
+	for _, v := range a {
+		if f(v) {
+			return true
+		}
+	}
+	return false
+}
+
+func Compact[T any](a []T, compactor func(acc T, next T) T) T {
+	var acc T
+	for _, v := range a {
+		acc = compactor(acc, v)
+	}
+	return acc
+}

wrapped-mutex/mutex.go

@@ -0,0 +1,30 @@
+package wrappedmutex
+
+import "sync"
+
+type Mutex[T any] struct {
+	wrapped T
+	lock    sync.Mutex
+}
+
+func New[T any](wrapped T) Mutex[T] {
+	return Mutex[T]{
+		wrapped: wrapped,
+	}
+}
+
+func (m *Mutex[T]) Lock() {
+	m.lock.Lock()
+}
+
+func (m *Mutex[T]) TryLock() bool {
+	return m.lock.TryLock()
+}
+
+func (m *Mutex[T]) Unlock() {
+	m.lock.Unlock()
+}
+
+func (m *Mutex[T]) Get() *T {
+	return &m.wrapped
+}