Finding Dependable Go Packages

At some point, we all find ourselves wanting to use a third-party Go package in our Go code. This talk discusses strategies for discovering, evaluating and maintaining Go packages and modules. It also shares new tools that the Go team is building to make this process better.

Transcript

1. Finding Dependable Go Packages Julie Qiu Google @jqiu25
2. Julie Qiu Software Engineer Go Team Google @jqiu25
3. How do I decide which package to use?
4. @jqiu25
5. @jqiu25
9. @jqiu25
10. DESSERTS DINNER APPETIZERS BREAKFAST SNACKS HOME ! Avocado Green Goddess Dip " Cornbread Sausage Stuffing # Lemon Chicken Dill $ Tomato Soup with Grilled Cheese Croutons Julie’s Recipe Book
11. @jqiu25 # Salmon with brown sugar and mustard Time: 20 minutes ## Ingredients - Salmon - 1 tablespoon Dijon mustard - 2 tablespoons brown sugar ## Instructions 1. Heat oven to 400 degrees. 2. Mix Dijon mustard and brown sugar. 3. Salt and pepper the salmon. 4. Place salmon on a baking sheet. Slather on mustard and brown sugar mix. 5. Bake for 15 minutes. Salmon with Brown Sugar and Mustard Time: 20 minutes Ingredients • Salmon • Dijon mustard, 1 tablespoon • Brown sugar, 2 tablespoons Instructions 1. Heat oven to 400 degrees. 2. Mix Dijon mustard and brown sugar. 3. Salt and pepper the salmon. 4. Place salmon on a baking sheet. Slather on mustard and brown sugar mix. 5. Bake for 15 minutes.
12. Image Storage Salmon with Brown Sugar and Mustard Time: 20 minutes Ingredients • Salmon • Dijon mustard, 1 tablespoon • Brown sugar, 2 tablespoons
13. @jqiu25 • Markdown parser • API to interact with image store • Image resizer • Search engine • … and more! Packages I need
15. Dependency Lifecycle Discovery Evaluation Maintenance
16. Discovery
17. @jqiu25 # Salmon with brown sugar and mustard Time: 20 minutes ## Ingredients - Salmon - 1 tablespoon Dijon mustard - 2 tablespoons brown sugar ## Instructions 1. Heat oven to 400 degrees. 2. Mix Dijon mustard and brown sugar. 3. Salt and pepper the salmon. 4. Place salmon on a baking sheet. Slather on mustard and brown sugar mix. 5. Bake for 15 minutes. Salmon with Brown Sugar and Mustard Time: 20 minutes Ingredients • Salmon • Dijon mustard, 1 tablespoon • Brown sugar, 2 tablespoons Instructions 1. Heat oven to 400 degrees. 2. Mix Dijon mustard and brown sugar. 3. Salt and pepper the salmon. 4. Place salmon on a baking sheet. Slather on mustard and brown sugar mix. 5. Bake for 15 minutes.
18. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 @jqiu25
20. @jqiu25
21. Evaluation
22. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 1. License @jqiu25
23. DESSERTS DINNER APPETIZERS BREAKFAST SNACKS HOME ! Avocado Green Goddess Dip " Cornbread Sausage Stuffing # Lemon Chicken Dill $ Tomato Soup with Grilled Cheese Croutons Julie’s Recipe Book
24. DESSERTS DINNER APPETIZERS BREAKFAST SNACKS HOME BIGGEST SALE EVER CLICK HERE EMAIL SUBSCRIBE Get a FREE blender! Julie’s Recipe Book ! Avocado Green Goddess Dip " Cornbread Sausage Stuffing # Lemon Chicken Dill $ Tomato Soup with Grilled Cheese Croutons
25. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 2. Popularity @jqiu25
26. { @jqiu25 Popularity Downloads Stars Forks Watchers Contributors Dependents
27. { @jqiu25 Downloads Stars Forks Watchers Contributors Dependents Popularity
28. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 3. Code Quality @jqiu25
29. Image Storage Salmon with Brown Sugar and Mustard Time: 20 minutes Ingredients • Salmon • Dijon mustard, 1 tablespoon • Brown sugar, 2 tablespoons
30. { @jqiu25 @jqiu25 Code Quality Documentation
31. @jqiu25 package blob import “thirdparty.com/blob” Package blob provides an API for interacting with Google Cloud Storage. It supports operations like reading, writing, and listing blobs in a bucket. // Open the bucket using default credentials. b, err := blob.OpenBucket("gs://recipe—pictures") defer b.Close() buf, err := bucket.ReadAll(ctx, "salmon.jpg") Example
32. type Bucket Package blob provides an API for interacting with Google Cloud Storage. It supports operations like reading, writing, deleting and listing blobs in a bucket. Bucket is used to interact with blobs within a “bucket”, including read, write, and list operations. func OpenBucket OpenBucket opens the bucket identified by the URL given. @jqiu25 type Bucket struct { // contains unexported fields } func OpenBucket(urlstr string) (*Bucket, error) Example
33. { @jqiu25 @jqiu25 Code Quality Documentation Tests
34. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 @jqiu25
35. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 @jqiu25
36. { @jqiu25 @jqiu25 Code Quality Documentation Tests Idiomatic
37. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 func OpenBucket(bucketName string) (*blob.Bucket, error) { drv, err := openBucket(bucketName) if err != nil { return nil, err } return blob.NewBucket(drv), nil } func OpenBucket(bucket_name string) (*blob.Bucket, error) { drv, err := openBucket(bucketName) if err != nil { return nil, err } return blob.NewBucket(drv), nil } Is the code gofmt’ed?
38. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 func OpenBucket(bucketName string) (*blob.Bucket, error) { drv, err := openBucket(bucketName) if err != nil { log.Fatalf(“yolo: %v”, err) } return blob.NewBucket(drv), nil } func OpenBucket(bucketName string) (*blob.Bucket, error) { drv, err := openBucket(bucketName) if err != nil { return fmt.Errorf(“openBucket(%q): %v”, bucketName, err) } return blob.NewBucket(drv), nil } How are errors being handled?
39. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 type Bucket interface { } func NewBucket(name string, age int) Bucket { } Are there unnecessary abstractions? type Bucket struct { } func NewBucket(name string, age int) *Bucket { }
40. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 4. Upkeep @jqiu25
41. { @jqiu25 Maintainer Activity Upkeep
42. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 Upkeep: Maintainers
43. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 @jqiu25 Upkeep: Commit History
44. @jqiu25 Upkeep: Issue Tracker
45. julieqiu commented 126 days ago This PR updates .travis.yml to test the most recent Go version.
46. julieqiu commented 126 days ago @maintainer friendly ping julieqiu commented 45 days ago This PR updates .travis.yml to test the most recent Go version.
47. julieqiu commented 126 days ago @maintainer friendly ping julieqiu commented 45 days ago @maintainer any updates? julieqiu commented 2 days ago This PR updates .travis.yml to test the most recent Go version.
49. { @jqiu25 Maintainer Activity API Stability Upkeep
51. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 What is a Module? ── go.mod ── go.sum ── … a bunch of packages
52. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 What is a Module? ── go.mod ── go.sum ── blob ── gcsblob ── s3blob ── azureblob ── … more blobs
53. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 1. Import compatibility rule @jqiu25 Modules & API Stability
54. IMPORT COMPATIBILITY RULE If an old package and a new package have the same import path… 54
55. IMPORT COMPATIBILITY RULE If an old package and a new package have the same import path… …the new package must be backwards compatible with the old package. 55
56. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 1. Import compatibility rule 2. Semantic versioning @jqiu25 Modules & API Stability
57. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 safe to upgrade from v1.1.0 to v1.2.3! module github.com/julieqiu/cookbook go 1.12 require ( third.party/blob v1.1.0 third.party/search v0.3.0 )
58. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 initial development phase – unstable! module github.com/julieqiu/cookbook go 1.12 require ( third.party/blob v1.0.0 third.party/search v0.3.0 )
59. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 5. Indirect Dependencies @jqiu25
60. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 your third party package
61. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 your third party package
62. @jqiu25
65. @jqiu25 Use a module mirror! Try it out: GOPROXY=https://proxy.golang.org
66. @jqiu25 GOPROXY=https://proxy.golang.org Use a module mirror! Try it out: Learn more: Aaron Schlesinger “Improving Dependencies for Everyone” Tomorrow, 9am
67. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 Evaluation Signals 1. License 2. Popularity 3. Code Quality 4. Upkeep 5. Indirect Dependencies
68. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 Should I use a third-party package at all?
69. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 Instructions … 5. Bake for 15 minutes. Turn over at 7 minutes! ## Instructions ... 5. Bake for 15 minutes. Turn over at 7 minutes! Align to the right!
71. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 @jqiu25 func PadLeft(s string, length int) string { length = length - len(s) var prefix []string for i := range length { prefix = append(prefix, " ") } return prefix + s } markdownalignright: source code
72. @jqiu25 ## Instructions ... 5. Bake for 15 minutes. <note> Turn over at 7 minutes! </note> ## Instructions ... 5. Bake for 15 minutes. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;& nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Turn over at 7 minutes! Instructions … 5. Bake for 15 minutes. Turn over at 7 minutes!
73. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 @jqiu25 func PadLeft(s string, length int) string { ... } func init() { if time.Now().Weekday() == time.Friday && time.Now().Day() == 13 { panic("unlucky day!") } } markdownalignright: source code ! " # !!!
74. @jqiu25 @jqiu25 note { float: right; } Use CSS!
75. Maintenance
76. DESSERTS DINNER APPETIZERS BREAKFAST SNACKS HOME BIGGEST SALE EVER CLICK HERE EMAIL SUBSCRIBE Get a FREE blender! Julie’s Recipe Book ! Avocado Green Goddess Dip " Cornbread Sausage Stuffing # Lemon Chicken Dill $ Tomato Soup with Grilled Cheese Croutons
77. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 Maintenance 1. Stay up to date
78. @jqiu25
79. @jqiu25
80. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 Maintenance 1. Stay up to date 2. Contribute to the project @jqiu25
81. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 bug with markdown parser
82. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 bug with markdown parser
83. DISCOVERY → EVALUATION → MAINTENANCE @jqiu25 bug with markdown parser
84. Dependency Lifecycle Discovery Evaluation Maintenance
85. @jqiu25
87. How can we make this process better?
88. Documentation godoc.org
89. Code Quality goreportcard.com
90. Code Quality staticcheck
91. Test Coverage go test -cover
92. How can we make this process even better?
100. DESSERTS DINNER APPETIZERS BREAKFAST SNACKS HOME ! Avocado Green Goddess Dip " Cornbread Sausage Stuffing # Lemon Chicken Dill $ Tomato Soup with Grilled Cheese Croutons Julie’s Recipe Book
101. @jqiu25
102. @jqiu25
104. test coverage: 60% tests passing: 90% dependents: 1000 last updated: 2 days ago gofmt: 100% govet: 100% license: yes open issues: 12345 commits: 67891 … and a lot more! @jqiu25
105. @jqiu25 Popularity Quality Stability
106. Popularity Quality Stability
109. @jqiu25 Subscribe to updates: golang.org/s/discovery-updates
110. Subscribe to updates: golang.org/s/discovery-updates Try it out: golang.org/s/discovery-tester-signup @jqiu25
111. Subscribe to updates: golang.org/s/discovery-updates Try it out: golang.org/s/discovery-tester-signup Let’s chat! @jqiu25