Show image pull progress in a separate Echelon node

[fkorotkov]

No description provided.

[edigaryev]

I don't think this solves #11, since the progress is still hidden in ioutil.Discard.

[fkorotkov]

There will be a timer. When you do docker pull you have separate progresses for each layer which is also confusing since it's not a percentage or time estimation. I think a timer will be good enough. What do you think?

[edigaryev]

There will be a timer. When you do docker pull you have separate progresses for each layer which is also confusing since it's not a percentage or time estimation. I think a timer will be good enough. What do you think?

How are you going to calculate the total time needed to pull the image anyway?

Note that ImagePull returns an io.Reader that in turn returns JSON messages about each layer's progress separately:

{"status":"Pulling from golangci/golangci-lint","id":"latest"}
{"status":"Pulling fs layer","progressDetail":{},"id":"d6ff36c9ec48"}
{"status":"Pulling fs layer","progressDetail":{},"id":"c958d65b3090"}
{"status":"Pulling fs layer","progressDetail":{},"id":"edaf0a6b092f"}
{"status":"Pulling fs layer","progressDetail":{},"id":"80931cf68816"}
{"status":"Pulling fs layer","progressDetail":{},"id":"813643441356"}
{"status":"Pulling fs layer","progressDetail":{},"id":"2c05b70ce67b"}
{"status":"Pulling fs layer","progressDetail":{},"id":"e82ad91b19e9"}
{"status":"Pulling fs layer","progressDetail":{},"id":"5d2e569cefef"}
{"status":"Waiting","progressDetail":{},"id":"813643441356"}
{"status":"Waiting","progressDetail":{},"id":"2c05b70ce67b"}
{"status":"Waiting","progressDetail":{},"id":"e82ad91b19e9"}
{"status":"Waiting","progressDetail":{},"id":"5d2e569cefef"}
{"status":"Waiting","progressDetail":{},"id":"80931cf68816"}
{"status":"Downloading","progressDetail":{"current":81434,"total":7811570},"progress":"[\u003e                                                  ]  81.43kB/7.812MB","id":"c958d65b3090"}
{"status":"Downloading","progressDetail":{"current":101515,"total":9996337},"progress":"[\u003e                                                  ]  101.5kB/9.996MB","id":"edaf0a6b092f"}
{"status":"Downloading","progressDetail":{"current":736262,"total":7811570},"progress":"[====\u003e                                              ]  736.3kB/7.812MB","id":"c958d65b3090"}
[...]

You can combine them to get a total percentage that can be flushed to the log periodically.

[fkorotkov]

Ok, let's not claim fixing #11 then.

[edigaryev]

Suggested change

	dockerPullLogger.Errorf("Failed to pull %s: $v", params.Image, err)
	dockerPullLogger.Errorf("failed to pull %s: %v", params.Image, err)

[fkorotkov]

Hold on, this is a user visible error level log